Medical Fitness Evaluation

Introduction

One major issue when considering reconstructive spinal surgery is medical fitness for surgery. This is defined as an individual’s ability to sustain the physiological stress of surgery and recovery. Medical fitness is related to the overall wellness of the patient and accumulated comorbidities.

Although some assessment of medical fitness can be done during initial evaluations for spine care, work-flow and staffing issues may make a full assessment during the spine surgical consult not feasible. Patients with significant medical issues are often brought back for a more thorough evaluation, optimally with cooperation and communications with other caregivers. There is a lot of debate about what provider is best able to perform a complete evaluation of medical fitness. Ultimately, the best provider to perform medical fitness is one who understands the risks of anesthesia, knows the surgery, and is able to assess comorbidities and determine strategies for risk reduction. The goals and outcomes of a quality evaluation of medical fitness include:

1.

Educated patient
2.

Unify patients with the surgeon’s anticipated outcomes
3.

Reduce operating room delays and cancellations
4.

Decreased postoperative complications
5.

Improve overall health of the patient.

Overall Wellness

Age

There is no age that is an absolute contraindication to surgery. Many studies have indicated that age increases mortality and complication rates. Advancing age is often accompanied by an accumulation of comorbidities and decreased postoperative resilience, which can drastically affect surgical outcomes. Life expectancy is considered when planning for a surgical procedure that requires extensive healing time. This is appropriate but it is important to remember that life expectancy depends most heavily on comorbidities rather than age. The chronological age on a chart should not be use as a main decision-making tool when evaluating a patient for surgery.

Frailty

Lack of postoperative resilience, or the physiological reserve to heal from surgery, is termed frailty. Frailty scores do not worsen at the same rate between patients and are not linked to chronological age. Frail patients have increased postoperative mortality across all surgical fields, with odds ratios (ORs) ranging from 1.1 to 4.97, and are at higher risk for falls, skilled nursing home placement, and readmissions. Although there is no universally accepted rating scale for frailty, several key components are measured.

1.

Weakness, also referred to as sarcopenia, is defined as progressive loss of skeletal muscle mass. Often this is assessed by grip strength with cutoff values based on body mass index (BMI) and sex (men: BMI above 28, cutoff of ≤32 kg; women: BMI above 29, ≤21 kg). Calculations of the psoas muscle area in the abdominal region based on magnetic resonance imaging (MRI) have been proposed to be helpful in determining sarcopenia but standard cutoff values have not been established. The use of MRI as an objective measure of sarcopenia will likely be particularly useful in spine surgery as lumbar MRI is often available.
2.

Functional status is the ability to independently complete activities of daily living (ADL). This can be assessed through patient and caregiver questioning about ADL and falls. In spine patients, the ability to ambulate independently and the absences of any falls in the 6 months before surgery have been linked to decreased length of stay and decreased readmission rates.
3.

Nutritional assessment should be conducted before surgery. Malnutrition impairs wound healing and increases the propensity for infections. Mini nutritional assessment, which evaluates BMI and unintentional weight loss, can be completed but this takes 10 to 15 minutes. An alternative to this is a laboratory test for albumin. Nutritionally deficient patients, as defined by a serum albumin of less than 36 g/L, showed 27.6% higher risk of postoperative pulmonary complications compared with patients with normal serum albumin levels.
4.

Dementia screening. This can be efficiently done through Mini-Cog 3 screening which assesses short-term recall and spatial recognition. Preoperative dementia is associated with increased postoperative cognitive dysfunction and postoperative delirium.

Although increased frailty is predictive of overall complications, it most strongly corresponds to increased rates of discharge to skilled nursing facilities. Increased frailty has also been linked to increased length of hospital stay and increased readmission rates.

If patients are found to have a high frailty index, several interventions are recommended ( Table 3.1 ). Patients should be evaluated for polypharmacy to ensure that medication use is optimized. Patients with nutritional deficiency may be supplemented with protein-rich enrichment formulas. If functional limitations are severe, “pre-habbing” therapy for ambulation and strengthening should be considered before surgery when possible. Such therapies can also work on strengthening the muscles involved in inspiration to decrease pulmonary risk. Modifications in surgical planning for frail patients should include consideration of regional anesthesia, shorter operating room time, and less invasive procedures.

Table 3.1

Strategies for Mitigation of Frailty

Factor	Evaluation	Concern	Modification
Sarcopenia	Circumferential muscle measurement Get-up-and-go test, history	Score >2	Consider preoperative physical therapy
Activities of daily living (ADL)	History	Dependent ADL	Discuss skilled nursing facility after surgery
Nutrition	Mini nutritional evaluation, albumin	Albumin <36 g/L	Supplement with protein enrichment
Dementia	Mini-Cog	Score <3	Assess polypharmacy preoperatively and decrease length of surgery; decrease psychotropic medications postoperatively

Affective Disorder

It is becoming increasing clear that mental well-being or the absence of psychological disorders affect surgical outcomes. This has been discussed for decades but continues to be supported by literature. The most common psychological disorders seen in the spine surgical population are anxiety and depression. Current rates of anxiety and depression in the general population are approximately 6% to 10% and 7.3%, respectively, and these numbers continue to increase. Often, anxiety and depression are present concurrently, which is termed affective disorder.

