Abstract:
The focus of this chapter is clinical management during the neonatal intensive care unit (NICU) and outpatient follow-up phases for neonates at neurodevelopmental risk and their parents. A theoretical framework for neonatal practice is presented, and an overview of neonatal complications associated with adverse outcomes is provided. In-depth discussion in the neonatal section includes neurodevelopmental examination and pain assessment, intervention plans, and therapy strategies in the NICU. The section on outpatient follow-up addresses critical time periods for neuromotor and musculoskeletal reexamination, assessment tools, and clinical cases.
Keywords:
high-risk clinical signs, medical complications of prematurity, neonatal intensive care unit environment, neuromotor assessment, neuromotor intervention, parent instruction, physiological and musculoskeletal risks, subspecialty training
Objectives
After reading this chapter the student or therapist will be able to:
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Discuss current theoretical frameworks guiding neonatal therapy services in the neonatal intensive care unit.
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Identify the physiological and structural vulnerabilities of preterm infants that predispose them to stress during neonatal therapy procedures.
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Outline mentored clinical training components and acute pediatric care experiences to prepare for entry into neonatal intensive care unit practice.
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Describe how the grief, fear, and emotional trauma may affect behavior and caregiving performance of parents of neonates in the intensive care unit.
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Differentiate the developmental course and neuromotor risk signs in infants with emerging neuromotor impairment from the characteristics of infants with typical variations in motor behaviors.
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Identify instruments for neuromotor examination of infants in neonatal intensive care units and in follow-up clinics and compare psychometric features of the tests.
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Describe program plans and follow-up for neonates and infants in neonatal intensive care unit and home settings.
Premature birth continues to be associated with an increased prevalence of major and minor neurodevelopmental disability despite ongoing advancement in newborn resuscitation and neonatal intensive care procedures. The risk of neurodevelopmental disability in infants born preterm remains high, with increasing prevalence of mild neurological impairment reported in infants with a late preterm birth (34 to 36 weeks of gestation). ,
Neurodevelopmental and movement assessments combined with brain imaging provide moderate to high prediction of neurodevelopmental outcome. , Serial clinical examinations and careful monitoring of neurodevelopmental status are critical during the neonatal period, at discharge from the neonatal intensive care unit (NICU), and sequentially in the outpatient follow-up phase of care. Pediatric therapists with mentored, subspecialty training in neonatology, infant examination, and infant therapy approaches can serve these increasing numbers of surviving neonates at neurodevelopmental risk by
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collaborating with neonatal care teams in NICU rounds and family conferences,
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providing diagnostic data through neurological, developmental, and behavioral examinations
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participating in developmental, feeding, and environmental interventions adapted to each infant’s physiological, motor, and behavioral needs
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facilitating parent teaching on developmental and feeding strategies
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reinforcing preventive aspects of health care through early intervention and long-term developmental monitoring
The focus of this chapter is clinical management during the NICU and outpatient follow-up phases for neonates at neurodevelopmental risk and their parents. A theoretical framework for neonatal practice is presented, and an overview of neonatal complications associated with adverse outcomes is provided. In-depth discussion in the neonatal section includes neurodevelopmental examination and pain assessment, intervention plans, and therapy strategies in the NICU. The section on outpatient follow-up addresses critical time periods for neuromotor and musculoskeletal reexamination, assessment tools, and clinical cases.
Theoretical framework
Concepts of dynamic systems, neuronal group selection theory (NGST), and parental hope-empowerment provide a theoretical framework for neonatal therapy practice. In this section, three models provide a theoretical structure for practitioners designing and implementing neuromotor and neurobehavioral programs for neonates and their parents.
Dynamic systems
Dynamic systems theory applied to infants in the NICU refers to multiple interacting structural and physiological systems within the infant as well as to dynamic interactions between the infant and the environment. The synactive model of infant behavioral organization is an example of a neonatal dynamic systems model for establishing physiological stability as the foundation for organization of motor, behavioral state, and attention or interactive behaviors in infants. Als and colleagues , described a “synactive” process of four subsystems interacting as the neonate responds to the stresses of the extrauterine environment. They theorized that the basic subsystem of physiological organization must first be stabilized for the other subsystems to emerge and allow the infant to maintain behavioral state control and then interact positively with the environment ( Figs. 9.1 and 9.2 ).
To evaluate infant behavior within the subsystems of function addressed in the synactive model, Als and associates developed the Assessment of Preterm Infants’ Behavior (APIB). With the development of this assessment instrument, self-regulation, a fifth subsystem of behavioral organization, was added to the synactive model. The self-regulation subsystem consists of physiological, motor, and behavioral state strategies used by the neonate to maintain balance within and between the subsystems (see Fig. 9.2 ). For example, many infants born preterm appear to regulate overstimulating environmental conditions with a behavioral state strategy of withdrawing into a drowsy or light sleep, thereby shutting out sensory input. The withdrawal strategy is used more frequently than crying because it requires less energy and causes less physiological drain on immature, inefficient organ systems. Neonatal therapists may find a dynamic systems framework useful in conceptualizing and assessing changes in infants’ multiple subsystems during and after therapy procedures. In Fig. 9.1 neonatal movement and postural control are targeted as a core focus in neonatal therapy, with overlapping and interacting influences from the cardiopulmonary, behavioral, neuromuscular, musculoskeletal, and integumentary systems. A change or intervention affecting one system may diminish or enhance stability in the other dynamic systems within the infant. Similarly, a change in the infant’s environment may impair or improve the infant’s functional performance.
This theory guides the neonatal practitioner to consider the many potential physiological and anatomical influences (dynamic systems within the infant) that make preterm infants vulnerable to stress during caregiving procedures, including neonatal therapy. In dynamic systems theory, emphasis is placed on the contributions of the interacting environments of the NICU, home, and community in constraining or facilitating the functional performance of the infant.
Neuronal group selection theory
This theoretical framework was developed by Edelman , on the hypothesis that specific behaviors are the product of neuronal groups, which are dynamically organized to be selected by development. Edelman described three tenets:
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Tenet 1: Development of primary repertoires
Millions of neurons are interconnected to form functional units known as neuronal groups.
Neuronal groups come together to form primary neuronal repertoires capable of adaptation and accommodation. Formation of primary repertoires does not rely on experience and are endogenously generated.
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Tenet 2: Development of secondary repertoires
Preexisting primary repertoires are modified by environmental and individual experiences.
The experience of movement strengthens or weakens repertoires based on value, repetition, or availability of other repertoires. Secondary repertoires develop as a result of this selection.
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Tenet 3: Development of neural maps
The selection process gives way to neural maps. Neuronal groups are distributed throughout the nervous system. These maps are organized in such a way that distinct and distant areas of perception, cognition, emotion, movement, and posture can be activated simultaneously for one task.
The NGST has been further explored in recent literature as one of the leading theories explaining the dynamic nature of infant development, with variability as one of the main properties of normal movement. , The continuity of neural functions from prenatal to postnatal life has been well documented over the years. Prechtl , documented the timing of prenatal, endogenously generated behaviors such as swallowing, sucking, yawning, hand-to-mouth movements, and general body movements.
Preterm infants are born with an innate repertoire of spontaneous movement with specific qualitative characteristics. Variability and complexity of movement are key indicators of central nervous system integrity. Changes in the quality of spontaneous movement with decreased variability may indicate neuromotor dysfunction. ,
Hope-empowerment model
A major component of the intervention process in neonatal therapy is developing a therapeutic relationship with the family and supporting family-centered care practices in neonatal care units. A hope-empowerment framework ( Fig. 9.3 ) may guide neonatal practitioners in building the therapeutic partnership with parents; facilitating adaptive coping; and empowering them to participate in caregiving, problem solving, and advocacy. The birth of an infant at risk for a disability, or the diagnosis of such a disability, may create both developmental and situational crises for the parents and the family system.
The developmental crisis involves adapting to changing roles in the transition to parenthood and in expanding the family system. Although not occurring unexpectedly, this developmental transition for the parents brings lifestyle changes that may be stressful and cause conflict. Because parents are experiencing (mourning) loss of the “wished for” baby they have been visualizing in the past 6 months, they may struggle with developing a bond with their “real” baby in the NICU.
A situational crisis occurs from unexpected external events presenting a sudden, overwhelming threat or loss for which previous coping strategies are not applicable or are immobilized. The unfamiliar, high-technology, often chaotic NICU environment creates many situational stresses that challenge parenting efforts and destabilize the family system. The language of the nursery is unfamiliar and intimidating. The sight of fragile, sick infants surrounded by medical equipment and the sound of monitor alarms are frightening. The high frequency of seemingly uncomfortable, but required, medical procedures for the infant are of financial and humanistic concern to parents. No previous experiences in everyday life have prepared parents for this unnatural, emergency-oriented environment. This emotional trauma of unexpected financial and ongoing psychological stresses during parenting and caregiving efforts in the NICU contributes to potential posttraumatic stress disorder in parents of infants requiring intensive care.
The quality and orientation of the helping relationship in neonatal therapy affect the coping style of parents as they try to adapt to developmental and situational crises (see Fig. 9.3 ). Although parents and neonatal therapists enter the partnership with established interactive styles and varying life and professional experiences, the initial contacts during assessment and program planning set the stage for either a positive or negative orientation to the relationship.
Despite many uncertainties about the clinical course, prognosis, and quality of social support, a positive orientation can be developed by acknowledging and validating parents’ feelings and experiences. Validation then becomes a catalyst to a hope-empowerment process in which many crisis events, negative feelings, and insecurities are acknowledged in a positive, supportive, nonjudgmental context in which decision making power is shared. In contrast, a negative orientation may be inadvertently facilitated by information overloading without exploring and validating parents’ feelings, experiences, and learning styles. Uncertainty, fear, and powerlessness may be experienced by parents attempting to participate in neonatal therapy activities.
In a hope-empowerment framework, parent participation in neuromotor and feeding intervention allows sharing of power and responsibility and can promote continuous, mutual setting and revision of goals with reality grounding. Adaptive power can be generated by helping parents stabilize and focus energy and plans and by encouraging active participation in intervention and advocacy activities. Exploring external power sources (e.g., online groups supporting parents of infants born preterm) early in the therapeutic relationship may help parents focus and mobilize.
Hope and empowerment are interactive processes. They are influenced by existential philosophy: the hope to adapt to what is and the hope to later find peace of mind and meaning for the situation, regardless of the infant’s outcome. In describing the effect of an infant born prematurely on the parenting process, Mercer stated that “hope seems to be a motivational, emotional component that gives parents energy to cope, to continue to work, and to strive for the best outcome for a child.” She viewed the destruction of hope as contributing to the physical and emotional withdrawal frequently observed in parents who attempt to protect themselves from additional pain and disappointment and then have difficulty reattaching to the infant.
