Impact of high-protein bariatric diet on the prevention of postoperative nausea and vomiting.

Background: Postoperative nausea and vomiting (PONV) commonly occurs following metabolic/bariatric surgery, contributing to increased health care utilization and length of stay (LOS). Studies have suggested the benefit of protein-predominant meals in suppressing gastric tachyarrhythmia and PONV.

Objective: To investigate the impact of a high-protein postoperative liquid diet on PONV and LOS after primary sleeve gastrectomy (SG).

Setting: University Hospital, United States.

Methods: This prospective randomized trial included adult patients undergoing primary SG. Exclusion criteria were history of bariatric/foregut surgery, chronic nausea/vomiting, HbA1C ≥9, or therapeutic anticoagulation. Patients were randomized 1:1 to receive a clear liquid (control) or high-protein full-liquid diet (intervention) starting 4 hours postoperatively. The primary endpoint was incidence of PONV. Secondary endpoint was increased LOS due to PONV. Pearson's chi squared test for independence compared outcomes between groups on an intention to treat basis.

Results: One-hundred and twelve patients were randomized (56 control, 56 intervention). Most patients were female (80.4%). All underwent laparoscopic (72.3%) or robotic (27.7%) SG and 90.2% received inhalational anesthesia. In the intervention arm, 15 patients had zero protein intake due to PONV, 6 had missing data, and 35 had a mean intake of 24.2 grams. There was no observed treatment effect on PONV (78.6% control versus 89.3% intervention; P = .20). Almost 70% of patients were discharged home on postoperative day (POD) 1. Delay in discharge due to PONV was not significant between groups (32.1% control versus 28.6% intervention; P = .84).

Conclusions: Early introduction of liquid protein after SG does not improve PONV or LOS.