Ranitidine and metoclopramide for prophylaxis of aspiration pneumonitis in elective surgery

The effects of preanesthetic oral ranitidine and metoclopramide on gastric contents were studied in 150 inpatients scheduled for elective surgery with random allocation into ten groups with fifteen patients in each group. Patients in group I served as controls. Group II patients received metoclopramide, 10 mg, in the morning. Patients in group III received ranitidine, 150 mg; while group IV patients received ranitidine, 150 mg, and metoclopramide, 10 mg, also in the morning. Group V patients received ranitidine, 150 mg, at bedtime and in the morning; while patients in group VI received ranitidine as in group V and, in addition, received metoclopramide, 10 mg, in the morning. Group VII patients received ranitidine, 300 mg, in the morning; while patients in group VIII received ranitidine, 300 mg, and metoclopramide, 10 mg, in the morning. Patients in group IX received ranitidine, 300 mg, at bedtime and in the morning; while group X patients received ranitidine as in group IX, and in addition, received metoclopramide, 10 mg, in the morning. Patients with gastric pH less than or equal to 2.5 or gastric content volume greater than or equal to 20 ml were defined to be at risk of pulmonary damage in the event of aspiration. Patients in group I had a mean gastric pH of 2.33 with 73% of the patients with pH less than or equal to 2.5, while 47% of the patients presented with a combination of pH less than or equal to 2.5 and volume greater than or equal to 20 ml. Ranitidine and metoclopramide independently and in combination significantly reduced risk factors.