Hope contributes to the resilience parents need to get through the arduous NICU hospitalization period and then begin to face the future in their home and community with an infant at neurodevelopmental risk. Groopman proposed that hope provides the courage to confront obstacles and the capacity to surmount them. He described the process of creating a middle ground where truth (of the circumstances) and hope reside together as one of the most important and complex aspects in the art of caregiving.
In a hope-empowerment context, parental teaching activities are carefully selected to contribute to pleasurable, reciprocal interaction between infant and parent. Gradual participation in infant care activities and therapeutic handling in the NICU provides experience and builds confidence for continuation in the home environment.
Conversely, if the parents’ learning styles, goals, priorities, values, time constraints, energy levels, and emotional availability are not considered in the design of the developmental program, parents may experience failure, low self-esteem, powerlessness, immobilization, or dependency. The neonatal therapist may recognize signs of learned helplessness in parents when they show nonattendance, noncompliance, negative interactions with infant and staff, or a hopeless, overwhelmed outlook during bedside teaching sessions.
New events in the infant’s health or developmental status may create new crises and destabilize the coping processes. In long-term neurodevelopmental follow-up, many opportunities occur within the partnership to validate new fears and chronic uncertainties within a hopeful, positively oriented, therapeutic relationship. This model provides a framework for understanding the processes of hope and empowerment for mediating emotional trauma of parents during the unexpected experience of parenting their baby in a NICU.
Neonatal complications associated with adverse outcomes
Improvements in neonatal intensive care over the last 30 years have led to increased survival of preterm and term infants. Specific obstetric advances include earlier identification of high-risk pregnancies, improvement in prenatal diagnosis using ultrasound and non-invasive prenatal screening, establishment of specialized tertiary care centers for high-risk pregnancies, and medications such as progesterone to assist in prolonging pregnancy and betamethasone to enhance fetal pulmonary development. Availability of commercial surfactant, advances in ventilator design, and improvement in the management of neonatal respiratory distress have resulted in significantly decreased pulmonary damage after preterm birth (refer to Table 9.6 for a description of ventilators and other specialized equipment in the NICU).
For infants born at 23 weeks gestation, survival has increased from approximately 0% to more than 50%, and for infants born at 26 weeks gestation, survival has increased from 25% to 85% over the past 20 years. Importantly, the incidence of severe neurological injury has decreased over time; however, an increased number of preterm infants will exhibit long-term neurological impairment owing to increased survival.
Preterm birth
Preterm birth is defined as any infant born alive under 37 weeks gestation. Late preterm infants (born between 34 and 36/7 weeks gestation) comprise more than 70% of all preterm births. These infants are at risk for respiratory compromise, apnea, feeding problems, jaundice, and temperature instability. In addition, they are at increased risk for neurodevelopment delay because a significant amount of brain growth, development, and maturation occurs during the last 6 weeks of gestation.
For infants born less than 34 weeks gestation, mortality and neurodevelopmental impairment increase with decreasing gestational age. Very preterm infants are born between 28 and 32 weeks gestation, and extremely preterm infants are born less than 28 weeks gestation; however, the exact gestational age of the preterm infant is frequently unknown, and infants are frequently categorized by birth weight groups to predict survival and the risk of short and long-term outcomes. Low birth weight (LBW) infants weigh less than 2500 g at birth and are usually under 37 weeks gestation. Very low birth weight (VLBW) infants weigh less than 1500 g and extremely low birth weight (ELBW) infants weigh less than 1000 g at birth regardless of gestational age. The most frequent reasons for an infant to have a birth weight less than expected for their gestational age (i.e., small for gestational age or growth restricted infants) are twin and higher order multiple pregnancy, maternal disease such as pregnancy-induced hypertension, maternal smoking, placental dysfunction, and/or chromosomal abnormalities.
Survival of extremely preterm infants has dramatically increased over time, resulting in increasing numbers of infants with neurodevelopmental delay. The neurodevelopmental outcome of extremely preterm infants assessed at 18 to 30 months of age is reported widely. Developmental outcome of Swedish infants born at less than 27 weeks gestation between 2004 and 2007 indicated that 56% had no cognitive, language, or motor impairment, and 20% had moderate to severe impairment. Moderate to severe language delay (16%) or motor impairment (15%) were more prevalent than cognitive disability (11%). Cerebral palsy (CP) was present in 7% of this extremely preterm cohort.
In France, in 2011, 49% of infants born at less than 27 weeks gestation survived to 2 years without detection of neurodevelopmental impairment. CP was present in 7% of this sample. Infants born between 27 and 31 weeks gestation had increased survival without impairment (90%) compared to very preterm infants born at less than 27 weeks gestation. Infants born at full term gestation rarely had neurodevelopmental impairment (2%).
In a study conducted from 2011 to 2015 in the United States, 19% of infants born at less than 27 weeks demonstrated neurodevelopmental delay. Ten percent had significant cognitive delay and 13% had motor impairment. Predictors of developing CP included decreasing gestational age, intraventricular hemorrhage (IVH), and chronic lung disease (CLD), with the incidence of CP decreasing over time. More than 50% of ELBW infants in a US sample had receptive language delay at 30 months, and 23% were severely delayed. Forty eight percent of the infants had some expressive language delay, and 30% were severely delayed. Infants requiring assistance with feeding were at higher risk of expressive language delay (2.3-fold increase). The need for feeding assistance and decreased cognition was significantly associated with receptive language delay.
At 6 to 7 years of age, only 36% of infants born at less than 27 weeks gestation in Sweden had a normal IQ. One-third of these very preterm infants had moderate to severely decreased IQ compared to 2.2% of term infants. The average IQ of preterm infants was 17 points lower than the IQ of term infants. Thirty percent of preterm infants had moderate to severe cognitive delay, specifically in verbal comprehension, working memory, reasoning, and processing speed. Overall, 36.2% of these preterm infants demonstrated no neurodevelopmental delay and 33.6% had moderate to severe delay.
Does cognitive and motor ability at 2 years of age predict outcomes at school age? A cohort of very preterm infants born in Sweden at less than 27 weeks gestation were tested at 2 and 6 years of age. Sixty six percent of infants had no or only mild delays at 6 years. Overall, 21% of infants exhibited improved outcome, 32% had worse outcome, and the remainder were stable. The percentage of infants with moderate to severe disability increased over time from 27% to 34% showing that disability level was inversely related to gestational age. At 6 years of age, decrease in cognitive ability was likely due to decreased executive functioning, a cognitive area not tested at the younger age; , thus neurodevelopmental testing at 2 years of age identifies most infants at risk for developmental delay and allows them access to needed therapy and educational assistance.
The fetal brain undergoes tremendous growth, development, and maturation during the second and third trimester. The preterm brain is especially vulnerable to injury from hypoxia, medications, stress, and pain. The long-term impact of adverse conditions depends on the gestational age of the infant as well as timing, frequency, nature, and duration of the insult. Expanded description of brain development can be accessed in Volpe’s Neurology of the Neonate, a comprehensive resource for health professionals.
Brain development and maturation are categorized into five primary phases (proliferation, migration, organization, synaptogenesis and apoptosis, and myelination). All neurons and glial (support) cells are generated in the germinal matrix, an area adjacent to the ventricle. Neuronal proliferation is nearly complete by 5 months of gestation, well before preterm delivery. Neuronal migration starts at 3 months of gestation and continues for 3 more months, with developing neurons guided by glial cells to form neuronal columns. The organization phase lasts from 5 months gestation through several years after birth. In this phase, neurons are oriented, neuronal projections (axons and dendrites) are elaborated, and interconnections between neurons are generated. Synaptic formation (neuronal interconnections) and elimination (programmed cell death—apoptosis) are present in the third trimester but are most active after birth. Synaptogenesis and apoptosis are experience-dependent and confer plasticity to the preterm brain, ensuring individuality. The final phase of brain maturation involves glial maturation of astrocytes and oligodendrocytes. Astrocytes help maintain the blood-brain barrier, provide nutrient support, regulate neurotransmitter and potassium concentration, and assist in neuronal repair after injury. Oligodendrocytes produce the myelin sheath that covers neurons and facilitates nerve transmission. Myelination starts in the second trimester and continues through adulthood. The oligodendrocytes are especially sensitive to hypoxia and other insults. Disruption of normal myelination results in white matter hypoplasia and periventricular leukomalacia (PVL) (see later discussion) leading to impaired motor function.
Specific insults to the fetal and neonatal brain are associated with impaired neurological functioning and long-term developmental delay. The next section focuses on specific diseases and conditions: IVH, PVL, hypoxic-ischemic (H/I) encephalopathy (HIE), CLD, sepsis, necrotizing enterocolitis (NEC), and in utero drug exposure ( Table 9.1 )
| Condition | Population |
|---|---|
| IVH PHVD | <28 weeks gestation |
| PVL | <32 weeks gestation |
| Cerebellar hemorrhage | Preterm infants |
| HIE | Term and near term infants |
| BDP/CLD | All infants |
| Sepsis | All infants |
| NEC | Preterm infants |
| In utero drug exposure | All infants |
Intraventricular hemorrhage
IVH is the most common brain injury in preterm infants born at less than 32 weeks gestation and is a significant risk factor for neurodevelopmental impairment. The incidence of IVH varies inversely with gestational age. The incidence of severe IVH has decreased over time and is currently less than 15% for infants born at under 27 weeks gestation.
The origin of IVH is in the microcirculation/capillary network of the germinal matrix. The germinal matrix is a highly vascularized area due to the high metabolic demand from rapidly proliferating neuronal stem cells. The vessels in the germinal matrix have thin walls and are fragile, predisposing them to rupture and hemorrhage. Preterm infants have impaired cerebral vascular autoregulation. During labor, delivery, and the immediate postpartum transition period, decrease in blood pressure can lead to cerebral hypoperfusion and ischemia and, conversely, increased blood pressure can lead to hyperperfusion and blood vessel rupture. Risk factors for IVH include asphyxia, alterations in serum carbon dioxide, rapid infusion of fluids (especially hypertonic solutions), platelet and coagulation disturbances, anemia, and pain. In infants with gestational age greater than 28 weeks, IVH is rarely seen owing to the developmental involution of vessels in the germinal matrix.
