Incidence and risk factors of acute kidney injury in the Japanese trauma population: A prospective cohort study.

INTRODUCTION

Previous studies have reported the prevalence and risk factors of acute kidney injury (AKI) in relatively young trauma patients. The aims of this study were to identify the prevalence and risk factors of AKI among older Japanese trauma patients.

METHODS

We conducted a prospective observational study in the 8-bed intensive care unit (ICU) of a Japanese tertiary-care hospital. Participants comprised trauma patients aged 18 years or older admitted to the ICU. Our primary outcome was the incidence of AKI within 10days of admission, according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

Among 333 patients, 66 (19.8%) developed AKI (Stage 1, n=54; Stages 2, n=5; and Stage 3, n=7). Multivariate logistic regression analysis revealed that the incidence of AKI was associated with increased age (odds ratio (OR), 1.38; 95% confidence interval (CI), 1.15-1.65), male sex (OR, 2.06; 95%CI, 1.04-4.07), greater amount of red blood cell transfusions (OR, 1.61; 95%CI, 1.04-1.17), and presence of underlying chronic kidney disease (CKD) (OR, 3.97; 95%CI, 1.78-8.83). Length of stay in the ICU was significantly longer in patients with AKI (6days) than in those without (3days; p<0.001). Patients ≥65 years old were more likely to develop AKI (26.2% vs 11.6%; p<0.001). No significant differences in ICU stay (median, 4 vs 4days; p=0.70), hospital stay (median, 24 vs 21days; p=0.45), or 28-day mortality (2.1% vs 1.4%; p=0.19) were evident between age groups.

CONCLUSIONS

Approximately 20% of trauma patients developed AKI, and the elderly were more likely to develop AKI. Older age, male, greater units of red blood cell transfusions, and underlying CKD were associated with incidence of AKI.