title: An oral sodium citrate-citric acid non-particulate buffer in humans.
abstract: We have investigated the effect on the pH of the gastric fluid of a single dose of sodium citrate 0.3 mol litre-1 (antacid) and a solution containing sodium citrate dehydrate (100 mg ml-1) with citric acid monohydrate (66 mg ml-1) (buffer). The dose for both solutions was 0.4 ml kg-1 via a nasogastric tube. Each group comprised 10 patients undergoing neurosurgical operations of 5-7 h duration. A control group of 10 patients received no gastric solution. The pH of the gastric aspirate was measured hourly using a Metrohm 632 digital pH meter (Synectics Medical, Sweden). Mean baseline gastric pH was 2.64 (SD 1.71). In the control group, pH increased to 4.4 (1.51) at 5 h, returning to baseline at 7 h. In the antacid group, pH increased to 6.11 (0.47) at 15 min and decreased to 3.70 (1.94) at 7 h (P < 0.01). In the buffer group, pH was stable at 3.80-3.95 (0.22) over 7 h (P > 0.01). Total mean gastric aspirate was 0.5 ml kg-1.
authors.affiliation: Anaesthesiology Department, Medical School, University of Stellenbosch, Parowvallei, South Africa.
authors.forename: J J
authors.initials: JJ
authors.lastname: Hauptfleisch
authors.forename: K A
authors.initials: KA
authors.lastname: Payne
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000863:Antacids / Q000494:pharmacology*; D001921:Brain / Q000601:surgery; D002021:Buffers; D019343:Citric Acid / Q000494:pharmacology*; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000517:prevention & control; D011183:Postoperative Complications / Q000517:prevention & control; D011446:Prospective Studies
chemical_list: D000863:Antacids; D002021:Buffers; D019343:Citric Acid