Association between intraoperative hypothermia and postoperative nausea and vomiting in patients undergoing gynecological laparoscopic surgery: a post-hoc analysis of a single-center prospective cohort study

Background Intraoperative hypothermia, defined as a core temperature below 36 °C, may compromise postoperative recovery. However, the impact of hypothermia on postoperative nausea and vomiting (PONV) remains unclear. In this post-hoc analysis, we aimed to determine whether intraoperative hypothermia is associated with an increased risk of PONV. Methods This post-hoc analysis of a prospective study included 167 patients undergoing gynecological surgery from April 2023 to August 2024. All patients received standardized general anesthesia and active perioperative temperature management. Intraoperative core temperature was continuously monitored using nasopharyngeal probes, with data recorded at 15-minute intervals. Patients were categorized by the lowest intraoperative core temperature into two groups: hypothermia (T < 36 °C) and non-hypothermia (T ≥ 36 °C). The primary outcome was the incidence of PONV in the first 24 h after surgery. Results A total of 133 patients were included in the final analysis. Patients with intraoperative hypothermia (T < 36 °C) had a significantly higher 24-hour PONV incidence (31.7% vs. 15.1%; adjusted risk ratio [RR] = 1.9; 95% confidence interval [CI], 1.0–3.7; P = 0.045), with adjustment for body mass index (BMI), blood loss, and tropisetron use. Further multivariable logistic analysis identified intraoperative hypothermia as an independent risk factor for PONV (adjusted odds ratio [OR] = 3.1; 95% CI, 1.2–7.7; P = 0.017). Additionally, hypothermia was associated with a higher incidence of postoperative fever (24–48 h) and with prolonged post-anesthesia care unit (PACU) and hospital stays. Conclusions Intraoperative body temperature below 36 °C is associated with an elevated incidence of PONV within the first 24 h following gynecological laparoscopic surgery. Trial registration This study was prospectively registered in the Chinese Clinical Trial Registry on May 20, 2024 (Registration Number: ChiCTR2400084553).