title: Pre-anesthetic cimetidine alteration of gastric fluid volume and pH.
abstract: Gastric volume and pH were studied immediately after induction of anesthesia and endotracheal intubation in 101 elective surgical patients. Of 44 patients not given cimetidine, 82% had a gastric pH less than 2.5 with a mean pH of 1.6; 45% of these patients had a gastric aspirate pH less than 2.5 associated with a volume exceeding 25 ml. In 57 patients premedicated with intravenous cimetidine at variable intervals (15 to 60 minutes) prior to induction of anesthesia, a significant time-dependent increase was noted in gastric pH (p less than 0.001) together with a decline in gastric volume (p less than 0.001). Of the patients given intravenous cimetidine (mean 4.5 mg/kg) 45 minutes prior to induction of anesthesia, 90% had a gastric pH greater than 2.5. The increase in gastric pH after cimetidine administration would result in a reduced chemical pulmonary reaction should aspiration occur during induction of anesthesia.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000758:Anesthesia; D002927:Cimetidine / Q000494:pharmacology*; D005750:Gastric Juice / Q000187:drug effects* / Q000378:metabolism; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D001239:Inhalation; D007442:Intubation, Intratracheal; D008875:Middle Aged; D011229:Preanesthetic Medication; D012306:Risk; D013997:Time Factors
chemical_list: D006146:Guanidines; D002927:Cimetidine