Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 1995
Randomized Controlled Trial Clinical TrialAdenosine increases the cutaneous heat pain threshold in healthy volunteers.
Adenosine is an endogenously produced substance which in animal experiments exerts anti-nociceptive effects. In humans, algesic effects have been presented following exogenous adenosine administration. A recent study on anaesthetized patients, however, suggested an anti-nociceptive effect during i.v. adenosine. ⋯ Furthermore, warm and cold perception thresholds were not influenced significantly by any drug. Adenosine, morphine and ketamine produced well-known side-effects but of a mild intensity not necessitating any treatment. The present results show that i.v. adenosine can provide a modest but selective increase of cutaneous heat pain thresholds, suggesting a pain-reducing capacity of adenosine in humans.
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Acta Anaesthesiol Scand · Aug 1995
Randomized Controlled Trial Clinical TrialRespiratory changes during treatment of postoperative pain with high dose transdermal fentanyl.
This study made a longterm (72 hours) evaluation of the efficacy and possible side-effects of transdermal delivery of fentanyl (TTS-system) for post-operative pain relief. The study was double-blind, placebo-controlled with either a TTS-system delivering fentanyl 100 micrograms.h-1 and rescue analgesic on demand or a placebo system and analgesic on demand. Analgesic consumption, pain, general satisfaction, respiratory rate, and levels of SpO2 and tcCO2 (pulse oximetry and transcutaneous CO2 measuring) were evaluated. ⋯ These findings terminated the study. The 100 micrograms transdermal fentanyl system is agreeable to the patients, but apparently too potent for routine postoperative pain relief due to a risk of respiratory depression. Respiratory frequency can not be relied upon as sole indicator of insufficient respiration.
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Acta Anaesthesiol Scand · Aug 1995
Randomized Controlled Trial Clinical TrialPerioperative monitoring of neuromuscular transmission using acceleromyography prevents residual neuromuscular block following pancuronium.
The frequency of postoperative residual neuromuscular block following the use of the long-acting non-depolarizing muscle relaxants is high, and manual evaluation of the response to nerve stimulation does not eliminate the problem. In this prospective and randomized study we evaluated the hypothesis that perioperative use of acceleromyography would allow for a more rational and precise administration of the long-acting muscle relaxant pancuronium resulting in a decrease in 1) the incidence and severity of postoperative residual neuromuscular block, 2) the amount of pancuronium used, and 3) the time from end of surgery to tracheal extubation. Forty adult patients were randomized into two groups, one managed without the use of a nerve stimulator, the other monitored using train-of-four (TOF) nerve stimulation and acceleromyography. ⋯ In the patients managed without a nerve stimulator, the trachea was extubated when the anaesthetist judged the neuromuscular function to have recovered adequately for upper airway protection and spontaneous ventilation. In patients monitored with acceleromyography, the trachea was extubated when the TOF ratio was above 0.70. In all 40 patients, TOF ratio was measured using mechanomyography immediately after tracheal extubation and the patients were evaluated for clinical signs of residual neuromuscular block.(ABSTRACT TRUNCATED AT 250 WORDS)
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Acta Anaesthesiol Scand · Aug 1995
Comparative StudyComparison of vascular effects of ropivacaine and lidocaine on isolated rings of human arteries.
Ropivacaine is a new local anaesthetic agent. Previous animal studies have indicated that vasoconstrictor effects are elicited by ropivacaine in vitro and subcutaneously and that it produces blanching of the skin if injected subcutaneously in humans. Lidocaine is a widely used local anaesthetic reported to exert a biphasic effect on the microvasculature with contraction at low concentrations and relaxation at high concentrations. ⋯ No statistically significant differences in contractile or relaxing effects were seen between the two drugs. Removal of the endothelium did not significantly affect contractile activity. In this study of human mammary artery preparations, ropivacaine is not a stronger vasoconstrictor than lidocaine.
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Acta Anaesthesiol Scand · Aug 1995
A new method of using gas exchange measurements for the noninvasive determination of cardiac output: clinical experiences in adults following cardiac surgery.
New mathematical algorithms have been applied to a computer controlled closed breathing circuit system for non-invasive measurement of cardiac output (COniv). This system has been described in an animal study. Forty patients were studied 5 and 18 hours after cardiac surgery using the thermodilution technique as the reference (COtd). ⋯ The reproducibility of COniv was 0.03 l/min and for COtd -0.03 l/min with a standard deviation of the difference being 0.35 l/min for COniv and 0.31 l/min for COtd. In awake, but sedated extubated patients, the method proved unsatisfactory on account for uneven tidal volumes and difficulties with leakage around the mouth piece. We conclude that this new technique provides reliable and reproducible measures of cardiac output in sedated, ventilated patients.