Acute Kidney Injury in COVID-19: multicentre prospective analysis of registry data

Wan, Yize I; Bien, Zuzanna; Apea, Vanessa J; Orkin, Chloe M; Dhairyawan, Rageshri; Kirwan, Christopher J; Pearse, Rupert M; Puthucheary, Zudin A; Prowle, John R

BACKGROUND: Acute kidney injury (AKI) is a common and important complication of COVID-19. Further characterisation is required to reduce both short and long-term adverse outcomes. METHODS: We examined registry data including adults with confirmed SARS-CoV-2 infection admitted to five London Hospitals from 1(st) January to 14th May 2020. Prior end-stage kidney disease was excluded. Early AKI was defined by Kidney Disease Improving Global Outcomes (KDIGO) creatinine criteria within 7 days of admission. Independent associations of AKI and survival were examined in multivariable analysis. Results are given as odds ratios (OR), or hazard ratios (HR) with 95% confidence intervals. RESULTS: Amongst 1855 admissions, 453 patients (24.5%) developed early AKI: 220 (44.0%) stage 1, 90 (19.8%) stage 2, 165 (36.3%) stage 3 (74 receiving renal replacement therapy). The strongest risk factor for AKI was high CRP (OR 3.35 [2.53-4.47], p < 0.001). Death within 30 days occurred in 242 (53.2%) with AKI compared to 255 (18.2%) without. In multivariable analysis, increasing severity of AKI was incrementally associated with higher mortality: stage 3 (HR 3.93 [3.04-5.08], p < 0.001). In 333 patients with AKI surviving to day 7, 134 (40.2%) recovered, 47 (14.1%) recovered then relapsed, and 152 (45.6%) had persistent AKI at day 7; an additional 105 (8.2%) patients developed AKI after day 7. Persistent AKI was strongly associated with adjusted mortality at 90-days (OR 7.57 [4.50-12.89], p < 0.001). CONCLUSIONS: AKI affected one in four hospital in-patients with COVID-19 and significantly increased mortality. Timing and recovery of COVID-19 AKI is a key determinant of outcome.