Aviat Space Envir Md
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Aviat Space Envir Md · Apr 2010
ReviewExpansion of postoperative pneumothorax and pneumomediastinum: determining when it is safe to fly.
The possibility of expansion of pneumothorax (PTX) and/or pneumomediastinum (PMED) during commercial flights makes air travel after thoracic surgery particularly worrisome. Guidelines from the Aerospace Medical Association (AsMA) suggest delaying air travel 2 to 3 wk following uncomplicated thoracic surgery and 1 wk following radiographic resolution of PTX; they also state that PTX is an "absolute contraindication" to air travel. However, both AsMA guidelines and thoracic surgeons' recommendations for postoperative air travel require further examination. ⋯ A wide variability exists among thoracic surgeons regarding their recommendations for air travel by patients with postoperative PTX and/or PMED. Both AsMA guidelines and surgeons' recommendations should rely more on scientific evidence. Studies of PTX and PMED expansion during simulated flight are needed to develop better guidelines.
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Aviat Space Envir Md · Apr 2010
Normoxic and hypoxic performance following 4 weeks of normobaric hypoxic training.
Although training in hypoxia has been suggested to improve sea level and altitude performance, most studies have only evaluated its effect on maximal aerobic capacity in either normoxia or hypoxia. The present study evaluated the effect of a live low-train high training regimen on both normoxic and hypoxic endurance performance and aerobic capacity. ⋯ The hypoxic training regimen used in the present study had no significant effect on altitude and sea level performance.
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Aviat Space Envir Md · Feb 2010
Exertional heat illness among overweight U.S. Army recruits in basic training.
Heat illness has not declined in the U.S. military despite preventive measures. The increase in overweight recruits entering the U.S. military may lead to an increase in heat-related events. This study compares the risk of heat illness among U.S. Army recruits who exceeded body fat standards at accession to those who met standards. ⋯ Although there were few heat illness events, the results indicate a significantly increased risk of heat illness and outpatient utilization among male recruits with excess body fat. It was estimated that approximately 70% of the relative risk for heat illnesses in men with excess body fat during basic training was associated with exceeding body fat standards. These findings may have implications for military accession and training.
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Aviat Space Envir Md · Feb 2010
Ectopy in trauma patients: cautions for use of heart period variability in medical monitoring.
Heart period variability measurements have been proposed for use in early prediction of mortality or the requirement for lifesaving interventions in trauma patients. However, the presence of even one ectopic beat (EB) and/or electromechanical noise compromises the accurate calculation of heart period variability. We tested the hypothesis that ECGs from trauma patients exhibit a greater frequency of EBs than healthy human research subjects. ⋯ A significant number of EBs occur in healthy subjects both at rest and during progressive reduction in central blood volume, and trauma is associated with a near doubling of this incidence. As both EBs ' and noise result in invalid heart period variability calculations, these metrics as currently calculated could not be used in approximately 36% of trauma patients. The limited use in nearly two of every five trauma patients indicate that it is unlikely that continuous heart period variability measurements could substantially improve pre-hospital or emergency room decision-support in trauma.