Specific clinical contexts - Part 1: The intensive care unit

The acutely ill patient who requires admission to the intensive care unit is at risk for a number of potentially life-threatening disorders of gut motility. Predisposing and/or precipitating factors may include the underlying illness itself, recent surgery, sepsis and a variety of medications. As these patients are often heavily sedated or unconscious, the development of these motility problems may be silent and not become clinically obvious until complications have developed, necessitating that the clinician be ever alert for their presence. Among the various motility syndromes that have been described in this context, megacolon is, perhaps, the most common. When detected, a number of therapeutic options are available for the management of megacolon, depending on its severity and rate of development. While aspiration and feeding difficulties are well-known challenges in the intensive care unit, their pathophysiology has been poorly understood. Studies of upper gastrointestinal motor function have demonstrated that the critically ill are subject to profound alterations in motor and sensory function of the esophagus, lower esophageal sphincter, stomach and duodenum which go some way towards explaining their propensity to reflux and gastroparesis, with their attendant risks. New data on the pathogenesis of postoperative ileus may throw light on ICU-related dysmotility, in general, and open some new therapeutic avenues. Indeed, recent studies have identified a number of strategies and new pharmacological approaches to the management of postoperative ileus which have the potential to be used in the nonsurgical ICU patient.