Continuous renal replacement therapy without anticoagulation in critically ill patients at high risk of bleeding: A systematic review and meta‐analysis

Abstract The current clinical guideline recommends continuous renal replacement therapy (CRRT) proceed without anticoagulation in patients with contraindication to citrate and increased bleeding risk. Nevertheless, the efficacy of anticoagulation‐free CRRT remains inconsistent. The purpose of our present systematic review is to evaluate the efficacy and safety of anticoagulant‐free CRRT based on the current literatures. The primary outcomes were filter lifespan and risk factors for filter failure. Seventeen observational studies and three randomized controlled trials were included in our present meta‐analysis. There was no significant difference in filter lifespan and azotemic control between the anticoagulation‐free and systemic heparin group. The regional citrate anticoagulation (RCA) protocol seems to be superior to the anticoagulation‐free protocol in terms of filter lifespan (WMD −23.01, 95% CI [−28.62, −17.39], p < 0.001; I 2 = 0%, p = 0.53) and azotemic control. Nafamostat protocol could significantly prolong filter lifespan (WMD −8.4, 95% CI [−9.9, −6.9], p < 0.001; I 2 = 33.7%, p = 0.21) as compared with anticoagulation‐free protocol without better azotemic control. The conventional coagulation parameters showed poor predictive performence for filter failure and the necessity of anticoagulants use before CRRT. Currently, the optimal choice of anticoagulation strategy for critically ill patients with increased bleeding risk could be RCA under close monitoring.