Acute Kidney Injury in COVID-19 Pneumonia: A Single-Center Experience in Bahrain

Abstract

Background Kidney disease accompanying coronavirus disease 2019 (COVID-19) is not well understood, and information about the presentation of acute kidney injury (AKI), its risk factors, and outcomes is scarce, particularly in Bahrain and the Gulf region. In this study, we aimed to determine the rate of AKI among patients hospitalized with COVID-19 pneumonia at a tertiary hospital in Bahrain and to describe the various aspects of AKI in these patients, including its relationship with respiratory failure and in-hospital mortality. Methods This retrospective observational cohort study of patients admitted with COVID-19 pneumonia from April 1 to May 31, 2020, excluded those aged less than 18 years, those with end-stage renal disease, and those with renal transplants. Clinical and laboratory patient data were collected. The Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to define AKI. Results The mean age across the 73 included patients was approximately 54 years; about 60% were men, and nearly 58% were Bahraini nationals. Of the patients, 39.7% (29) developed AKI during hospitalization, out of which 11.0% reached stage 1, 15.1% reached stage 2, and 13.7% reached stage 3. Of all patients, seven (9.6%) required hemodialysis. Chronic kidney disease conferred an increased risk for AKI (P = 0.003) as did critical COVID-19 status (P < 0.001) and the necessity for mechanical ventilation or intensive care admission (P < 0.001 for both). Additionally, AKI was significantly associated with a lower PaO₂/FiO₂ (partial pressure of arterial oxygen/percentage of inspired oxygen) ratio (P < 0.001) and a greater number of medications for COVID-19 pneumonia (P = 0.003). Finally, in-hospital death tolls were remarkably higher in patients with AKI (P < 0.001). No association was found between AKI and each of the following therapies: angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, tocilizumab, and convalescent plasma. Conclusions The rate of AKI in patients hospitalized with COVID-19 pneumonia at our institution is relatively high and is strongly associated with disease severity, respiratory failure, and in-hospital mortality. Awareness of kidney disease in COVID-19 patients is crucial and of vital importance.

Keywords: acute kidney injury; covid-19; covid-19 pneumonia; novel coronavirus.

Figure 1. Clustered bar chart of the relationship between disease severity and acute kidney injury (P < 0.001).

Figure 2. Clustered bar chart of the relationship between mechanical ventilation and acute kidney injury (P < 0.001).

Figure 3. Clustered bar chart of the relationship between ICU admission and acute kidney injury (P < 0.001).

ICU, intensive care unit

Figure 4. Error bars chart of the relationship between the PaO2/FiO2 ratio and acute kidney injury (P < 0.001).

PaO₂, partial pressure of arterial oxygen; FiO₂, percentage of inspired oxygen.

Figure 5. Clustered bar chart of the relationship between in-hospital death and acute kidney injury (P < 0.001).