Effect of Preanesthetic Cimetidine on Gastric pH and Volume of Patients for Elective Cesarean Section

Moon, Sung Ho; Choi, Soo Han

Abstract

Aspiratian of gastric contents during anesthesia is the most common cause of maternal anesthetic death. Particularly, the parturient is predisposed to the catastrophe of aspiration for many reasons. So, the effect of cimetidine premedication on gastric pH and volume were studied. 120 ASA Class I patients scheduled for elective obstetric and gynecologic surgery were randomly divided into six groups as follows: Class A(n=80) is pregnant women scheduled for elective cesarean section. In the class A, group 1(n=20)(control group) was received no cimetidine premedication, group 2(n=20) was received cimetidine 300 mg p.o. hs. group 3(n=20) was received cimetidine 300 mg p.o. 2hrs before anesthesia, and group 4(n=20) was received cimetidine 200 mg iv 2hrs before anesthesia. Class B (n=40) is 20-40 aged non-pregnant women scheduled for elective surgery. ln the class B, group 5(n=20)(control group) was received no cimetidine premedication and group 6(n=20) was received cimetidine 200 mg iv 2hrs before anesthesia. Immediately following induction of anesthesia, the gastric fluid was obtained by suction on a nasogastric tube and its volume and pH were measured. The results were as follows: 1) When cimetidine is not premedicated, number of patient with a gastric pH less than 2,5 and gastric volume greater than 25 ml was increased in the group 1 compared with group 5. 2) In the class A, there was significant increased gastric pH and decreased gastric volume in the group 2, 3, and 4 compared with group l. 3) In the class B, there was significant increased gastric pH and decreased gastric volume in the group 6 compared with group 5. In conclusion, it would seem that the risk of aspiration pneumonitis can be increased in the pregnant women compared with nonpregnant women. The authors recommend that the incidence of severe aspiration pneumonia can be decreased by cimetidine premedication before general anesthesia even though there is any gastric aspiration.