Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Nov 1993
Cold and warm infusion of Ringer's acetate in healthy volunteers: the effects on haemodynamic parameters, transcapillary fluid balance, diuresis and atrial peptides.
The effects of Ringer's acetate (RAc) infusion with different temperatures, 18 degrees C compared to 36 degrees C, were studied in 20 healthy volunteers. An infusion volume of 20% of the estimated extracellular volume was given over 45 min. Before and after the RAc infusion, interstitial colloid osmotic pressure and interstitial fluid hydrostatic pressure were measured on the lateral part of the thorax and in the lower leg. ⋯ Warm infusion induced a nearly identical haemodilution. Interstitial colloid osmotic pressure fell from 11.6 (+/- 2.3) mmHg to 8.9 (+/- 2.7) mmHg (1.5-1.2 kPa) after warm infusion while cold infusion gave no changes. The changes in interstitial fluid hydrostatic pressure were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)
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Acta Anaesthesiol Scand · Nov 1993
Monitoring of neuromuscular transmission by electromyography (II). Evoked compound EMG area, amplitude and duration compared to mechanical twitch recording during onset and recovery of pancuronium-induced blockade in the cat.
The feasibility of the compound electromyogram (EMG) was evaluated during onset and recovery from pancuronium block in the tibialis anterior muscle of ten cats. The evoked EMG area, amplitude and duration of the total response and of the major negative deflection were evaluated and compared to the mechanomyogram during 0.1 Hz and train-of-four (TOF) stimulation. EMG areas and amplitudes were found to be linearly and similarly related to the mechanomyogram during onset and recovery. ⋯ In contrast, agreement between EMG parameters was found to be high. In conclusion, EMG is more reliable than the mechanomyogram for evaluation of neuromuscular transmission in the cat. EMG amplitudes and areas both reflect the degree of neuromuscular blockade equally well.
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Acta Anaesthesiol Scand · Nov 1993
Brain energy metabolism and blood flow during sevoflurane and halothane anesthesia: effects of hypocapnia and blood pressure fluctuations.
The effects of halothane and sevoflurane on cat brain energy metabolism and regional cerebral blood flow (rCBF) were evaluated during normo- and hypocapnia. Brain energy status was evaluated with phosphorous nuclear magnetic resonance spectroscopy (31P-MRS) and rCBF was measured by the hydrogen clearance method. A high concentration of halothane (3 MAC) impaired brain energy metabolism, while even a higher concentration of sevoflurane (4 MAC) had no untoward effect on brain energy metabolism. ⋯ Following administration of a vasopressor, metaraminol, the abnormal brain energy metabolism induced by 2 MAC of halothane at a PaCO2 of 1.33 kPa was normalized in parallel with the improved rCBF values. We conclude that hyperventilation and fluctuating blood pressure contribute to the occurrence of abnormal brain energy metabolism during halothane and sevoflurane anesthesia. This is more pronounced with halothane than with sevoflurane.(ABSTRACT TRUNCATED AT 250 WORDS)
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Acta Anaesthesiol Scand · Nov 1993
Randomized Controlled Trial Comparative Study Clinical TrialComparison of cardiovascular changes during anaesthesia and recovery from propofol-alfentanil-nitrous oxide and thiopentone-halothane-nitrous oxide anaesthesia in children undergoing otolaryngological surgery.
Propofol/alfentanil anaesthesia was compared with thiopentone/halothane anaesthesia in 86 midazolam-atropine premedicated children undergoing minor otolaryngological surgery. The study was randomised, and evaluation of recovery from anaesthesia was double-blind. The children were divided into two age groups: 1-3 years and 4 years and older. ⋯ Recovery with respect to times to eye opening or response to verbal contact was significantly faster after propofol/alfentanil anaesthesia than after thiopentone/halothane anaesthesia in the older but not in the younger age group. Furthermore, in the younger age group significantly more crying occurred after propofol/alfentanil than after thiopentone/halothane anaesthesia. On the basis of this study, thiopentone/halothane anaesthesia is recommended for children aged 1-3 years and propofol/alfentanil anaesthesia for older children undergoing adenoidectomy and/or tonsillectomy.
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Acta Anaesthesiol Scand · Nov 1993
Randomized Controlled Trial Comparative Study Clinical TrialComparison of two fentanyl doses to improve epidural anaesthesia with 0.5% bupivacaine for caesarean section.
Ninety women undergoing elective caesarean section under epidural anaesthesia were double blindly randomised into three groups to receive either 2 ml of saline or 50 or 100 micrograms of fentanyl in 2 ml volume added to 0.5% bupivacaine. Both doses of fentanyl intensified the epidural anaesthesia and reduced patient discomfort during the operation. In both fentanyl groups the epidural blockade more often reached the 5th thoracic segment (P = 0.0258), the patients had significantly less pain (P = 0.0256), needed less intravenous diazepam medication during the operation (P = 0.0005) and the operating conditions were were better when compared to the saline group (P = 0.0416). ⋯ The postoperative time until treatment for pain was requested by the patients was more than 1 h longer in the fentanyl groups, but there was no difference in the total amount of postoperative analgesics needed during the first 24 h when compared to the saline group. Mild pruritus not requiring treatment was more common in fentanyl groups than in the saline group (P = 0.0187). The results suggest that 50 micrograms of fentanyl added to 0.5% bupivacaine increases patient comfort and improves the quality of epidural anaesthesia for caesarean section, and that adding 100 micrograms does not give further advantage.