British journal of anaesthesia
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Circulatory response to hypoventilation is aimed at eliminating carbon dioxide and maintaining oxygen delivery (DO(2)) by increasing cardiac output (CO). The hypothesis that this increase is more pronounced with xenon than with isoflurane anaesthesia was tested in pigs. ⋯ The cardiovascular effects observed in this model of moderate hypoventilation were sufficient to maintain DO(2). Although the haemodynamic response appeared more pronounced with xenon, differences were not clinically relevant. An increase in FAC with xenon is attributed to its lack of negative inotropic effects.
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Comparative Study
Pressure recording analytical method (PRAM) for measurement of cardiac output during various haemodynamic states.
Cardiac output (CO) can be measured using the pressure recording analytical method (PRAM), which is a new, less invasive technique allowing beat-by-beat stroke volume monitoring from the pressure signals recorded in femoral or radial arteries. ⋯ In a porcine model we have demonstrated accuracy of PRAM during various haemodynamic states. PRAM is a reliable tool to detect changes in cardiac output in pigs and has ability as a basic research tool.
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Comparative Study
Preservation of static and dynamic cerebral autoregulation after mild hypothermic cardiopulmonary bypass.
Dysfunction of cerebral autoregulation might contribute to neurological morbidity after cardiac surgery. In this study, our aim was to assess the preservation of cerebral autoregulation after cardiac surgery involving cardiopulmonary bypass (CPB). ⋯ Autoregulation of cerebral blood flow remains preserved after mild hypothermic CPB.
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One-lung ventilation-related hypoxaemia (OLV-RH) can occur in patients with healthy lungs. In this case, PEEP frequently improves oxygenation. The aim of this study was to determine, in a healthy lung model of OLV, whether the increase in PEEP improved oxygenation and whether the mechanisms involved include both inspiratory lung recruitment and an end-expiratory lung volume increase. Since inhaled nitric oxide (iNO) may have a synergistic effect on oxygenation in the case of PEEP-induced recruitment, their association was also tested. ⋯ In a healthy porcine lung model of OLV-RH, moderate PEEP can improve oxygenation. This effect implies both expiratory and inspiratory pulmonary recruitment. Co-administration of 4 p.p.m. iNO was ineffective.
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Neuropathic pain sometimes needs invasive pain therapy. We present the case of a patient with cancer-related neuropathic pain untreatable with conventional pain therapy after tumour-embolization. ⋯ Plasma concentrations of S(+)-ketamine were measured regularly throughout the treatment. Continuous i.t. administration of S(+)-ketamine over a period of 3 months demonstrated low plasma levels and no unwanted side-effects.