A Population-Based Study of Severity in Patients With Acute on Chronic Pancreatitis

Objectives: The objectives of this study were to evaluate the severity of patients with acute pancreatitis (AP) on chronic pancreatitis (CP) and compare this to patients with AP without CP. Methods: The Maryland Health Services database was queried for all adult inpatient discharges with a primary diagnosis of AP from 1994 to 2010. Acute pancreatitis on CP and AP without CP were defined by the presence of the associated diagnosis code for CP. Severity was defined as organ failure, intensive care unit stay, or mortality. Results: Acute pancreatitis on CP accounted for 13.7% of all AP discharges (9747/70,944). The proportion of AP-on-CP discharges doubled during the study period (8.8% to 17.6%; P < 0.0001). When compared with patients with AP without CP, AP-on-CP patients were younger, were more likely to be male and black, had higher rates of alcohol and drug abuse, and had less severe disease with lower rates of mortality, organ failure, need for mechanical ventilation, and intensive care unit stay. Among AP-on-CP patients, significant predictors of severity included advanced age, weight loss, and 2 or more comorbidities. Conclusions: Patients with AP on CP have less severe disease than do those with AP without CP. Weight loss, advanced age, and comorbidity increase the risk of severity in patients with AP on CP.