title: Effect of preanesthetic intramuscular ranitidine on gastric acidity and volume in children.
abstract: OBJECTIVE
  To evaluate the effects of preanesthetic administration of intramuscular (IM) ranitidine on pH and volume of gastric contents in children.
  
  
  METHODS
  Three randomized treatment groups.
  
  
  METHODS
  Central operating rooms at a university hospital.
  
  
  METHODS
  Forty children age 1 to 10 years undergoing a variety of elective surgical procedures requiring general anesthesia with endotracheal intubation.
  
  
  METHODS
  IM ranitidine 1 mg/kg (n = 15) or 2 mg/kg (n = 15) was administered 2 hours prior to induction of anesthesia. Ten patients without ranitidine served as the control group. An orogastric tube was inserted into each patient.
  
  
  RESULTS
  Gastric fluid pH and volume were measured every hour in the three groups. Plasma ranitidine concentrations were measured in ten patients of the ranitidine-treated groups. The mean volume of gastric fluid at induction of anesthesia was significantly lower in the ranitidine-treated patients (2.4 ml for ranitidine 1 mg/kg, 3.2 ml for ranitidine 2 mg/kg) than in the controls (8.6 ml; p less than 0.05). The mean pH values at induction of anesthesia were significantly higher in the ranitidine-treated patients (4.6 for 1 mg/kg, 6.7 for 2 mg/kg) than in the controls (2.1; p less than 0.05). Dose-dependent plasma ranitidine concentrations were obtained.
  
  
  CONCLUSIONS
  Preanesthetic IM ranitidine 1 to 2 mg/kg resulted in a higher pH and lower volume of gastric fluid at the time of induction and in a higher pH during 3 hours of anesthesia. This therapy may be a useful adjunct to premedication for children who have a greater than normal risk of pulmonary aspiration during anesthesia.
authors.affiliation: Department of Anesthesiology, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Kemmotsu
authors.forename: M
authors.initials: M
authors.lastname: Mizushima
authors.forename: Y
authors.initials: Y
authors.lastname: Morimoto
authors.forename: R
authors.initials: R
authors.lastname: Numazawa
authors.forename: S
authors.initials: S
authors.lastname: Kaseno
authors.forename: T
authors.initials: T
authors.lastname: Yamamura
authors.forename: S
authors.initials: S
authors.lastname: Yokota
mesh_terms: D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005766:Gastrointestinal Contents / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007273:Injections, Intramuscular; D011229:Preanesthetic Medication; D011899:Ranitidine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*
chemical_list: D011899:Ranitidine