Anaesthesia
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A randomised, prospective trial was conducted to assess the efficacy of various means of alleviating the pain of subcutaneous lidocaine infiltration. One hundred and twenty-two patients were randomly allocated to different groups to receive buffered lidocaine 1%, warmed lidocaine 1% or infiltration by the counter-irritation technique. A visual analogue pain score was recorded at different stages of cannulation and results showed that pain scores were significantly lower in the group receiving buffered lidocaine 1% (p < 0.02) and in the counter-irritation group (p < 0.05). Thus buffering lidocaine 1% and administration of lidocaine 1% by the counter-irritation technique is effective in relieving the pain of lidocaine infiltration.
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Randomized Controlled Trial Clinical Trial
A comparison of patient-controlled epidural analgesia following gynaecological surgery with and without a background infusion.
We conducted a randomised, controlled study to investigate the effect of adding a background infusion to patient-controlled epidural analgesia for postoperative pain relief. Forty-two patients scheduled for elective lower abdominal gynaecological surgery received patient-controlled epidural analgesia postoperatively using a mixture of 0.2% ropivacaine and 2.0 microg x ml-1 fentanyl. Patients in group B (n = 20) were given a background infusion of 5 ml x h-1, whereas those in group N (n = 21) were not. ⋯ Patients in group B had a higher total drug consumption (156.8 +/- 34.8 ml vs. 89.5 +/- 41.0 ml; p < 0.0001) and incidence of side-effects (71.4% vs. 30.0%; p = 0.007). Motor blockade during the 24-h study period was also greater in group B (median [range] area under the curve 7.5 [0.0-39.0] h vs. 3.0 [0.0-36.0] h; p = 0.035). We conclude that the addition of a background infusion to patient-controlled epidural anaesthesia is not recommended as it confers no additional benefits.
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A new practical classification of laryngeal view at laryngoscopy is presented and evaluated. The best laryngeal view obtained with or without anterior laryngeal pressure is recorded. The laryngeal view is easy (E) when the laryngeal inlet is visible. ⋯ The new classification stratified increasing difficulty with intubation (time for intubation longer and increasingly complex methods needed) better than the Cormack and Lehane classification. The new classification is as sensitive and more specific than the Cormack and Lehane classification in predicting difficult intubation. It is also more sensitive and more specific in predicting easy intubation.
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We describe the target-controlled administration of propofol and remifentanil, combined with monitoring of the bispectral index, during an awake craniotomy for removal of a left temporo-parietal tumour near the motor speech centre. Target concentrations of the two drugs were adjusted according to the patient's responses to painful stimuli and surgical events, and the need for speech testing. ⋯ Although the bispectral index was not used as a guide for the administration of the drugs, its value correlated better with the patient's responsiveness than did the predicted effect-site concentrations of propofol. Side-effects, comprising hypotension, respiratory depression and airway obstruction, were related to rapid increases in drug infusion rates and were easily managed.
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Cricoid pressure is used to protect the lungs from contamination with gastric contents during tracheal intubation. We studied the effect of cricoid pressure applied with a yoke on 30 anaesthetised patients examined fibreoptically through a laryngeal mask airway. We assessed the effect of 20, 30 and 44 N on the internal appearance of the cricoid and vocal cords. ⋯ Associated difficulty in ventilation was present in 15 patients (50%) and 18/30 (60%) had vocal cord closure with associated difficult ventilation, at forces up to 44 N. Cricoid occlusion was unrelated to age and body mass index but females were at greater risk. Orthodox values of cricoid pressure, applied with a yoke, may produce obstruction at the level of the cricoid cartilage or vocal cords, with implications for tracheal intubation and ventilation by mask.