Abstract and Introduction
Background & Aims There is no consistency between the individual studies in the literature on whether organ failure (OF) or infected pancreatic necrosis (IPN) is the main determinant of severity in acute pancreatitis. We aimed to statistically aggregate the available data and determine the pooled influence of OF and IPN on mortality in patients with acute pancreatitis.
Methods The search for relevant observational studies was undertaken in the , EMBASE, and Scopus electronic databases, as well as in the proceedings of major gastroenterology meetings. The summary estimates are presented as relative risk (RR) and 95% confidence interval (CI).
Results Fourteen studies comprising 1478 patients with acute pancreatitis were meta-analyzed. A total of 600 patients developed OF and 179 of them died (mortality, 30%); 314 patients developed IPN and 102 of them died (mortality, 32%). In a stratified analysis, patients with OF and IPN had a significantly higher risk of death in comparison with patients with OF and no IPN (RR = 1.94; 95% CI: 1.32–2.85; P = .0007) and in comparison with patients with IPN and no OF (RR = 2.65; 95% CI: 1.30–5.40; P = .0007).
Conclusions In patients with acute pancreatitis, the absolute influence of OF and IPN on mortality is comparable and thus the presence of either indicates severe disease. The relative risk of mortality doubles when OF and IPN are both present and indicates extremely severe disease or critical acute pancreatitis.
Acute pancreatitis is a protean disease that varies locally from mild pancreatic edema and inflammation to extensive infected pancreatic and peripancreatic necrosis, and systemically from a mild hypoxemia to multiple organ failure. Determinants of disease severity in acute pancreatitis continue to be the subject of debate. Fitz, at the end of 19th century, believed that pancreatic hemorrhage and disseminated fat necrosis were the determinants of severity. A century later, the Atlanta classification stated that the presence of local pancreatic complications and extrapancreatic organ failure (OF) were the determinants of severity. More recently, it has been postulated that OF is the key determinant of severity regardless of the presence or absence of local pancreatic complications.
It has also been appreciated that local pancreatic complications, such as fluid collections, pseudocysts, and necrosis, are not all equal contributors to disease severity. The widespread introduction of fine-needle aspiration of pancreatic tissue has helped to highlight the importance of pancreatic infection, particularly infected pancreatic necrosis (IPN), as a key determinant of disease severity. However, studies that have examined the relationship between pancreatic infection and mortality are not all in agreement. Some have demonstrated a strong association between the infection status of pancreatic necrosis and mortality, while others have failed to do so. There may be a number of legitimate reasons for the lack of accord between these studies, including heterogeneous study population of patients with and without OF and small sample size of the studies.
The aim of this study was to conduct a meta-analysis of published clinical studies to determine the influence of OF and IPN, both individually and combined, on the mortality in patients with acute pancreatitis.