Acute Kidney Injury in Critically-Ill COVID-19 Patients

Abstract

Purpose: Acute kidney injury (AKI) is common in patients with COVID-19, however, its mechanism is still controversial, particularly in ICU settings. Urinary proteinuria profile could be a non-invasive tool of interest to scrutinize the pathophysiological process underlying AKI in COVID-19 patients. Material and Methods: We conducted a retrospective study between March 2020 and April 2020. All patients with laboratory-confirmed COVID-19 and without end-stage kidney disease requiring renal replacement therapy before ICU admission were included. Our objectives were to assess the incidence and risk factors for AKI and to describe its clinical and biological characteristics, particularly its urinary protein profile. Results: Seventy patients were included; 87% needed mechanical ventilation and 61% needed vasopressor during their ICU stay; 64.3% of patients developed AKI and half of them needed dialysis. Total and tubular proteinuria on day 1 were higher in patients with AKI, whereas glomerular proteinuria was similar in both groups. The main risk factor for AKI was shock at admission (OR = 5.47 (1.74−17.2), p < 0.01). Mortality on day 28 was higher in AKI (23/45, 51.1%) than in no-AKI patients (1/25, 4%), p < 0.001. Risk factors for 28-days mortality were AKI with need for renal replacement therapy, non-renal SOFA score and history of congestive heart failure. Conclusions: AKI is common in COVID-19 patients hospitalized in ICU; it seems to be related to tubular lesions rather than glomerular injury and is related to shock at ICU admission.

Keywords: COVID; SARS-CoV2; acute kidney injury; dialysis; proteinuria; tubular necrosis.

Figure 1

Boxplot of urine protein profile of COVID-19 critically ill patients on days 1, 3, and 7. (a) total proteinuria expressed as protein/creatinine ratios (median [IQR], min–max); white boxes: no-AKI patients; blue boxes: AKI patients; (b) glomerular proteinuria expressed as protein/creatinine ratios (median [IQR], min–max); white boxes: no-AKI patients; green boxes: AKI patients; (c) tubular proteinuria expressed as protein/creatinine ratios (median [IQR], min–max); white boxes: no-AKI patients; red boxes: AKI patients.