Outcomes of renal replacement therapy in critically ill COVID-19 patients

ABSTRACT

Introduction: Our goal is to describe outcomes of critically ill COVID-19 patients submitted to renal replacement therapy (RRT), in particular the association of RRT with mortality. Multi-system organ failure or direct kidney injury caused by SARS-CoV-2 is associated with the development of acute kidney injury (AKI) which subsequently increases the need for RRT and may affect the outcomes. Method(s) This is a retrospective observational study of 338 critically ill patients admitted with COVID-19 pneumonia in the ICU of a tertiary center in Portugal, between March 2020 and December 2021. Clinical, analytical and baseline patient characteristics were evaluated. Logistic regression analysis was performed to correlate patient data with the need for RRT and ICU mortality. Result(s) From a total of 338 patients, 5% required RRT (n = 16), 25% of which received intermittent hemodialysis (n = 4) and 87,5% continuous veno-venous hemofiltration (n = 14). Baseline characteristics are described in Table 1. In our sample, 61 patients (18%) presented with acute AKI, from whom 14 (23%) were submitted to RRT. From all the patients receiving RRT, 10 (62.5%) did not have pre-existing chronic kidney disease. In the logistic regression analysis, AKI (OR 45.4;95% CI 7.7-269.5;p < 0.001), higher SOFA (OR 1.24;95% CI 103-1.51;p = 0,03), creatinine (OR 2.01;95% CI 1.4-3.0;p < 0.001) and C-reactive protein (OR 1.09;95% CI 1.02-1.16;p = 0,01) on admission were associated with the need for RRT. Additionally, ICU mortality associated with RRT was 75% compared to 28.3% in the group not submitted to RRT (OR 7.6;2.4-24.2;p = 0.001). Conclusion(s) The need for RRT in critically ill COVID-19 patients is associated with an increased mortality rate in our study. We were also able to identify AKI, higher SOFA, creatinine and C-reactive protein at admission as risk factors for RRT. However, due to the retrospective nature of our analysis and our small sample size, more studies on this topic are needed to confirm these results.