Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Epidural infusion of low-dose bupivacaine and opioid in labour. Does reducing motor block increase the spontaneous delivery rate?
Labouring women were randomly allocated to receive epidural infusions during labour of either 0.125% plain bupivacaine (n = 200) or a combination of 0.0625% bupivacaine with either 2.5 micrograms.ml-1 fentanyl or 0.25 micrograms.ml-1 sufentanil (n = 199) each starting at 12 ml.h-1 and adjusted as necessary to maintain analgesia. The dose of bupivacaine, both hourly (p < 0.001) and total (p < 0.001), was significantly lower in the group receiving the combination. Motor block was significantly less common and less severe in the combination group (p < 0.001). ⋯ Maternal satisfaction with first (p < 0.001) and second stage analgesia (p < 0.001) was significantly increased in the combination group. The addition of opioid to the epidural infusion did not reduce the incidence of perineal pain. There were no significant differences between the groups in neonatal outcome or the incidence of early postnatal symptoms.
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The performance of breathing systems is tested by means of physical lung models. We describe a new lung model, allowing direct measurement of the dead space/tidal volume ratios produced by any breathing system at different fresh gas flows. The model allows a range of different patterns of spontaneous respiration to be studied. Although rebreathing is measured by capnography, the design ensures that the results are unaffected by changes in carbon dioxide inflow, or even calibration drift in the capnograph.
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A laboratory study of a new circle system is presented. The inspiratory limb encloses a coaxial tube, delivering fresh gas close to the patient, immediately upstream of the inspiratory one-way valve. ⋯ This is markedly improved by the new system. The advantages of the system are largely independent of respiratory pattern.
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Randomized Controlled Trial Comparative Study Clinical Trial
Tropisetron and metoclopramide in the prevention of postoperative nausea and vomiting. A comparative, placebo controlled study in patients undergoing ophthalmic surgery.
One hundred and twenty patients undergoing elective ophthalmic surgery under general anaesthesia were investigated in a randomised, double-blind, parallel group study of postoperative nausea and vomiting. Patients received tropisetron 0.1 mg.kg-1, metoclopramide 0.25 mg.kg-1 or placebo given at the end of anaesthesia. ⋯ The patients in the placebo group required rescue antiemesis more often in the postanaesthesia care unit. Our results suggest that tropisetron may not be suitable as a routine, primary therapy for the prevention of postoperative nausea and vomiting.
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Comparative Study Clinical Trial Controlled Clinical Trial
The influence of cold on the recovery of three neuromuscular blocking agents in man.
The Arrhenius hypothesis suggests that change in temperature has a less marked effect on the rate of physical processes than on biological reactions. We have investigated the process underlying recovery from neuromuscular block in man by studying the effect of cooling on the rate of recovery from depolarising and non-depolarising block. Vecuronium, rocuronium and decamethonium (C10) neuromuscular block were investigated using the isolated forearm technique on awake human volunteers. ⋯ The mean Q10 (the anticipated change in rate of a reaction across of 10 degrees C temperature gradient) of the rate of recovery for vecuronium was 3.21, rocuronium 2.86 and decamethonium 1.29. This suggests a different process in the recovery of these two types of drug. According to the Arrhenius hypothesis this would suggest that the recovery from non-depolarising drugs is likely to involve a biochemical mechanism and that recovery from decamethonium is controlled by a physical process.