Pulmonary aspiration of gastric contents: prevention and prophylaxis

Pulmonary aspiration of gastric contents is one of the most fatal complications not only in the scenario of an operating room but also in critically ill patients, who have an increased risk for silently aspirating oropharyngeal secretions and regurgitated gastric contents. Prevention is the key to avoid this feared event. Strict adherence to guidelines regarding fasting in the preoperative period, avoidance of residual muscle paralysis and early return of protective airway reflexes by carefully choosing appropriate anaesthetic agents are corner stones of safe anaesthetic practice. Routine preoperative pharmacoprophylaxis to reduce gastric acidity and volume is not recommended and tolerance to commonly used histamine 2 receptor antagonists may occur and use of proton-pump inhibitors may be necessary. In the critical care arena small-volume clinically silent aspirations of oropharyngeal secretion are more common and head-of-bed elevation has been identified as the single most important factor which can greatly reduce the risk of aspiration and thereby reduce the incidence of ventilator associated pneumonia. Most of the intensivists favours use a continuous enteral feed and checking of correct placement of feeding tube at regular interval to reduce the frequency of pulmonary aspiration of gastric contents. In this review we summarise the pathophysiologic mechanism and predisposing factors to pulmonary aspiration of gastric contents. We will also present evidence for and rationale behind the practices adopted in critical care area and operation theatre setup to prevent aspiration.