British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effects of ketamine-midazolam with those of fentanyl-midazolam on cortical somatosensory evoked potentials during major spine surgery.
Cortical somatosensory evoked potentials (CSEP) allow monitoring of spinal cord function during surgery. Ketamine has been shown to enhance CSEP amplitude, but there is no previous study comparing its effects with those of other anaesthetic regimens. Therefore, we have compared the effects of ketamine with those of fentanyl, both combined with midazolam, on CSEP monitoring during major spine surgery. ⋯ Nevertheless, we did not observe any significant differences in amplitudes or latencies between the two groups. The delay in obtaining the first voluntary postoperative motor response was significantly greater in the ketamine group (170 (54) vs 55 (17) min, P < 0.01). Both ketamine and fentanyl allowed us to obtain reliable CSEP during major spine surgery, and there were no significant difference between these two anaesthetic regimens for CSEP monitoring, but a longer delay for voluntary postoperative motor assessment was observed in the ketamine group.
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Randomized Controlled Trial Clinical Trial
Intrathecal infusion of bupivacaine with or without morphine for postoperative analgesia after hip and knee arthroplasty.
Postoperative pain after major orthopaedic operations can be controlled by continuous intrathecal administration of opioids or local anaesthetics. Effective intrathecal analgesia can be achieved through synergism of low doses of the two analgesic drugs and, possibly, less drug-related adverse effects. Therefore, we have evaluated the usefulness of a combined low-dose bupivacaine and morphine infusion in patients undergoing hip and knee arthroplasty. ⋯ One patient in the same group had minor decubitus on the heel of the operated leg, probably because of prolonged motor block. We conclude that intrathecal infusion of a combination of bupivacaine 1 mg h-1 and morphine 8 micrograms h-1 produced adequate postoperative analgesia. Unfortunately, postoperative nausea and vomiting was a frequent disturbing adverse effect.
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We have compared the effects of progressive (30% and 60%) in vitro haemodilution with hydroxyethyl starch (HES), gelatin (GEL) and albumin (ALB) with haemodilution using 0.9% saline in 96 patients by thrombelastography. Haemodilution with HES, GEL and ALB significantly (P < 0.05) compromised coagulation time (k), angle alpha and maximal amplitude (MA), with HES having the most negative effect at 30% and 60% haemodilution (P < 0.05). ⋯ Prolongation of reaction time (r) was found for HES at 30% and 60% haemodilution and for ALB at 60% haemodilution and an increase in clot lysis by HES, GEL and ALB became evident. We conclude that HES, GEL and ALB compromised blood coagulation, while the maximum effect was found with HES.
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The processed electroencephalogram (pEEG) was monitored in eight patients undergoing gynaecological laparotomy under combined extradural and nitrous oxide-isoflurane anaesthesia. Pre-incisional mean spectral edge frequency 95 percentile (SEF95) and median frequency (MF) were 11.67 (SD 1.63) Hz and 3.74 (0.24) Hz, respectively. ⋯ After introduction of extradural analgesia, these variables returned to pre-incisional values (SEF95 11.65 (1.73); MF 4.02 (0.41)). Reduction of end-tidal isoflurane from 1.0% to 0.5% after extradural analgesia did not cause significant pEEG changes. pEEG may assist anaesthetists to recognize adequacy of combined general-extradural anaesthesia.