Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 1997
Randomized Controlled Trial Clinical TrialAnalgesic and psychomotor effects of thiopental at subanesthetic concentrations in human volunteers.
Studies of the effects of barbiturates on the modulation of pain have produced mixed results. In a prospective, double-blind, randomized, placebo-controlled trial, we studied the effects of thiopental at presumed steady-state, "conscious sedation" levels on cold-pressor-induced pain in 12 healthy volunteers. ⋯ Our laboratory results do not support the long-held belief that barbiturates are "antanalgesic" or hyperalgesic, at least for cold-pressor-induced pain.
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Acta Anaesthesiol Scand · Aug 1997
Randomized Controlled Trial Clinical TrialMinimum alveolar concentration of sevoflurane for tracheal extubation in children.
One advantage of tracheal extubation during deep anaesthesia is that respiratory complications are reduced. Sevoflurane is a suitable anaesthetic agent for children. This study was conducted to determine the minimum alveolar concentration of sevoflurane required to prevent cough or movement during and after tracheal extubation (MACextubation). ⋯ Tracheal extubation in 50% of anaesthetized children age 2-10 yr may be accomplished without coughing or moving at 2.3% end-tidal concentration of sevoflurane.
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Acta Anaesthesiol Scand · Aug 1997
Randomized Controlled Trial Clinical TrialEffects of halothane and isoflurane on left ventricular diastolic function during surgical stress in patients with coronary artery disease.
The effects of inhalation anesthetics on left ventricular (LV) systolic function are well documented, while the effects of these agents on LV diastolic function have mainly been evaluated in animal studies, with conflicting results. ⋯ Both halothane and isoflurane impair early diastolic relaxation in patients with CAD, when used to control intraoperative surgical stress. In contrast to halothane, isoflurane induced a change in the LVED P/A relationship, suggestive of an increased LVED stiffness.
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Acta Anaesthesiol Scand · Aug 1997
Calculated versus measured oxygen consumption during and after cardiac surgery. Is it possible to estimate lung oxygen consumption?
Lung tissue is metabolically active and consumes oxygen. The oxygen content difference between arterial and mixed venous blood does not include the effect of pulmonary tissue oxygen uptake. Thus, oxygen consumption (VO2) of the lung should be reflected as a difference between VO2 measured by gas exchange and VO2 derived by the Fick principle. The purpose of this study was to measure in clinical conditions this difference (taken to represent the VO2 of the lung), and to evaluate the sources of error in lung VO2 estimation. ⋯ A constant difference between measured and calculated VO2 can be detected in carefully controlled clinical conditions. The difference between the two methods is due to both lung oxygen consumption and errors in the measurement of VO2 thermodilution cardiac output, haemoglobin and blood oxygen contents. We suggest that the perioperative changes of the VO2-difference are due not only to variation of the measurements but also to changes in lung metabolic activity.