IVH is diagnosed by cranial ultrasound and graded in severity from 1 to 4. The IVH Grade 1 is considered mild, with the hemorrhage confined to the germinal matrix. In IVH Grade 2, the hemorrhage extends into the ventricle ( Fig. 9.4 ). Grade 3 hemorrhage occurs when more than 50% of the ventricle is filled and causes ventricular distention. The evolution of IVH Grade 3 over 10 days is shown in Fig. 9.5 . Grade 4 IVH, or periventricular hemorrhagic infarct (PVHI) illustrated in Fig. 9.6 , is not caused by germinal blood vessel rupture but, instead, is derived from venous congestion of the terminal veins that border the lateral ventricles, resulting in white matter necrosis and the development of a porencephalic cyst. The usual distribution of PVHI as seen on cranial ultrasound is initially fan-shaped in the periventricular location. The PVHI lesion is usually unilateral (~70%) and approximately ¾ are associated with severe IVH.
IVH may not be apparent on ultrasound in the first few days after birth, but 90% of IVH can be detected by 4 days of age. Grades 1 and 2 IVH are not associated with a significant increase in neurodevelopmental impairment. Infants with severe IVH (Grade 3 and/or 4) have increased mortality and are at markedly increased risk for developmental disabilities, specifically spastic hemiplegia and diplegia because the motor tracts innervating the lower extremities are in close proximity to the germinal matrix (refer to Fig. 9.7 for schematic diagram of corticospinal [motor] tracks). Infants with small unilateral PVHI have no increased risk of developmental delay compared to infants with Grade 3 IVH. If the PVHI is bilateral or if large or multiple porencephalic cysts are present, the risk for severe motor impairment is significantly increased. The full extent of the hemorrhage may not be appreciated for several days after the initial diagnosis of IVH is made. The extent and impact of cerebral damage from IVH may not be evident on cranial ultrasound at term gestation, and magnetic resonance imaging (MRI) may give more information on the extent of injury. Owing to plasticity of the preterm brain, undamaged portions may assume tasks lost to damage, potentially leading to less impact on neurodevelopmental outcome than anticipated.
Posthemorrhagic ventricular dilatation
Approximately 50% of infants with severe IVH (Grade 3 or 4) will develop posthemorrhagic ventricular dilatation (PHVD) caused by either blockage of the normal flow of cerebrospinal fluid (CSF) or decreased absorption of CSF. Approximately 50% to 75% of these infants will develop progressive PHVD resulting in the need for treatment. The severity of ventricular dilatation can be measured on serial cranial ultrasounds. , Severe ventricular dilatation is usually evident by 2 to 3 weeks after birth while pathological increase in head circumference does not occur until 1 to 2 weeks later. PHVD is treated with serial removal of CSF by spinal tap, subgaleal shunt, or placement of Ommaya reservoir. Removal of CSF has been shown to decrease intracranial pressure and improve cerebral perfusion and increase cortical gray and white matter. In addition, there is indirect evidence that ventricular distention itself may cause secondary brain injury through axonal stretching and disruption, gliosis, and loss of oligodendrocytes (cells that make the myelin sheath).
No consensus has been reached on the optimal management of PHVD. , Infants with PHVD that does not resolve with serial removal of CSF require ventriculoperitoneal (VP) shunt placement. Significant complications of VP shunt include sepsis, specifically ventriculitis, or shunt malfunction, such as blockage or leaking, necessitating a shunt revision. These complications further impact the neurodevelopmental outcome of infants with VP shunts. The National Institute of Child Health and Development, a consortium of 17 tertiary NICUs, reported results on the neurodevelopmental outcome at 2 years in ELBW infants with Grade 3 and 4 IVH, born between 1993 and 2002. Infants who required shunt placement had significantly worse outcome when compared to infants with Grade 3 or 4 as assessed by the Bayley Scale of infant Development ( Table 9.2 ). A score of less than 70 denotes an infant who is severely delayed. Moreover, the number of infants who were untestable (score = 49) owing to severe neurodevelopmental handicap and the incidence of CP were significantly increased in infants who received a VP shunt compared to infants with only Grade 3 or 4 IVH.
| No VP Shunt | VP Shunt | ||
|---|---|---|---|
| MDI < 70 | 326/719 (45.3%) | 146/214 (68.2%) | <0.001 |
| MDI = 49 | 130/719 (18.1%) | 87/214 (40.7%) | <0.001 |
| PDI < 70 | 263/711 (37%) | 163/214 (76.2%) | <0.001 |
| PDI = 49 | 146/711 (21%) | 113/214 (52.8%) | <0.001 |
| CP | 217/767 (28.3%) | 128/227 (69.6%) | <0.001 |
Retrospective studies from the Netherlands indicated that earlier intervention when the ventricles were only moderately dilated significantly decreased the need for VP shunt from 62% to 16% and tended to improve long-term developmental outcome with a decreased incidence of moderate to severe handicap. , Halting the progression of PHVD and decreasing the need for VP shunt are likely to improve long-term outcome in these infants. With the possibility of spontaneous resolution of PVHD without intervention, identification of factors for accurate prediction is needed to determine which infants will develop persistent PHVD and subsequently require VP shunt placement.
Periventricular leukomalacia
PVL is the most common ischemic injury to the preterm infant’s brain. This injury involves nonhemorrhagic (ischemic) cellular necrosis of periventricular white matter in the arterial watershed area caused by the lack of cerebral autoregulation. Like IVH, PVL is inversely related to gestational age and is present in less than 10% of preterm infants. The PVL lesion can either be cystic or global and may be difficult to identify on radiological images. Cystic PVL ( Fig. 9.8 ) results from the focal dissolution of cellular tissue approximately 3 to 4 weeks after the asphyxial insult and can be identified on ultrasound if greater than 0.5 cm in diameter; however, cysts visualized by cranial ultrasound may disappear over time owing to fibrosis and gliosis; thus the incidence of cystic PVL is considered to be underestimated by cranial ultrasounds. Global PVL results from diffuse white matter injury and myelin loss. This finding can be subtle with moderate ventricular dilatation and/or a mild increase in extraaxial fluid on cranial imaging. Infants with severe PVL have marked ventricular dilatation, increased extraaxial fluid, and decreased head growth.
Brain imaging by MRI obtained at term may be more sensitive in identifying white matter injury from PVL and can be predictive of subsequent neurosensory impairment and cognitive delay present in up to 50% of extremely preterm infants. Newer techniques, such as diffusion tensor imaging (DTI), functional connectivity MRI (fcMRI), and morphometry for analysis of cortical folding, are being investigated as early markers of impaired neurodevelopmental outcome. With DTI, the restriction of water diffusion in the myelin sheath surrounding axons is measured and yields information at the microstructure level about axon caliber change and aberrations in myelination. In addition, DTI allows for visualization of brain fiber tracks and neuronal connectivity. The interaction between areas of the brain at rest and during tasks using changes in blood flow is examined with fcMRI, currently a research tool. Morphometric analysis of sequential MRI scans has been used to create maps of cortical folding with quantification of surface area and degree of gyral formation. White matter injury results in delayed myelination and altered cortical folding.
Cerebellar injury
The cerebellum is essential for gross and fine motor control, coordination, motor sequencing, and also plays an important role in attention and language. Although the hallmark of damage to the cerebellum is ataxia, recent advances in fcMRI have demonstrated interactions between the cerebellum and nonmotor brain areas involved in language, attention, and mental imagery. Cerebellar injury can also be noted by cranial ultrasound on specific mastoid views. The incidence of cerebellar injury may be as high as 20% in ELBW infants. While the mechanism for damage is unknown, IVH is present in more than 75% of infants with cerebellar injury, implicating similar risk factors. The majority of cerebellar lesions (70%) are unilateral.
Cerebellar lesions are usually clinically silent at birth, and the full impact of the damage is noted over time. As a result of the intricate interconnections between the cerebellum and cerebrum, damage in one area can greatly impact development in other areas of the brain, thereby amplifying the damage. Preterm infants with isolated cerebellar hemorrhage had significant neurological impairments: hypotonia (100%), abnormal gait (40%), ophthalmological abnormalities (;40%), and microcephaly (17%). Overall, preterm infants with cerebellar hemorrhage had visual deficits and performed significantly lower on tests of gross and fine motor and expressive and receptive language. Infants with both cerebellar injury and IVH had greater motor impairment than infants with isolated cerebellar hemorrhage. Socially, infants with isolated cerebellar hemorrhage exhibited lower communication skills, more withdrawn behavior, and decreased attention skills. Cerebellar injury therefore increases the risk for poor neurodevelopment outcome in cognition, learning, and behavior in preterm infants.
Bronchopulmonary dysplasia
Bronchopulmonary dysplasia (BPD) or CLD is the result of mechanical ventilation and supplemental oxygen delivered to preterm infants to treat their immature lungs that lack surfactant. It was originally defined as an oxygen requirement at 28 days of life in conjunction with classic x-ray findings of atelectasis (areas of collapsed lung) and multiple cysts. The presence of BDP leads to the need for continued respiratory support owing to insufficient air exchange and, frequently, the placement of a tracheostomy tube. With recent treatment advancements such as maternal betamethasone to promote fetal lung maturity, exogenous surfactant, gentler, refined ventilation strategies, and careful supplemental oxygen administration, BPD is now defined as oxygen requirement at 36 weeks corrected gestational age. The level of BPD can be either moderate (requires supplemental oxygen) or severe (requires tracheostomy and ventilator support). The incidence of BPD in infants born at less than 27 weeks gestation or birth weight 500 to 750 g is 60%. The incidence of BPD for infants with birth weight 751 to 1000 g, 1001 to 1250 g, and 1251 to 1500 g is 33%, 14%, and 6%, respectively.
Infants with BPD can have altered pulmonary function, reactive airway disease, asthma, and delayed neurodevelopment. They may have decreased pulmonary reserve and frequent hospitalizations related to bacterial or viral pneumonia. Owing to the need for prolonged ventilation, infants with BPD may develop oral aversion resulting in difficulty with oral feeding and delayed expressive language. Dexamethasone has been used to decrease the dependence on mechanical ventilation but alters brain development, thereby negatively affecting neurodevelopmental outcome. , Hydrocortisone used instead of dexamethasone may result in lowering the incidence of BPD and appears to have decreased impact on neurodevelopmental outcome at 2 years of age.
