British journal of anaesthesia
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The dynamic performance of arterial manometers depends upon the values of the natural frequency fo and the damping factor beta. Satisfactory reproduction of all arterial waveforms requires that fo should be greater than about 13 Hz; for an fo of 13 Hz, beta should have a value of 0.5, but, as fo increases, an increasing range of beta values is permissible. ⋯ We also investigated the performance of a commercial device, the Accudynamic, designed to allow beta to be increased without affecting fo. We found that the Accudynamic worked well, allowing acceptable performance to be obtained from the Gould Disposable transducer with catheters up to 200 cm in length.
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Neuromuscular blockade was obtained with vecuronium 108 micrograms kg-1 in 44 patients undergoing diagnostic muscle biopsy as part of an investigation of malignant hyperthermia (MH) susceptibility. At the termination of anaesthesia doxapram 1.43 mg kg-1 was given in an attempt to antagonize postoperative respiratory depression. Rectal, muscle and skin temperatures, blood lactate concentration and venous PCO2 were measured before, during and after anaesthesia. ⋯ There were no differences between the three groups in rectal or muscle temperature, blood lactate concentration or venous PCO2 at any time. Doxapram did not prevent an increase in postoperative PCO2. It is concluded that vecuronium and doxapram may be safely administered to patients susceptible to MH.