Effect of single oral dose of Nizatidine administered a night before surgery on the intragastric pH and volume in adult patients undergoing elective surgery' a triple blind placebo controlled clinical trial

Objectives: To evaluate the effect of preanaesthetic administration of oral Nizatidine on pH and volume of gastric contents excluding samples contaminated with duodenogastric reflux.Design: Prospective, triple blind, randomized and placebo controlled clinical trial. Methods: The patients in Group C (Control) received Placebo while Group N (Nizatidine 300 mg) orally at 9.00 p.m., a night before elective surgery. Next day, gastric contents were aspirated with a large bore, multi-orifices gastric tube passed through an endotracheal tube placed blindly in esophagus after tracheal intubation and analyzed for the presence of bile salts, pH and volume.Results: Thirty five samples (29.66 %) out of 118 were contaminated with duodenal contents. One sample was contaminated with blood while one patient has no gastric contents. Duodenogastric reflux significantly affected pH and volume. Nizatidine, after excluding those samples contaminated either with duodenal fluid or blood, did not decrease significantly pH (p 0.0554), volume (p 0.5202) and the proportion of the patients (28.57% versus 24.39%) considered' at risk' compared with Placebo (p 0.8044) according to the criteria defined (pH [less than or equal to] 2.5 and volume [greater than or equal to] 25 ml).Conclusion: Nizatidine 300 mg given orally, a night before surgery did not afford adequate prophylaxis for the acid aspiration syndrome excluding those samples contaminated with duodenogastric reflux. Keywords: Aspiration | duodenogastric refluxate | gastric pH & volume | Nizatidine
Introduction Pulmonary aspiration of gastric contents is the inhalation of gastric contents into the larynx and lower respiratory tract. General anesthesia itself is a potential major risk factor that predisposes [...]