Aviat Space Envir Md
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Aviat Space Envir Md · Aug 2010
Randomized Controlled TrialTime of day effects on neurobehavioral performance during chronic sleep restriction.
Chronic nocturnal sleep restriction results in accumulation of neurobehavioral impairment across days. The purpose of this study was to determine whether time of day modulates the effects of sleep restriction on objective daytime performance deficits and subjective sleepiness across days of chronic sleep restriction. ⋯ This study provides evidence that the circadian system has a substantial modulatory effect on cumulative impairment from chronic sleep restriction and that it facilitates a period of relatively protected alertness in the late afternoon/early evening hours when nocturnal sleep is chronically restricted.
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Aviat Space Envir Md · Dec 2009
Randomized Controlled TrialPre-dive vibration effect on bubble formation after a 30-m dive requiring a decompression stop.
The preconditioning of divers to reduce post-dive decompression sickness (DCS) has gained increased interest in diving medical research over the last few years. The beneficial effects of physical exercise, oxygen breathing, hyperbaric exposure, heat exposure, hyperhydration, or nitroglycerin administration before the dive are only a few examples of ongoing research. In this work, we investigated the effects of pre-dive whole-body vibration on post-dive bubble formation. ⋯ As there was no observed change in FMD after vibration, we do not believe a nitric oxide mediated mechanism is involved; rather, a mechanical dislodgement or enhanced lymphatic elimination of gas nuclei is hypothesized.
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Aviat Space Envir Md · Feb 2006
Randomized Controlled TrialCerebral blood flow velocity and psychomotor performance during acute hypoxia.
The physiological effects of hypoxic environments can help determine safe limits for workers where cognitive and motor performance is important. We investigated the effects of a PIO2 of 15 kPa and 10 kPa on medial cerebral artery blood flow velocity (CBFV) and psychomotor performance. ⋯ A PIo2 of 15 kPa did not affect subject performance, and should not cause operational risk. At 10 kPa PIO2, accuracy and vigilance were slightly affected; however, the reduction in oxygenation was not great enough to cause major decrements. CBFV was not a good indicator of mental stress during hypoxia.
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Aviat Space Envir Md · Nov 2004
Randomized Controlled Trial Clinical TrialWarming by immersion or exercise affects initial cooling rate during subsequent cold water immersion.
We examined the effect of prior heating, by exercise and warm-water immersion, on core cooling rates in individuals rendered mildly hypothermic by immersion in cold water. ⋯ These results suggest that prior warming by both active and, to a greater extent, passive warming, may predispose a person to greater heat loss and to experience a larger decline in core temperature when subsequently exposed to cold water. Thus, functional time and possibly survival time could be reduced when cold water immersion is preceded by whole-body passive warming, and to a lesser degree by active warming.
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Aviat Space Envir Md · Oct 2002
Randomized Controlled Trial Clinical TrialThe impact of sertraline on psychomotor performance.
Aircrew receiving treatment for depression are grounded during treatment and follow-up observation, generally amounting to at least 1 yr. Selective serotonin re-uptake inhibitors (SSRls) offer new treatment options for depression, of which sertraline (Zoloft) has the least imposing side-effect profile. There has been considerable interest in the possibility of returning aircrew to restricted flying duties once stablized on an SSRI with resolution of depression. This study was undertaken to determine whether or not sertraline effects psychomotor performance. ⋯ While we found some of the expected side effects due to sertraline, there was no effect on psychomotor performance. These findings support the possibility of selected use in aircrew and should be helpful in the ongoing aeromedical discussion about this evolving issue.