Sepsis
Preterm infants are at high risk of developing sepsis owing to immature immune responses and decreased concentration of acquired maternal antibodies through the placenta. Approximately 2% of infants will be born septic, and 21% will develop sepsis during their NICU stay, with a mortality of 10% to 30% depending on infant age and other confounding factors. Cytokines are released from cells of the immune system in response to bacterial infection and can damage organs (e.g., lungs, kidneys, and brain). Infants with sepsis require increased time on mechanical ventilation and supplemental oxygen and have an increased incidence of BPD with its associated morbidities. Hypotension often accompanies sepsis leading to malperfusion of the brain and impaired development of oligodendrocytes. A two- to threefold increase in the risk for CP and neurodevelopmental impairment is reported in infants with sepsis. For infants with acquired sepsis, an increase in white matter injury is seen on MRI, especially if repeated episodes of sepsis occur.
Central line–associated blood stream infections (CLABSI) are hospital-acquired infections in conjunction with the presence of a central line. Much effort has been focused on decreasing CLABSI such as requiring stringent hand hygiene practices, minimizing central line use, decreasing number of central line interruptions, improving skin care, and enforcing strict infection control monitoring.
Necrotizing enterocolitis
NEC is the most common neonatal intestinal disease with an incidence of 10% in extremely preterm infants. An early presentation occurs within the first month of life, and NEC is frequently associated with intestinal perforation. Surgery is necessary for 50% of infants with NEC when medical management is insufficient or persistent intestinal perforation is present. Surgery is associated with an increased risk of mortality (20% to 40%) compared to infants treated medically. The etiology of NEC is not established, but risk factors include prematurity, umbilical artery catheterization, asphyxia, congenital heart disease, blood transfusion, and enteral feedings. Several viruses (adenovirus, enterovirus, and rotavirus) and bacteria have been implicated as causative agents for NEC. Infants with NEC are usually bacteremic either at the time of presentation of NEC or secondary to intestinal perforation.
Complications of NEC include sepsis, wound infection, and stricture formation that occurs in 10% to 35% of infants and requires additional surgeries to remove the stricture. If removal of intestines is required, wound infection and short gut condition are further complications. Growth of infants with NEC can be impaired owing to feeding intolerance, prolonged parenteral nutrition, removal of a significant amount of intestine, and repeated surgeries and infections. Persistence of weight at under 10% for age is correlated with decreased neuromotor and neurodevelopmental outcome. Failure to achieve normalization of head growth is associated with abnormal performance at 1 year and probably reflects significant white matter injury. Infants with surgically managed NEC have significantly increased incidence of CP (24% vs 15%), deafness (4.1% vs 1.5%), and blindness (4.1% vs 1%), compared to infants with medically treated NEC. , A meta-analysis of 7 studies investigating the impact of NEC on neurodevelopmental outcome showed that infants with surgically treated NEC have a statistically significant increase in cognitive, psychomotor, and neurodevelopmental impairment compared to preterm infants without NEC. Impaired neurodevelopmental outcome in infants with NEC is further exacerbated by sepsis with the release of inflammatory cytokines and mediators leading to white matter injury as noted above.
Hypoxic-ischemic encephalopathy in term and near term neonates
Perinatal asphyxia affects approximately 3 to 5 per 1000 infants annually and can lead to HIE in 0.5 to1/1000 live births. Approximately 15% to 20% of infants with HIE will die, and 25% of the surviving infants will exhibit permanent neurological sequelae. Clinical findings will vary depending on the timing and duration of the H/I insult, preconditioning, fetal adaptive mechanisms, comorbidities, and resuscitative efforts. Impaired oxygen delivery to the fetus leading to asphyxia can result from maternal hypotension, abruption placenta, placental insufficiency, cord prolapse, prolonged labor, and fetal-maternal transfusion. Frequently, infants who develop HIE have associated factors such as abnormal maternal thyroid status, chorioamnionitis, and intrauterine growth retardation.
It is important to note that the injury from a H/I insult is an evolving and progressive process that begins at the time of the insult and continues through the recovery period, allowing the opportunity to decrease the damage from the asphyxial event. The H/I insult leads to decreased oxygen and glucose delivery to the brain causing a shift from aerobic to anaerobic metabolism. This shift causes a decrease in high-energy compounds such as adenosine triphosphate (ATP) production leading to failure of the energy-dependent membrane sodium potassium pump. Sodium enters the neuronal cell causing depolarization and release of excitatory neurotransmitters. This initial phase can last several hours and is marked by significant acidosis, depletion of high-energy compounds, cellular swelling caused by entry of sodium and water, and cellular necrosis causing spillage of intracellular contents into the extracellular space and activation of microglia. The degree of neuronal necrosis is directly related to the duration and severity of the H/I insult. During the reperfusion phase, an increase in free radical production and activation of microglia occur with release of inflammatory mediators caused by improved oxygen delivery. The second phase of energy failure ensues with calcium entering the mitochondria to activate the apoptotic pathway (programmed cell death). During this second phase of energy failure, seizures are often present. Activation of the apoptotic pathway accounts for the majority of cellular death and inactivation of this apoptotic pathway is the target for treatment.
The damage from HIE in term infants is located in the deep structures of the brain (basal ganglia, thalamus, and posterior limb of the internal capsule) as well as in the subcortical and parasagittal white matter. Diffusion-weighted imaging MRI (DWI) is an early and sensitive technique to identify damage after the H/I insult. As shown in Fig. 9.9 , a marked increase in signal is found in the subcortical and parasagittal white matter as well as in the deep nuclear structures. MRI spectroscopy, usually in the area of the basal ganglia, yields information about the degree of secondary energy failure by analyzing the depletion of the high-energy compound N-acetylaspartate and the presence of lactate. The degree of secondary energy failure is predictive of death and poor neurodevelopmental outcome at 1 and 4 years of age.
The Sarnat score ( Table 9.3 ) classifies the severity of HIE based on clinical signs. Approximately 20% of infants with stage 1 HIE will have long-term sequelae. Infants with Grade 2 or moderate HIE have abnormal tone and reflexes and decreased spontaneous activity. Seizures are a common finding in infants with moderate HIE, and approximately 10% of these infants will die and up to 30% will have neurodevelopmental delay. Infants with severe HIE (Grade 3) have minimal or no spontaneous activity or reflexes, and approximately 50% of these infants will die and, of the survivors, more than 60% to 80% are profoundly impaired. Seizures are present in up to 40% of infants with HIE and are identified either clinically or by EEG or amplitude integrated EEG. Long-term consequences of HIE include bulbar palsies with difficulties in sucking, swallowing, and facial movement. Upper extremity involvement is more prominent than lower extremity deficits. The development of epilepsy occurs in approximately 30% of infants with HIE. Owing to the fact that approximately 50% of infants with moderate or severe HIE treated with hypothermia will exhibit normal neurodevelopmental outcomes, other modalities such as Xenon gas, topiramate, melatonin, tetrahydrocannabis, and erythropoietin are being investigated to enhance the efficacy of hypothermia.
| Stage Encephalopathy | Normal | Stage 1 (Mild) | Stage 2 (Moderate) | Stage 3 (Severe) |
|---|---|---|---|---|
| 1. Level of consciousness | Alert, responsive | Hyper-alert, responds to minimal stimulation | Lethargic | Stupor/coma |
| 2. Spontaneous activity | Changes position | Normal or ↓ | Decreased | None |
| 3. Posture | Flexed when quiet | Mild flexion distal | Distal flexion, full extension | Decerebrate |
| 4. Tone | Strong flexor tone | Normal or slightly ↑ | Hypo- or hyper- | Flaccid or rigid |
| 5. Reflex: Suck Moro | Strong Complete | Weak or incomplete Intact | Weak Incomplete | Absent Absent |
| 6. Autonomic: Pupils HR Respirations | Normal 100-160 Regular | Mydriasis Tachycardia Hyperventilation | Myosis Bradycardia Periodic breathing | Variable Variable Apnea, assisted |
Mild hypothermia (33.5°C) is becoming the standard of care for infants under 36 weeks gestation who present with moderate or severe HIE. Hypothermia has been shown to decrease metabolic demand and therefore help preserve high-energy compounds, delay membrane depolarization, and decrease neuronal excitotoxicity. Free radical production and microglial activation are also decreased. Most importantly, the activation of the apoptotic pathway is diminished. Transient side effects of hypothermia, such as bradycardia, mild hypotension, thrombocytopenia, and persistent pulmonary hypertension, can be treated medically and are usually not significant. A meta-analysis of published randomized studies comparing infants with moderate and severe HIE treated with either hypothermia or normothermia showed that hypothermic treatment significantly decreased mortality and morbidity ( Table 9.4 ). It is known that hypothermia is most effective when administered prior to the onset of the second phase of energy failure. As the timing of the H/I insult can occur prior to delivery, hypothermia should be initiated as quickly as possible after delivery to increase the likelihood that it will diminish the neuronal damage and improve neurodevelopmental outcome.
| Risk Ratio (95% Confidence Interval [CI]) | Risk Difference (95% CI) | Number Needed to Treat (95% CI) | P Value | |
|---|---|---|---|---|
| Death or severe disability a | 0.81 (0.71–0.93) | −0.11 (−0.18–−0.04) | 9 (5–25) | .002 |
| Survival with normal outcome b | 1.53 (1.22–1.93) | 0.12 (0.06–0.18) | 8 (5–17) | <.001 |
| Mortality | 0.78 (0.66–0.93) | −0.07 (−0.12–−0.02) | 14 (8–47) | .005 |
| Severe disability in survivors a | 0.71 (0.56–0.91) | −0.11 (−0.20–−0.03) | 9 (5–30) | .006 |
| Cerebral palsy in survivors | 0.69 (0.54–0.89) | −0.12 (−0.20–−0.04) | 8 (5–24) | .004 |
| Severe neuromotor delay in survivors c | 0.73 (0.56–0.95) | −0.10 (−0.18–−0.02) | 10 (6–71) | .02 |
| Severe neurodevelopmental delay in survivors d | 0.71 (0.54–0.92) | −0.11 (−0.19–−0.03) | 9 (5–39) | .01 |
| Blindness in survivors | 0.57 (0.33–0.96) | −0.06 (−0.11–0.00) | 17 (9–232) | .03 |
| Deafness in survivors | 0.76 (0.36–1.62) | −0.01 (−0.05–0.03) | NA | .47 |
a Severe disability was defined in the CoolCap and TOBY trials as the presence of at least one of the following impairments: Mental Development Index score of less than 70 (2 standard deviations below the standardized mean of 100) on the Bayley Scales of Infant Development; gross motor function classification system level 3 to 5 (where the scale is from 1 to 5, with 1 being the mildest impairment); or bilateral cortical visual impairment with no useful vision. The NICHD trial defined disability as a Mental Developmental Index score of 70 to 84 plus one or more of the following impairments: gross motor function classification system level 2; hearing impairment with no amplification; or a persistent seizure disorder.
b Survival with normal outcome was defined as survival without cerebral palsy and with a Mental Developmental Index score of more than 84, a Psychomotor Developmental Index score of more than 84, and normal vision and hearing.
c Severe neuromotor delay was determined on the basis of a Psychomotor Developmental Index score of less than 70 in survivors.
d Severe neurodevelopmental delay was determined on the basis of a Mental Developmental Index score of less than 70 in survivors.
