Efficacy and Complications of Regional Citrate Anticoagulation During Continuous Renal Replacement Therapy in Critically Ill Patients with COVID-19

Abstract

\n Background: Enhanced coagulation in coronavirus disease 2019 (COVID-19) patients is considered a major obstacle for continuous renal replacement therapy (CRRT), but systematic analyses are sparse. We compared filter survival and citrate-induced complications during CRRT with regional citrate anticoagulation (RCA) in COVID-19 and Non-COVID-19 patients.Methods: In this retrospective study we included all consecutive adult patients (n=97) with acute kidney injury (AKI) treated with RCA-CRRT at seven ICUs of a tertiary university hospital over the tree month period. Medical data were collected to compare the efficacy and complications of RCA-CRRT between COVID-19 (n=44) and Non-COVID-19 patients (n=53).Results: There was no significant difference in the number of CRRT filters used per patient in COVID-19 vs. Non-COVID-19 patients (median 5 vs 3 filters, p=0.103). Mean filter run-time was significantly higher in COVID-19 patients compared to Non-COVID-19 patients (68.4 (95%CI 67.0-69.9) vs. 65.2 (95%CI 63.2-67.2) hours, respectively; log-rank 0.014). COVID-19 patients showed significantly higher activated partial thromboplastin time (aPTT) throughout the CRRT due to systemic anticoagulation compared to Non-COVID-19 patients (54 (IQR 45 – 61) vs. 47 (IQR 41 - 58) seconds, respectively; p<0.001). A significantly higher incidence of combined metabolic disturbances (metabolic alkalosis, hypercalcemia and hypernatremia), consistent with reduced filter patency and citrate overload during RCA, was observed in COVID-19 patients compared to Non-COVID-19 patients (19.1% vs. 12.7%, respectively; p=0.04). These metabolic disarrangements were resistant to per-protocol adjustments and disappeared after replacement of the CRRT-filter. Conclusions: In contrast to initial concerns, adequate filter life-span can be achieved with RCA during CRRT in COVID-19 patients. However, close monitoring of the acid-base balance appears warranted, as these patients tend to develop reduced filter patency leading to a higher incidence of citrate overload and metabolic disturbances. Trial Registration (local authority): EA1/285/20 (Ethikkommission der Charité - Universitätsmedizin Berlin); date of registration 08.10.2020.