Anaesthesia
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Randomized Controlled Trial Clinical Trial
Prevention of needle-stick injury. Efficacy of a safeguarded intravenous cannula.
One possible method of reducing the incidence of needle-stick injury is to use needles with safeguard mechanisms. The needle of the Insyte AutoGuard intravenous cannula can be retracted into the safety barrel. One hundred patients were randomly allocated to receive either an 18-gauge conventional Insyte intravenous cannula (group C) or the AutoGuard cannula (group AG) to assess the ease of use and efficacy of the AutoGuard device. ⋯ Handling the withdrawn needle was judged significantly safer in group AG than in group C (p < 0.001). Blood contamination often occurred where a withdrawn needle was placed in group C, whereas no blood stain was detected in any case in group AG (p < 0.001). The AutoGuard cannula provides safer handling of a withdrawn needle without reducing its ease of insertion.
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Randomized Controlled Trial Comparative Study Clinical Trial
Conditions for laryngeal mask insertion. A comparison of propofol versus sevoflurane with or without alfentanil.
One hundred unpremedicated ASA 1 or 2 patients scheduled for elective surgery were divided equally into four groups and recruited into this prospective, randomised parallel groups study. Induction was with propofol 2.5 mg.kg-1 or vital-capacity breath induction with sevoflurane (> 7% in the inspiratory gas) in 65% nitrous oxide and oxygen, or gaseous induction with sevoflurane plus alfentanil 5 micrograms.kg-1 or propofol 2.5 mg.kg-1 and alfentanil 5 micrograms.kg-1. ⋯ Excellent or satisfactory conditions were observed in 25 (100%) patients in the sevoflurane-alfentanil group, 22 (88%) in the propofol-alfentanil group and 16 (64%) patients each in the propofol and sevoflurane groups (p < 0.001). A sevoflurane-alfentanil combination provides better conditions for laryngeal mask insertion when compared with sevoflurane alone, or a propofol-alfentanil combination.
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The decision as to whether prophylaxis against postoperative nausea and vomiting is better than treatment of established postoperative nausea and vomiting could be made on the basis of cost-effectiveness. The cost-effectiveness of ondansetron was calculated using data from published quantitative systematic reviews of randomised trials. Milligrams of ondansetron required to achieve a desired endpoint were chosen as a cost unit. ⋯ Fewer patients experience any postoperative nausea and vomiting symptoms with prophylaxis compared with treatment. But prophylaxis is only marginally more effective than treatment, and treatment of established postoperative nausea and vomiting with effective doses (i.e. 1 or 4 mg) is more cost-effective and safer than prophylaxis with effective doses (i.e. 4 or 8 mg). Reasons for this are the selective treatment of patients who actually need treatment, the high success rate with a lowest dose tested (1 mg) in established postoperative nausea and vomiting, and the disappointing antinausea effect of prophylactic ondansetron even at an eight-fold higher dose.
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Comparative Study
Comparison of supine and upright positions on autonomic nervous activity in late pregnancy: the role of aortocaval compression.
In order to understand the effect of aortocaval compression on autonomic nervous activity, we compared the effects of supine and upright postures on measures of heart rate variability in late pregnancy. Thirty-two women in late pregnancy and 23 nonpregnant age-matched women were studied. Both time and frequency domain heart rate variability measures were compared between the supine and upright positions, and between pregnant women and controls. ⋯ In contrast, the percentage change in normalised high-frequency power was decreased and the percentage change in low- to high-frequency power ratio was increased in pregnant women when the position was changed from upright to supine. These results indicate that the vagal enhancing effect seen in normal subjects when changing position from upright to supine was reversed in women in late pregnancy. Aortocaval compression in the supine position in pregnant women might be responsible for this reversal in the autonomic response to lying down.
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In December 1996, the Association of Anaesthetists of Great Britain and Ireland produced a series of recommendations outlining the safe conduct of interhospital transfers for patients with acute head injuries. We assessed the current ability of UK hospitals to implement these recommendations and opinions on the formation of transfer teams, using a postal questionnaire. This was sent to all Royal College of Anaesthetists tutors, 268 of whom replied (94% response rate). ⋯ As a result of the anaesthetist's involvement in the transfer, emergency operating could be delayed in 169 (81.3%) hospitals. One hundred and fifty-eight (76%) respondents thought that the formation of transfer teams to transport critically ill patients would have some merit. Hospitals are responding to the published guidelines, but improvements are still needed in levels of equipment and insurance provision, along with the identification of a designated consultant at each hospital with responsibility for transfers.