SIRS is the Optimal Simple Predictor of Severity in Acute Pancreatitis: Presidential Poster

Abstract

Purpose: Predictors of severity in acute pancreatitis range from the simple to the complex; however, limited data is available on the systemic inflammatory response syndrome (SIRS) as a predictor of clinically important outcomes. The aim of our study was to evaluate the role of SIRS in predicting outcomes in acute pancreatitis compared with other simple markers of severity. Methods: We retrospectively identified nontransfer patients admitted to our center with acute pancreatitis between 1985 and 2009. Patients were stratified based on SIRS at admission (n=118), at 24 hours (n=82), at 48 hours (n=80), and at 72 hours (n=56). The primary outcomes were pancreatic necrosis, persistent organ failure (POF; i.e., organ failure at 72 hours), ICU admission, length of stay (LOS) >7 days, and mortality. Results: SIRS on admission and at 72 hours was associated with a higher incidence of pancreatic necrosis, with hazard ratios (HR) of 6.2 (95% confidence interval [CI] 1.1-34) and 5.9 (95% CI 1.2-30), respectively. SIRS at 24 hours was associated with POF and a HR of 11 (95% CI 4.2-26) compared to 2.6 (95% CI 1.1-6.2) on admission, 5.4 (95% CI 2.3-13) at 48 hours, and 7.1 (95% CI 3.0-17) at 72 hours. There was a correlation between transfer to the ICU and SIRS on admission (HR 2.6; 95% CI 1.2-5.3), at 24 hours (HR 8.6; 95% CI 4.0-18), 48 hours (HR 9.2; 95% CI 4.2-20), and 72 hours (HR 8.2; 95% CI 3.8-18). Prolonged hospital stays (defined as a LOS >7 days) correlated with SIRS on admission (HR 1.7; 95% CI 1.1-2.6), at 24 hours (HR 3.1; 95% CI 1.9-5), 48 hours (HR 4.2; 95% CI 2.5-7), and 72 hours (HR 4.9; 95% CI 2.7-9.2). Mortality was associated with a HR of 3.4 (95% CI 1.1-10) for SIRS on admission, 6.7 (95% CI 2.3-20) for SIRS at 24 hours, 4.1 (95% CI 1.3-13) for SIRS at 48 hours, and 7.1 (95% CI 2.0-25) for SIRS at 72 hours. A BUN >25 on admission was associated with POF (HR 9.9; 95% CI 4.1-24), transfer to the ICU (HR 4.6; 95% CI 2.1-9.9), prolonged hospital stays (HR 2.1; CI 1.2-3.5), and death (HR 6.2; 95% CI 2.2-17). There was no clinically significant correlation between elevated hematocrit (Hct >44) and any of our primary outcomes. Advanced age (i.e., >60 years) was associated with POF (HR 3.7; 95% CI 1.5-9.3) but not pancreatic necrosis, ICU transfer, prolonged hospitalization, or mortality. Conclusion: SIRS on admission and/or at 24, 48, and 72 hours is an excellent predictive marker of important clinical outcomes, outperforming hematocrit and comparable to admission BUN >25 as a marker of severity in acute pancreatitis.