The effect of three different ranitidine dosage regimens on reducing gastric acidity and volume in ambulatory surgical patients.
OBJECTIVE
To evaluate three different preoperative oral dosing regimens of ranitidine in ambulatory patients who had significant risk of aspiration pneumonitis (gastric pH < or = 2.5 or volume > or = 25 ml at intubation or extubation).


METHODS
Double-blind, placebo-controlled, randomized trial.


METHODS
St. Francis Hospital of Buffalo, New York.


METHODS
Two hundred seventy-one ambulatory patients about to undergo a surgical procedure under general anesthesia, of whom 241 (89%) completed the trial and were considered evaluable.


METHODS
Patients were randomly assigned to receive one of four regimens administered orally before surgery: placebo at bedtime the night before and in the morning on the day of surgery; ranitidine 150 mg at bedtime and in the morning; ranitidine 150 mg at bedtime and placebo in the morning; or ranitidine 300 mg at bedtime and placebo in the morning.


RESULTS
Patients who received ranitidine 150 mg twice/day, ranitidine 150 mg at bedtime, or ranitidine 300 mg at bedtime had a significantly (p < 0.05) lower frequency of a gastric pH 2.5 or below at intubation or extubation than those taking placebo twice/day (3%, 45%, and 31%, respectively, vs 86%). In addition, gastric volume at intubation or extubation was 25 ml or above in significantly fewer patients receiving ranitidine 150 mg at bedtime than placebo (37% vs 13%, p < 0.05). Overall, the number of patients with risk factors for aspiration pneumonitis was significantly lower with ranitidine 150 mg twice/day (20%), ranitidine 150 mg at bedtime (48%), and ranitidine 300 mg at bedtime (35%) than placebo (86%) (p < 0.001), and significantly lower with ranitidine 150 mg twice/day than ranitidine 150 mg at bedtime (p < 0.05).


CONCLUSIONS
Ranitidine 150 mg twice/day preoperatively reduced to the greatest degree the percentage of patients who developed significant risk factors for aspiration pneumonitis after surgery under general anesthesia.
O'Connor
T A
TA
St. Francis Hospital of Buffalo, New York, USA.
Basak
J
J
Parker
S
S
D000556:Ambulatory Surgical Procedures; D000768:Anesthesia, General; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005750:Gastric Juice / Q000378:metabolism*; D006801:Humans; D008297:Male; D011015:Pneumonia, Aspiration / Q000517:prevention & control; D011183:Postoperative Complications / Q000517:prevention & control; D011899:Ranitidine / Q000008:administration & dosage* / Q000494:pharmacology
D011899:Ranitidine