Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Prevention of hypotension during spinal anaesthesia for caesarean section: ephedrine infusion versus fluid preload.
We compared the efficacy of prophylactic ephedrine infusion over fluid preloading in prevention of maternal hypotension during spinal anaesthesia for Caesarean section. Forty-six women undergoing elective Caesarean section at term were allocated randomly to receive either intravenous fluid preloading with Hartmann's solution 20 ml.kg-1 (fluid group) or prophylactic intravenous ephedrine 0.25 mg.kg-1 (ephedrine group). Moderate hypotension was defined as > or = 20% reduction in systolic blood pressure and severe hypotension as > or = 30% reduction in systolic blood pressure. ⋯ Mean umbilical venous pH was higher in the ephedrine group than in the fluid group (7.33 vs. 7.29, p = 0.02) and the number of patients shivering was lower in the ephedrine group (2 vs. 9, p = 0.02). No difference was found between pre- and postspinal uterine artery pulsatility indices in either group. We conclude that prophylactic ephedrine infusion alone is at least as good as fluid preload alone in combating the hypotension associated with spinal anaesthesia for Caesarean section.
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Comparative Study Clinical Trial Controlled Clinical Trial
A comparison of intercuff and single cuff techniques of intravenous regional anaesthesia using 0.5% prilocaine mixed with technetium 99m-labelled BRIDA.
Intravenous regional anaesthesia of the upper limb is a widely used technique first described by Bier in 1908. The exact site of action of injected local anaesthetic has not been determined. We have performed intravenous regional anaesthesia on volunteers using prilocaine mixed with technetium 99m-labelled 2,4,6 trimethyl-3-bromo iminodiacetic acid. ⋯ The onset of action was similar for both techniques. The local anaesthetic was mainly retained in the antecubital fossa in both techniques but in the 'normal' technique, the local anaesthetic subsequently showed some retrograde spread. This would suggest that the main site of action of local anaesthetic used for intravenous regional anaesthesia is the larger nerves in the vicinity of the antecubital fossa.
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of the infusion pharmacokinetics and pharmacodynamics of cisatracurium, the 1R-cis 1'R-cis isomer of atracurium, with atracurium besylate in healthy patients.
We have compared the pharmacokinetics of cisatracurium with atracurium when given by bolus dose followed by continuous infusion. Twenty healthy patients were anaesthetised with thiopentone, midazolam, fentanyl and 70% nitrous oxide in oxygen. Ten patients (Group C) were randomly allocated to receive cisatracurium 0.1 mg.kg-1 and 10 patients (Group A) were given atracurium 0.5 mg.kg-1. ⋯ The different isomer groups of atracurium have different pharmacokinetics, the trans-trans group having the highest clearance (1440 ml.min-1) and the cis-cis group the lowest (499 ml.min-1). The clearance of cisatracurium (425 ml.min-1) is less than that of cis-cis atracurium and its elimination half-life is longer (34.9 min and 21.9 min, respectively). The plasma concentration of laudanosine after cisatracurium was one-fifth of that after atracurium.
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Randomized Controlled Trial Clinical Trial
The effect of cricoid pressure and neck support on the view at laryngoscopy.
Fifty female patients were studied to compare the view of the larynx at direct laryngoscopy under general anaesthesia with and without cricoid pressure applied. We also compared the view using the standard technique of cricoid pressure with that using cricoid pressure in an upward and backward direction and further investigated whether these views were improved with a firm foam rubber neck support. The order in which the types of cricoid pressure were applied was randomised and also blinded with a drape over the neck. ⋯ Both types of cricoid pressure applied without neck support were more likely to give a better view than no cricoid pressure (p < 0.01) and cricoid pressure in an upward and backward direction was more likely to give a better view at laryngoscopy than the standard technique (p < 0.01). Neck support during the standard technique of cricoid pressure did not improve the view of the larynx at laryngoscopy. Cricoid pressure is likely to improve the view at laryngoscopy which may be further improved by applying it in an upward and backward direction.
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We report a case where two consecutive blood patches failed to relieve postdural puncture headache and hearing loss following inadvertent dural puncture. Initial conservative therapy with analgesics, fluids and later two blood patches had no effect and the patient's symptoms only resolved after an epidural dextran 40 patch performed 8 weeks after the dural tap. Two months later, the patient is still asymptomatic.