Maternal medication
The impact of maternal medications on the developing fetal brain depends on the specific drug or combinations of drugs, as well as on the timing and duration of the drug exposure. Whereas the insults discussed previously cause predominantly cellular necrosis and apoptosis, medications given to the fetus and preterm infant can also cause alterations in the structure and function of genetic material. The hypothesis that factors acting early in life have a long-lasting impact on development is called the Barker hypothesis or the fetal origins of adult disease. , It is proposed that the biological value of this reprogramming is to prepare the fetus for maximal adaptation through methylation and deacetylation of histones, thereby determining the quantity of specific proteins that are produced. This section will focus on maternal use of opioids, cocaine, cannabis, and selective serotonin reuptake inhibitors (SSRIs) during pregnancy.
Opioids
In the past decade, increasing concern has emerged over the marked use of opioids, both by prescription for pain relief and illicit use, leading to an increase in deaths owing to overdose. Most commonly used are naturally occurring opioids (morphine and codeine) and synthetic opioids (heroin, methadone, buprenorphine, and, recently, fentanyl). Opioids act on receptors present in both the central nervous system and gastrointestinal tract leading to euphoria and constipation, respectively. Continued use of opioids leads to tolerance resulting in a need to increase the drug’s dose for the same effect. Physical dependence is manifested by withdrawal symptoms when the drug is discontinued. Addiction is a complex issue including tolerance, dependence, and psychological compulsion to use the drug.
Use of pain relievers, specifically opioids, during pregnancy has increased fivefold during the past decade. These drugs are highly addictive to the mother and can readily cross the placenta and affect the fetus. Methadone and buprenorphine are commonly used in pregnant females to decrease the need for illicit drug use and stabilize maternal narcotic dependence. Opioid use during pregnancy has been associated with premature rupture of membranes, uterine irritability, preterm labor, preeclampsia, and growth-retarded infants.
Neonatal abstinence syndrome (NAS) is a constellation of symptoms in infants exposed prenatally to opioids and, after delivery, are subject to cessation of opioids leading to withdrawal symptomatology. Infants will demonstrate neurological hyperexcitability with high-pitched crying, increased muscle tone, irritability, decreased sleep, hyperalert state, and tremors at rest. Gastrointestinal symptoms can also be present such as vomiting and diarrhea. Impaired oral feeding and an increased need to suck on a pacifier are common. Autonomic signs include sweating, mottling of the skin, increased temperature, and nasal stuffiness. Occasionally, seizures are present. In Ohio, hospital admissions for infants with NAS increased from 1.4 to 5.6 per 1000 live births.
Withdrawal from narcotics occurs 2 to 5 days after delivery depending on the opioid. Withdrawal from heroin and morphine usually starts by 24 hours after delivery. Neonatal withdrawal from maternal methadone or buprenorphine use is delayed up to 5 days after delivery owing to the long half-life on these medications. Severity of neonatal withdrawal symptoms is not exclusively related to the dose of maternal medications, but is influenced by polysubstance drug exposure, cigarette use, and genetics differences. Two commonly used scoring methods for determining the severity of NAS and the need for treatment are scales by Lipsitz and Finnegan and colleagues. The Lipsitz scale has 11 components scored from 0 to 3, with any score over 4 necessitating treatment. The Finnegan scale is a comprehensive assessment with more than 30 elements. A modified Finnegan assessment tool has been validated and is most frequently used.
Nonpharmacological supportive care consists of minimizing environmental stimuli by decreasing light and noise and decreasing irritability with swaddling, holding, pacifier use, and on-demand feeding. Maternal rooming-in and breastfeeding have beneficial effects on decreasing symptoms of withdrawal. This supportive care should be implemented even if the infant is on medications because they continue to demonstrate hyperexcitable behavior and have decreased tolerance to stimulation. Approximately 30% to 80% of in utero opioid-exposed infants will require medical treatment for NAS with either morphine or methadone. Phenobarbital and/or clonidine have been used as adjunctive treatment if symptoms continue. The goal of treatment is to decrease irritability, improve nippling efforts and weight gain, and decrease vomiting and diarrhea. The incidence of apnea and sudden infant death syndrome (SIDS) is increased in opioid-exposed infants. Long-term effects of in utero exposure to opioids include tremulousness, hypertonicity, irritability, and increased crying episodes. In addition, they are less able to interact with people, demonstrate decreased age-appropriate free play, and have delayed fine motor coordination. An appropriate and nurturing home environment is essential after discharge from the hospital to maximize neurodevelopmental outcome.
Cocaine
It is difficult to ascertain the exact frequency of cocaine use during pregnancy because its use is frequently associated with other illicit drugs. Cocaine is extracted from the leaves of the coca plant and induces an intense and immediate euphoric state through inhibiting uptake of neurotransmitters, specially serotonin and dopamine. Dependence can occur, and cocaine is highly addictive with severe and intense cravings lasting for several months with potential recurrence years after cessation of cocaine use.
Cocaine can cause vasoconstriction leading to placental abruption, preterm labor, uterine irritability, and premature rupture of membranes. In the fetus, there is an increased risk for H/I injury and middle cerebral artery stroke. Cocaine also negatively affects fetal neuronal proliferation, migration, growth, and connectivity, which distort neuronal cortical architecture; however, the effects of intrauterine exposure to cocaine are difficult to determine because cocaine use is frequently associated with the abuse of other illicit drugs, cigarettes, and alcohol. Other confounding variables increasing the risk for negative fetal outcomes include inadequate maternal nutrition and limited prenatal care. In a large prospective blinded study, more infants exposed to cocaine in utero were delivered prematurely and exhibited decreased weight, length, and head circumference compared with matched controls. Neonates with prenatal cocaine exposure demonstrate tremors, hypertonia, irritability, poor feeding ability, and abnormal sleep patterns and are at a threefold to sevenfold increased risk of SIDS. In addition, in utero cocaine exposure has been linked to increased incidence of behavioral problems and special education referrals in school-aged children with abnormalities in executive functioning.
Cannabis
As a result of the legalization of marijuana (cannabis) in many states, an increasing number of pregnant females are using cannabis during pregnancy to treat nausea and vomiting in addition to recreational use. Marijuana use is increased in mothers who are younger (18 to 25 years), habitually smoke, use illicit drugs, have completed high school, are unemployed, and are enrolled in federal subsidy programs (e.g., women, infants, and children nutrition program). Mixed reports about the impact of marijuana on the brain of the developing fetus are a result, in part, of concomitant exposure to cigarette smoking and other confounding drugs (cocaine, opioids, etc). Marijuana readily crosses the blood-brain barrier and modulates the release of specific neurotransmitters from glial and neuronal cells that are important for the normal maturation of the brain in utero. Marijuana use has been implicated in an increased incidence of stillbirths and preterm labor, increased risk of infection, and increased neurological morbidity (specifically IVH and PVL). Infants tend to have decreased birth weight and an increased risk of admission to the NICU. Long-term in utero exposure to maternal marijuana appears to impact attention span and short-term memory, with increased risk of impulsivity and hyperactivity in school-aged children. The American Academy of Pediatrics (AAP) discourages the use of marijuana during pregnancy owing to concerns for the long-term impact on the developing brain. The AAP also discourages the use of marijuana during breastfeeding because the active compound is present in breast milk.
Selective serotonin reuptake inhibitors
Depression during pregnancy can cause serious side effects in both the mother and the developing fetus. At least 600,000 infants are born yearly to mothers who have a major depressive disorder during their pregnancy. It is reported that at least 6% of pregnant woman use SSRIs during pregnancy, and almost 40% of depressed women have been reported to use antidepressants at some time during pregnancy. The most common SSRI medications used to treat anxiety and depression during pregnancy are fluoxetine (Prozac, Fontex, Seromex, and Seronil), sertraline (Zoloft, Lustral, Serlain, and Asenta), paroxetine (Paxil, Seroxat, Sereupin, and Paroxat), fluvoxamine (Luvox and Favoxil), escitalopram (Lexapro, Cipralex, and Esertia), and citalopram (Celexa, Seropram, Citox, and Cital). A meta-analysis found that maternal depression was significantly associated with an increased incidence of preterm labor and neonatal birth weight less than 2500 g but not intrauterine growth retardation of the fetus. Unfortunately, this study was unable to evaluate the effect of only SSRI therapy on these outcomes.
The SSRI drugs readily cross the placenta and inhibit serotonin reuptake in neuronal cells. The serotonergic system is present early in gestation and is important in fetal brain development. Perturbations in this system are associated with alterations in somatosensory processing and emotional responses. Infants exposed to SSRIs in the third trimester have symptoms similar to withdrawal from opioid exposure (irritability, tremors, jitteriness, agitation, and difficulty sleeping). These symptoms are transient, appearing 2 to 4 days after birth and disappearing by the second week of life. Neonatal feeding difficulties are quite common in infants exposed to SSRIs. Seizures and abnormal posturing are occasionally noted. In addition, infants exposed to SSRIs in utero have a twofold increased risk of developing pulmonary hypertension. It is difficult to identify any specific adverse neurodevelopmental outcomes in infants exposed prenatally to SSRIs from published studies because of the variability in the specific SSRI taken, the duration and timing of SSRI use, and the confounding factors of maternal depression and the use of multiple medications.
