Impact of Pyloric Injection of Magnesium Sulfate-Lidocaine Mixture on Postoperative Nausea and Vomiting After Laparoscopic Sleeve Gastrectomy: a Randomized-Controlled Trial

Background One of the most common adverse effects of laparoscopic sleeve gastrectomy (LSG) is postoperative nausea and vomiting (PONV). The present study aimed to assess the impact of local injection of a mixture of magnesium sulfate and lidocaine into the pylorus on gastric intraluminal pressure (ILP) and PONV after LSG. Methods Patients with morbid obesity who underwent LSG were randomly allocated to one of two equal groups: treatment group (pyloric injection of a mixture of magnesium sulfate and lidocaine) and control group (pyloric injection of normal saline). PONV and antiemetic requirements were recorded at 6 and 24 h postoperatively. Results Seventy patients (63 female) with a mean age of 34.69.9 years were included. The mean preoperative and postoperative gastric ILP was comparable in the two groups. The pyloric injection of magnesium sulfate-lidocaine mixture resulted in 31% reduction in the mean gastric ILP (19.4 +/- 4.7 mmHg before injection to 13.4 +/- 4.1 mmHg after injection, p < 0.0001). Pyloric injection of saline did not result in significant change in ILP (19.9 +/- 4.9 vs 20.3 +/- 5.1 mmHg). Of the treatment group patients, 17.1% had significant PONV at 6 h compared to 91.4% of control group patients (p < 0.0001). At 24 h, none of the treatment group patients had significant PONV versus 40% of the control group patients (p < 0.0001). Conclusion Pyloric injection of magnesium sulfate-lidocaine mixture during LSG resulted in lower incidence of PONV and less use of antiemetic medications in the first 24 h after LSG without being associated with higher complication rate.