J Trauma
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Endothelin-1 (ET-1), a 21-amino-acid peptide produced by vascular endothelium, is a potent vasoconstrictor and a component of local regulation of vascular tone through its effect on underlying vascular smooth muscle. Hemorrhagic shock (HS) is characterized by compensatory regional vasoconstriction to decrease peripheral tissue perfusion and to maintain core organ perfusion. Decompensation occurs with prolonged duration of HS. In the present study, we hypothesized that systemic and vital organ tissue ET-1 concentrations would correlate with changes in systemic and vital organ perfusion associated with compensatory and decompensatory states of HS. ⋯ Decreased vital organ and peripheral tissue perfusion, a primary decompensation effect of HS, was apparent with 90 minutes of HS but not with 30 minutes, and was associated with increased vital organ tissue and plasma ET-1 concentrations. These data suggest a role for ET-1 in control mechanisms of progressive vasoconstriction that occurs with prolonged duration of HS.
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Compensation for hemorrhage and shock requires coordination of responses and sufficient physiologic reserve capacity of the cardiovascular, respiratory, renal, and neuroendocrine systems. Intake of ethanol (EtOH) is known to degrade physiologic response to stress. The purpose of this study was to investigate how acute EtOH exposure changes responses to severe blood loss, shock, and resuscitation. ⋯ Acute EtOH exposure, with blood EtOH concentration similar to legal intoxication levels, limits physiologic reserve during hemorrhagic shock and resuscitation. In survivors of shock and resuscitation, compensation is compromised and physiologic reserve is adversely affected by acute EtOH intake.
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Multicenter Study Comparative Study
Variability in computed tomography and magnetic resonance imaging in patients with cervical spine injuries.
The purpose of this study was to describe the performance of adjunctive radiologic imaging in patients with cervical spine injury. ⋯ The majority of patients with cervical spine injury undergo MRI and/or CT imaging. In clinical practice, MRI is superior at identifying soft tissue injuries, whereas CT performs better in identifying bony injuries. Cervical myelograms and tomograms are rarely obtained.