Prevalence and outcome of acute kidney injury in burn victims at a tertiary centre in Cape Town, South Africa

Abstract

Background. Burn victims commonly experience acute kidney injury (AKI), which can lead to significant morbidity and mortality. Objective. To investigate the prevalence of AKI in burn patients, the causes of AKI and the rate of in-hospital mortality. Methods. A retrospective cohort study was conducted on patients admitted to the Tygerberg Hospital Burn Unit between 1 April 2018, and 31 March 2019. The study included all burn patients >18 years old, except for those with end-stage kidney disease or cold burn wounds, skin donors or readmissions. AKI was defined using the Kidney Disease Improving Global Outcomes criteria, and multivariable logistic regression was used to identify predictors of AKI and death, along with Kaplan-Meier survival analysis. Results. The prevalence of AKI was 27% (58/215). The most common causes of burns were open fires (37%) and shack fires (17%). Patients with AKI had higher scores on the abbreviated burn severity index (ABSI) (7 v. 5, p<0.01), required more mechanical ventilation (69% v. 33%, p<0.01) and experienced more sepsis (35% v. 12%, p<0.01). Predictors of AKI included ABSI score (adjusted odds ratio (aOR) 1.48, 95% confidence interval (CI) 1.21 - 1.80, p<0.01), mechanical ventilation (aOR 7.75, 95% CI 1.23 - 48.65, p=0.03) and high admission lactate (aOR 1.57, 95% CI 1.04 - 2.39, p=0.03). Mortality was higher in patients with AKI (34% v. 6%, p<0.01). ABSI score (aOR 2.16, 95% CI 1.56 - 2.99, p<0.01) and vasopressor use (aOR 7.71, 95% CI 2.15 - 27.60, p<0.01) were identified as predictors of death. The survival analysis revealed that AKI was associated with higher mortality (log rank, p<0.01). Conclusion. The study highlights the high prevalence of AKI among burn victims requiring tertiary care and its association with high mortality rates. Improving living conditions in informal settlements could help prevent burns and their complications.