Acute pancreatitis (AP) is a self-limiting disease. However, 20–30% of patients will develop into severe AP (SAP), and infectious pancreatic necrosis in the late course of SAP is the leading cause of death for such patients. This review aims to provide a comprehensive and systematic report of the currently published risk factors for complicated infectious pancreatic necrosis in patients with severe acute pancreatitis by meta-analysis of published retrospective case-control studies.

Five electronic database systems were selected to search for articles on risk factors of infectious pancreatic necrosis in patients with severe acute pancreatitis. According to the heterogeneity among studies, the standardized mean difference (SMD), odds ratio and 95% confidence interval (95%CI) were calculated by applying a random-effects model or fixed-effects model, respectively.

As of 2nd Jun, 2021, a total of 1408 articles were searched, but only 21 articles were finally included in this meta-analysis. The results found that patients with severe acute pancreatitis complicated by infected pancreatic necrosis had higher APACHE II scores and higher levels of lipase (LPS), C-reactive protein (CRP) and procalcitonin (PCT) compared to patients with severe acute pancreatitis alone. The differences were statistically significant (APACHE II: SMD = 0.86, 95%CI: 0.55, 1.18; LPS: SMD = 1.52, 95%CI: 1.13, 1.92; CRP: SMD = 1.42, 95%CI: 1.05, 1.79; PCT: SMD = 1.82, 95%CI: 1.36, 2.28).

Compared with patients with severe acute pancreatitis alone, high levels of LPS, CRP, PCT and high APACHE II score were risk factors for infectious pancreatic necrosis in patients with severe acute pancreatitis.