Depression has been strongly correlated with chronic pain and disability. The US Preventative Service Task Force (USPSTF) states that depression is the leading cause of disability. In the spine patient population, chronic pain and health-related disability are always present. Therefore, unsurprisingly, a large percentage of spine surgery patients experience depression. A cyclic depression model for spine-related disability was first described decades ago and continues to gain support in the literature ( Fig. 3.1 ). This model begins with a back injury and pain resulting in patient disability. In some patients, depression can occur during this time. Patients more commonly experience depression during this time if they have a history of depression. Regardless of depression status, the patient goes on to seek medical care, which can progress to surgery. If the surgery is not successful at relieving all of the symptoms of their pain condition, the patient may rapidly spiral into increased disability progressing to unemployment, making them very vulnerable to depression. Depression decreases the ability to deal with chronic pain, driving the patient to once again seek medical care and surgery. This cyclic progression needs to be carefully considered when making decisions about revision spine surgery. In some cases, a successful initial surgery can improve depression attributed to relief of back and leg pain and decreased disability. This is less common in revision cases because patients have already experienced one surgery that failed to relieve pain.

Psychological distress is a predictor of poor outcomes following spinal surgery. Multiple studies have shown that the patient-reported disability, as measured by the Oswestry Disability Index (ODI), shows a more substantial decrease in patients who are not depressed compared with depressed patients, regardless of preoperative disability. Patient-reported outcomes of spine surgery also show less improvement in depressed patients compared with nondepressed patients. Depressed patients are more likely to report poor patient-to-provider communication.

Preoperative screening for depression is easily done. There are multiple validated depression scales including the Patient Health Questionnaire 9 (PHQ-9), Hospital Anxiety and Depression Scale (HADS), Zung Self Rating Depression Scale (SDS), and Becks Depression Index (BHI). All these studies have been used in the spine literature. The USPSTF recommends general depression screening using the PHQ-9 or HADS ( Tables 3.2 and 3.3 ). Both of these studies are patient questionnaires. HADS has the advantage of also screening for anxiety. For geriatric patients, screening for depression with the single question “Do you think you suffer from depression?” has been suggested. Spine-specific studies favor the Hamilton Rating Scale for Depression (HRSD). The drawback to HRSD is that it is a clinician-administered screening which can be difficult to complete owing to staffing and time constraints. In these spine-specific studies, the BDI and PHQ-9 were only mildly inferior to HRSD and may be easier to administer.

Table 3.2

Patient Health Questionnaire 9 and Patient Health Questionnaire 2

From Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16:606–613.

Over the Last 2 Weeks, How Often Have You Been Bothered By Any of the Following Problems?	Not At All	Several Days	More Than Half the Days	Nearly Every Day
1. Little interest or pleasure in doing things ^a	0	1	2	3
2. Feeling down, depressed, or hopeless ^a	0	1	2	3
3. Trouble falling or staying asleep, or sleeping too much	0	1	2	3
4. Feeling tired or having little energy	0	1	2	3
5. Poor appetite or overeating	0	1	2	3
6. Feeling bad about yourself, or that you are a failure, or have let yourself or your family down	0	1	2	3
7. Trouble concentrating on things, such as reading the newspaper or watching television	0	1	2	3
8. Moving or speaking so slowly that other people could have noticed, or the opposite—being so fidgety or restless you have been moving around a lot more than usual	0	1	2	3
9. Thoughts that you would be better off dead or of hurting yourself in some way	0	1	2	3
Total the scores from all answers . No depression: 0 4 Mild depression: 5 9 Moderate depression: 10 14 Moderately severe depression: 15 19 Severe depression: 20 27

a Patient Health Questionnaire 2 questions.

Table 3.3

Hospital Anxiety and Depression Scale

From Zigmond AS, Snaith RP. The Hospital Anxiety and Depression Scale. Acta Psychiatr Scand. 1983;67:361–370.

Hospital Anxiety and Depression Scale Anxiety	Not At All	From Time to Time	A Lot of the Time	Most of the Time
1. I feel tense and wound up	0	1	2	3
2. I still enjoy the things I used to enjoy	0	1	2	3
3. I get sort of frightened as if something awful is about to happen	0	1	2	3
4. I can laugh and see the funny side of things	0	1	2	3
5. Worrying thoughts go through my mind	0	1	2	3
6. I feel cheerful	0	1	2	3
7. I can’t sit at ease and feel relaxed	0	1	2	3
8. I feel as if I have slowed down	0	1	2	3
9. I get sort of frightened feeling like “butterflies in the stomach”	0	1	2	3
10. I have lost interest in my appearance	0	1	2	3
11. I feel restless as if I have to be on the move	0	1	2	3
12. I look forward with joy to things	0	1	2	3
13. I get sudden feelings of panic	0	1	2	3
14. I can enjoy a good book, or radio or TV program	0	1	2	3
Total the scores for the even number questions (anxiety-related questions). Total the scores for odd number questions (depression-related questions). For each category: Absence of condition: 0 7 Borderline/possible condition: 8 10 Presence of condition: 11 21