Clinical Features of Recurrent Acute Pancreatitis: Experience From a Single Center
We have read with great interest the recent article by Lee et al1 published in the April 21, 2015, issue of Pancreas, entitled “Decreased severity in recurrent versus initial episodes of acute pancreatitis.” In this article, the authors showed that the disease severity of recurrent acute pancreatitis (RAP) was significantly reduced when compared with that of the initial episode. This article reminds us that there might be a relationship between the number of acute pancreatitis (AP) attacks and clinical outcomes. However, in our opinion, some aspects of this study need to be clarified for better understanding.
First, the authors defined RAP as AP occurring at least 2 months after the previous episode. However, according to the study by Khurana and Ganguly,2 time interval between AP attacks must be more than 3 months, as most of the abdominal pain or elevated pancreatic enzymes are sequel of the previous attack rather than the result of RAP. Second, most of the patients enrolled in the study by Lee et al only presented mild AP, which might have some influence on the results.
As one of the tertiary referral centers for AP in China, we here present some data on RAP in our center, which is substantially different from those of Lee et al. We retrospectively investigated 441 patients with AP admitted from January 2013 to December 2014. Of which, 68 (15.42%) patients were defined as having RAP (Table 1). The median age of the patients with RAP was 42 years [interquartile range (IQR), 35.25–49.74 years), predominantly male patients. The median lengths of intensive care unit and hospital stay were 4 days (IQR, 2–8 days) and 7 days (IQR, 5–17 days) days, respectively. The proportions of patients with mild, moderate, severe, and critical AP were 19.12%, 26.47%, 27.94%, and 26.47%, respectively. The rate of mortality of patients with RAP in our study was much higher (5.88%), which is different from the study by Lee et al. Moreover, hyperlipidemia (47.06%) was the most common etiology for RAP in our study, followed by biliary (41.18%) and alcohol (4.41%). Thirty-eight (55.88%) patients with RAP had a history of smoking, and 33 (48.53%) had a history of alcoholism. Almost half of the patients with RAP (30/68, 44.12%) had multiple organ dysfunctions. Of all the study patients, 21 (30.88%) developed acute respiratory distress syndrome (ARDS), 13 (19.12%) developed shock, and 19 (27.94%) developed acute kidney injury. Most of the enrolled patients (48/68, 72.06%) developed pancreatic necrosis during the clinical course, and about two thirds (43/68, 63.64%) of the patients recovered with conservative management only.
The etiology, diagnosis, management, and clinical outcome of RAP have always been critical concerns of many clinicians. The study by Lee et al first evaluated the correlation between disease severity and episodes of AP, whereas the exact mechanism for RAP has not been well understood. According to the study by Lee et al, loss of acinar cells and parenchymal fibrosis might play a protective role in the development of RAP.
Nevertheless, inconsistent with the study by Lee et al, a large proportion of patients with RAP in our study developed pancreatic necrosis, with a median computed tomography severity index of 6. Taking this into account, the theory of Lee et al might not be totally true. Therefore, further studies may be needed to determine the exact severity of RAP and its correlation with the number of AP attacks. Furthermore, another difference between our study and the studies by Lee et al and other researchers was that hyperlipidemia was the most common etiology of RAP in our study.