Clinical management: Neonatal period
Pediatric therapists with mentored subspecialty training in neonatology and infant therapy approaches can expand neonatal services by creating clinical protocols and pathways designed to optimize the development and interaction of neonates and parents. The therapeutic partnership between parents and neonatal therapists during developmental intervention in the NICU sets the stage for parental support and competency in caregiving and compliance with follow-up in the outpatient period. General aims of NICU clinical management of infants at risk for neurological dysfunction, developmental delay, or musculoskeletal complications are to
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promote posture and movement appropriate to gestational age and medical stability
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support symmetry and biomechanical alignment of extremities, neck, and trunk while multiple infusion lines and respiratory equipment are required
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decrease potential skull and extremity musculoskeletal deformities and acquired joint-muscle contractures
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foster infant-parent attachment and interaction
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modulate sensory stimulation in the infant’s NICU environment to promote behavioral organization and physiological stability
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provide consultation or direct intervention for neonatal feeding dysfunction and oral-motor deficits
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enhance parents’ caregiving skills (feeding, dressing, bathing, positioning of infant for sleep, interaction and play, and transportation)
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prepare for hospital discharge and integration into home and community environments
Educational requirements for therapists
Examination and intervention for neonates are advanced-level, not entry-level, clinical competencies. Neonatology is a recognized subspecialty within the specialty areas of pediatric physical therapy , , and pediatric occupational therapy. No amount of literature review, self-study, or experience with other pediatric populations can substitute for competency-based clinical training with a mentor in a NICU. The potential for causing harm to medically fragile infants during well-intentioned intervention is enormous. , The ongoing clinical decisions made by neonatal therapists in evaluating and managing physiological and musculoskeletal risks while handling small (2 or 3 lb), potentially unstable infants in the NICU should not be a trial-and-error experience at the infant’s expense. Therapists with adult-oriented training and even those with general pediatric clinical training (excluding neonatal) are not qualified for neonatal practice without a supervised clinical practicum (2 to 6 months). The NICU is not an appropriate practice area for physical therapy assistants, occupational therapy assistants, or student therapists on affiliations for reasons outlined by Sweeney and colleagues : “handling of vulnerable infants in the NICU requires ongoing examination, interpretation, and multiple adjustments of procedures, interventions, and sequences to minimize risk for infants who are physiologically, behaviorally, and motorically unstable or potentially unstable.” The physical or occupational therapy assistant and student therapist are not prepared, even with supervision, to “provide moment-to-moment examination and evaluation of the infant and have the ability to modify or stop preplanned interventions when the infant’s behavior, motor, or physiological organization begins to move outside the limits of stability with handling or feeding.” Appropriate nonhandling, observational experiences for physical therapist or occupational therapist students in the NICU are delineated by Rapport and colleagues, with a wide range of observational learning experiences with a preceptor recommended in this specialized practice environment (refer to Box 9.1 for appropriate nonhandling, observational experiences for entry-level students during hospital clinical affiliations).
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Reviewing neonatal literature and neonatal therapy clinical practice guidelines before site visit to neonatal intensive care unit (NICU)
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“Shadowing” neonatal nurses to observe:
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Neonatal equipment (refer to Table 9.6 )
TABLE 9.6
Equipment Commonly Encountered in the Neonatal Intensive Care Unit
Equipment
Description
Thermoregulation
Radiant Warmer
Double Walled Incubator
Unit composed of mattress, adjustable side panels, and radiant heat source controlled either manually or by servo-control.
Advantage: ready access to infant
Disadvantage: increases convective heat loss, insensible heat loss, and encourages excessive stimulation
Enclosed unit providing heat and humidity controlled either by environmental or servo control. Access to infant is through port holes or opening up incubator
Advantage: barrier to tactile stimulation, decrease heat loss
Disadvantage: difficult to gain access to infant and no decreased ambient noise
Respiratory Assistance
Oxyhood
Nasal Cannula (NC)
Humidified High Flow NC
Continuous Positive Airway Pressure
Conventional Ventilator
High Frequency Ventilator
Oscillator
Jet
Clear hood that fits over infant’s head to provide heated and humidified supplemental oxygen
Delivers specific concentration of oxygen via soft nasal cannula, usually <2 L/min
Delivers specific concentration of heated and humidified oxygen via slightly larger soft nasal cannula, usually <6 L/min with some distending pressure to assist in lung inflation.
Nasal prongs or mask provides constant pressure and heated and controlled oxygen delivery provided by bubble or ventilator.
Delivers positive pressure ventilation with positive end expiratory pressure and either a specific delivered pressure or volume.
Delivers shorts bursts of supplemental oxygen at high rate (240–720 breaths/min) with active inhalation and exhalation.
Delivers shorts bursts of supplemental oxygen at high rate (240–480 breaths/min) with active inhalation and passive exhalation, is noisy, and requires conventional ventilator.
Monitors
Cardiorespiratory
Oxygen (O 2 ) Saturation
Transcutaneous carbon dioxide (CO 2 )
Near Infrared Spectroscopy (NIRS)
Amplitude Integrated Electro-encephalogram (aEEG)
Displays heart rate, respiratory rate, and blood pressure with high and low limits.
Measures arterial oxygen saturation and uses a light sensor.
Measures partial pressure of O 2 and CO 2 noninvasively using a heated sensor.
Noninvasive method to measure tissue (brain, renal, intestinal) oxygen saturation to ensure adequate oxygen delivery.
Continuous recording of cerebral electrical activity to evaluate presence of seizures and maturation of the brain.
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Caregiving routines
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Teaching styles with parents and grandparents
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Feeding procedures and equipment
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Unique culture of the NICU compared with adult intensive care units
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Skin-to-skin holding by parent
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Environmental adaptations (light, sound, and clustered handling)
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“Shadowing” neonatal therapist to observe:
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Chart reviews
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Interdisciplinary rounds
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Discharge planning conferences
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Behavioral and physiological baseline examinations
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Examination and intervention procedures adapted for medically stable infants at varying gestational ages, acuity levels, and behavioral organization
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Parental teaching
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Collaboration with neonatal nurses for positioning, feeding, and parent instruction
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Observing and participating with neonatal therapist in NICU follow-up clinic
Delineation of advanced-level roles, competencies, and knowledge for the physical therapist, , occupational therapist, and speech pathologist in the NICU setting have been described separately by national task forces from the respective national professional organizations. These practice guidelines provide a structure for assessing competence of individual therapists working in NICU settings and offer an ethicolegal practice framework for designing clinical paths and an evidence base for specific neonatal therapy services.
A gradual, sequential entry to neonatal practice is advised by building clinical experience with infants born at term gestation as well as with physiologically fragile older infants and children and their parents. The experience may include managing caseloads of hospitalized children on physiological monitoring equipment, external feeding lines, and supplemental oxygen or ventilators. Participating in discharge planning and in outpatient follow-up of high-risk neonates are other options for providing exposure to examination, intervention, and family issues when the infants and parents are more stable. This clinical experience and a competency-based, precepted practicum in the NICU offer the best preparation for appropriate, accountable, and ethical practice in neonatal therapy. , In-depth study of perinatal and neonatal medicine and related obstetrical, neonatal nursing, high-risk parenting, and neonatal therapy literature is recommended before pediatric therapy clinicians begin to participate on the intensive care nursery team.
Neonatal pain and neurological assessment
Multiple neonatal neurological and neurobehavioral examinations have been developed to assess the integrity and maturation of the nervous system and to describe newborn behavior. Most of these tests offer information on the quality of motor performance, attention, and interaction and because these assessments are based on gestational age, an accurate calculation of gestational age is necessary at the time of the testing.
Pain assessment
Despite immature myelinization, premature infants definitely perceive pain and retain the memory of painful experiences. Skin receptors are developed by 14 to 16 weeks of gestation. In addition, the density of pain receptors in the skin of neonates at 28 weeks of gestation is considered similar to, and even exceeds, adult density during maturation from birth to 2 years of age. , Blackburn explained that although pain transmission in neonates occurs mainly through the slower, unmyelinated C fibers, the shorter distance in neonates that impulses travel to reach the brain compensates for the slower rate of transmission and creates substantial pain reception. Early pain experiences may create later increased sensitivity to pain and vulnerability to stress disorders. If neonatal therapy assessment or intervention procedures immediately follow a noxious procedure in the NICU, handling techniques may need to be modified or therapy session rescheduled to avoid contributing to a cascade of aversive experiences for the infant. Parents showing distress and concern about infant pain may benefit from training in comfort care techniques of swaddling, pacifier use, touch, soft conversation, and holding.
Psychometric data and clinical use of the pain tools are described for infants as early as 28 weeks of gestation. Many elements in the pain assessments have been identified by Als as signs of excessive stimulation and stress in the preterm infant. Specific extremity movements, such as hand-to-face, elevated leg extension, salute, lateral extension of arms, finger splay, and fisting, have been proposed by Holsti and Grunau as indicators of stress and/or pain.
In addition to practice guidelines on pain assessment developed primarily by neonatal nurses, numerous instruments are available to assess pain in infants. Pain scale data are integrated into NICU nursing assessments and can be a valuable adjunct to the neonatal therapist’s baseline and post-therapy observations. Indicators of pain are detailed in the instruments outlined below. These pain assessments provide documentation for pain or distress signs in the following three categories: (1) physiological (heart rate, oxygen saturation, and breathing pattern), (2) behavioral (eye squeeze, brow bulge, facial grimace, and behavioral state, including crying and sleeplessness), and (3) motor (tone and movement in extremities).
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The Premature Infant Pain Profile (PIPP ) assigns points for changes in three facial expressions (brow bulge, eye squeeze, and nasolabial fold), heart rate, and oxygen saturation. Gestational age and preprocedural behavioral state are included in the assessment. The maximal PIPP score is 21; the higher the score, the greater the pain. A score of 0 to 6 points indicates minimal or no pain, whereas a score of 12 or more indicates moderate to severe pain.
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The Face, Legs, Activity, Cry, and Consolability Behavioral tool (FLACC) uses grades of 0 to 2 for facial expression, leg activity, general activity, cry nature, and ability to be consoled and has been used in pediatric and adult settings. This test is capable of assessing pain in normal as well as cognitively impaired children, thereby giving it a high degree of versatility and usefulness. Change in FLACC score has been used to demonstrate that the use of sucrose and a pacifier during venipuncture is more effective in consoling infants younger than 3 months of age compared to infants older than 3 months of age.
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The Neonatal Pain, Agitation, and Sedation Scale (N-PASS) uses five indicators: (1) crying and irritability, (2) behavioral state, (3) facial expression, (4) extremity movement and tone, and (5) vital signs. As with the PIPP scale, additional points are added for decreasing gestational age. Good correlation was established between the N-PASS and the PIPP assessments during routine heelstick in infants younger than 1 month old born at 23 to 42 weeks’ gestation.
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The Neonatal Infant Pain Scale (NIPS) has six indicators for pain or distress and can be used with both preterm and full term infants. On a 7-point scale, pain behavior is assessed by facial expression, cry nature, breathing pattern, arm and leg posture, and arousal state.113
Neonatal behavioral assessment scale
To document individual behavioral and motor differences in infants at term gestation to 2 months of age, Brazelton and Nugent developed a neonatal behavior scale to assess neuromotor responses within a behavioral state context. The 30- to 45-minute examination consists of observing, eliciting, and scoring 28 biobehavioral items on a 9-point scale and 18 reflex items on a 4-point scale. This interactive test assesses the infant’s ability to respond to stimuli and return to an alert state. The reflex items are derived from the neurological examination protocol of Prechtl and Beintema.
