Nutrition in Severe Acute Pancreatitis

Acute pancreatitis (AP) is a debilitating disease caused by proteolytic auto-injury from inappropriate intra-acinar activation of the proenzymes. The majority of patients have a mild disease that resolves with supportive care, but ~20 % have a severe disease marked by intense systemic inflammation and organ failure associated with significant morbidity and mortality. Bowel rest allows the inflamed pancreas to rest, but prolonged fasting deprives the body of the essential nutrients necessary to withstand the hypercatabolic state associated with severe AP. In addition, the disturbed gut mucosal integrity and splanchnic metabolism from starvation allow bacterial and endotoxin translocation that amplifies systemic inflammation. Enteral nutrition (EN) has been shown to play a pivotal role in minimizing the infectious complications, need for surgical interventions, length of hospitalization, and mortality by preserving gut function, modulating systemic inflammation, and organ failure. EN can be delivered by nasogastric or nasojejunal feeding and appears to be more beneficial when delivered early in the course of severe disease. Jejunal feeding has the advantage of causing less pancreatic stimulation than gastric feeding and making EN feasible in patients with gastric outlet obstruction due to the pancreatic inflammatory mass or fluid collections. Parenteral nutrition (PN) allows pancreatic rest but exacerbates the gut mucosal atrophy and is associated with increased risk of septicemia and metabolic complications. Consequently, PN should be reserved for those who cannot tolerate EN.