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 34.6 ± 9.9 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.