British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Reduction in standard MAC and MAC for intubation after clonidine premedication in children.
We examined the relative effects of different doses of oral clonidine on the MAC for endotracheal intubation (MACEI) and the MAC for skin incision (MAC) in children. We studied 90 children (15 in each group) (age range 2-8 yr, weight 10-27 kg, height 89-124 cm) who received one of three preanaesthetic medications: placebo (control), oral clonidine 2 micrograms kg-1, or oral clonidine 4 micrograms kg-1 100 min before anaesthesia. Anaesthesia was induced and maintained with sevoflurane in oxygen and air without i.v. anesthetics and neuromuscular relaxants. ⋯ Mean (SD) MACEIs of sevoflurane were 2.9 (0.1)%, 2.5 (0.1)% and 1.9 (0.1)% (P < 0.05), and MACs were 2.3 (0.1)%, 1.8 (0.1)% and 1.3 (0.1)% (P < 0.05), respectively, in control, clonidine 2 micrograms kg-1 and clonidine 4 micrograms kg-1 groups. The MACEIs and MACs decreased dose-dependently. The MACEI/MAC ratio (1.4) was not affected by clonidine.
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Randomized Controlled Trial Clinical Trial
Duration of exposure to sevoflurane affects dose-response relationship of vecuronium.
The purpose of this study was to quantify the relationship between the dose-response curve of vecuronium and duration of exposure to an end-tidal concentration of 1.7% sevoflurane in 67% nitrous oxide and oxygen. Forty adult patients, in groups of 10, were allocated randomly to receive vecuronium by a cumulative dose method at intervals of 15 min (group 15), 30 min (group 30), 60 min (group 60) or 90 min (group 90) after starting inhalation of sevoflurane. Neuromuscular function was monitored by acceleromyographic train-of-four (TOF) responses of the adductor pollicis muscle to ulnar nerve stimulation. ⋯ Mean (SEM) ED50, ED90 and ED95 were 16.8 (0.5), 32.6 (1.7) and 40.9 (2.4) micrograms kg-1, respectively, in group 15; 10.6 (1.0), 20.8 (1.7) and 26.2 (2.2) micrograms kg-1, respectively, in group 30; 11.2 (1.1), 21.7 (1.6) and 27.3 (1.8) micrograms kg-1, respectively, in group 60; and 11.0 (1.1), 21.7 (1.6) and 27.5 (1.9) micrograms kg-1, respectively, in group 90. The values obtained in group 15 were significantly higher than those in the other three groups (P < 0.05). The results indicate that the duration of sevoflurane anaesthesia influences the dose-response of vecuronium and 30 min inhalation of 1.7% end-tidal concentration is sufficient to achieve a stable potentiating effect.
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The excretion of rocuronium and its potential metabolites was studied in 38 anaesthetized patients, ASA I-III and 21-69 yr old. Rocuronium bromide was administered as an i.v. bolus dose of 0.3 or 0.9 mg kg-1. In Part A of the study, the excretion into urine and bile, and the liver content were studied. ⋯ In most samples, irrespective of the type of biological material, only small amounts of the metabolite 17-desacetyl-rocuronium was found. The results demonstrate that rocuronium is taken up by the liver and excreted into bile in high concentrations. The faecal and urinary excretion of unchanged rocuronium are the major routes of rocuronium elimination.
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We reviewed the prevalence and severity of pruritus in 85 patients after cardiac surgery. EloHAES, a long-lasting hydroxyethylated starch, was given to 59 of these patients. ⋯ The timing of onset, duration and severity of the pruritus are similar to those found previously for other hydroxyethylated starches, and the cause of this pruritus is likely to be similar. Hydroxyethyl starch can cause long-term pruritus.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Rapacuronium 2.0 or 2.5 mg kg-1 for rapid-sequence induction: comparison with succinylcholine 1.0 mg kg-1.
The purpose of this nine-centre study in 602 patients was to show that the frequency of acceptable intubating conditions after rapacuronium 2.0 or 2.5 mg kg-1 is not more than 10% lower than the frequency after succinylcholine 1.0 mg kg-1 during rapid-sequence induction of anaesthesia with fentanyl 1-2 micrograms kg-1 and thiopental 2-7 mg kg-1. Laryngoscopy and intubation were carried out 60 s after administration of muscle relaxant by an anaesthetist blinded to its identity. Intubating conditions were clinically acceptable (excellent or good) in 91.8% of patients given succinylcholine and in 84.1 and 87.6% of patients given rapacuronium 2.0 and 2.5 mg kg-1 respectively. ⋯ The increase in heart rate was significantly greater during the first 5 min in the rapacuronium groups, but the arterial pressure increased significantly only in the succinylcholine group (P < 0.001). Respiratory side-effects were observed in 4.0, 13.5 and 18.5% of patients after succinylcholine and rapacuronium 2.0 and 2.5 mg kg-1 respectively (P < 0.05). As the non-inferiority of intubating conditions after rapacuronium 2.0 and 2.5 mg kg-1 could not be proven, succinylcholine should be considered the neuromuscular blocking agent that provides better intubating conditions for rapid-sequence induction.