Mortality and renal long-term outcome of critically ill COVID-19 patients with acute kidney failure, continuous renal replacement therapy and invasive mechanical ventilation

Background: There are limited data describing the long-term renal outcomes of critically ill COVID-19 patients with acute kidney injury (AKI) and continuous renal replacement therapy (CRRT) and invasive mechanical ventilation.

Methods: In this retrospective observational study we analyzed the long-term clinical course and outcomes of 30 critically ill patients hospitalized with COVID-19 during the peak of highest incidence in the first wave, with acute respiratory distress syndrome (ARDS) and AKI that required CRRT. Baseline features, clinical course, laboratory data, therapies and filters used in CRRT were compared between survivors and non-survivors to identify risk factors associated with in-hospital death. Renal parameters: glomerular filtration rate, proteinuria and microhematuria were collected at 6months after discharge.

Results: 19 patients (63%) died and 11 were discharged. Mean time to death was 48days (7-206) after admission. Patients with worse baseline renal function had higher mortality (P=.009). Patients were treated with CRRT for an average of 18.4days. Filters with adsorptive capacity (43%) did not offer survival benefits. Regarding long-term renal outcomes, survivor patients did not receive any additional dialysis, but 9 out of 11 patients had an important loss of renal function (median of eGF of 44 (13-76)ml/min/1.73m²) after 6months.

Conclusion: Mortality among critically ill hospitalized patients diagnosed with COVID-19 on CRRT is extremely high (63%). Baseline renal function is a predictor factor of mortality. Filters with adsorption capacity did not modify survival. None survivor patients required long-term dialysis, but an important loss of renal function occurred after AKI episode related to COVID-19 infection.