Early Acute Kidney Injury in Adult Patients With Burns in Australia & New Zealand

Introduction

Acute kidney injury (AKI) following burns is associated with increased mortality and morbidity. Some patients require renal replacement therapy. There is limited large-scale data to sufficiently validate risk factors influencing the incidence and severity of early AKI, defined as AKI within the first 72 h since admission to a burn center following burn injury. The aims of this study were to compare the profile of adult patients admitted to Australian and New Zealand burn centers, with burns ≥10% total body surface area (TBSA) who developed early AKI with patients who did not develop AKI and to quantify the association between early AKI and in-hospital outcomes.

Methods

Data were extracted from the Burns Registry of Australia and New Zealand for adults (≥18 y), with burns ≥10% TBSA admitted to Australian or New Zealand burn centers between July 2016 and June 2021. All patients with two valid serum creatinine blood tests within the first 72 h were included. Differences in patient profiles and in-hospital outcomes were investigated. Univariable and multivariable logistic and linear regression models were used to quantify associations between early AKI and outcomes of interest.

Results

There were 1297 patients who met the inclusion criteria for this study. Eighty-three patients (6.4%) developed early AKI. Compared to patients without AKI, patients with an AKI were older (P = 0.006), had a greater median %TBSA burned (P < 0.001), and had an inhalation injury (P < 0.001). In adjusted models, the development of early AKI was significantly associated with in-hospital mortality (adjusted odds ratio (aOR) [95% CI] 2.73 [1.33, 5.62], P < 0.001) and the need for mechanical ventilation (aOR [95% CI] 3.44 [1.77, 6.68], P = 0.001), but there was no significant increase in the hospital length of stay or intensive care unit length of stay.

Conclusions

This is the first large-scale study looking at early AKI in adult burns ≥10% TBSA. The incidence of AKI was lower than previously reported and AKI was associated with higher in-hospital mortality and increased need for mechanical ventilation. These findings support the notion that development of AKI in the immediate phase post burns injury can potentially have consequences and the appropriate care should be given to prevent its development.