The Role of Abdominal Computed Tomography Scan in Acute Pancreatitis
Acute pancreatitis (AP) is one of the most common causes for frequent admissions in the United States causing huge financial health care burden.1,2 Some of these resources were unwarranted such as abdominal computed tomography (CT) scan especially in mild to moderate AP. There have been few studies assessing the clinical role of abdominal CT scan. Hence, our objective was to explore the role of abdominal CT scan in patients with AP and whether clinical outcome differs. Retrospective analysis of 1044 patients with AP who were admitted to our hospital in New York from 2010 to 2014 was performed. Acute pancreatitis etiologies include 40% gallstones, 35% due to alcohol, 15% hypertriglyceridemia, 2% post–endoscopic retrograde cholangiopancreatography, and 8% idiopathic. Among the 1044 patients, 656 patients with AP (63%) had an abdominal CT scan assessment, whereas 388 patients with AP (37%) did not have an abdominal CT scan imaging. Of the 656 patients, 518 patients (79%) had no evidence of fever or leukocytosis, whereas 34 patients (5.2%) did have fever and/or leukocytosis as part of their initial presentation, in which 10 patients developed systemic organ failure. Only 10 patients (1.9%) of the 518 patients without fever or leukocytosis have diagnosis of pancreatic necrosis on abdominal CT scan, whereas 48 patients (9.3%) of the same 518 patients have evidence of pancreatic pseudocyst. Of the remaining 460 patients (88.8%), 305 patients (58%) showed evidence of AP without complications, and 155 patients (29%) showed no evidence of AP. Local complications of AP were noted in 68 patients (6.5%); most were pancreatic pseudocyst of approximately 5% and pancreatic necrosis of approximately 1.5%. Further analysis showed that mortality and 30-day readmission rates for AP showed no difference in comparison between patients with AP who had no abdominal CT scan on presentation (388 patients, 37%) versus patients with AP who had a CT scan imaging (656 patients, 63%), with P values of 0.5 and 0.1, respectively. The use of abdominal CT scan made no clinical difference in the mortality outcome and 30-day readmission rate in patients with AP (Fig. 1).
Acute pancreatitis is the one of the most common causes of inpatient hospitalization and the principal common gastrointestinal diagnosis on 2009 in the United States. This led to hospitalization cost of approximately 2.9 billion dollars annually, with mean cost of AP hospitalization of approximately $10,000 to $13,000 per day in the United States.1,2 Part of these massive expenses is the abdominal imaging, specifically abdominal CT scan, and the average cost of abdominal CT scan is approximately $600 to $900 million annually based on Medicare fee reimbursement.2 Cost burden is not the only dilemma; obtaining abdominal CT scan is becoming part of the routine clinical workup in the emergency department. In fact, there is an increase in the ordering of CT scans by providers with an average of 14% (from 81 to 181 examinations) annually.3
Acute pancreatitis can be divided into mild, moderate, or severe according to the revised Atlanta classification (2012). Mild AP is determined as AP with an absence of organ failure, as well as an absence of local complications, whereas severe AP is identified as AP with persistent organ failure of more than 48 hours. Moderate AP is identified with local complications and/or transient organ failure (of <48 hours).4 Current guidelines from the American College of Gastroenterology (2013) and the American College of Radiology (2013) recommended to limit the use of abdominal CT scan imaging for patients with mild AP.