There are many preparations a patient may undergo during the weeks or months leading up to a non-emergency surgery. One important component is dietary habits and additional nutritional support.
Preoperative malnutrition or suboptimal nutritional status is correlated with poor postoperative outcomes, including higher death rates, length of stay, readmission rates, morbidities, and hospital costs. One study found that approximately one third of the patients scheduled for elective colorectal surgery met the criteria for being undernourished or at risk of malnourishment. Out of those patients, 23% were readmitted to the hospital within the first month compared to 7% of the well-nourished patients.
Preoperative Nutritional Support
Researchers have identified several preoperative nutritional support options. These include carbohydrate loading, immunonutrition (a combination of omega-3 fatty acids, arginine, glutamine, antioxidants, and nucleotides), individualized programs, and protein.
A systematic review and meta-analysis found that nutritional support with or without exercise before colorectal surgery significantly decreased hospital length stay by 2 days. Upon further review, the researchers found the nutrition-only pre-habilitation led to a significant effect, making it likely that nutrition made the difference and not exercise. For the included studies, nutrition intervention was defined as the use of oral nutritional supplements to change carbohydrate, fat, and protein content for at least 7 days before the surgery, but it did not include parenteral nutrition, enteral nutrition, carbohydrate-only plans, or specialized immunonutrition products.
BCAA May Benefit Surgical Outcomes
There are three essential amino acids: leucine, isoleucine, and valine. Supplementation with these branched-chained amino acids (BCAA) have been shown to be effective.
One study found that patients undergoing a hepatectomy who supplemented with BCAA experienced a reduction in lactate levels, which correlate to surgical stress. Another study found that oral BCAA supplementation led to better, long-term outcomes after hepatic resection in those with hepatocellular carcinoma. In this randomized controlled trial, one group took the BCAA supplementation for 2 weeks preoperatively and 6 weeks postoperatively, and the control group consumed a conventional diet. The BCAA group had a significantly better recurrence rate at 30 months than the control group. At 36 months, the BCAA group experienced significant decreases in tumor markers, although there was no difference in survival rates.
A systematic review comparing preoperative and perioperative nutritional supplementation on postoperative outcomes after liver resection due to cancer found that supplementing with BCAA during the preoperative and perioperative periods reduced overall complications by 26.9% in a cohort study. Preoperative support using immunonutrition was likewise beneficial, reducing postoperative ascites by 25.4% in another cohort study. The studies that were included in the systematic review also identified that BCAA supplementation preoperatively led to faster restoration of serum levels of albumin and reduction in the total insulin required to maintain blood glucose levels. Preoperative and perioperative enteral BCAA supplementation also reduced the mean length of hospital stay by 6.8 days.
When a non-emergency surgery is planned, the patient and health-care team should devise a supportive preoperative strategy to reduce the risk of serious complications. These strategies may include several pathways, including individualized nutrition support focused on protein and other potential nutrients of concern, especially in patients already undernourished or malnourished.
By Kendra Whitmore, MS, CNS