ABSTRACT
Introduction: The second wave of coronavirus disease 2019 (COVID-19) in India was characterised by rapid surge in cases, higher rates of hospitalisation and mortality. Acute kidney injury (AKI) is a common complication of severe COVID-19 infection and has been associated with increased morbidity and mortality. The pathophysiology and risk factors of AKI in COVID –19 is inadequately studied especially in the setting of the second wave. There is scarcity of data from India regarding incidence, risk factors and outcome of AKI in critically ill COVID-19 patients. Methods: This was a prospective observational study conducted during the second wave of COVID-19 at a teaching hospital in south India. All the adult patients (>18 years old) with COVID-19 confirmed by a positive reverse-transcriptase-polymerase-chain reaction (RT-PCR) test and admitted to the intensive care unit (ICU) were included in this study. Severe COVID-19 was defined as SpO2 <94% in room air, PaO2/FiO2 <300 mm Hg, respiratory rate >30/min or lung infiltrates>50%. The study was conducted from 1st April 2021 to 31st July 2021. AKI was defined according to KDIGO (Kidney Disease: Improving Global Outcomes) criteria. Patients who were on maintenance dialysis prior to admission and those without a positive COVID RT PCR report were excluded. All patients were followed up until discharge or death as applicable. Results: A total of 76 patients were admitted during the study period. 74 were included in the study (Figure 1). The average age of the patients was 55.6 ± 13.8 years. 78.4% of the patients were male. 34 (45.9%) of 74 patients developed AKI. Out of them 47.1% had stage 1 AKI, 17.6% had stage 2 AKI, 11.8% had stage 3 AKI and 23.5 % had stage 3 AKI requiring dialysis. When the baseline characteristics were compared between those who developed AKI versus those who did not develop AKI, the former had more co-morbidities as indicated by higher Charlson co-morbidity index (CCI score) p=0.001, higher proportion of diabetes mellitus (p=0.01) and pre-existing chronic kidney disease (CKD) (p= 0.04). The patients who developed AKI had more severe illness with 41.1% of them requiring non-invasive ventilation (NIV) and 44.1% mechanical ventilation (p= 0.001 and p= 0.04 respectively). 50% of patients who developed AKI required inotropic support as compared to 20% of those without AKI (p=0.007). Serum lactate dehydrogenase (LDH) and serum ferritin were significantly elevated in patients who developed AKI as compared to those who did not develop AKI (Figure 2). On stepwise multivariate regression analysis, presence of diabetes mellitus (OR (95% CI): 6.8 (1.50-30.96), p=0.013), serum LDH >/= 386 (OR (95% CI): 12.38 (1.66-92.46) p= 0.014, serum ferritin >/=835 (OR (95% CI): 3.84 (0.86-17.14) p=0.07 and delay from symptom onset to admission in days (OR (95% CI): 3.55 (0.89-14.15), p=0.07 were independent risk factors for development of AKI in our study population. The overall mortality rate of the study population was high at 56.7%, with 64.7% in the AKI group and 50% in the non- AKI group (p=0.20) Fig 1: Details of study population [Formula presented] Fig 2: Box and whisker plots of serum LDH and serum ferritin in those with AKI and those without AKI [Formula presented] [Formula presented] Conclusions: There is high incidence of AKI in critically ill patients of COVID-19 admitted to ICU. Diabetes mellitus, high serum LDH and serum ferritin were found to be independent predictors for AKI development. No conflict of interest