Pancreatitis is a nasty disease. It attacks young and old alike, often occurring without warning signs. Fortunately, most cases are rather mild and resolve spontaneously. However, a subpopulation of patients develops life-threatening disease, spending a month (usually longer) in the hospital with a large part of the stay spent in the intensive care unit (ICU). The disease poses several management problems for the clinician. First, the patients are hypermetabolic, rapidly immobilizing lean tissues in an aggressive catabolic state. Second, infectious complications—both respiratory and intra-abdominal (infected pancreatic tissue, retroperitoneal abscesses, etc)—present a difficult management problem requiring aggressive ICU care, antibiotic (often multiple) therapy, respiratory support, and frequently, surgical debridement. Although enteral access can be safely obtained during laparotomy and successfully used for postoperative enteral nutrition, 1 operative therapy occurs weeks rather than days into the course of the disease process. During the acute preoperative phase, a massive retroperitoneal phlegmon impairs gastric emptying, precluding any form of intragastric nutrition support. The inflamed, edematous duodenum usually makes advancement of a nasojejunal tube technically impossible. Hence, in addition to hemodynamic, respiratory, and other critical care therapies, parenteral nutrition provides the primary method of nutrition support for these patients, often for prolonged periods of time. Even if enteral access is obtained at laparotomy, advancement of jejunostomy feedings is often slow, requiring a very gradual transition from parenteral to enteral therapy.