Temporal Dysregulation of the Angiopoietin-2/-1 Ratio After Trauma and Associations With Injury Characteristics and Outcomes.

Traumatic injury and hemorrhagic shock result in endothelial cell activation and vascular dysfunction that, if not corrected, can propagate multiorgan failure. Angiopoietin-1 and angiopoietin-2 are important regulators of endothelial cell function, and the ratio of plasma angiopoietin-2-to-1 is a useful indicator of overall vascular health. We therefore characterized plasma angiopoietin-2/-1 ratios over time after trauma in adults in an effort to gain insight into the pathophysiology that may drive post-traumatic vasculopathy and organ injury. We performed a single-center prospective observational study to measure plasma angiopoietin-1 and -2 levels and determine angiopoietin-2/-1 ratios in adult trauma patients upon hospital arrival and after 12, 24, and 48 h. Compared with levels in healthy adults, angiopoietin-1 levels were significantly elevated at hospital arrival, and angiopoietin-2 levels were significantly elevated at 12, 24, and 48 h. These kinetics translated in angiopoietin-2/-1 ratios that were significantly greater than controls at 24 and 48 h. After regression analysis, elevated angiopoietin-2 levels were independently associated with blunt injuries at admission, with coagulopathy at admission and 12 h, and with hemorrhagic shock at 24 and 48 h. Significant correlations were observed between both angiopoietins and 24-h transfusion requirements. Angiopoietin-2/-1 ratios correlated with mechanical ventilation duration and intensive care unit and hospital lengths of stay. In this study, we demonstrate novel temporal associations between angiopoietin dysregulation and blunt injuries, acute coagulopathy, and hemorrhagic shock. Moreover, our findings highlight the presence of endothelial activation following traumatic insults in adults that may contribute to worse clinical outcomes.

Plasma Angiopoietin-2/-1 Ratio is Elevated and Angiopoietin-2 Levels Correlate With Plasma Syndecan-1 Following Pediatric Trauma.

BACKGROUND: Angiopoietin-1 (Agpt-1) and Agpt-2 are cytokine regulators of vascular endothelial integrity. Elevated plasma Agpt-2 levels and ratios of Agpt-2:Agpt-1 are associated with adverse outcomes in adult trauma and pediatric sepsis populations. However, the behavior of the angiopoietins after pediatric trauma has not been characterized, and their relationship to endothelial glycocalyx damage, indicated by plasma syndecan-1 (Syn-1) levels, has not been established. METHODS: We performed a secondary analysis of prospectively collected data from 52 pediatric trauma patients and 12 control patients at a level one pediatric trauma center from 2013 to 2016. We measured Agpt-1, Agpt-2, and Syn-1 levels from plasma taken upon hospital arrival and 24 h after admission. Angiopoietin levels were compared to controls, and the correlation between Agpt-2 and Syn-1 was assessed. RESULTS: Plasma Agpt-1 and Agpt-2 levels are elevated immediately after pediatric trauma compared with controls. At 24 h, trauma patients demonstrated significantly elevated plasma Agpt-2:Agpt-1 ratios relative to controls due to decline of Agpt-1 levels to near that of controls. Higher 24-h Agpt-2 levels are associated with more hypoperfusion, and elevated 24-h Agpt-2:Agpt-1 ratios are associated with adverse clinical outcomes. Significant positive correlations between Agpt-2 and Syn-1 upon admission and at 24 h after injury were identified. CONCLUSION: Our findings suggest dysregulation of circulating angiopoietins after pediatric trauma that may be linked to endothelial glycocalyx injury. Larger prospective studies are needed to validate these findings and determine the relationship of Agpt-2 with other markers of endotheliopathy.

In-flight ultrasound identification of pneumothorax.

Ultrasound is a standard adjunct to the initial evaluation of injured patients in the emergency department. We sought to evaluate the ability of prehospital, in-flight thoracic ultrasound to identify pneumothorax. Non-physician aeromedical providers were trained to perform and interpret thoracic ultrasound. All adult trauma patients and adult medical patients requiring endotracheal intubation underwent both in-flight and emergency department ultrasound evaluations. Findings were documented independently and reviewed to ensure quality and accuracy. Results were compared to chest X-ray and computed tomography (CT). One hundred forty-nine patients (136 trauma/13 medical) met inclusion criteria. Mean age was 44.4 (18-94) years; 69 % were male. Mean injury severity score was 17.68 (1-75), and mean chest injury score was 2.93 (0-6) in the injured group. Twenty pneumothoraces and one mainstem intubation were identified. Sixteen pneumothoraces were correctly identified in the field. A mainstem intubation was misinterpreted. When compared to chest CT (n = 116), prehospital ultrasound had a sensitivity of 68 % (95 % confidence interval (CI) 46-85 %), a specificity of 96 % (95 % CI 90-98 %), and an overall accuracy of 91 % (95 % CI 85-95 %). In comparison, emergency department (ED) ultrasound had a sensitivity of 84 % (95 % CI 62-94 %), specificity of 98 % (95 % CI 93-99 %), and an accuracy of 96 % (95 % CI 90-98 %). The unique characteristics of the aeromedical environment render the auditory element of a reliable physical exam impractical. Thoracic ultrasonography should be utilized to augment the diagnostic capabilities of prehospital aeromedical providers.

Novel microRNA correlations in the severely injured.

PURPOSE: Severe injury initiates an inflammatory response that can perpetuate immunological dysfunction, uncontrolled inflammation, and subsequent multisystem organ failure. MicroRNAs (miRNAs) have recently been identified as regulators of this inflammatory response. Our study sought to identify the differential expression of unique miRNAs and their correlations with genes of the Toll-like receptor (TLR) pathways, and clinical parameters in the severely injured. METHODS: Fourteen trauma patients requiring transfusion were prospectively enrolled in this institutional review board-approved study. Inclusion criteria consisted of adult patients deemed clinically to be in hemorrhagic shock necessitating transfusion in the acute phase of their injury care. Peripheral blood samples were obtained after admission to the surgical intensive care unit. Expression of circulating mature miRNA from each patient, as well as from 10 healthy, age-matched controls, was determined and compared using the HiSeq 2500 sequencing system and the R software system. Gene expression of TLR signaling pathways for each patient was examined using custom gene expression polymerase chain reaction arrays. Statistical analyses were performed using general linear models and empirical Bayes methods to determine differential expression and Spearman's nonparametric correlation analysis. RESULTS: Subjects were 21-77 years old (mean, 42), 80% male, Injury Severity Score 11-43 (mean, 26), with 11 blunt and 3 penetrating injuries. Three were intubated and 5 received blood products before arrival. Base deficit upon hospital admission was 3 to 20 (mean, 9). All patients required blood transfusion secondary to blood loss sustained during injury. Survival to discharge was 93%. Controls were 27-64 years old (mean, 40) and 60% male. Sequencing analysis revealed 69 differentially expressed miRNAs (P < .05) in the severely injured. Within the differentially expressed miRNAs, there were 12 direct and 6 indirect correlations with multiple genes involved in the TLR3 and TLR4 signaling pathways. The relationships between these same miRNAs and clinical parameters were also analyzed. We discovered 4 direct correlations with base deficit and HCO3, and 7 indirect correlations involving total fresh frozen plasma transfused, base deficit, HCO3, and PaCO2 levels. CONCLUSION: Differential expression and correlations between miRNAs, genes of the TLR pathways, and clinical parameters are unique findings in the severely injured and may lead to a greater understanding of the regulation of sterile inflammation after severe injury.