MO312: Long-Term Kidney Function Outcome After COVID-19 Associated Acute Kidney Injury and Kidney Replacement Therapy in Intensive Care

Abstract

BACKGROUND AND AIMSAcute kidney injury (AKI), frequently with concurrent albuminuria and haematuria, is common and increases mortality in COVID-19 infection. We present the clinical course and long-term outcomes of COVID-19 survivors with AKI and continuous kidney replacement therapy (CKRT) with follow-up of kidney function at 6 and 12 months.METHODA total of 29 non-CKD COVID-19 infected patients with AKI required mechanical ventilation and CKRT at the intensive care unit (ICU). Of those, 15 died (52%) and 14 survived. Written informed consent to collect and publish data was obtained from 13 survivors.We estimated eGFR with CKD-EPI creatinine in population-based healthy controls (n = 80, median age 62 years) for comparison.RESULTSA total of 13 survivors, median age 58 years, 85% male, 15% diabetes and median BMI 30 kg/m2. None had CKD before admission or at admission following rehydration.The typical scenario was a normal or slightly elevated creatinine level at admission, normalizing after IV fluids, but rising creatinine from day 8 (median) and the start of CKRT on day 10 (median). Urine analysis was available in 7 patients, of which only 1 had no urinary findings, 6 had albuminuria and/or haematuria and/or leukocyturia. Dialysis could be weaned in all 13 survivors after a median time of 16 days in dialysis (range 1–40 days). The median length of stay at the ICU was 41 days (range 10–72 days) and the median weight loss was 16 kg (range 8–27 kg).The survivors had a median eGFR of 100 mL/min/1.73 m2 (range 66–113) at baseline and a median eGFR of 69 mL/min/1.73 m2 (range 49–97) at 12 months estimated with CKD-EPI creatinine. Population-based control subjects had a median eGFR of 85 mL/min/1.73 m2 estimated CKD-EPI creatinine. Urine analysis was available in 11 patients at 12 months, of which 5 had no urinary findings, 3 had microalbuminuria and 3 had haematuria and/or leukocyturia.Since the weight loss was accompanied by a decline in creatinine, we used both creatinine-based, and cystatin C-based eGFR to evaluate kidney function at 6 month follow-up. At 6 months, the survivors had a median eGFR of 70 mL/min/1.73 m2 (range 44–111) estimated with CKD-EPI creatinine as compared with 46 mL/min/1.73 m2 (range 36–65) estimated with cystatin C eGFR, suggesting that cystatin C-based formulae are clinically more useful after COVID-19 associated critical illness.CONCLUSIONThe AKI mortality in COVID-19 despite CKRT is high, but a substantial number of patients survive and can be weaned off dialysis. Kidney function at 12 months did improve substantially but did not return to its baseline values and was lower compared with healthy age-matched population-based control subjects. Kidney outcome follow-up after COVID-19 and AKI is likely to be important for assessing long-term CKD prognosis and is proposed to be evaluated with both creatinine and cystatin C as well as urinalysis.