Comparison of pirenzepine, ranitidine, and pirenzepine-ranitidine combination for reducing preoperative gastric fluid acidity and volume in children.
We conducted a two-part controlled study to evaluate the efficacy of preoperative oral pirenzepine (muscarinic receptor antagonist known to inhibit gastric secretion), ranitidine, and the combination pirenzepine-ranitidine in controlling gastric fluid pH and volume in 210 ASA I children, aged 2-14 yr, undergoing elective surgery. In the first part of the study (n = 90), the proportion of children considered at risk for aspiration pneumonitis was reduced with pirenzepine 25 mg (P < 0.05) but not with 12.5 mg. In the second part of the study, the other 120 children were allocated randomly to one of four groups: pirenzepine 25 mg with placebo; ranitidine 75 mg with placebo; pirenzepine 25 mg with ranitidine 75 mg; and placebo and placebo. These medications were administered 1 h before anaesthesia. After tracheal intubation, volume and pH of the gastric fluid aspiration via a multiorifice orogastric tube were measured. Pirenzepine 25 mg decreased gastric fluid volume (P < 0.05) but failed to increase gastric pH. Ranitidine 75 mg increased gastric pH (P < 0.05) but failed to decrease fluid volume. The pirenzepine-ranitidine combination reduced gastric fluid acidity and volume (P < 0.05).
Maekawa
N
N
Department of Anaesthesiology, Kobe University School of Medicine, Japan.
Nishina
K
K
Mikawa
K
K
Shiga
M
M
Obara
H
H
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004338:Drug Combinations; D005744:Gastric Acid; D005745:Gastric Acidity Determination; D005750:Gastric Juice / Q000187:drug effects*; D006635:Histamine H2 Antagonists / Q000627:therapeutic use*; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000627:therapeutic use*; D010890:Pirenzepine / Q000627:therapeutic use*; D011015:Pneumonia, Aspiration / Q000517:prevention & control; D011183:Postoperative Complications / Q000517:prevention & control; D011229:Preanesthetic Medication; D011899:Ranitidine / Q000627:therapeutic use
D004338:Drug Combinations; D006635:Histamine H2 Antagonists; D018727:Muscarinic Antagonists; D010890:Pirenzepine; D011899:Ranitidine