The effect of perioperative oral carbohydrate loading on postoperative outcomes in patients undergoing orthopedic...

Oral carbohydrate loading is a core element used in Enhanced Recovery after Surgery (ERAS) protocols and has shown benefits in several surgical fields. However, evidence in orthopedic surgery is mixed. This systematic review and meta-analysis of randomized controlled trials aims to evaluate the impact of preoperative oral carbohydrate loading on postoperative outcomes in orthopedic surgery patients.

Studies comparing preoperative oral carbohydrate loading versus fasting in orthopedic surgery measuring outcomes of hospital stay, pain, nausea, vomiting, or thirst were searched in PubMed, Cochrane, and Scopus database from 2013 up to July 2025. The review was registered in Prospero and follows PRISMA guidelines. Meta-analysis was performed using Review Manager 5.4 and R statistical software with a random effects model, and heterogeneity was assessed using the I² statistic. Risk of bias was evaluated using Cochrane ROB2.

A total of 10 randomized controlled trials were included in this meta-analysis. A significant reduction was observed in postoperative thirst among patients receiving CHO compared with fasting (MD = - 2.58, 95% CI - 4.10 to - 1.05; P = 0.0009) among 3 studies (n = 190). Pooled analysis of six RCTs (n = 472) showed that preoperative oral carbohydrate loading also led to significant reduction in hospital stay compared with fasting (MD = - 0.36 days, 95% CI - 0.70 to - 0.02; P = 0.0391). For postoperative vomiting, data from four studies (n = 268) indicated no significant difference between groups (RR = 0.71, 95% CI of 0.12 to 4.05; P = 0.6960), similarly, pooled analysis of four studies (n = 268) assessing postoperative nausea showed no significant effect (RR = 0.72, 95% CI 0.30 to 1.70; P = 0.4506). For postoperative pain, seven RCTs (n = 512) demonstrated a non-significant overall reduction in pain scores (SMD = - 0.31, 95% CI - 0.65 to 0.04; p = 0.0797) and the subgroup analysis revealed a significant benefit in studies using spinal anesthesia (SMD = - 0.05, 95% CI: - 0.29 to 0.19, P = 0.007).

Preoperative oral carbohydrate loading consistently reduced postoperative thirst in patients undergoing orthopedic surgery. It also was associated with a modest reduction in length of hospital stay; however, this effect was may not be consistently observed across all clinical settings. Although trends toward reduced pain, nausea and vomiting were observed, these did not reach statistical significance. The overall certainty of evidence is limited by moderate to substantial heterogeneity across studies. Despite limitations, the intervention appeared safe, adheres to ERAS standards, and necessitates further exploration through multicenter trials especially in high risk groups.