Risk factors and outcomes of sepsis-associated acute kidney injury in intensive care units in Johannesburg, South Africa.

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) has been shown to be a significant contributor to morbidity and mortality in both children and adults with critical illness. In sub-Saharan Africa, there is a lack of information on factors associated with development of SA-AKI and outcomes after intensive care unit (ICU) admission.

OBJECTIVES

To assess the rate of SA-AKI, factors associated with its development, and predictors of mortality at 90 days in critically ill patients admitted to the ICU with sepsis.

METHODS

This was a prospective observational study conducted at two of the biggest teaching hospitals in Johannesburg, South Africa, from 15 February 2016 to 15 February 2020. The study included consecutive patients with confirmed sepsis who were admitted to the ICU within 24 hours of admission to hospital. The primary outcome of the study was development of SA-AKI (defined according to Kidney Disease Improving Global Outcome (KDIGO) criteria), and secondary outcomes were risk factors for SA-AKI and predictors of mortality at 90 days. Multivariate logistic regression analysis was employed to determine the factors associated with SA-AKI and 90-day mortality.

RESULTS

In total, 327 critically ill patients with sepsis admitted to the ICUs were included in the study. The median (interquartile range) age was 39 (30 - 52) years, and 185 patients (56.6%) developed SA-AKI. Of these patients, blacks and whites comprised 91.0% and 6.1%, respectively, and the prevalent comorbidities were HIV/AIDS (19.3%), hypertension (14.2%) and diabetes mellitus (10.1%). Patients with SA-AKI were likely to be older and of male gender, and to have cardiovascular disease, malignancies, hypotension and a low serum albumin level. In multivariate analysis, the predictors of SA-AKI were age ≥55 years (odds ratio (OR) 2.43; 95% confidence interval (CI) 1.27 - 4.65), inotropic support (OR 3.61; 95% CI 2.18 - 5.96) and a low serum albumin level (OR 2.93; 95% CI 1.40 - 6.13). SA-AKI and need for inotropic support were respectively associated with 1.9-fold and 1.7-fold increased mortality at 90 days after ICU admission.

CONCLUSION

SA-AKI was found to be frequent in this study in two tertiary hospital ICUs in Johannesburg, and the need for inotropic support predicted mortality after ICU admission.