Prophylaxis for pulmonary acid aspiration.

Pulmonary acid aspiration in the perioperative period was first noted as a medical concern more than 40 years ago. Despite this awareness, identification of the patient at risk is by no means certain, and the true incidence of this condition is not known. Various therapeutic interventions have been proposed and tried. Physical therapies, such as pressure on the cricoid, have been successful, as has the administration of clear antacids prior to surgery. The histamine (H2)-receptor antagonists cimetidine and ranitidine have also been used successfully as prophylactic therapy when enough time is available prior to operation to make preoperative dosing practical. Metoclopramide, which can be given intravenously, may be useful in emergency surgery. When the degree of risk is high, concurrent use of physical and pharmaceutical interventions is recommended.