Introduction
Kidney injury in COVID-19 occurs by complex mechanisms involving direct viral cytopathic effect, cytokine storm, angiotensin II pathway activation, complement dysregulation, hypercoagulability, microangiopathy and organ cross talk between the lungs and kidneys. There is a paucity of data on the clinical characteristics of such patients.
Methods
This was a prospective, observational study conducted at Madras Medical College between April 15, 2020 and November 22, 2020. All patients admitted with COVID-19 (as confirmed by either RT-PCR or CT chest) who developed dialysis-requiring renal failure were included in the study. Data pertaining to the clinical and laboratory characteristics and outcomes of patients were collected by direct interview and daily follow up of case records. Statistical analysis was done using IBM SPSS v23.
Results
Among the 109 patients admitted with suspicion of COVID-19 and initiated on hemodialysis, 13 were excluded being negative for both RT-PCR swab and CT findings. The mean age of the 96 patients recruited in the study was 54.4±13.2 years of which 68.8% were males. Sixty-three (65.6%) patients were hypertensives, 49 (51%) were diabetic and 18 (18.8%) had coronary artery disease. Seventy-three patients (76%) were symptomatic at presentation with the most common symptom being shortness of breath in 67 patients (69.8%) followed by cough in 31 (32.3%) and fever in 27 (28.1%) patients. Loose stools and altered sensorium were present in 7 (7.3%) and 9 (9.4%) patients respectively. Eighty-two patients (85.4%) had acute worsening of underlying chronic kidney disease, 9 (9.4%) had acute kidney injury and five (5.2%) patients had unclassified renal failure. The median duration of hospitalisation was 8.5 days (IQR 5 – 11). Chest CT was done in 83 patients of whom 68 had features suggestive of COVID-19. Dexamethasone, low molecular weight heparin (LMWH) and remdesivir were given in 63 (65.6%), 47 (49%) and 23 (24%) patients respectively. Six patients received convalescent plasma therapy. Sixty-six patients required oxygen support and 13 (13.5%) required non-invasive ventilation. Forty-two (43.8%) patients died during hospitalisation, the most common cause of death being respiratory failure in 26 (27.2%) followed by encephalopathy in 8 (8.4%) and sepsis in 5 (5.2%) patients. Four (44.4%) patients with AKI, 34 (41.5%) with acute on CKD and 4 (80%) with unclassified renal failure have died during hospitalisation. C-reactive protein (CRP), lactate dehydrogenase and ferritin were significantly higher at baseline in those who succumbed to the illness compared to those who survived [p values 0.001, <0.001 and 0.018 respectively (Fig 1)]. In binary logistic regression analysis, older age, dyspnoea at presentation, pre-existing diabetes and higher LDH were found to be independently associated with mortality. Among survivors, dexamethasone and remdesivir were not found to have any effect on duration of hospitalisation, time taken for swab negativity and mortality
Conclusions
Patients with COVID-19 and renal failure requiring initiation of hemodialysis were found to have higher mortality. Older age, diabetes and dyspnoea at presentation were associated with increased risk of mortality.
No conflict of interest