Acute kidney injury development in polytrauma and the safety of early repeated contrast studies: A retrospective cohort study.

BACKGROUND: The role of repeat intravenous contrast doses beyond initial contrast imaging in the development of acute kidney injury (AKI) for multiple injury patients admitted to the intensive care unit (ICU) is not fully understood. We hypothesized that additional contrast doses are potentially modifiable risk factors for worse outcomes. METHODS: An 8-year retrospective study of our institutional prospective postinjury multiple organ failure database was performed. Adult ICU admissions that survived >72 hours with Injury Severity Score (ISS) of >15 were included. Patients were grouped based on number of repeat contrast studies received after initial imaging. Initial vital signs, resuscitation data, and laboratory parameters were collected. Primary outcome was AKI (Kidney Disease: Improving Global Outcomes criteria), and secondary outcomes included contrast-induced acute kidney injury (CI-AKI; >25% or >44 µmol/L increase in creatinine within 72 hours of contrast administration), multiple organ failure, length of stay, and mortality. RESULTS: Six-hundred sixty-three multiple injury patients (age, 45.3 years [SD, 9.1 years]; males, 75%; ISS, 25 (interquartile range, 20-34); mortality, 5.4%) met the inclusion criteria. The incidence of AKI was 13.4%, and CI-AKI was 14.5%. Multivariate analysis revealed that receiving additional contrast doses within the first 72 hours was not associated with AKI (odds ratio, 1.33; confidence interval, 0.80-2.21; p = 0.273). Risk factors for AKI included higher ISS ( p < 0.0007), older age ( p = 0.0109), higher heart rate ( p = 0.0327), lower systolic blood pressure ( p = 0.0007), and deranged baseline blood results including base deficit ( p = 0.0042), creatinine ( p < 0.0001), lactate ( p < 0.0001), and hemoglobin ( p = 0.0085). Acute kidney injury was associated with worse outcomes (ICU length of stay: 8 vs. 3 days, p < 0.0001; mortality: 16% vs. 3.8%, p < 0.0001; MOF: 42% vs. 6.6%, p < 0.0001). CONCLUSION: There is a limited role of repeat contrast administration in AKI development in ICU-admitted multiple injury patients. The clinical significance of CI-AKI is likely overestimated, and it should not compromise essential secondary imaging from the ICU. Further prospective studies are needed to verify our results. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

The epidemiology of injuries related to falling trees and tree branches.

BACKGROUND: Trees are an essential component of our environment. However, falling trees and/or branches have the potential to cause serious morbidity and mortality. The aim of this study is to describe the nature and severity of tree related injuries based on admissions to a level 1 trauma centre. METHODS: A retrospective review of all trauma admissions related to accidental tree failures was undertaken from January 2013 to June 2021. Patients were identified from the trauma registry using ICD-10 code 'W20'. We included basic demographics, hospital admission details and inpatient mortality. Weather information was obtained through the Bureau of Meteorology and remoteness was classified using the Accessibility/Remoteness Index of Australia. Results are presented as mean, standard deviation, median and percentages. RESULTS: Out of 13 884 admissions, 37 (0.26%) were attributed to trees. 21 (0.15%) of those were injuries due to accidental tree failures and were included in the analysis. 38% were considered to be severely injured based on an injury severity score of greater than 15. 23.8% were polytrauma patients. The chest was the most commonly injured body region (47.6%). Two patients required intensive care admission with ventilator support. The majority of injuries occurred in outer regional areas and 52% of patients were injured when wind speed exceeded 20 km/h. CONCLUSION: We demonstrated that the likelihood of being injured by falling trees is very low. This information should be taken into account when planning future developments or considering the removal of existing trees in the interest of public safety.