Renal Recovery After Acute Kidney Injury in Mechanically Ventilated Patients with COVID-19 Infection

Introduction: Mechanical ventilation in COVID-19 infection range between 5-20% and the incidence of Acute kidney injury (AKI) from 20.2-36.6%. The mortality rate in the AKI subset ranges from 54.8-90% in various studies(1-5). The AKI group tends to be promptly admitted to ICU and require mechanical ventilation due to burned of the disease(4). Methods: A retrospective cohort study with SARS-CoV2 positive by RT-PCR on Mechanical Ventilation. Subjects with End stage renal disease, death <24 hours following endotracheal intubation, intubated out of our institution were excluded. AKI was defined according with KDIGO guideline. Renal recovery was defined creatine level that does not meet criteria for AKI stage 1. Kaplan-Maier curve and long-rank test were applied for survival analysis. Cox Proportional. Hazzard Regression was conducted to determine risk factors for Mortality simultaneously. A significant p-value was considered as <0.05. Result: Of 347 patients on mechanical ventilation included to the study, 183(52.7%) where admitted with AKI and 148(42.7%) develop AKI during the hospital course. The rate of mortality in the AKI group was higher compared with patient without AKI(80.7% vs. 31.3%, p<0.000). Subjects with AKI stage 1 had median time of survival 48.5 (95%CI,[36.8-60.1]) days;AKI stage 2 had median time of 13.6 (95%CI,[3.7-23.5]) days;and AKI stage 3 had median time of 10.0 (95%CI,[8.8-11.1]) days. Significant differences were found by Long Rank tests (p=0.000). AKI increased mortality risk in patient on mechanical ventilation (HR, 2.9[1.2-7.0], p=0.018). After adjustment, we determined that Renal recovery at the end of hospital course has comparable mortality risk with subjects without AKI (aHR, 0.82,[0.28-2.38], p<0.70). Increased mortality risk was noted among patient with partially renal recovery (aHR, 8.55,[3.37-21.6], p<0.000) and without recovery (aHR, 7.07,[2.71-18.39], p<0.000). Discussion: Mortality rate in patients with AKI on mechanical ventilation was high but did not differ from other studies in NYC(6) .Various pathophysiological mechanisms are associated with AKI in COVID-19 infection;prerenal azotemia, acute tubular injury, glomerular disease and thrombotic microangiopathy has been reported(7). At any study of COVID-19, patients with AKI are more likely to be admitted in ICU, required mechanical ventilation or died;and the outcomes get worse with higher AKI stages or if progress to Acute kidney disease(4,8). Our cohort found a comparable mortality risk between patients without AKI and whose recover renal function after adequate management. It is imperative to closely monitor patient that develop AKI and inquired in modifiable precipitant factors to prevent progression and facilitate renal recovery. (Table Presented).