British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Continuous monitoring of blood glucose concentration during open-heart surgery.
Continuous monitoring of blood glucose concentration was compared with frequent intermittent sampling in 12 non-diabetic adult patients undergoing open-heart surgery with cardiopulmonary by-pass using priming fluids free of glucose. Continuous monitoring revealed several changes which were not detected on intermittent sampling. ⋯ Rewarming from hypothermic by-pass was associated with a 3 (+/- 0.5)-mmol litre-1 increase in blood glucose concentration (P less than 0.01). Commencement of infusions of sympathomimetic agents resulted in a similar increase.
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Randomized Controlled Trial Clinical Trial
Comparison of diazepam and midazolam for sedation during local anaesthesia for bronchoscopy.
Bronchoscopy was performed in 76 outpatients using local anaesthesia plus diazepam 0.2 mg kg-1 i.v. or midazolam 0.05 or 0.1 mg kg-1 i.v. Patient co-operation and ease of bronchoscopy were good in all patients. ⋯ Two hours after sedation, the patients' performances in three psychomotor tests were similar to those measured before sedation in each group, but the patients' ability to stand steadily and walk along a straight line reverted to normal significantly (P less than 0.05) more slowly in patients receiving midazolam 0.1 mg kg-1 than in the patients given diazepam. The results suggest that midazolam offers no advantage over diazepam in terms of speed of recovery of psychomotor function, when doses of similar potency are given for bronchoscopy.
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The in vitro sensitivities to local anaesthetic blockade of A, B and C nerve fibres in rabbit vagus nerves were examined using a series of structurally similar amino-ester agents which varied in lipid solubility and anaesthetic potency. A fibres were found to be the most sensitive and C fibres the least sensitive to conduction blockade with all the agents, provided that equilibrium blockade was allowed to develop. A correlation existed between the intrinsic anaesthetic potency of the various agents and their lipid solubilities. ⋯ As lipid solubility decreased through the series studied, so the onset of conduction blockade of A fibres was prolonged. It is suggested that this related to decreasing ability to penetrate the lipid diffusion barriers around A fibres. The traditional view that C fibres were more sensitive to block may have arisen because of confusion between absolute sensitivity and rate of development of conduction blockade.
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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.