British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Circulatory responses to thiopentone and tracheal intubation in patients with coronary artery disease. Effects of pretreatment with labetalol.
The haemodynamic responses to induction and tracheal intubation have been studied in patients with coronary artery disease randomly assigned to a labetalol pretreatment group (n = 14) or to a placebo group (n = 16). Twelve hour before operation, treated patients received a bolus dose of labetalol 0.5 mg kg-1 followed by a constant infusion of 0.1 mg kg-1 h-1 i.v. ⋯ At intubation, the changes in heart rate (P less than 0.01), mean arterial pressure (P less than 0.05) and rate-pressure product (P less than 0.01) were significantly smaller in the labetalol group compared with the placebo group. Labetalol pretreatment appears satisfactory and may be useful in patients with coronary artery disease who have a normal left ventricular ejection fraction.
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Randomized Controlled Trial Clinical Trial
Maternal and neonatal responses related to the volatile agent used to maintain anaesthesia at caesarean section.
A standardized technique of general anaesthesia, with one randomly selected variable, was provided for 237 patients undergoing elective and 540 undergoing emergency Caesarean section. The variable was the volatile agent used to maintain anaesthesia, the choice resting between trichloroethylene (0.2 or 0.3 vol.%) and halothane (0.2, 0.3, 0.4 or 0.5 vol.%). No association was found between the type of agent and the duration of anaesthesia, or the duration of either the I-D or the U-D interval. ⋯ The incidence of maternal awareness plus unpleasant dreams was unacceptably high when the lower concentrations were used, and it is recommended that either trichloroethylene 0.3 vol.% or halothane 0.4 or 0.5 vol.% be used. Neither agent, at these concentrations, was associated with neonatal depression in group A elective sections in which the fetus presented by the vertex, and although there was a possible tendency for their use in cases of fetal compromise to be associated with an increase in the incidence of neonatal respiratory depression, the degree of depression was of little consequence to neonatal well-being. It was confirmed that breech presentation and prolongation of the U-D interval are important determinants of depression and birth asphyxia among infants delivered by Caesarean section under general anaesthesia.