[Oral administration of sodium citrate before general anesthesia in elective cesarean section. Effect on pH and gastric volume].

A study was carried out to assess the effects of oral sodium citrate on the pH and volume of gastric content in 52 unpremedicated women undergoing elective Caesarean section under general anaesthesia. The patients were randomly assigned to two groups: group T (n = 26) without antacids and group C (n = 26) receiving orally 30 ml of 0.3 M sodium citrate solution 5 min before induction of anaesthesia. After tracheal intubation, a size 18 double lumen naso-gastric tube was introduced. The gastric content was sampled 10 min (n = 52), 50 min (n = 52) and 80 min (n = 24) later. Before extubation, the stomach was completely emptied and the naso-gastric tube removed. On each sampling time, the pH was measured with a digital pHmeter; a search for biliary salts (pyloric reflux) was carried out with thin layer chromatography; the volume of the gastric content was measured using the phenol red dilution method. At 10 min, none patient in group C had a gastric pH less than 2.5, in the opposite to 92% of patients in the control group T. The alkalinizing effect of the citrate lasted throughout the evaluation time. The mean pH was respectively 5.3 +/- 1.07, 5.23 +/- 1.2 and 5.53 +/- 1.3 at 10, 50 and 80 min in group C (controls: 1.9 +/- 0.7; 2.49 +/- 1.3; 2.40 +/- 0.61). However, the citrate solution increased significantly the volume of the gastric content. It was respectively 51.1 +/- 29.9 ml, 79.15 +/- 70.9 ml and 32.9 +/- 22.1 ml; 29.6 +/- 28.5 ml; 26.6 +/- 10.9 ml).(ABSTRACT TRUNCATED AT 250 WORDS)