Brazilian researchers have developed a score that allows for predicting the risk of developing Acute Kidney Injury (AKI) in patients with Covid-19. The study was carried out in partnership between the D’Or Institute for Research and Education (IDOR), the Rede D’Or (Vila Nova Star Hospital and São Luiz Itaim Hospital), the Evandro Chagas National Institute of Infectious Diseases/FIOCRUZ and the ABC Medical School and published in the scientific journal BMC Nephrology. Dr. Thiago Romano, coordinator of the Lato Sensu postgraduate course in Intensive Care at IDOR College of Medical Sciences, and Dr. Fernando Bozza, physician and researcher in public health at FIOCRUZ and coordinator of research in Intensive Care at IDOR, participated in the research.  

Frequently used in the clinical evaluation of a patient admitted to intensive care units (ICU), the prognostic score allows for predicting the evolution and severity of a patient from the moment of admission. Systemic complications caused by Covid-19, such as AKI, contribute to greater complexity of treatment and are associated with higher mortality in these patients.   

The study included 1131 patients with Covid-19 admitted to the ICU in 23 different hospitals in Brazil from January 10 to August 30, 2020. “We have the collaboration of the ICUs of Rede D’Or nationally, demonstrating that, in addition to the issue of care excellence, there is data management and research potential like this that has the potential to improve the care of our patients”, summarizes Dr. Romano, who also coordinates the General ICU of Hospital Vila Nova Star and the Oncology ICU of Hospital São Luiz Itaim. 

The variables selected for the development of the prognostic score were age, diabetes, use of angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), chronic kidney disease and hypertension. The criterion used to define AKI was an increase in blood creatinine by 0.3 mg/dL within 48 hours or a change in creatinine ≥ 1.5 times the normal range within 1 week.  

It is important to remember that angiotensin-converting enzyme 2 (ACE2) acts on the renin-angiotensin-aldosterone system, an important regulator of blood pressure and renal stability. However, angiotensin receptors have also been recognized as a gateway for SARS-CoV-2 to enter cells. ACEI and ARB act on the system, protecting kidney cells.  

The mean age of the patients was around 52 years, and 60% were men. The most common comorbidities included hypertension and diabetes. The results showed that 33% of patients developed AKI, of which 78% did not require dialysis. The overall mortality was 11%, while the mortality rate for patients with AKI was 21%.  

The score was titled COV-AKI (Covid-19-AKI, acute kidney injury) and performed well in the calibration analysis, indicating similar results between the risk predicted by the score and that observed in Covid-19 patients for developing AKI.   

The score should allow clinicians to identify early Covid-19 patients at the highest risk of developing AKI, enabling earlier interventions to minimize the impact of kidney injury. The authors point out that it is still necessary to evaluate the effectiveness of the score in other hospitalization settings, such as wards.   

The research highlights the importance of monitoring and early identification of patients with Covid-19 who are at higher risk of developing an acute kidney injury, as this complication can lead to increased morbidity and mortality. The COV-AKI score can be easily calculated at the bedside, without the need for complex laboratory tests or clinical variables that are difficult to calculate daily, making it also appropriate for application in countries with limited resources.