Acute kidney injury and mortality in patients with critical COVID-19 in Mexico: case-control study

We aimed to test the association between acute kidney injury (AKI) and mortality in critically ill patients with Coronavirus disease 2019 (COVID-19).

We conducted a single-center case-control study at the intensive care unit (ICU) of a second-level hospital in Mexico. We included 100 patients with critical COVID-19 from January to December 2021, and collected demographic characteristics, comorbidities, APACHE II, SOFA, NEWS2, and CO-RADS scores at admission, incidence of intrahospital complications, length of hospital and ICU stay, and duration of mechanical ventilation, among others.

The median survival of deceased patients was 20 days. After multivariable logistic regression, the following variables were significantly associated to mortality: AKI (adjusted odds ratio [AOR] 6.64, 95% confidence intervals [CI] = 2.1-20.6, p = 0.001), age > 55 years (AOR 5.3, 95% CI = 1.5-18.1, p = 0.007), and arrhythmias (AOR 5.15, 95% CI = 1.3-19.2, p = 0.015). Median survival was shorter in patients with AKI (15 vs. 22 days, p = 0.043), as well as in patients with overweight/obesity (15 vs. 25 days, p = 0.026).

Our findings show that the development of AKI was the main risk factor associated with mortality in critical COVID-19 patients, while other factors such as older age and cardiac arrhythmias were also associated with this outcome. The management of patients with COVID-19 should include renal function screening and staging on admission to the Emergency Department.