Military medicine
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Repeated blast exposures result in structural damage to the peripheral auditory system (PAS) and the central auditory system (CAS). However, it is difficult to differentiate injuries between two distinct pathways: the mechanical damage in the PAS caused by blast pressure waves transmitted through the ear and the damage in the CAS caused by blast wave impacts on the head or traumatic brain injury. This article reports a preliminary study using a 3D printed chinchilla "helmet" as a head protection device associated with the hearing protection devices (e.g., earplugs) to isolate the CAS damage from the PAS injuries under repeated blast exposures. ⋯ The biomechanical modeling and animal experiments demonstrated that this four-case study in chinchillas with helmet and hearing protection devices provides a novel methodology to investigate the blast-induced damage in the PAS and CAS.
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Prolonged field care for junctional wounds is challenging and involves limb movement to facilitate transport. No studies to date have explored the efficacy of gauze products to limit rebleeding in these scenarios. ⋯ Our findings highlight the difficulty of controlling hemorrhage from junctional wounds with hemostatic gauze in the context of prolonged field care and casualty transport. Our research can guide selection of hemorrhage control gauze when patients have prolonged field extraction or difficult transport. Our data demonstrates the frequency of junctional wound rebleeding after movement and thus the importance of frequent patient reassessment.
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With blunt and penetrating trauma to the chest, warfighters and civilians frequently suffer from punctured lung (pneumothorax) and/or bleeding into the pleural space (hemothorax). Optimal management of this condition requires the rapid placement of a chest tube to evacuate as much of the blood and air as possible. Incomplete drainage of blood leading to retained hemothorax may be the result of the final tube tip position not being in contact with the blood collections. To address this problem, we sought to develop a "steerable" chest tube that could be accurately placed or repositioned into a specific desired position in the pleural space to assure optimal drainage. An integrated infusion cannula was added for the instillation of anticoagulants to maintain tube patency, thrombolytics for clot lysis, and analgesics for pain control if required. ⋯ Initial preliminary studies on a novel steerable chest tube have demonstrated the ability to appropriately position the tube in a desired location. The addition of an extendable cannula will allow for safe clot lysis or maintained tube patency. Additional studies are planned to confirm the benefit of this device in preventing retained hemothorax.
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Tactile-based quantitative sensory assessments have proven successful in differentiating concussed vs. non-concussed individuals. One potential advantage of this methodology is that an experimental animal model can be used to obtain neurophysiological recordings of the neural activity in the somatosensory cortex evoked in response to the same tactile stimuli that are used in human sensory assessments and establish parallels between various metrics of stimulus-evoked cortical activity and perception of the stimulus attributes. ⋯ The results demonstrate suggestive similarities between neurophysiological observations made in the experimental rat mTBI model and observations made in post-concussion individuals with regard to three sensory assessment metrics (amplitude discrimination, RT, and RT variability). This is the first successful model that demonstrates that perceptual metrics obtained from human individuals are impacted by mTBI in a manner consistent with neurophysiological observations obtained from rat S1.