To the Editor:

Thanks to Dr. Miranda's recent letter and thoughtful comments regarding our article. We really appreciate and agree with his suggestion that the cutoff level of intra-abdominal pressure (IAP, 15 mmHg for the maximal value and 12 mmHg for the mean value) demonstrated from the ROC curves1 should be cautiously used; however, there are several important issues that need to be clarified.

We agree with Dr. Miranda's statement that pancreatic infection could not be adequately detected 72 h after admission. In fact, secondary pancreatic infections we mentioned in this study were mostly diagnosed 2 weeks after the onset of severe acute pancreatitis (SAP), which is in accordance with previous studies and the natural course of SAP.2 Moreover, we have stated our standards for the diagnosis of pancreatic infection in the Methods section, which is “positive findings in bacterial culture of abdominal fluid and temperature increased consistently.” The samples were obtained through imaging-guided aspiration or drainage, and/or imaging-guided fine needle aspiration, and/or surgical drainage. Consistently increased temperature was confirmed in patients whose body temperatures were greater than 38°C for three consecutive days. In the article, we did not describe the criteria in detail for concision.

It is really true that a prospective controlled trial with a large sample size will make great sense. Actually, there were several studies regarding the different outcomes between SAP patients with or without raised IAP like what Dr. Miranda suggested in the letter had been published, some of which used the reference level (15 mmHg) we demonstrated in our article.3,4 However, these studies including ours were all single-center ones with limited sample size. We do agree that causality between increased IAP and the onset of infection or other important complications need to be further confirmed by a large, multi-center, prospective study.