Acute gastrointestinal complications after cardiac surgery.

Gastrointestinal problems, with an incidence of about 1%, may complicate the postoperative period after cardiovascular surgery, increasing morbidity, length of stay, and mortality. Several risk factors for the development of these complications, including preexisting conditions; advancing age; surgical procedure, especially valve, combined bypass/valve, emergency, reoperative, and aortic dissection repair; iatrogenic conditions; stress; ischemia; and postpump complications, have been identified in multiple research studies. Ischemia is the most significant of these risk factors after cardiovascular surgery. Mechanisms that have been implicated include longer cardiopulmonary bypass and aortic cross-clamp times and hypoperfusion states, especially if inotropic or intra-aortic balloon pump support is required. These risk factors have been linked to upper and lower gastrointestinal bleeding, paralytic ileus, intestinal ischemia, acute diverticulitis, acute cholecystitis, hepatic dysfunction, hyperamylasemia, and acute pancreatitis. Gastrointestinal bleeding accounts for almost half of all complications, followed by hepatic dysfunction, intestinal ischemia, and acute cholecystitis. Identification of these gastrointestinal complications may be difficult because manifestations may be masked by postoperative analgesia or not reported by patients because they are sedated or require prolonged mechanical ventilation. Furthermore, clinical manifestations may be nonspecific and not follow the "classic" clinical picture. Therefore, astute assessment skills are needed to recognize these problems in high-risk patients early in their clinical course. Such early recognition will prompt aggressive medical and/or surgical management and therefore improve patient outcomes for the cardiovascular surgical population.