The scale was designed to assess newborn behavior in healthy 3-day-old term (40 weeks of gestation) Caucasian infants whose mothers had minimal sedative medication during an uncomplicated labor and delivery. Use of this examination with infants born preterm requires modification of the examination procedure to the environmental constraints of an intensive care nursery and interpretation of findings relative to the gestational age and medical condition of the infant. For preterm infants approaching term gestation (minimum of 36 weeks of gestation), nine supplementary behavioral items are offered. Many of these items were developed by Als for use with preterm and physiologically stressed infants (see discussion of the APIB, later). In the manual, methods of adapting the Neonatal Behavioral Assessment Scale (NBAS) for preterm neonates with accompanying case scenarios are described to illustrate use of the findings to enhance parent-infant interaction and guide developmental interventions.
Six behavioral state categories are outlined in the NBAS: deep sleep, light sleep, drowsiness or semi-dozing, quiet alert, active alert, and crying. Behavioral state prerequisites are provided for each biobehavioral and reflex item to reduce the state-related variables in testing. During the assessment the examiner systematically maneuvers the infant from the sleep states to crying and back to the alert states to evaluate physiological, organizational, motor, and interactive capabilities during stimulation and physical handling. The scoring is based on the infant’s best performance, with flexibility allowed in the order of testing, repetition of items encouraged, and scheduling of the assessment midway between feedings to give the infant every advantage to demonstrate the best possible responses.
Four dimensions of newborn behavior are analyzed in the NBAS: interactive ability, motor behavior, behavioral state organization, and physiological organization. Interactive ability describes the infant’s response to visual and auditory stimuli, consolability from the crying state with intervention by the examiner, and ability to maintain alertness and respond to social or environmental stimuli.
Motor behavior refers to the ability to modulate muscle tone and motor control for the performance of integrated motor skills, such as the hand-to-mouth maneuver, pull-to-sit maneuver, and defensive reaction (e.g., removal of cloth from face). In the assessment of behavioral state organization, the infant’s ability to organize behavioral states when stimulated and to shut out irritating environmental stimuli when sleeping are analyzed. Physiological organization is evaluated by observing the infant’s ability to manage physiological stress (changes of skin color, frequency of tremulous movement in the chin and extremities, number of startle reactions during the assessment). For analysis, the information is divided into seven clusters: habituation, orientation, motor, range of state, regulation of state, autonomic stability, and reflexes. The cluster systems are highly useful for clinical interpretation and for data analysis in clinical research. Performance profiles of worrisome or deficient interactive-motor and organizational behavior are identified by clusters of behavior associated with potential developmental risk.
Definite strengths of the NBAS are the well-defined indicators of autonomic stress, analysis of coping abilities of high-risk infants experiencing external stimuli and handling, and quality of infant-examiner interaction. These features generate specific findings to assist therapists in grading the intensity of assessment and treatment within each infant’s physiological and behavioral tolerance and in guiding the development of parental teaching strategies to address the individual behavioral styles of infants. The NBAS has proved to be more sensitive to the detection of mild neurological dysfunction in the newborn period compared to classic neurological examinations that omit the behavioral dimensions. This assessment is not predictive but gives a good analysis of the infant’s strengths and weaknesses. Improved performance from repeat examinations over time is a better predictor of the infant’s ability and potential.
Participation of the parent in the newborn assessment may yield long-term positive effects on infant-parent interaction and later on cognitive and fine motor development. Widmayer and Field reported significantly better face-to-face interaction and fine motor-adaptive skills at 4 months of age and higher mental development scores at 12 months of age when teenage mothers of preterm infants (mean gestational age at birth, 35.1 weeks) were given demonstrations of the NBAS. These demonstrations were scheduled when the premature infants had reached an age equivalence of 37 weeks of gestation.
A four-step examiner training involving self-study, skill test, practice, and certification phases is coordinated through the Brazelton Institute/Touch Points Center, Children’s Hospital, Boston, Massachusetts. For clinicians beginning to develop competence in examining at-risk infants, the NBAS provides a system for developing basic handling skills with healthy, term infants without concerns of stressing medically fragile preterm infants during the training period. Learning the NBAS in term infants before entering NICU practice provides familiarity with similar testing and scoring procedures for preterm infants.
Newborn behavioral observations system
The Newborn Behavioral Observations (NBO) system, developed from the pioneering work and philosophy of Brazelton, is an interactive, observational tool for use with infants and parents in hospital, clinic, and home settings. The focus is on prematurely born infants and at-risk infants, with emphasis on cultural competence, family-centered care, and infant development. The NBO system helps determine the behavioral profile of the infant and allows the practitioner to provide parents with individualized and unique information about their infant. This behavioral information promotes positive parent-infant interaction and also a positive partnership between parents and practitioners.
Certification in administering, interpreting, and scoring the 18-item NBO assessment is arranged through the Brazelton Institute/Touch Points Center, Boston, MA, in a 2-consecutive-day format. The training encompasses the following observation categories: (1) habituation to external light and sound; (2) muscle tone and motor activity level; (3) behavioral self-regulation (crying and consolability); and (4) visual, auditory, and social-interactive abilities.
Neurological assessment of the preterm and full-term newborn infant
The Neurological Assessment of the Preterm and Full-Term Newborn Infant is a streamlined neurological and neurobehavioral assessment designed by Dubowitz and colleagues to provide both a systematic, quickly administered newborn examination applicable to infants born preterm or at term gestation and a longer infant examination for children to 24 months of age. A distinct advantage of this tool is the minimal training or experience required by the examiner and the ease of adapting it to the infant and the environment. The adaptability of the test and use of the scoring form with stick figure diagrams have made it useful for implementation in developing countries where English is not widely spoken.
The test includes the six behavioral state categories of the NBAS and seven orientation and behavior items scored on a 5-point grading scale and sequenced according to the intensity of response. The orientation and behavior items consist of the following categories: (1) auditory and visual orientation responses; (2) quality and duration of alertness; (3) irritability (the frequency of crying to aversive stimuli during reflex testing and handling throughout the examination); (4) consolability (the ability after crying to reach a calm state independently or with intervention by the examiner); (5) cry (quality and pitch variations); and (6) eye appearance (absent, transient, or persistent appearance of sunset sign, strabismus, nystagmus, or roving eye movements).
The 15 items that assess movement and tone and the six reflex items evolved from clinical trials on 50 term infants using the clinical assessment of gestational age by Dubowitz and colleagues, the neurological examination of the newborn by Parmelee and Michaelis, and the neurological examination of the full-term newborn infant by Prechtl. The examination format was then used during a 2-year period on more than 500 infants of varying gestational ages. After 15 years the authors revised the assessment in the second edition by eliminating seven items, expanding the tone pattern section, and developing an optimality score. Reliability data are not reported, but modification of examination procedures occurred during the pilot phase that promoted objectivity in scoring and a high interrater reliability among examiners, regardless of experience level.
The examination protocol is available in two formats: (1) Hammersmith Short Neonatal Neurological Examination and (2) Hammersmith Infant Neurological Examination (HINE; age range, 2 to 24 months) (see later in this chapter). The examination forms are illustrated with stick figures and can accommodate both baseline and repeat assessments. For neonatal therapy examinations the forms can be effectively combined with a narrative impression, treatment goals, and plan of care. A numerical score for each item and a summary score are provided in the revised edition of the test. The authors advised that the scoring system was primarily intended for the purpose of research and for numerical charting of progress with sequential examinations. Because of the continued clinical emphasis on patterns of responses, selected parts of the protocol (without summary scoring) are appropriate for examining premature or acutely ill infants on ventilators, in incubators, or attached to monitoring or infusion equipment. Scheduling of examinations is recommended two-thirds of the way between infant feeding sessions.
Evolution of neurological patterns in infants with IVH, PVL, and HIE is described in the test manual and correlated with brain imaging. Abnormal neonatal clinical signs associated with long-term neurological sequelae were persistent asymmetry, decreased lower-extremity movement, and increased tone. Infants with IVH had significantly higher incidence of abnormally tight popliteal angles, reduced mobility, decreased visual fixing and following, and roving eye movements. The authors cautioned that early signs of motor asymmetry in neonates with cerebral infarction may be associated with normal outcome, but normal neonatal neurological examinations after cerebral infarction do not exclude the possibility of later hemiplegia.
Long-term follow-up data beyond 1 year have not been reported with this examination. Dubowitz and colleagues reassessed 116 infants (27 to 34 weeks of gestation) at 1 year of age. Of 62 infants assessed as neurologically normal in the newborn period, 91% were also normal at 1 year of age. Of 39 infants assessed as neurologically abnormal in the newborn period, 35% were found to be normal at 1 year of age. The predictive value of a negative test result with this instrument was 92%, and the predictive value of a positive test result was 64%.
Assessment of preterm infant behavior
Als designed the APIB to structure a comprehensive observation of a preterm infant’s autonomic, adaptive, and interactive responses to graded handling and environmental stimuli. It involves six maneuvers with increasing challenging and complex interactions with a highly structured format. As previously described in the theoretical framework section of this chapter, this assessment is derived from synactive theory and is focused on assessing the organization and balance of the infant’s physiological, motor, behavioral state, attention and interaction, and self-regulation subsystems. The APIB has testing sequences and a scoring format similar to those used in Brazelton’s NBAS, with increased complexity and expansion for premature infants.
Administration and scoring of the APIB may require 2 to 3 hours per infant and often two or more sessions with the infant depending on examiner experience and infant stability. Although the APIB may be an instrument of choice for the clinical researcher, it is not usually practical (time efficient) for many neonatal clinicians with heavy caseloads in managed-care environments. Extensive training and reliability certification are required to safely administer and accurately score and interpret the test for clinical practice or research.
Neonatal individualized developmental care and assessment program
Als and colleagues developed Neonatal Individualized Developmental Care and Assessment Program (NIDCAP) to document the effects of the caregiving environment on the neurobehavioral stability of neonates. This naturalistic observation protocol includes continuous observation and documentation at 2-minute intervals of an infant’s behavioral state and autonomic, motor, and attention signals, with simultaneous recording of vital signs and oxygen saturation. Documentation occurs before, during, and after routine caregiving procedures. The infant’s strengths, weaknesses, and coping skills are identified. A narrative description of the infant’s responses to the stress of handling by the primary nurse and to auditory and visual stimuli in the NICU environment is provided to assist caregivers and parents in identifying the infant’s behavioral cues and providing appropriate interaction. Options are described in the care plans for reducing aversive environmental stimuli and modifying physical handling procedures. This clinical tool allows neonatal therapists to determine the infant’s readiness for assessment and intervention by observing the baseline tolerance of the infant to routine nursing care before superimposing neonatal therapy procedures. Sequential documented observations occur weekly or biweekly. Parental involvement is strongly encouraged and instrumental in facilitating a smooth transition from hospital to home. Examiner training in the NIDCAP may be coordinated through the NIDCAP Federation International where priority is given to NICU teams, rather than to individuals.
