Outcomes of renal replacement therapy in the critically ill with COVID-19

OBJECTIVE: To describe outcomes of critically ill patients with COVID-19, particularly the association of renal replacement therapy to mortality. DESIGN: A single-center prospective observational study was carried out. SETTING: ICU of a tertiary care center. PATIENTS: Consecutive adults with COVID-19 admitted to the ICU. INTERVENTION: Renal replacement therapy. MAIN VARIABLES OF INTEREST: Demographic data, medical history, illness severity, type of oxygen therapy, laboratory data and use of renal replacement therapy to generate a logistic regression model describing independent risk factors for mortality. RESULTS: Of the total of 166 patients, 51% were mechanically ventilated and 26% required renal replacement therapy. The overall hospital mortality rate was 36%, versus 56% for those requiring renal replacement therapy, and 68% for those with both mechanical ventilation and renal replacement therapy. The logistic regression model identified four independent risk factors for mortality: age (adjusted OR 2.8 [95% CI 1.8-4.4] for every 10-year increase), mechanical ventilation (4.2 [1.7-10.6]), need for continuous venovenous hemofiltration (2.3 [1.3-4.0]) and C-reactive protein (1.1 [1.0-1.2] for every 10mg/L increase). CONCLUSIONS: In our cohort, acute kidney injury requiring renal replacement therapy was associated to a high mortality rate similar to that associated to the need for mechanical ventilation, while multiorgan failure necessitating both techniques implied an extremely high mortality risk.