British journal of anaesthesia
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Sevoflurane is widely used in anaesthetic protocols for patients undergoing surgical procedures. However, there are no reports on the influence of sepsis on minimum alveolar concentration of sevoflurane (MAC(SEV)) in animals or in humans. The aim of this study was to test the hypothesis that sepsis could alter the MAC(SEV) in a normotensive septic pig model. ⋯ Significant increases in mean artery pulmonary pressure, filling, epinephrine and vascular pulmonary resistances occurred in the sepsis group. MAC(SEV) for the saline group was 2.4% [95% confidence interval (CI) 2.1-2.55%] and the MAC(SEV) for the sepsis group was 1.35% (95% CI 1.2-1.45%, P<0.05). These data indicate that MAC(SEV) is significantly decreased in this normotensive septic pig model.
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Randomized Controlled Trial Clinical Trial
Clonidine decreases propofol requirements during anaesthesia: effect on bispectral index.
Assessment of the effect of clonidine on depth of anaesthesia is difficult because clonidine combines analgesic, sedative and direct haemodynamic effects. We thus evaluated the influence of clonidine on the bispectral index (BIS) and its potential dose-sparing effect on propofol. After induction of anaesthesia with target-controlled infusion of propofol and obtaining an unchanged bispectral index (pre-BIS), clonidine 4 microg kg(-1) or placebo was administered randomly to 50 patients in a double-blind manner. ⋯ Administration of clonidine resulted in a decrease in the BIS from 45 (SD 4) to 40 (6) (P<0.001), which allowed a reduction of propofol target concentration from 3.3 (0.6) to 2.7 (0.7) microg ml(-1) (P<0.001) and measured propofol concentration from 2.9 (0.6) to 2.5 (0.7) kg ml(-1) (P=0.009) in order to maintain the pre-BIS value. During subsequent surgery, propofol requirements were reduced by 20% (P=0.002) in the clonidine group and a similar amount of remifentanil was used in each group. The increase in anaesthetic depth given by clonidine can therefore be measured with bispectral EEG analysis and allows reduction of the propofol dose to achieve a specific depth of anaesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Double-blind comparison of ropivacaine 7.5 mg ml(-1) with bupivacaine 5 mg ml(-1) for sciatic nerve block.
Two groups of 12 patients had a sciatic nerve block performed with 20 ml of either ropivacaine 7.5 mg ml(-1) or bupivacaine 5 mg ml(-1). There was no statistically significant difference in the mean time to onset of complete anaesthesia of the foot or to first request for post-operative analgesia. ⋯ Although there was no statistically significant difference in the mean time to peak plasma concentrations the mean peak concentration of ropivacaine was significantly higher than that of bupivacaine. There were no signs of systemic local anaesthetic toxicity in any patient in either group.
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Patients suspected of anaphylaxis during anaesthesia have been referred to the senior author's clinic since 1974 for investigation. Since release of rocuronium on to the worldwide market, concern has been expressed about its propensity to cause anaphylaxis. ⋯ The incidence of rocuronium allergy in New South Wales, Australia has risen in parallel with sales, while there has been an associated fall in reactions to other neuromuscular blocking drugs. Data from intradermal testing suggested that rocuronium is intermediate in its propensity to cause allergy in known relaxant reactors compared with low-risk agents (e.g. pancuronium, vecuronium) and higher-risk agents (e.g. alcuronium, succinylcholine).