Interactions of pre-operative erythromycin administration with general anaesthesia

Abstract

Previous reports have demonstrated a gastric emptying effect of erythromycin due to a motilin-like mechanism. We studied 50 patients, scheduled for daycase laparoscopy, randomly assigned to one of two groups: Group P patients received 30 min before induction of anaesthesia, in a double-blind manner an infusion of 250 ml dextrose 5% while patients in Group E (n = 25) received 500 mg of erythromycin diluted in 250 ml dextrose 5%. An orogastric tube was inserted to measure both gastric pH using a pHmeter and residual gastric volume (RGV) using the phenol red dilutional technique. Six patients were excluded for surgical reasons. More patients in Group P (6/22) than in Group E (0/22) had RGV > 25 ml and more patients in Group P (17/22) presented with a gastric pH < 2.5 than in Group E (5/22), P < 0.05. Since coma and respiratory depression have been reported recently after midazolam and alfentanil administration in patients having received erythromycin, recovery conditions were assessed and were found to be comparable between groups. In conclusion, the administration of iv erythromycin before outpatient laparoscopy decreased residual gastric volume and increased gastric pH without affecting recovery from general anaesthesia.