Characterisation of Acute Kidney Injury in Critically Ill Patients with Severe Coronavirus Disease-2019 (COVID-19)

Background: COVID19-associated acute kidney injury frequency, severity and characterisation in critically ill patients has not been reported. Methods: Single-center cohort performed from March 3, 2020, to April 14, 2020 in 4 intensive care units in Bordeaux University Hospital, France. All patients with COVID19 and pulmonary severity criteria were included. AKI was defined using KDIGO criteria. A systematic urinary analysis was performed. The incidence, severity, clinical presentation, biological characterisation (transient vs. persistent acute kidney injury; proteinuria, hematuria and glycosuria), and short-term outcomes was evaluated. Results: 71 patients were included, with basal serum creatinine of 69 +/- 21 micromol/L. At admission, AKI was present in 8/71 (11%) patients. Median follow-up was 17 [12-23] days. AKI developed in a total of 57/71 (80%) patients with 35% Stage 1, 35% Stage 2, and 30% Stage 3 acute kidney injury; 10/57 (18%) required renal replacement therapy. Transient AKI was present in only 4/55 (7%) patients and persistent AKI was observed in 51/55 (93%). Patients with persistent AKI developed a median urine protein/creatinine of 82 [54-140] (mg/mmol) with an albuminuria/proteinuria ratio of 0.23 +/- 20 indicating predominant tubulo-interstitial injury. Only 2 (4%) patients had glycosuria. At Day 7 onset of after AKI, six (11%) patients remained dependent on renal replacement therapy, nine (16%) had SCr > 200 micromol/L, and four (7%) died. Day 7 and day 14 renal recovery occurred in 28% and 52 % respectively. Conclusion: COVID19 associated AKI is frequent, persistent severe and characterised by an almost exclusive tubulo-interstitial injury without glycosuria