Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jul 1989
Removal of halogenated anaesthetics from a closed circle system with a charcoal filter.
Halogenated anaesthetics may be removed from a closed circle system by means of a charcoal filter. With this technique dispersion to the atmosphere and a possibly destructive effect of the halogenated volatiles on the protective layer of ozone is avoided. Removal of halothane or isoflurane with a charcoal filter was studied in a closed circle system connected to an artificial lung. ⋯ However, the slopes deviated significantly from the theoretically predicted slopes, possibly because of adsorption to hoses and bags and unequal distribution of the volatiles in the system. Halothane was eliminated more slowly than isoflurane. This study demonstrates that halogenated volatiles are eliminated in an exponential way following charcoal filtration and the rate depends on the ventilation and type of volatile.
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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 · Jul 1989
Randomized Controlled Trial Comparative Study Clinical TrialComparative clinical study of induction and emergence time in sevoflurane and enflurane anaesthesia.
The induction and emergence times in patients who received minor oral surgery under sevoflurane with nitrous oxide or enflurane with nitrous oxide were compared. The induction time required for the loss of eyelid reflex when using sevoflurane (1.6 +/- 0.2 min) was significantly shorter than that in the enflurane group (2.9 +/- 0.4 min). There was no significant difference in the recovery time in the two groups.
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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 · May 1989
Comparative StudyCardiovascular effects of vecuronium, atracurium, pancuronium, metocurine and RGH-4201 in dogs.
The effect on the cardiovascular haemodynamic status of five neuromuscular blocking drugs, RGH-4201, vecuronium, atracurium, pancuronium and metocurine, was studied in five conditioned foxhounds anaesthetised with fentanyl. Changes in heart rate, mean arterial blood pressure, central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac output were recorded at 2, 5, 10, 20 and 30 min after administration of the drugs. From these, stroke volume, systemic vascular resistance and pulmonary vascular resistance were calculated. ⋯ Changes after atracurium, vecuronium and metocurine were minimal. It is concluded that RGH-4201 causes major alterations in the cardiovascular haemodynamic status in dogs anaesthetised with fentanyl when compared to vecuronium, atracurium, metocurine and pancuronium. With respect to cardiovascular stability, atracurium and vecuronium offer advantages.