Abnormal Renal Function Tests at Presentation in Severe COVID-19 Pneumonia and its Effect on Clinical Outcomes
Keywords:Glomerular filtration rate (eGFR), blood urea nitrogen (BUN), creatinine clearance (CrCl), COVID-19, mortality rate, mechanical ventilation
Objective: To determine the incidence of abnormal renal function tests at presentation in patients from Karachi admitted with severe COVID-19 pneumonia and determine its effect on disease severity and clinical outcomes.
Study type, settings & duration: This was a cross-sectional study conducted at the COVID Intensive care unit of a large tertiary care government hospital in Karachi from February 2021 to June 2021.
Methodology: One hundred ninety patients admitted over five months were included in the study. Patient demographic characteristics, comorbidities, and clinical manifestations of COVID-19 infection were recorded. Laboratory values at the time of presentation, including hemoglobin, neutrophil lymphocyte ratio, platelets, blood urea nitrogen, estimated glomerular filtration rate (eGFR), inflammatory markers, liver function tests, and electrolytes were recorded. Patient outcome and need for mechanical ventilation were assessed 28 days after admission and compared with the incidence of abnormal renal functions at presentation.
Results: Mean eGFR and BUN at presentation were 69.7 and 28.4 respectively. Of the total 109 (57.4%) patients had abnormal renal function tests at the time of presentation. About 76 (40%) patients had low eGFR and 33 (17.4%) had only raised BUN with normal eGFR. Mean eGFR was lower in non-survivors vs survivors (p-value 0.000) and in patients who required mechanical ventilation (p-value 0.008). Patients who had low eGFR showed greater mortality than those with normal eGFR (p-value 0.04) and were more likely to require mechanical ventilation (p-value 0.04).