Intraoperative electroencephalography predicts postoperative nausea and vomiting in laparoscopic sleeve gastrectomy

Postoperative nausea and vomiting (PONV) is one of the most common causes for rehospitalization and emergency department visits after bariatric surgery. The current understanding of risk factors prediction for PONV remains still incomplete.

A total of 64 adult patients morbidly obese patients with selective laparoscopic sleeve gastrectomy (LSG) were prospectively enrolled. Perioperative electroencephalography (EEG) information was recorded separately at different brain regions (F7, F8, Fp1, and Fp2) using the SedLine root monitor. EEG was processed into five time points corresponding to perioperative events, including anesthesia induction, tracheal intubation, skin incision, pneumoperitoneum, and gastrectomy. Group-based trajectory modeling (GBTM) was applied to identify different patterns of longitudinal trajectories of largest lyapunov exponents (LLE) indices in EEG analysis.

Among the 64 participants, 75 % were female, the average age was 31.5 years with a standard deviation (SD) of 5.5 years, and the average body mass index was 41.3 kg/m² with a SD of 5.0 kg/m². Nearly 60 % obese patients had a preoperative Apfel scores of 2. Two different patterns of longitudinal trajectories of LLE indices were identified as the optimal model using GBTM, which were categorized into a stable group (n = 20) and a variable group (n = 44). The incidence of PONV was significantly higher in the stable group compared to the variable group (50.0 % vs 25.0 %, P = 0.048). A logistic regression analysis suggested that compared to stable group, patients in the variable group had a significantly lowered risk of PONV (OR = 0.28, 95 %CI: 0.08-0.98), after adjusting for age, sex, BMI, and Apfel score.

Perioperative EEG monitoring may help to predict PONV in morbidly obese patients with LSG. The comprehensive PONV management should consider perioperative EEG assessment.