A prospective study assessing the effect of preoperative nutrition on the surgical recovery of elderly patients

Tarifin Sikder, MSc¹, Mehdi Tahiri, MD¹, Geva Maimon, PhD², Debby Teasdale, RN², Shannon Fraser, MD, FRCSC, FACS², Simon Bergman, MD, MSc, FRCSC, FACS². ¹McGill University, ²Jewish General Hospital

Introduction: Fifteen to twenty percent of surgical patients are malnourished before surgery. Although the literature acknowledges that nutrition is an important factor in patient health, its impact on surgical recovery has not yet been determined. The primary objective of this study is to understand the effect of nutritional status on the postoperative recovery of elderly patients.

Methodology: This is a prospective cohort study of patients aged 70 years and older undergoing elective general surgery (n=114), between July 2012 and July 2014. The Subjective Global Assessment (SGA), a validated tool for evaluating nutritional status, was used to determine preoperative (T0) nutritional status of each patient. The primary outcomes were upper body function (measured by hand grip strength) and lower body function (measured by the Short Physical Performance Battery (SPPB)). Patients were evaluated at 1-week (T1), 4 weeks (T2), 12 weeks (T3) and 24 weeks (T4) post-surgery. Repeated measures analyses were used to test whether SGA nutritional status affects the rates of recovery of grip strength and SPPB scores. The statistical models were adjusted for gender, age, Charleson Comorbidity Index (CCI), body mass index (BMI), minor or major surgery, postoperative complications, as well as the corresponding preoperative grip strength and SPPB scores.

Results: The study included 65 males and 49 females with a mean age of 77.6 (5.1) years. The mean BMI was 28.4 (4.5) and the median (Q1-Q3) CCI was 5 (2-7). Participants were categorized as well nourished (n=99), moderately malnourished (n=15) and extremely malnourished (n=0). The mean preoperative grip strength for each SGA group was 25.6 (8.1) kg and 20.1 (7.2) kg, respectively. The mean preoperative SPPB score for each SGA group was 9.9 (2.1) and 9.5 (1.9), correspondingly. Patients were considered recovered if postoperative values returned to or surpassed preoperative measures. The percent recovered patients for grip strength was 36% T1, 48% T2, 43% T3 and 59% T4 for the well nourished SGA group and for the moderately malnourished SGA group was 17% T1, 0% T1, 30% T3 and 20% T4. The percent recovered patients for SPPB was 17% T1, 37% T2, 45% T3 and 39% T4 for the well nourished SGA and for the moderately malnourished SGA group was 1% T1, 6% T1, 7% T3 and 6% T4. SGA group was found to significantly affect grip strength, with a well-nourished patient on average having an increase of 2.4 kg of strength as compared to a moderately malnourished patient. However, the rate of recovery for grip strength did not significantly differ between the SGA groups (p-value = 0.47), increase for patients in both groups. As for lower body function, SGA group was found to have no significant effect on SPPB score or its recovery rate.

Conclusion: Nutritional status is a good predictor of grip strength. Although the postoperative recovery between SGA groups is similar, our study suggests that patients with superior preoperative nutritional status benefit from greater upper body function during recovery. Therefore, optimizing patient nutrition prior to surgery may have a moderate to long-term impact on postoperative recovery.