SUMMARY BackgroundPredictors of organ failure and the impact of early endoscopic retrograde cholangiopancreatography (ERCP) on outcomes in patients with acute cholangitis are unclear.

SIRS, We appreciate the interest raised by Tabibian and Kane 1 regarding our recent study demonstrating increased likelihood of persistent organ failure among hospitalised patients who received delayed ERCP ≥48 h compared to early ERCP <48 h from presentation. 2We agree with the comments regarding the potential for unmeasured confounders that may impact the association of delayed ERCP on persistent organ failure. However, when we adjusted for the two additional factors stated in the letter to multivariate analyses (coagulopathy defined by INR >1.5 and hypoxaemia requiring oxygen supplementation on presentation), the adjusted odds ratio of delayed compared to early ERCP (AOR = 3.1, 95% CI: 1.4-7.1) and 17% (95% CI: 7-29%) relative risk of every 1-day delay in ERCP on persistent organ failure were identical to the primary analyses in the study. Furthermore, even in most unstable patients, hypoxaemia or coagulopathy should not preclude early ERCP after adequate volume resuscitation with primary goals of biliary decompression as a definitive treatment for biliary sepsis.Finally, selection bias resulting from excluding outpatients with cholangitis in our study is likely not important in clinical practice given that most cases of cholangitis are managed as inpatients.Although we are in agreement that a prospective study comparing different periods of time to ERCP would be desirable, cholangitis is an infrequent cause of hospitalisation in major centres (90-203 patients during 8-16 years in retrospective studies).2-4 Furthermore, time-sensitive inclusion criteria, substantial but relatively infrequent outcome (i.e. in-hospital mortality 2-9%), [2][3][4] and clinical instability of some patients may pose challenges to enrolment and will certainly require multicentre collaboration. ACKNOWLEDGEMENTThe authors' declarations of personal and financial interests are unchanged from those in the original article.