Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Multicenter Study Clinical Trial
Bolus administration of esmolol for controlling the haemodynamic response to tracheal intubation: the Canadian Multicentre Trial.
A multicentre trial was designed to determine the dose-response and side-effects of esmolol when administered as a single iv bolus prior to induction of anaesthesia for controlling the haemodynamic response to tracheal intubation. Five hundred and forty-eight patients from 12 university-affiliated centres across Canada were randomized prospectively to receive either placebo (PLAC) or esmolol (E) in a dose of 100 mg (E100) or 200 mg (E200). Study medication was given immediately before induction of anaesthesia with thiopentone 3-5 mg.kg-1 and succinylcholine 1.5 mg.kg-1. ⋯ Other side-effects, such as bradycardia, bronchospasm or pain on injection, occurred no more frequently in either esmolol group than with placebo. It is concluded that a 100 mg bolus of esmolol is safe and effective for controlling the haemodynamic response to tracheal intubation. This dose of esmolol combined with a low dose of narcotic (fentanyl 2-3 micrograms.kg-1 or equivalent) results in effective control of both heart rate and blood pressure, while avoiding important side-effects.
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Randomized Controlled Trial Comparative Study Clinical Trial
Brachial plexus block with bupivacaine: effects of added alpha-adrenergic agonists: comparison between clonidine and epinephrine.
The effects of clonidine and epinephrine, administered into the brachial plexus sheath, were evaluated in 60 patients who underwent surgery of the upper limb. All patients received 40 to 50 ml of 0.25% bupivacaine, injected into the brachial plexus sheath, using the supraclavicular technique. The patients were randomly allocated to two groups so that 30 patients received 150 micrograms clonidine hydrochloride (Group I), and 30 received 200 micrograms epinephrine (Group II). ⋯ The block produced with the addition of clonidine was longer (994.2 +/- 34.2 vs 728.3 +/- 35.8 min) and superior to that with epinephrine (P less than 0.001). No major side-effects were recorded. We conclude that the injection of clonidine into the brachial plexus sheath is an attractive alternative to epinephrine to prolong the duration of analgesia following upper limb surgery under conduction anaesthesia.
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Randomized Controlled Trial Clinical Trial
Nitrous oxide potentiates vecuronium neuromuscular blockade in humans.
This study was designed to measure the potency of vecuronium with and without nitrous oxide. Anaesthesia was induced with thiopentone and fentanyl in 56 adult patients. The subjects were randomly assigned to receive nitrous oxide, 70%, or intermittent boluses of thiopentone and fentanyl for maintenance of anaesthesia. ⋯ By analysis of covariance, the dose-response curves were shown to be shifted with respect to one another (P less than 0.05). Administration of nitrous oxide was associated with a 19.5% increase in potency (95% confidence limits: 1.7 to 40.4%). It is concluded that nitrous oxide has a slight potentiating effect on neuromuscular blockade, and that this effect occurs within five to ten minutes after the beginning of its administration.