Comparison of renal replacement therapy and renal recovery before and during the COVID-19 pandemic: a single center observational study.

Rebecca Ryan,Mervyn Singer,Niall Maccallum,Dereck Gondongwe,Nishkantha Arulkumaran,Chris Laing,Isabel Taylor

doi:10.23736/s0375-9393.21.15595-6

Abstract

Our objective was to the describe indications, management, complications and outcomes of renal replacement therapy (RRT) in COVID-19 critically ill patients. To contextualize these findings, comparisons were made against 36 non-COVID-19 consecutive patients requiring RRT on ICU. We conducted a retrospective single center observational cohort study of patients requiring acute RRT between 1st March and 30th June 2020. Comparison was made against those receiving RRT in the pre-COVID-19 period from January 2019 to February 2020. Of 154 COVID-19 patients, 47 (30.5%) received continuous venovenous hemofiltration (CVVHF), all of whom required mechanical ventilation and vasopressor support. The requirement for RRT was related to fluid balance rather than azotemia. Compared to 36 non-COVID-19 patients, those with COVID-19 were younger (P=0.016) with a lower serum creatinine on hospital admission (P=0.049), and lesser degrees of metabolic acidosis (P<0.001) and lactatemia (P<0.001) before initiation of RRT. In addition, the duration of RRT requirement was longer (P<0.001). Despite lower CVVHF exchange rates with higher serum creatinine levels following RRT initiation in the COVID-19 patients, metabolic abnormalities were corrected. Hospital mortality was 60% among COVID-19 patients requiring RRT, compared to 67% in non-COVID-19 patients (P=0.508), and renal recovery among survivors without pre-existing CKD was similar (P=0.231). The requirement for RRT in COVID-19 patients was primarily related to fluid balance. Using lower CVVHF exchange rates was effective to correct metabolic abnormalities. Renal recovery occurred in all but one patient by 60 days in the 40% of patients who survived.

Highlights

Provision of renal replacement therapy (RRT) for patients with COVID-19 was challenging for both logistical and disease-related factors [1]
We addressed differences in initiation criteria for RRT, fluid balance and azotaemia with different clearance rates, incidence of hemofilter clotting, duration of RRT prior to renal recovery, hospital survival, and renal recovery
Of 154 patients admitted to our ICU with COVID-19 disease, 47 (30.5%) required RRT

Summary

Introduction

Provision of renal replacement therapy (RRT) for patients with COVID-19 was challenging for both logistical and disease-related factors [1]. Patients with COVID-19 are at increased risk of thrombotic complications [3], creating challenges around optimizing the anticoagulation to preserve filter life. This was further compounded by the lack of citrate regional anticoagulation. To assess the impact of these modifications, and any differences in thresholds for the initiation of RRT, and we drew comparison against consecutive non-COVID-19 critically ill patients in our intensive care unit requiring RRT over the previous year. To compare differences in indications, management, complications and outcomes of renal replacement therapy (RRT) in COVID-19 patients compared to non-COVID critically ill patients

Methods

Results

Conclusion