Bacterial infection and extent of necrosis are determinants of organ failure in patients with acute necrotizing pancreatitis

Background: The risk factors predisposing to organ failure in patients with necrotizing pancreatitis remain unclear. The relationship between the extent of pancreatic necrosis, the presence of infection and the incidence of organ failure was analysed. Methods: In a retrospective review, the occurrence of pulmonary insufficiency, renal insufficiency, shock, sepsis/sepsis-like syndrome (SLS) and coagulopathy was evaluated in 273 patients with necrotizing pancreatitis, and a comparison was made between patients with sterile or infected necrosis. Additionally, the relation between the incidence of organ failure and extent of pancreatic parenchymal necrosis was investigated by classifying the patients into three groups according to the amount of necrotic tissue found by contrast-enhanced computed tomography (group 1, extent less than 30 per cent; group 2, 30-50 per cent; group 3, more than 50 per cent). Results: Organ failure was more frequent in patients with infected necrosis than in those with sterile necrosis. Differences were found in the incidence of pulmonary insufficiency, sepsis/SLS and coagulopathy. Organ failure occurred more frequently in group 3 than in group 2 or 1 (95 verses 79 and 66 per cent; P=0.0004). The extent of infected necrosis was not related to the incidence of organ failure (group 1, 88 per cent; group 2, 86 per cent; group 3, 96 per cent). However, there was a relation between the incidence of organ failure and the extent of sterile necrosis (group 1, 59 per cent; group 2, 74 per cent; group 3, 94 per cent; P=0.0001). Multivariate analysis confirmed the presence of infection and the extent of necrosis as independent determinants of organ failure. Conclusion: The incidence of organ failure is determined by both bacterial infection and extent of necrosis. The incidence of organ failure is determined by the extent of necrotic parenchyma in patients with sterile necrosis. Infected necrosis is associated with a high incidence of organ failure irrespective of the extent of necrosis.