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

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

Method: 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.

Results: 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).

Conclusion: 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.