Aviat Space Envir Md
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Aviat Space Envir Md · Feb 2014
Cardiac indexes in young subjects with and without bicuspid aortic valve.
Bicuspid aortic valve (BAV) is a common congenital anomaly. The aeromedical implications of this condition are unclear. This study attempts to evaluate a possible association between BAV with or without aortic regurgitation (AR) and cardiac and aortic morphology in young healthy subjects. ⋯ BAV in young healthy subjects may influence cardiac morphology irrespective of the presence of aortic regurgitation. Aeromedical disposition for patients with BAV should be based on the presence of the condition and not on the presence of AR, considering the AR is of a mild or minimal degree.
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Aviat Space Envir Md · Jan 2014
Individual susceptibility to high altitude and immersion pulmonary edema and pulmonary lymphatics.
High-altitude pulmonary edema (HAPE) and immersion pulmonary edema (IPE) are potentially life-threatening conditions that affect athletes, including high-altitude climbers, long-distance swimmers, and underwater divers. The objectives of this study were to measure lung density (before and after exercise) and quantify the pulmonary lymphatic network in individuals susceptible and resistant to HAPE/IPE. ⋯ Subjects susceptible to HAPE/IPE had lower lung density, significantly lower lung mass, and fewer interlobular septa than subjects resistant to HAPE/IPE, suggesting a smaller pulmonary lymphatic network. The observed differences in lymphatics could represent either predisposing factors to, or sequelae of, these potentially lethal conditions.
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Aviat Space Envir Md · Jan 2014
Spine injuries related to high-performance aircraft ejections: a 9-year retrospective study.
During an aircraft ejection, the pilot is exposed to accelerations to the point of human tolerance, which may cause spinal injuries. Many nations have reported a spinal trauma rate of about 20-30%, with plain radiography as the first-line exam. Insofar as ejection seats and diagnostic imaging have improved, the objectives of this study are to describe the spine injuries among recently ejected French aircrew, to analyze the spinal imaging used, and, if necessary, to propose a better standardized radiological procedure. ⋯ New generation ejection seats remain highly traumatic for the spine. It is recommended that all ejected aircrews be assessed with computed tomography to improve the sensitivity of the screening for fractures. The risk of asymptomatic lesions makes necessary the systematic use of a stretcher for initial evacuation when possible.
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Aviat Space Envir Md · Jan 2014
Optic nerve sheath diameter measurement techniques: examination using a novel ex-vivo porcine model.
Ultrasound (U/S) and MRI measurements of the optic nerve sheath diameter (ONSD) have been proposed as intracranial pressure measurement surrogates, but these methods have not been fully evaluated or standardized. The purpose of this study was to develop an ex-vivo model for evaluating ONSD measurement techniques by comparing U/S and MRI measurements to physical measurements. ⋯ This model appears to be a valid test-bed for continued scrutiny of ONSD measurement techniques. In this model, 7T MRI was accurate and potentially useful for in-vivo measurements where direct measurements are not available. Current limitations with ultrasound imaging for ONSD measurement associated with image acquisition technique and equipment necessitate further standardization to improve its clinical utility.
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Aviat Space Envir Md · Jan 2014
Photorefractive keratectomy in young Asian aviators with low-moderate myopia.
The high prevalence of myopia among Asians led the Republic of Singapore Air Force (RSAF) to introduce photorefractive keratectomy (PRK) as a means of enlarging its pilot recruitment pool at the end of 2005. This study aims to address the efficacy and safety of PRK performed on young Asian patients with low-moderate myopia, as well as audit the RSAF's corneal refractive surgery (CRS) program. ⋯ The results of this study suggest that PRK performed within the context of a stringent and structured CRS program on young Asian eyes with low-moderate myopia is both efficacious and safe, with refractive stability achieved by 3 mo.