Patients on ventilators for respiratory failure due to pulmonary disease may develop three major complications requiring general surgical evaluation: gastrointestinal (GI) bleeding, paralytic ileus, and mesenteric vascular insufficiency. GI bleeding from acute hemorrhagic gastritis (stress ulceration) can be avoided by aggressive medical therapy consisting of volume replacement, antacids, nutrition, and treatment of the precipitating causes. When conservative therapy fails, surgery will be needed to control bleeding. Intestinal ileus is of uncertain etiology. Initially, it is treated conservatively. Rarely, when the patient develops peritoneal irritation or a cecal diameter of greater than 9 cm, surgery is indicated. Mesenteric vascular insufficiency of the nonocclusive type occurs in elderly individuals with heart disease, who develop a low cardiac output syndrome. Therapy must consist of avoiding a low flow state with proper fluid management, cardiorespiratory care, and drug therapy. Surgical intervention is indicated when physical examination and laboratory data point to a loss of intestinal viability.