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.