Reflux and aspiration in the intensive care unit

Critical illness often involves multisystem organ dysfunction and/or failure. Therapeutic interventions aimed at one source of illness may have undesired consequences elsewhere. Gastroesophageal reflux is common in critically ill patients, and is promoted or further exacerbated by the initiation of mechanical ventilation necessitated by respiratory failure. Prophylaxis against stress ulcers of the gastrointestinal mucosa may promote bacterial overgrowth and perhaps ventilator-associated pneumonia (VAP) by eliminating protective gastric acidity. Identification of which subgroups of critically ill patients should receive stress-ulcer prophylaxis, and which pharmacological agents should be used for this purpose, are areas of ongoing investigation. Provision of enteral nutrition is an essential therapeutic intervention for critically ill patients; however, risk of aspiration of oropharyngeal and gastric contents is increased by the administration of feeds to the gastrointestinal tract. Delivery of enteral feeds beyond the gastric pylorus directly into the small intestine has been supported as a strategy to decrease the incidence of aspiration and to optimize the amount of nutrition delivered to the patient, however supportive data are not robust and debate continues. The severe consequences of VAP have stimulated the development of multi-component patient care “bundles” (including head-of-bed elevation and oral care with chlorhexidine) that have shown some success in decreasing occurrence of VAP and other unwanted iatrogenic consequences in the intensive care unit (ICU), but outcomes to date have been mixed, and individual components of the bundle have shown discordant effects on patientcentered outcomes.