80 Admission Creatinine is Associated with Poor Outcomes in Burn Patients

Abstract

Acute kidney injury (AKI) is a common occurrence in severely burned patients. However, definitions and protocols vary and therefore the impact of AKI is not well known. The most utilized clinical biomarkers are creatinine and blood urea nitrogen. The purpose of this study was to determine if admission serum creatinine is associated with mortality and other organ dysfunction. We hypothesized that a high admission creatinine is associated with adverse outcomes. We conducted a cohort study of adult patients admitted from 2006 to 2016 to a regional burn centre. Patients were included if they had a burn ≥ 5% total body surface area (TBSA) and a serum creatinine level measured within the first 72 hours post-injury. Patients were divided into two groups based on serum creatinine levels measured within the first 72 hours post-injury. Patients categorized in the high creatinine group if they had a measured creatinine > 106 μmol/L (>1.2 mg/dL); this value was chosen as the flag for “high” creatinine from our institution’s reference range. Clinical outcomes included morbidities, hospital length of stay, and mortality. Multivariable logistic regression was used to model the association between high admission creatinine and each outcome, adjusting for patient and injury characteristics. We studied 923 patients, mean age 47 ± 18 years and median 13% (IQR 8–24) TBSA burned. There were 718 patients categorized with low admission creatinine and 205 patients with high admission creatinine. Patients in the high admission creatinine group had significantly greater percent TBSA burn, and a significantly greater proportion of patients with inhalation injury, complications, and mortality (p<0.05). After adjustment for patient and injury characteristics, high admission creatinine was associated with a significantly higher rate of mortality (OR 3.68; 95% CI 1.88–7.21), pneumonia (OR 3.36; 95% CI 1.29–8.74), and sepsis (OR 3.32; 95% CI 2.02–5.47). Elevated creatinine on admission is associated with an increased risk of morality and inpatient complications. Renal function is influenced during the initial acute resuscitation period by adequate fluid titration; however, renal function of patients with a high admission creatinine level might be overwhelmed by added effects of injury. Future studies are needed to determine if early initiation of renal replacement therapy improves outcomes. Providers should be aware of increased morbidity and mortality in this cohort to optimize care.