Continuous passive paracentesis versus large-volume paracentesis in the prevention and treatment of intra-abdominal hypertension in the critically ill cirrhotic patient with ascites (COPPTRIAHL): study protocol for a randomized controlled trial

Background Critically ill patients with cirrhosis and ascites are at high risk for intra-abdominal hypertension (IAH) which increases mortality. Clinical guidelines recommend maintaining intra-abdominal pressure (IAP) below 16 mmHg; nonetheless, more than three quarters of critically ill patients with cirrhosis develop IAH during their first week of ICU stay. Standard-of-care intermittent large-volume paracentesis (LVP) relieves abdominal wall tension, reduces IAP, optimizes abdominal perfusion pressure, and is associated with short-term improvement in renal and pulmonary dysfunction. However, there is no evidence of the superiority of different paracentesis strategies in the prevention and treatment of IAH in critically ill patients with cirrhosis.This trial aims to compare the outcomes of continuous passive paracentesis versus LVP in the prevention and treatment of IAH in patients with cirrhosis and ascites.Methods An investigator-initiated, open label, randomized controlled trial, set in a general ICU specialized in liver disease, was initiated in August 2022, with an expected duration of 36 months. Seventy patients with cirrhosis and ascites will be randomly assigned, in a 1:1 ratio, to receive one of two methods of therapeutic paracentesis. A stratified randomization method, with maximum creatinine and IAP values as strata, will homogenize patient baseline characteristics before trial group allocation, within 24 h of admission.In the control group, LVP will be performed intermittently according to clinical practice, with a maximum duration of 8 h, while, in the intervention group, continuous passive paracentesis will drain ascitic fluid for up to 7 days.The primary endpoint is serum creatinine concentration, and secondary endpoints include IAP, measured creatinine clearance, daily urine output, stage 3 acute kidney injury and multiorgan dysfunction assessed at day 7 after enrollment, as well as 28-day mortality rate and renal replacement therapy-free days, and length-of-stay. Prespecified values will be used in case of renal replacement therapy or, beforehand ICU discharge, liver transplant and death. Safety analysis will include paracentesis-related complication rate and harm. Data will be analyzed with an intention-to-treat approach.Discussion This is the first trial to compare the impact of different therapeutic paracentesis strategies on organ dysfunction and outcomes in the prevention and treatment of IAH in critically ill patients with cirrhosis and ascites.