Prehabilitation for the Enhanced Recovery After Surgery Patient

Preoperative Exercise

Studies are inconsistent in the type and duration of exercise, the level of supervision, and compliance necessary to earn a meaningful benefit.

A systematic review evaluated only aerobic exercise training interventions in 10 studies of 524 patients. ¹ Eight studies reported an objective increase in fitness. One study reported a reduction in length of stay in elective cardiac surgery patients.

Another systematic review evaluated total body exercise interventions in 21 studies of 1371 patients with a median duration of 6 weeks. ² Exercise capacity was improved in some, but not all, studies. A meta-analysis suggested that length of stay was reduced in participants, although the effect on postoperative complications was inconsistent.

Lung training exercises have been considered to reduce postoperative pulmonary complications. However, a systematic review did not find evidence that incentive spirometry alone reduced the risk of postoperative pulmonary complications in cardiac and upper abdominal surgery patients. ³ A Cochrane systematic review of seven trials evaluating the effect of inspiratory muscle strength with 443 patients showed a reduction in length of stay, pulmonary complications such as pneumonia, and basal atelectasis with training. ⁴ However, the quality of the studies was low.

Preoperative Nutrition

A surgical patient may be malnourished due to neoplasm, chronic inflammation, gastrointestinal dysfunction, depression, or excessive alcohol use. ⁵ Malnourished patients have a higher rate of prolonged hospitalization and morbidity and mortality. Following surgery, the patient experiences a catabolic state that can last for weeks. Proteolysis and lipolysis occur to provide precursors for gluconeogenesis, which can cause significant muscle or protein loss and slow recovery. An insulin-resistant state is also present.

A small study showed that a week of nutrition supplementation in poorly nourished patients for abdominal surgery reduced major complications such as infection, wound healing, and cardiac, renal, or respiratory dysfunction by 50%. ⁶ Another study showed that nutrition supplementation in undernourished patients reduced the length of stay and infective complications. ⁷

Preoperative carbohydrate loading to maintain “the fed state” reduces postoperative insulin resistance, thirst, hunger, and anxiety. ⁸ A systematic review demonstrated a reduction in hospital length of stay, but no significant effect on complication rates with preoperative carbohydrate loading. ⁹

Smoking Cessation

Preoperative smoking increases pulmonary, cardiovascular, and wound healing complications. Disease diagnosis, pregnancy, and hospitalization are associated with triple the rate of increased smoking cessation compared to the general population. ¹⁰

One study randomized 1090 patients with small abdominal aortic aneurysms to immediate repair or watchful waiting until aneurysms reached a certain size. ¹¹ Many were current smokers. At 1 year, survival was less with patients undergoing immediate repair due to surgical risk. However, at 8 years, survival was significantly improved in patients undergoing early repair due to higher smoking cessation. Smoking cessation counseling and therapy are therefore life-saving elements of perioperative care.

Alcohol Cessation

Excessive alcohol intake can cause immune dysfunction, subclinical cardiac insufficiency and arrhythmias, increased bleeding time, and an exaggerated neurohumoral response to surgery. ⁵ An intervention targeting abstention in those consuming greater than 50 alcohol units a week with behavioral counseling and medication showed a reduction in postoperative complications ¹² with no effect on mortality or long-term postoperative alcohol consumption. ¹³

Diabetes Optimization

Chronic hyperglycemia is known to increase the risk of stroke, cardiovascular disease, poor wound healing, and renal failure. Acute hyperglycemia is known to cause a proinflammatory state and compromise the immune system.

There is currently not a defined threshold HgbA1C level that is associated with reduced postoperative complications, although establishing an upper limit may serve as a useful screening tool to activate a care team to optimize a patient's diabetes regimen before surgery. ¹⁴ It may be that perioperative glycemic control is more important than HgbA1C in affecting postoperative outcomes.

All diabetics should have blood glucose checked preoperatively as well as in the operating room for cases of longer duration, and in the postanesthesia care unit for treatment with short-acting insulin as necessary. ¹⁴ Increased 30-day wound complications after total joint arthroplasty were reported in patients with average in-hospital blood glucose levels of >2000 mg/dL and glucose spikes to >260 mg/dL. ¹⁵ However, normoglycemia is not the goal as stress hyperglycemia, resulting from increased hepatic release and not from impaired uptake, is protective if levels are not excessive. ¹⁶ Furthermore, complications with hypoglycemia have been noted with extremely tight glycemic control and has not provided an apparent complication advantage. ¹⁷

Anemia

One-third of preoperative patients are anemic. ⁵ Causes include iron deficiency, anemia of chronic disease, hemoglobinopathies, chronic kidney disease, or gastrointestinal hemorrhage.

Preoperative anemia is associated with increased length of intensive care and hospital stay, postoperative complications, and mortality. ¹⁸ These risks increase as the degree of anemia increases.

Compared with propensity-matched patients who did not receive an intraoperative transfusion, transfusion of a single unit of packed red blood cells increased the risk of mortality, wound problems, pulmonary complications, renal dysfunction, sepsis, composite morbidity, and postoperative length of stay. ¹⁸ In the case of iron deficiency anemia, intravenous iron has been shown to be effective and modern preparations have good evidence for safety and efficacy. ¹⁹

Erythropoietin therapy in colorectal surgery patients failed to show any significant change in hemoglobin with preoperative use and did not decrease the number of patients who received allogenic blood. ²⁰ In orthopedic and cardiac surgery patients, preoperative erythropoietin therapy did show a reduction in the proportion of patients given allogenic blood transfusions. ²¹ There remain safety concerns regarding the use of perioperative erythropoietin, including hypertension, thrombosis, and ischemic events (possibly as a consequence of raised hemoglobin), and possible secondary effect of erythropoietin on other cells, including tumor growth stimulation. ¹²

Psychological Support

Patients about to undergo major surgery have stress regarding their underlying diagnosis, treatment, and pending disability. ⁵ Preoperative depression is associated with higher mortality after cardiac surgery. Furthermore, anxiety and low expectations of future health are associated with worse functional status after cardiac surgery. ²² Cognitive behavioral therapy in the preoperative setting may increase early functional recovery after spinal surgery. ²³

Identifying High Risk/High Benefit Patients

Preoperative functional capacity predicts postoperative morbidity, mortality, and functional recovery. The functional reserve of a patient can be measured with cardiopulmonary exercise testing to assess both the anaerobic threshold and peak oxygen uptake (VO2 peak), although this requires equipment, time, personnel, and expertise. ²⁴ In the preoperative setting, a 6-minute walk test may be a more practical assessment.

Further screening with a thorough history and physical and relevant laboratory studies can help us identify poor preoperative nutritional status (Nutritional Risk Score), low hemoglobin, tobacco use, and excessive alcohol intake. Psychological screening for anxiety and depression can also help identify patients who would most benefit from an intervention for anxiety and depression, to improve the patient's motivation to engage in behavior to improve his outcome.

Conclusion

The preoperative setting presents an opportunity for healthcare providers to engage a patient who is attentive to his health due to his upcoming surgery. Preoperative health interventions may improve a patient's recovery in the immediate postoperative period or improve his health years later.