title: Sodium bicarbonate as a single dose antacid in obstetric anaesthesia.
abstract: Gastric pH and volumes were measured in 84 women who had general anaesthesia for emergency Caesarean section. Forty-eight received only 20 ml 8.4% sodium bicarbonate immediately before induction of anaesthesia and 36 ranitidine 150 mg 6-hourly during labour in combination with NaHCO3. Gastric pH was less than 2.5 in four women who received only bicarbonate. All aspirates from the ranitidine plus bicarbonate group had a pH greater than 2.5. Mean volumes of gastric content aspirated were 87 (SD 87.4) and 60 (SD 46.3) ml for the bicarbonate alone and bicarbonate plus ranitidine series respectively. These differences were not significant. Twenty millilitres of 8.4% NaHCO3 cannot be recommended as a single dose antacid for emergency Caesarean section. Ranitidine plus bicarbonate is considered a reliable antacid regimen to ensure elevation of gastric pH to safe levels.
authors.affiliation: Department of Anaesthetics, Queen's University of Belfast.
authors.forename: H M
authors.initials: HM
authors.lastname: Mathews
authors.forename: J
authors.initials: J
authors.lastname: Moore
mesh_terms: D000768:Anesthesia, General; D000773:Anesthesia, Obstetrical; D000863:Antacids / Q000008:administration & dosage / Q000627:therapeutic use*; D001639:Bicarbonates / Q000008:administration & dosage / Q000627:therapeutic use*; D002585:Cesarean Section; D004630:Emergencies; D005260:Female; D005766:Gastrointestinal Contents; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007743:Labor, Obstetric; D011015:Pneumonia, Aspiration / Q000517:prevention & control; D011247:Pregnancy; D011292:Premedication; D011899:Ranitidine / Q000627:therapeutic use; D012964:Sodium / Q000008:administration & dosage / Q000627:therapeutic use*; D017693:Sodium Bicarbonate
chemical_list: D000863:Antacids; D001639:Bicarbonates; D011899:Ranitidine; D017693:Sodium Bicarbonate; D012964:Sodium