British journal of anaesthesia
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We assessed the accuracy and precision of a new near-patient testing system (Hemochron Response) by measuring prothrombin time and activated partial thromboplastin time (PT and APTT) in 50 patients undergoing cardiac surgery using cardiopulmonary bypass and comparing the results with laboratory assays. ⋯ We found good agreement in the PT and clinically acceptable levels of agreement in the APTT during the pre-bypass period. After bypass, bias became greater for both PT and APTT and the limits of agreement could be clinically unacceptable.
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Insertion of a needle into the lumbar subarachnoid space may cause damage to the spinal cord. Current techniques to identify a safe interspace have limitations. Ultrasound was investigated as a means to improve anatomical accuracy. ⋯ These results suggest that ultrasonography may be a useful adjunct to safe subarachnoid anaesthesia.
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We present a case of paradoxical air embolism in a patient undergoing neurosurgery of the posterior fossa in the sitting position. Paradoxical air embolism was detected in the descending aorta by a transoesophageal Doppler probe, which was inserted primarily for non-invasive haemodynamic monitoring. The patient suffered no serious complications of paradoxical air embolism and recovered well. We suggest that paradoxical air embolism can be detected intraoperatively not only by transoesophageal echocardiography, but also with a transoesophageal Doppler probe.
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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.