British journal of anaesthesia
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The relationship between the larynx and the subclavian arteries was studied in a series of magnetic resonance images (MRIs) from 50 patients without neck pathology. ⋯ When performing a percutaneous tracheostomy, a 'safe' distance between the incision site and subclavian artery cannot be assumed or reliably predicted from the neck length.
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Halothane shortens ventricular action potential duration (APD), as a consequence of its inhibitory effects on a variety of membrane currents, an effect that is greater in sub-endocardial than sub-epicardial myocytes. In hypertrophied ventricle, APD is prolonged as a consequence of electrical remodelling. In this study, we compared the effects of halothane on transmural APD in myocytes from normal and hypertrophied ventricle. ⋯ In the SHR, hypertrophic remodelling was not homogeneous; APD(-50 mV) was prolonged to a greater extent in sub-endocardial than sub-epicardial cells. Halothane reduced APD to a greater extent in sub-endocardium than sub-epicardium in both WKY and SHR but this effect was larger proportionately in SHR myocytes. The transmural gradient of repolarization was reduced in WKY and effectively abolished in SHR by halothane, which might disturb normal ventricular repolarization.
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Comparative Study
Pharmacological effects of intravenous melatonin: comparative studies with thiopental and propofol.
Possible utility of high-dose i.v. melatonin as an anaesthetic adjuvant has not been studied. This study compared its effects with thiopental and propofol. ⋯ I.V. melatonin can exert hypnotic effects similar to those observed with thiopental and propofol. Melatonin exhibited significant antinociceptive effects but was less effective in abolishing the response to tail clamping.