7 Fevers and Infections in the Neuro-ICU

7.1 Brain

7.1.1 Meningitis

Meningitis is inflammation of the leptomeninges which consist of three layers (dura, arachnoid, and pia mater) which surround the brain and spinal cord. There are various causes of meningitis (▶ Table 7.1).

Signs/Symptoms

Most patients present with one or more of the following symptoms:

• Headache

• Fever

• Stiff neck

• Nausea/Vomiting

• Rash (petechial or vesicular)

• Altered mental status

• Sensitivity to light or sound

• Physical examination findings of:

◦ Brudzinski’s sign—flexion of the knees and hips upon neck flexion

◦ Kernig’s sign—flexion of the knees and hips to 90 degrees, and then extension of knees causes pain and resistance

Risk Factors

• Age

• Living conditions

• Medical conditions/diseases

• Exposure

• Travel

• Lumbar puncture (LP) sending cell count and culture can help to narrow the diagnosis (▶ Table 7.2). For patients on anticoagulants or antiplatelet agents other than aspirin, a hematology consultation can be considered prior to reversal recommendations. Do not delay antibiotics if the LP is delayed.

Imaging

Computed tomography (CT) scan of brain is not recommended routinely prior to the LP. According to the Infectious Disease Society of America, a CT scan should be performed prior to performing the LP when any of the following conditions apply (▶ Table 7.3).

7.1.2 Acute Bacterial Meningitis

According to Centers for Disease Control and Prevention (CDC), bacterial meningitis affects 4,000 people every year worldwide. Common causative organisms include: Streptococcus pneumoniae (61%) and Neisseria meningitidis (16%). Group B streptococcus (14%), Haemophilus influenzae (7%), and Listeria monocytogenes (2%).

All patients with suspicion of bacterial meningitis should get immediate blood cultures and LP (lumbar puncture) and antibiotics started without significant delay. ▶ Fig. 7.1 details the algorithm for suspected bacterial meningitis.

Table 7.3 Conditions when patients should obtain CT of head prior to performing lumbar puncture. (Adapted from Tunkel et al.³)

Fig. 7.1 Management algorithm for adults with suspected bacterial meningitis.³(Adapted from Tunkel A, et al. Practice guidelines for the management of bacterial meningitis.)

Empiric antibiotics should be started as soon as possible. Broad-spectrum antibiotics are chosen initially based on risk factors or age (▶ Table 7.4). As specific pathogens are identified, the antibiotic of choice should be narrowed. Dexamethasone (10 mg IV every 6 hours) should be started 10 to 20 minutes prior to first dose of antibiotics whenever pneumococcal meningitis is suspected.²⁷ Steroids should be continued for 2 to 4 days when pneumococcal meningitis is confirmed. If LP results are not consistent with bacterial meningitis then steroids should be discontinued. Antibiotics can be continued until cultures are finalized.

7.1.3 Aseptic Meningitis

LP should be done in all patients with suspected meningitis (▶ Fig. 7.1).

Treatment

All patients with suspected meningitis should be started on antibiotics until bacterial causes are ruled out.

7.1.4 Viral Meningitis

Table 7.5 Common fungal infections and treatment

7.1.5 Fungal Meningitis

Although relatively rare in the United States, they can occur in patients who are immunocompromised. Risk factors include organ transplantation, chemotherapy, or chronic steroid use. They present in a subacute or chronic fashion. Fungal meningitis does not spread person to person but rather patients inhale the spores which then spread from the lungs to the brain or spinal cord. Special attention should be paid to patients who have recently moved and may have been exposed based on their prior geographic location. ▶ Table 7.5 notes some of the more common fungal infections according to the CDC.

7.1.6 Ventriculitis

• Causes include meningitis, cerebral abscess, trauma, external ventricular drains, intraventricular shunts, and intrathecal chemotherapy³¹

• Common causative organisms include staphylococcus species, gram-positive skin flora, gram-negative rods, and S. pneumoniae

Incidence

Ventriculitis rates ranges from 0 to 45% in the setting of intraventricular catheter.²⁵

Clinical Features

Fever, seizures, nuchal rigidity, new headache,¹ photophobia, nausea, lethargy, altered mental status, erythema, and tenderness over the tubing in patients with ventriculoperitoneal shunt (VPS). Pleuritis in cases of ventriculopleural shunt infection, peritonitis, abdominal pain, abdominal fluid collections in cases of ventriculoperitoneal shunt infection,^2,3 and blood stream infection and endocarditis in cases of ventriculoatrial shunt infection.

Diagnosis

• According to Infectious Diseases Society of America (IDSA) guidelines¹ diagnosis of a cerebrospinal fluid (CSF) drain infection

◦ Single or multiple positive CSF culture with pleocytosis, hypoglycorrhachia, and increasing cell count and clinical symptoms are ventriculitis and meningitis.

• However, abnormalities in CSF cell count and glucose/protein may not be reliable indicators of infection, and normal CSF does not exclude infection.

• If cultures are negative initially, they should be held for at least 10 days for slow growing organisms.

• If a CSF device (including shunt, intrathecal pump, deep brain stimulatory, vagal nerve stimulator or associated hardware) is infected then current recommendations are to remove the infected device. Any device/shunt that is removed should be sent for culture.

• In addition to CSF cultures, blood cultures should be obtained for any patient with a ventriculoatrial shunt and should be considered for patients with a ventriculoperitoneal or ventriculopleural shunt.

Imaging

• Magnetic resonance imaging (MRI) with gadolinium is recommended for anyone with suspected CSF device infection.

• CT of head with contrast can be considered an alternative if MRI is unavailable or contraindicated.

• Abdominal imaging with CT of chest/abdomen or ultrasound of the abdomen should be completed in patients with peritoneal or pleural shunts and abdominal or pleuritic chest pain.

Table 7.6 Empiric antibiotic coverage in patients with suspected healthcare-associated ventriculitis/meningitis

• Includes antibiotic therapy and removal of infected shunt or device (▶ Table 7.6).

• Once a specific pathogen is identified, antibiotics should be narrowed (▶ Table 7.7).

• Duration of antibiotic is between 10 and 14 days depending on the pathogen, can extend to 21 days for some gram-negative bacilli. Duration should be determined after the last positive CSF culture.

7.1.7 HIV-Related Infections

Central nervous system (CNS) opportunistic infections caused by the parasite Toxoplasma gondii.⁴

Related posts:

Brain Tumor Postoperative Management Treatment of Status Epilepticus in Adults Ventilation Strategies in Neuro-ICU Cerebrovascular Emergency: Spontaneous Intracerebral Hemorrhage (ICH) Pain Management in the Neuro-Intensive Care Unit (ICU) Nutrition

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