Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jul 1989
Influence of propranolol on the in vitro response to caffeine and halothane in malignant hyperthermia-susceptible muscle.
In vitro contracture tests for susceptibility to malignant hyperthermia (MH) were performed with halothane and caffeine in 27 patients according to the protocol of the European MH Group. Additional halothane and caffeine tests were performed in the presence of propranolol 80 micrograms/l. ⋯ Propranolol did not influence the caffeine results in the normal response group group (n = 12). It is concluded that beta-blockers should be discontinued before investigation for MH susceptibility.
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Acta Anaesthesiol Scand · Jul 1989
Constant-flow ventilation in canine experimental pulmonary emphysema.
The efficacy of constant-flow ventilation (CFV) was investigated in eight mongrel dogs before (control-phase) and after development of papain-induced panlobular emphysema (PLE-phase). For CFV, heated, humidified and oxygen-enriched air was continuously delivered via two catheters positioned within each mainstem bronchus at flow rates (V) of 0.33, 0.5 and 0.66 l/s. Data obtained during intermittent positive pressure ventilation (IPPV) served as reference. ⋯ In dogs with emphysematous lungs CFV maintains sufficient gas exchange. This may be due to preferential ventilation of basal lung units, thereby counterbalancing the effects of impaired lung morphometry and increased airtrapping. Conventional mechanical ventilation is more effective in terms of oxygenation and CO2-elimination.
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Acta Anaesthesiol Scand · May 1989
Randomized Controlled Trial Comparative Study Clinical TrialIntravenous regional analgesia--a new modification.
A modification of the standard intravenous regional analgesia technique is described whereby excess local anaesthetic solution is removed from the veins of the isolated arm once analgesia has been established. This simple procedure was shown to reduce the incidence of oozing at the site of operation without affecting the quality of analgesia. Measurement of the quantity of local anaesthetic agent removed from the isolated arm 15 min after injection revealed that the amounts removed were small, indicating rapid uptake and binding in the tissues. This would imply that removal of excess local anaesthetic agent from the isolated arm after 15 min does not confer added safety as regards reducing the risk of leakage of agent into the general circulation in the event of cuff failure.
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Acta Anaesthesiol Scand · May 1989
Randomized Controlled Trial Comparative Study Clinical TrialSpontaneous recovery of residual neuromuscular blockade after atracurium or vecuronium during isoflurane anaesthesia.
With atracurium and vecuronium, spontaneous recovery of residual neuromuscular blockade monitored electromyographically during 0.5% isoflurane anaesthesia was studied in 60 patients undergoing plastic surgery. After thiopentone, in random order, either atracurium 0.5 mg kg-1 or vecuronium 0.1 mg kg-1 was administered and isoflurane added to N2O and O2 mixture. Following spontaneous recovery of both the single twitch amplitude (T1) to 75% of the control value and the train-of-four ratio (TOF ratio) to 75%, incremental doses of the relaxant were given to maintain the T1 at less than 10%. ⋯ The recovery time from T1 75% to TOF ratio 75%, indicating the recovery rate of residual neuromuscular blockade, with atracurium was about 15 min after both the initial and the second recoveries. With vecuronium, the respective recovery times were significantly (P less than 0.001) longer (25.6 min and 38.5 min, respectively). It is concluded that with vecuronium there is slower spontaneous recovery of residual neuromuscular blockade than with atracurium.
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Acta Anaesthesiol Scand · May 1989
EEG spectral power during halothane anaesthesia. A comparison of spectral bands in the monitoring of anaesthesia level.
The EEG of ten elective abdominal surgery patients was studied during halothane anaesthesia. The EEG was analysed by compressed spectral array. The total power and various power bands were analysed. ⋯ EEG analysis was performed from the data collected before induction and during anaesthesia at steady states of 1 MAC, 1.5 MAC, and 2 MAC. The correlation between deepening anaesthesia and power values was strongest in the 10-14 Hz band power and in the 18-32 Hz band power. This study confirms the usefulness of high frequency power in estimating the effect of halothane in patients.