Prolonged overnight fasting prior to surgery was advocated to reduce the risk of aspiration during or after surgery. Recent studies suggest prolonged fasting is associated with increased insulin resistance, increased acute phase stress response and decreased well-being among surgical patients. Our hypothesis is that pre-operative oral carbohydrate loading 2 hours prior to surgery is associated with improved patient reported well-being.
The double-blind randomized control study evaluated 140 patients undergoing elective primary total knee replacement (TKR) surgery. Patients above the age of 55 years, of either gender, were randomized into the study group (that received oral carbohydrate solution up to 2 hours prior to induction of anesthesia) and control group (that received plain water in the same amount as the study group). The well-being of patients in the pre and post-operative period was assessed using visual analogue scores (VAS) for pain, thirst and hunger. Additionally, blood samples were collected in the pre and post-operative period for biochemical assays. The study compared the pre and postoperative changes in the insulin resistance, C-reactive protein and the Prognostic Inflammatory and Nutritional Index (PINI) as secondary outcome measures.
140 subjects (99 females, 41 males) were enrolled. There was significant reduction in the VAS scores of thirst, hunger and pain in the study group (p < 0.001). Post-operative insulin resistance was lower in the study group compared to the control group (10.77 ± 1.11 vs. 11.22 ± 1.43), but not statistically significant.
Pre-operative oral carbohydrate loading before elective TKR surgery was associated with significantly better well-being. Although there was a reduction in insulin resistance, it was not statistically significant. The role of pre-operative carbohydrate loading in reducing length of stay and insulin resistance will require further investigation in patients undergoing orthopedic surgery.