British journal of anaesthesia
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Twelve patients (4.3-25.3 kg) undergoing minor surgical procedures were investigated during halothane anaesthesia with spontaneous breathing through a modified T-piece (Mapleson F) with an apparatus deadspace that could be changed from 2 ml (VDsmall) to 16 ml (VDlarge). Immediately following the switch from VDsmall to Vlarge ETCO2 (mean +/- 1 SD) increased from 6.89 +/- 1.09% to 7.61 +/- 1.14% (ns) then gradually decreased during a 10-min period. The initial plateau of FlCO2 (mean +/- 1 SD) with VDlarge was 0.74 +/- 0.34%, but gradually decreased to 0.63 +/- 0.25% after 10 min. ⋯ After 10 min VE had increased by more than 40% (P less than 0.01) as a result of an increase in VT (mean +/- 1 SD) of 14.6 +/- 6.5 ml. After 10 min of VDlarge ventilation, VA and VCO2 were maintained at VDsmall values. The adequate ventilatory response to the large deadspace was seen in all patients, but the ventilatory efficiency, as judged by VD/VT and VENCO2 ratios, was reduced significantly in the children weighing less than 10 kg.
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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.
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Randomized Controlled Trial Comparative Study Clinical Trial
Zomepirac, dihydrocodeine and placebo compared in postoperative pain after day-case surgery. The relationship between the effects of single and multiple doses.
Zomepirac 100 mg and dihydrocodeine 30 mg were compared with placebo in a controlled randomized, double-blind, single-dose postoperative study. Patients continued to receive either zomepirac or dihydrocodeine for pain relief for 5 days at home in a double-blind study, being allowed to titrate the consumption of tablets to their degree of pain. ⋯ In the multiple dosing phase, zomepirac was statistically better than dihydrocodeine. Non-parametric statistical tests indicated highly significant correlations between single- and multiple-dose analgesic measurements for both zomepirac and dihydrocodeine.
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Randomized Controlled Trial Clinical Trial
Effects of the extradural administration of local anaesthetic agents and morphine on the urinary excretion of cortisol, catecholamines and nitrogen following abdominal surgery.
Twenty patients undergoing major abdominal surgery were allocated randomly to receive either general anaesthesia with low-dose fentanyl plus intermittent systemic morphine for postoperative pain or the same general anaesthetic plus extradural analgesia during and following surgery (local anaesthetics from before skin incision until 24 h after skin incision plus extradural morphine 4 mg every 12 h from 3 h to 72 h after skin incision). Postoperative pain scores were lower (P less than 0.05) in the group receiving extradural analgesia, but this regimen failed to prevent the increase in the urinary excretion of cortisol, adrenaline, noradrenaline and nitrogen both on separate days and on cumulative measurements over 4 days. Pain scores did not correlate to urinary excretion of the various endocrine-metabolic indices either on separate days or over the cumulative 4-day period. It is concluded that the relief of pain per se has no major influence on the catabolic response to abdominal surgery.