Anaesthesia
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A technique of balanced anaesthesia involving propofol infusions and a rapidly metabolised opioid offers advantages over traditional anaesthetic techniques for eye surgery. The most appropriate mode of delivery of propofol is by a 'Diprifusor' target controlled infusion system. This paper discusses the use of a 'Diprifusor' target controlled infusion system for eye surgery. Published data are reviewed and the results of a retrospective analysis of 138 successive eye surgery patients are presented.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effect of EMLA and semicircular subcutaneous anaesthesia in the prevention of tourniquet pain during plexus block anaesthesia of the arm.
In 54 patients who were to undergo surgery of the upper extremity in plexus block anaesthesia the effect of 5 g EMLA (group E) on tourniquet pain was examined and compared with the effect of a semicircular subcutaneous anaesthesia using 10 ml 0.25% bupivacaine (group B) or 10 ml 1% mepivacaine (group M). Among the patients with satisfactory brachial plexus analgesia allowing for surgery (n = 51), the incidence of tourniquet pain was not significantly different between groups E, M and B. Notably, there was no significant difference in the time of tourniquet application. We conclude that topical application of EMLA is as effective as a semicircular subcutaneous anaesthesia with mepivacaine or bupivacaine in the prevention of tourniquet pain during brachial plexus anaesthesia.
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The 'Diprifusor' target controlled infusion system has been developed as a standardised infusion system for the administration of propofol by target controlled infusion. A preferred set of pharmacokinetic parameters for propofol was selected using computer simulation of a known infusion scheme with pharmacokinetic parameters described in published literature. The selected model was included in a 'Diprifusor' module that was interfaced with, and later incorporated into, a computer-compatible infusion pump. ⋯ Standardisation of the delivery performance (+/- 5%) of commercial systems has been achieved with a laboratory performance specification. Clinical studies indicate that the actual blood concentrations achieved were about 16% greater than the calculated values displayed by the system. In an individual patient, titration of the target concentration is required in the same manner as an anaesthetic vapouriser is adjusted to obtain a specific pharmacodynamic effect.
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Comparative Study Clinical Trial Controlled Clinical Trial
Evaluation of the HemoCue for measuring intra-operative haemoglobin concentrations: a comparison with the Coulter Max-M.
We compared haemoglobin concentration values obtained using a portable haemoglobinometer, the HemoCue, in the operating theatre with the results obtained by the Coulter Max-M in the laboratory. Haemoglobin concentrations were measured on 52 arterial blood samples obtained from 13 patients during aortic surgery, in theatre with the HemoCue and again by the Coulter Max-M. Twenty routine samples from the laboratory were also analysed by both methods. ⋯ The coefficients of repeatability of the 20 samples analysed in duplicate on each device were 0.26 g.dl-1 and 0.33 g.dl-1, respectively. The coefficients of variance were 0.74% (HemoCue) and 0.93% (Coulter). With adequate training and monitoring, the HemoCue provides comparable haemoglobin results for near-patient testing in theatre.
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Randomized Controlled Trial Comparative Study Clinical Trial
Postoperative respiratory function in children after abdominal surgery. A comparison of epidural and intramuscular morphine analgesia.
Thirty children undergoing urological and abdominal surgery were entered into a randomised trial comparing the effects of epidural and intramuscular morphine on postoperative respiratory function. The forced vital capacity and the forced expired volume in 1 s were measured before and 6 h after surgery and on each of the following seven days. Significant decreases (p < 0.01) in forced vital capacity and forced expired volume in 1 s were seen after surgery. ⋯ There were no statistically significant differences between the two groups during the study with respect to forced vital capacity and forced expired volume in 1 s. The quality of analgesia was better in the epidural morphine group than in the intramuscular morphine group. The incomplete recovery of pulmonary function suggests that pain is not the only cause of postoperative respiratory changes in these patients.