Cimethidine pre-anesthetic. A prophylactic method against Mendelson's syndrome in cesarean section

Twenty patients undergoing cesarean section received cimethidine 400 mg intramuscularly as pre-anesthetic approximately 70 minutes prior to gastric aspiration. The average pH was 5.05, as against 2.97 in the control group (p less than 0.01). No significant reduction in the aspirated volumes was observed. In the cimethidine group the proportion of patients at risk of developing Mendelson's syndrome (pH less than 2.5 and volume greater than 25 ml) was significantly reduced, viz. 5% as against 42% in the control group (P = 0.014). No perinatal effects attributable to cimethidine was observed in the infants. Hence, cimethidine is a safe and useful pre-anesthetic for patients undergoing cesarean section, irrespective of indication and, consequently, much to be preferred to oral antacids.