Anaesthesia and intensive care
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Anaesth Intensive Care · May 2009
Comparative StudyEffects of propofol on calcium homeostasis in human skeletal muscle.
Malignant hyperthermia is a pharmacogenetic skeletal muscle disorder of intracellular calcium (Ca2+) homeostasis with an autosomal dominant inheritance. The objective of this study was to investigate the safety of propofol by investigating its effects on calcium homeostasis and its effect sites in human skeletal muscles. Muscle specimens were obtained from 10 individuals with predisposition to malignant hyperthermia. ⋯ A rise of Ca2+ was not seen under 100 microM propofol and the EC50 value for propofol was 274.7 +/- 33.9 microM, which is higher than the clinical levels for anaesthesia. Propofol-induced Ca2+ responses were remarkably attenuated in the presence of Ca2+ channel blocker or Ca(2+)-induced Ca+ release inhibitor compared with the results obtained with caffeine. We conclude firstly that propofol is safe for individuals with predisposition to malignant hyperthermia when it is used within the recommended clinical dosage range, and secondly that its mode of action upon ryanodine receptors is likely to be different from that of caffeine.
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Anaesth Intensive Care · May 2009
Randomized Controlled Trial Comparative StudySore throat or hoarse voice with bronchial blockers or double-lumen tubes for lung isolation: a randomised, prospective trial.
Double-lumen endotracheal tubes and bronchial blockers allow lung isolation for one-lung ventilation. Few studies, however, directly compare these devices. Further, a new endobronchial blocker (Coopdech) is available in some countries. ⋯ Compared to the double-lumen tubes the bronchial blockers took about two minutes less to position but five minutes longer for lung deflation. Surgical exposure was uniformly good across the four groups. We conclude that clinical use of the Coopdech endobronchial blocker is similar to the Arndt and Univent blockers and that all three are associated with less sore throat or hoarse voice than double-lumen tubes.
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Anaesth Intensive Care · May 2009
Randomized Controlled Trial Comparative StudyRelative efficiency of two warming devices during laparoscopic cholecystectomy.
Intraoperative hypothermia is a known consequence of general anaesthesia. Forced air warming devices are commonly used to prevent hypothermia in anaesthesia, but there are limited data on the use of radiant warming devices. Previous trials comparing the efficacy of forced air and radiant warming devices have reported discordant results. ⋯ Postoperative headache was recorded in four Sun-touch and no Warm-touch patients (P = 0.04). No difference in the efficacy of the Sun-touch warming device compared with the Warm-touch was demonstrated. Operational-mode side-effects may limit the use of the Sun-touch device.
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Anaesth Intensive Care · May 2009
Perioperative mortality risk score using pre- and postoperative risk factors in older patients.
We developed a risk score for 30-day postoperative mortality: the Perioperative Mortality risk score. We used a derivation cohort from a previous study of surgical patients aged 70 years or more at three large metropolitan teaching hospitals, using the significant risk factors for 30-day mortality from multivariate analysis. We summed the risk score for each of six factors creating an overall Perioperative Mortality score. ⋯ The Hosmer-Lemeshow test (P = 0.35) indicated good calibration in the validation cohort. The Perioperative Mortality score is straightforward and may assist progressive risk assessment and management during the perioperative period. Risk associated with surgical complexity and urgency could be added to this baseline patient factor Perioperative Mortality score.