Incidence, Risk Factors and Outcome of COVID-19 Associated AKI- A Study from South India.

BACKGROUND

Acute Kidney Injury (AKI) is a dreaded complication of Covid-19 infection with high morbidity and mortality. Limited data exists on Indian experience. In a tertiary care hospital situated in South India, we analysed the incidence, clinical profile and outcomes of patients diagnosed with AKI due to COVID-19.

METHODS

Retrospective data of Adult cases admitted with COVID-19 over a 8 month period from April - November 2020 was collected. Incidence, Demographics, Clinical profile, Management and Outcomes of COVID-19 associated AKI were analysed. Primary outcome was In- hospital mortality. Secondary outcomes were Dialysis Requirement and Renal Recovery.

RESULTS

52 (7%) out of a total 718 patients with COVID-19 developed AKI. Mean Age was 58 years (IQR 51-69) with a striking male predominance of 92%.(Male:Female -9.4:1) (P< 0.001). Co morbidities seen were Diabetes in 38 (73%) and Hypertension in 31(59%) and Coronary Artery Disease in 17(32%). Fever with myalgia was seen in 29 (46%), Respiratory symptoms in 31(59%), Oliguria in 26(50%) and Diarrhea in 2 (3%) patients. At admission, Hypoxemia and Hypotension were seen in 27 (51%) and 16 (30%) patients respectively. Urinalysis revealed > 2+ dipstick Proteinuria in 24 (46%) and Microscopic hematuria in 16(34%) patients. 25 (48%) were admitted in Stage 3 AKI with a mean S.Creatinine level of 4.4 + 3.4 mg/dl. CT chest showed > 50% lung involvement in 23 patients (44%). Mechanical ventilation was required in 20(38%). Hemodialysis was required in 12 (23%). The median duration of hospitalisation was 10 + 5 days. Primary Outcome of Mortality occurred in 44% of AKI cohort in comparison to 7% in Non AKI cohort (Relative Risk[RR]6.2; 95% Confidence Interval[CI], 4.1 to 9.4) (P= 0.001). Hypoxemia [RR,3.76;95% CI,1.4-9.5], Hypotension [RR 2.54; CI,1.5-4 ], Low Serum albumin [RR1.6;CI,1.1 - 2.3] and Requirement for mechanical ventilation [RR,11.3; CI, 2.9 - 23 ] were significant risk factors for mortality. All 5 patients who required both mechanical ventilation and Dialysis died. 31 patients (59%) were treated with Remdesivir therapy without survival benefit. Significantly higher C-Reactive Protein, Interleukin -6, D-Dimer levels and lower serum albumin levels were seen in those who died. Among the 29 patients who survived, the estimated GFR (e GFR) had recovered in 12 (41%) at discharge. After further followup of 4-6 weeks, the total number of patients who recovered renal function rose to 21 (72%).

CONCLUSION

Mortality in COVID associated AKI stood at 44%. Multiple factors contributed to high mortality such as Severe disease with hypotension and extensive pulmonary involvement, High Neutrophil to Lymphocyte Ratio, Absolute Monocyte Count, inflammatory markers, d-Dimer and low serum albumin. It was encouraging to note that 72% of survivors recovered renal function by 4-6 weeks after discharge from hospital which means that it is worth the struggle to treat AKI in COVID-19.