Articles: anesthetics.
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The interactions of a steroid anaesthetic, alphaxalone, with the GABA receptor-ionophore complex were investigated by two different experimental approaches. In the rat cuneate nucleus slice, alphaxalone (0.1-10 microM) potentiated depolarizing responses to superfused GABA and muscimol, but not those to glycine. The potentiating effect of alphaxalone was unaltered by the benzodiazepine antagonist Ro 15-1788. ⋯ Analysis of binding curves for [3H]muscimol indicated that the steroid anaesthetic increases the affinity for [3H]muscimol of low affinity binding sites; this property is shared by pentobarbitone. The physiologically inactive beta-hydroxy isomer of the steroid was without activity in either of the experimental situations at 30 microM. It is suggested that alphaxalone and pentobarbitone share a common mode of action on the GABA system, which may be relevant to the mechanisms by which these drugs produce anaesthesia.
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Acta Anaesthesiol Scand · Dec 1984
Midazolam as adjunct to high-dose fentanyl anaesthesia for coronary artery bypass grafting operation.
The usefulness of midazolam as an adjunct during high-dose fentanyl anaesthesia was studied by following the changes in the haemodynamics and total body oxygenation after an intravenous injection of 0.075 mg/kg and 0.15 mg/kg of midazolam during the induction of fentanyl (75 micrograms/kg)-oxygen anaesthesia for a coronary artery bypass operation. These responses were then compared to the changes seen in patients receiving the same fentanyl anaesthesia without the midazolam. A rapid decline after the midazolam injection was seen in the mean systemic arterial pressure (24-32%--the lowest individual value was 45 mmHg (6.0 kPa)) and in the systolic and diastolic pulmonary arterial pressures (29-33% and 30-31%) in 1-3 min. ⋯ The tissue oxygenation seemed to be sufficient in all groups during the study period. An intravenous injection of a relatively low dose of midazolam during the induction of high-dose fentanyl anaesthesia seems to be followed by rapidly increased venous pooling and a moderately to severely decreased systemic arterial pressure. Based on the results of this study, midazolam cannot be recommended as an adjunct during high-dose fentanyl anaesthesia.
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Clinical Trial Controlled Clinical Trial
Heated humidification in major abdominal surgery.
The influence of heated humidification on body temperature and postoperative shivering was studied in 30 patients undergoing major intra-abdominal surgery. In the control group (I) the anaesthetic gases, administered in a non-rebreathing system, were humidified by a sponge heat and moisture exchanger. In group II the gases were humidified and heated to 37 degrees C and in group III up to 40 degrees C. ⋯ A good correlation was found between heat gain during the first hour of recovery, the feeling of cold and intensity of shivering. Intraoperative heat loss was minimal in all groups. Heated humidification had no statistically significant effect on the body temperatures or postoperative shivering and thus provided no additional advantage compared to the control group.
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Clin. Orthop. Relat. Res. · Sep 1984
The effects of epidural injection of local anesthetics and corticosteroids on patients with lumbosciatic pain.
Although epidural cortisone injections are commonly used for treatment of lumbosciatic pain, insufficient critical analysis of the end result can be found in the literature. The present study is a retrospective critical analysis of 367 patients with leg pain who were engaged for a minimum of two weeks or an average of two months in multifaceted conservative management without relief of pain. Injections of 10 cm3 of 0.5% bupivacaine and 100 mg of methylprednisolone were given to inpatients treated by the same anesthesiologist. ⋯ The most favorable results (approaching 70% offd-excellent) were observed in patients with subacute radicular leg pain (of less than three months' duration) and chronic leg pain (of greater than three months' duration) with no prior surgery. Negative myelograms and electromyograms (EMGs), in the absence of reflex or motor deficits on physical examination, also pointed toward optimal results. Those patients with chronic pain who had had prior lumbar spine surgery had the least satisfactory results.