Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Feb 1987
Haemodynamic effects of intravenous bupivacaine during high thoracic epidural anaesthesia.
Administration of small doses of bupivacaine epidurally at the upper thoracic level will partially block the cardiac sympathetic nerves but not the sympathetic outflow via the adrenals. Local anaesthetics have direct systemic effects on the myocardium and the systemic circulation. The present study aimed to examine the effect of high thoracic epidural anaesthesia (TEA) in elderly patients, and to examine the effect of raising plasma bupivacaine concentrations in these patients, who had earlier had the sympathetic innervation of the heart blocked by thoracic epidural anaesthesia. ⋯ After TEA was established, heart rate, mean arterial blood pressure and cardiac output decreased. When bupivacaine was given to these patients intravenously during the block, mean arterial blood pressure increased, while cardiac output decreased still more. The mechanisms behind these effects seem to be a direct constriction of the systemic blood vessels and a depressive effect on the myocardium, which was blocked from the influence of the cardiac sympathetic nerves by the high thoracic epidural block.
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Acta Anaesthesiol Scand · Feb 1987
Comparative StudyEffect of spinal versus epidural anaesthesia with 0.5% bupivacaine on lower limb blood flow.
Changes in the haemodynamics of the lower extremities, big toe temperature, blood pressure and heart rate were studied in 20 patients undergoing spinal or epidural anaesthesia for transurethral surgery. Calf blood flow was determined by strain gauge plethysmography (SGP) and Doppler ultrasound. Bupivacaine 0.5% was injected at the L3-L4 interspace, the dose being 3-4 ml (mean 3.6) in the spinal and 17-20 ml (mean 18.6) in the epidural group. ⋯ The venous capacity and maximum venous outflow remained practically unchanged in both groups. Obviously, epidural anaesthesia with bupivacaine causes a more intensive sympathetic block than does spinal anaesthesia. As probably no venous pooling occurred, when examined by SGP and Doppler ultrasound, neither of the blocks is likely to contribute to the initiation of deep vein thrombosis.
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Acta Anaesthesiol Scand · Feb 1987
Preservation of humidity and heat of respiratory gases during anaesthesia--a laboratory investigation.
Humidification and heating of anaesthetic gases are desirable to prevent respiratory tract damage and a fall in body temperature during operative procedures. Numerous studies on the humidity and temperature of inspiratory gases in different breathing systems for anaesthesia have been carried out, but comparisons are difficult since different methods have been used. ⋯ The temperature of the inspired gases was highest with the Bennett Cascade humidifier, followed by the low-flow circle system. The circle absorber system used with low fresh gas flow gave higher inspiratory gas temperature and humidity than the non-rebreathing system with a good disposable humidifier.
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Acta Anaesthesiol Scand · Feb 1987
Circulatory effects of short-term hypercapnia during thoracolumbar epidural anaesthesia.
In ten elderly patients subjected to extensive thoracolumbar epidural anaesthesia, circulatory changes were studied before and during sympathetic stimulation. Induced hypercapnia was used as a sympathetic stimulus. ⋯ Hypercapnia before the epidural block increased heart rate, arterial blood pressure and cardiac output, while hypercapnia after established epidural block induced only a slight increase in arterial blood pressure. The results indicate that in spite of an extensive epidural block, there are some "escaped" sympathetic nerve fibres that can be mobilized during sympathetic stimulation.
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Acta Anaesthesiol Scand · Feb 1987
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of bupivacaine and morphine on pain and bowel function after colonic surgery.
Sixty patients scheduled for colonic surgery were randomly allocated to four groups according to postoperative pain medication: I. Control group, the patients received oxycodone intramuscularly (0.15 mg kg-1) on request. II. ⋯ Pain intensity (visual analogue scale) was lower in Groups II and III at 3 h and in Group IV at 24 h compared to the control Group I. All the epidurally treated groups needed less additional analgesics than the control Group I. Postoperatively bowel movements occurred on the second day in Group II (bupivacaine) as compared to the fourth day in all other groups (P less than 0.05).