NICU network neurobehavioral scale
Lester and Tronick designed a tool for preterm and drug-exposed infants from 30 weeks of gestation to 6 weeks postterm. The test includes items from the NBAS, APIB, Finnegan abstinence scale, and other neurological assessments and consists of 115 items in general categories of neurological and neuromotor integrity (tone, reflexes, and posture), behavioral state and interaction (self-regulatory competence), and physiological stress abstinence signs (drug-exposed infants). This test is state dependent and gives a comprehensive and integrated picture of the infant. More than half of the test items are infant observations, and 45 items require physical handling of the infant. Test-retest reliability of preterm infants indicated correlations of 0.30 to 0.44 at 34, 40, and 44 weeks of gestation. This test is useful for the management of drug-exposed infants but may have limited predictive value. Training and certification in administration and scoring of the test are coordinated through Brookes Publishing Company and available in the United States and internationally with use of videoconferencing for lectures and demonstrations.
Test of infant motor performance
Developed by Campbell and colleagues, , the 42-item Test of Infant Motor Performance (TIMP) is focused on evaluating postural control, spontaneous movement, and head control for neonates at 34 to 35 weeks of gestation to 16 weeks postterm. Functional motor performance is assessed through observation of infant movement and through responses to various body positions and to visual or auditory stimuli. Because the elicited reflex and tone items on the TIMP may contribute to physiological and behavioral stress for infants born preterm, a shorter form of the test is available, the Test of Infant Motor Performance Screening Items (TIMPSI). The elicited tone and reflex items in the screening test still require judicious use with the tone and reflex items and careful monitoring with hospitalized late preterm infants.
Psychometric components of the TIMP have been developed. These components include (1) construct validity and ecological validity, (2) concurrent validity at 3 months of age with the Alberta Infant Motor Scale (AIMS), and (3) predictive validity at 5 to 6 years of age with the Bruininks-Oseretsky Test of Motor Proficiency and at 4 to 5 years of age with the Peabody Developmental Motor Scales and Home Observation for Measurement of the Environment: Early Childhood. Training on test procedures is available through 2-day workshops or through a self-guided training method with a CD-ROM from the test developer.
Neurobehavioral assessment of the preterm infant
The Neurobehavioral Assessment of the Preterm Infant (NAPI) was developed by Korner as a developmental test to assess medically stable infants from 32 weeks to term gestation using a sequence of specific movements. This test focuses on tone, reflexes, movement, response to visual and auditory stimulation, and observation of cry and state. This tool does not require a specific preassessment state as is required by the previously mentioned tests, but starts with the infant asleep. It does not take as long to administer (< ½ hour) than the previously described tests and is easy to analyze. The data are categorized into seven clusters and compared with standardized scores. With repeated examinations over time, persistent deviations from the normative scores indicate that the infant is at risk for developmental delays and is in need of close follow-up. In addition, the NAPI has been shown to be predictive of short-term and long-term neurodevelopmental outcomes.
General movement assessment
The assessment tools reviewed so far in this chapter require direct handling of the infant. Infants born preterm are particularly vulnerable to developing physiological stress during the maneuvers required by most tools available for infant assessment. Instead, noninvasive, repeated observation and assessment are needed to accommodate the concurrent motor variability, immature nervous system, and physiological vulnerability of the preterm infant. Based on the pioneering work of Prechtl examining the continuity of prenatal to postnatal fetal movement, this criterion-referenced test focuses on evaluating the quality of spontaneously generated movements in preterm, term, and young infants until 16 weeks postterm. A wide repertoire of spontaneous motility in the fetus including isolated limb movements, stretches, hiccups, yawning, and breathing movements can be identified as early as 9 weeks.
General movements (GMs) are spontaneously generated, complex movements involving the trunk, limbs, and neck in varied speed and intensity. These movements are among the number of movement patterns emerging during fetal life and continuing until approximately 16 weeks postterm, when goal-oriented movements appear. The quality of movement is assessed through observation and scoring of videotaped spontaneous movement of an infant in supine position without stimulation or handling. A distinct difference occurs between the GMs in the preterm infant and those in the term and postterm infant. GMs in the term infant, and for the first 8 weeks, change in amplitude and speed, taking on a writhing quality. The writhing movements gradually give way to the fidgety movements, which are present in awake infants between 9 and 16 to 20 weeks postterm. Fidgety movements are small, circular movements of small amplitude and varying speed involving the neck, trunk, and extremities.
This neonatal and young infant assessment instrument has gained substantial attention in the past 20 years for its high reliability, sensitivity, and predictive validity. In a comprehensive review of the psychometric qualities of neuromotor assessments for infants, the GM assessment was rated among the tools with the highest reliability, averaging interrater and intrarater correlation coefficient, or k, greater than 0.85. Multiple studies have corroborated the predictive validity and sensitivity of this method. The sensitivity for identifying abnormal movement is lower during the preterm period and writhing movement stage, but improved during the fidgety movement period of the older infant. Sensitivity as high as 95% has been reported.
Hadders-Algra created a scoring system for infant general movements based on the original work of Prechtl. Many similarities are described between the two approaches in the observation of complexity and variation in general movements of neonates. Hadders-Algra has expanded the general movement assessment by profiling preterm infants with mild neurological impairment and by extending the observational movement assessment from 3 to 18 months of age in a new assessment, The Infant Motor Profile. ,
Testing variables
Neuromuscular and behavioral findings in the newborn period may be influenced by several variables. Increased reliability in examination results and in clinical impressions may occur when these variables are recognized. Medication may produce side effects of low muscle tone, drowsiness, and lethargy. Such medications include anticonvulsants, sedatives for diagnostic procedures (computed tomography [CT] scan, electroencephalography, and electromyography), and medication for postsurgical pain management. Intermittent subtle seizures may produce changes in muscle tension and in the level of responsiveness. Mild, ongoing seizures may occur in the neonate as lip smacking or sucking, staring or horizontal gaze, apnea, and bradycardia. Stiffening of the extremities occurs in neonatal seizures more frequently than clonic movement. Fatigue from medical and nursing procedures can result in decreased tolerance to handling, decreased interaction, and magnified muscle tone abnormalities. Fatigue may also result when neurodevelopmental assessment is scheduled immediately after laboratory (hematologic) procedures, suctioning, ultrasonography, or respiratory therapy. Tremulous movement in the extremities may be linked to conditions of metabolic imbalance (hypomagnesemia, hypocalcemia, and hypoglycemia), and low muscle tone may be associated with hyperbilirubinemia, hypoglycemia, hypoxemia, and hypothermia.
Summary
Practitioners must be aware of the normative and validation data and of the predictive characteristics of the test(s) administered to allow appropriate interpretation of the results. Specific clinical training with a preceptor is essential to administer, score, and interpret neonatal assessment instruments accurately; to establish interrater reliability; and to plan treatment based on the evaluative findings. Even low-risk, healthy preterm infants are vulnerable to becoming physiologically and behaviorally destabilized during neurological assessment procedures. This risk is reduced with precepted, competency-based clinical training in the NICU.
Intervention planning
Level of stimulation
The issue of safe and therapeutic levels of sensory and neuromotor intervention is a high priority in the design of developmental intervention programs for infants who have been medically unstable. The concept of “infant stimulation,” introduced by early childhood educators in the 1980s to describe general developmental stimulation programs for healthy infants, is highly inappropriate in an approach based on concepts of dynamic systems, infant behavioral organization, and individualized developmental care.
For intervention to be therapeutic in a NICU setting, the amount and type of touch and kinesthetic stimulation must be customized to each infant’s physiological tolerance, movement patterns, unique temperament, and level of responsiveness. Rather than needing more stimulation, many preterm or acutely ill term infants have difficulty adapting to the routine levels of noise, light, position changes, and handling in the nursery environment. General, nonindividualized stimulation can quickly magnify abnormal postural tone and movement, increase behavioral state lability and irritability, and stress fragile physiological homeostasis in preterm or chronically ill infants. Implementation of careful physiological monitoring and graded handling techniques are essential to prevent compromise in patient safety and to facilitate development. Infant modulation, rather than stimulation, is the aim of intervention. Techniques of sensory and neuromotor facilitation and inhibition developed for healthy infants and children are inappropriate for the developmental needs and expectations of an infant with physiological fragility or premature birth history (<37 weeks of gestation).
Timing
The timing of neurodevelopmental examination and intervention for infants in the NICU is based on the medical stability of the infant and, in some centers, gestational age. All therapy activities must be synchronized with the schedules of the neonatal nurses and intensive care unit routines.
Neonatal therapists should not interrupt infants in a quiet, deep sleep state but instead wait approximately 15 minutes until the infant cycles into a light, active sleep or semi-awake state. Higher peripheral oxygen saturation has been correlated with quiet rather than with active sleep in neonates. Preterm infants reportedly have a higher percentage of active sleep periods in contrast to the higher percentage of quiet sleep observed in term infants. Allowing the preterm infant to maintain a deep, quiet sleep by not interrupting is a therapeutic strategy for enhancing physiological stability.
Timing of parental teaching sessions is most effective when they express readiness to participate in the care of the infant. Some parents need time and support to work through the acute grief process related to the birth of a fragile, potentially impaired child before they can begin to participate in developmental activities. Other parents find the neonatal therapy program to be a way of contributing to the care of their infant that also helps them cope with often overwhelming fears, stresses, and grief.
Physiological and musculoskeletal risk management
Many maturation-related anatomical and physiological factors predispose preterm infants to respiratory dysfunction ( Table 9.5 ). For this reason many preterm neonates require the use of a wide range of respiratory equipment and physiological monitors ( Table 9.6 ). Pediatric therapists preparing to work in the NICU and those involved with designing risk management plans are referred to the neonatal nursing literature for evidence and perspectives on assessing and managing neonatal stressors during interventions in the NICU. Owing to the fact that infants born prematurely or experiencing critical illness communicate through subtle behavioral cues, their understated language is “not easily interpreted unless caregivers understand how infants’ ability to respond to stress reflects their maturation and neurodevelopment.” Their behavioral cues are considered more subtle and more likely to be disregarded than those of infants born at term gestation.
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