Gastric fluid volume and pH in elective inpatients. Part II: Coffee or orange juice with ranitidine

In order to assess the effect of preoperative oral fluids, with and without ranitidine, on gastric fluid volume and pH 300 elective surgical inpatients, ASA physical status I and II, were randomly allocated to one of six groups. The three ranitidine groups (Groups 4, 5, and 6) are discussed in this paper (Part II), and the three placebo groups (Groups 1, 2, and 3) in Part I. Between two and three hours before the scheduled time of surgery, patients received 150 ml coffee with oral ranitidine 150 mg (Group 4), 150 ml orange juice with oral ranitidine 150 mg (Group 5), or oral ranitidine alone (Group 6). No opiate or belladonna premedication was given. Immediately following induction of anaesthesia a # 18 Salem sump tube was passed and its position in the stomach confirmed by auscultation of insufflated air. The volume of residual gastric fluid, which was aspirated into a 60 ml syringe, was recorded, and its pH was measured. There were no statistically significant differences between groups with respect to volume (Group 4: 14.3 +/- 15.4; Group 5: 14.8 +/- 17.0; Group 6: 9.7 +/- 12.6 ml). The mean pH in all groups was greater than 5.40 (Group 4: 5.65 +/- 2.12; Group 5: 5.41 +/- 2.12; Group 6: 6.21 +/- 1.51).