Anaesthesia
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Randomized Controlled Trial Clinical Trial
Effectiveness of continuous positive airway pressure to enhance pre-oxygenation in morbidly obese women.
Morbid obesity is associated with a reduction in time to desaturate during apnoea following standard pre-oxygenation and induction of anaesthesia. We have compared the effects of using 7.5 cmH2O of continuous positive airway pressure (CPAP) for pre-oxygenation with a standard technique using a Mapleson A breathing system, in 20 morbidly obese women. In a prospective, open, randomised trial, we measured the time taken to desaturate to 90% from time of giving a succinylcholine bolus as part of a rapid induction of anaesthesia. ⋯ No statistically significant difference in mean time to desaturate to 90% could be demonstrated in the CPAP group compared to the Mapleson A group (240 s and 203 s, respectively). A brief period of lower mean heart rate in the CPAP group was the only statistically significant difference in cardiovascular parameters. There was no significant difference in the volume of gastric gas after induction between groups.
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Randomized Controlled Trial Clinical Trial
Combined pre-incisional oral dextromethorphan and epidural lidocaine for postoperative pain reduction and morphine sparing: a randomised double-blind study on day-surgery patients.
The reduction in acute pain perception following dextromethorphan has previously been investigated in patients undergoing general anaesthesia. This random and double-blind study examined the effects of pre-incisional oral dextromethorphan on postoperative pain and intravenous patient-controlled morphine demand in 60 day-surgery patients undergoing lower body surgery under lidocaine (1.6%-16 ml) epidural anaesthesia after receiving placebo, 60 or 90 mg dextromethorphan, 90 min pre-operatively. Postoperative pain was scored on a visual analogue scale from 1 to 10. ⋯ Dextromethorphan-treated patients reported significantly (p < 0.05) less pain and sedation, and felt better. Patients who received dextromethorphan 90 mg had significantly (p < 0.05) lower heart and respiratory rates than those who received 60 mg. Medicated patients required half the morphine and diclofenac of placebo patients: 38% of patients who received 90 mg and 21% who received dextromethorphan 60 mg used no morphine or diclofenac whatsoever, a previously unreported finding.
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Randomized Controlled Trial Comparative Study Clinical Trial
Redistribution of halothane and sevoflurane under simulated conditions of acute airway obstruction.
Forty patients having surgery requiring muscle paralysis and tracheal intubation were randomly allocated to receive either halothane (n = 20) or sevoflurane (n = 20). Following intravenous anaesthesia and tracheal intubation, inhalation induction of anaesthesia was simulated. ⋯ The decrease in alveolar concentration of sevoflurane following 3 min of airway obstruction was found to be significantly greater than that of halothane. We conclude that even if the airway obstructs completely during inhalational induction of general anaesthesia, awakening would be faster with sevoflurane than with halothane.