Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Dec 1983
Clinical TrialNitrous oxide augments the systemic and coronary haemodynamic effects of isoflurane in patients with ischaemic heart disease.
The effects of 70% nitrous oxide, added to 1% end-tidal isoflurane and administered by intermittent positive pressure ventilation (IPPV), on coronary haemodynamics and myocardial oxygenation were investigated in 10 patients with ischaemic heart disease. Standard methods were used for determination of their central haemodynamic effects. Coronary blood flow was measured by the retrograde thermodilution technique and coronary sinus blood sampled for measurement of myocardial oxygen consumption and lactate extraction. ⋯ The myocardial ischaemia was worsened in three of the six patients with ECG and metabolic signs of impaired oxygenation during isoflurane alone. It is concluded that nitrous oxide potentiates the systemic and coronary haemodynamic effects of isoflurane in patients with coronary artery disease. The mechanisms for myocardial ischaemia seem to be decreased coronary perfusion pressure and/or redistribution of coronary blood flow by direct coronary vasodilation.
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Acta Anaesthesiol Scand · Dec 1983
Comparative StudyThe effect of local scavenging on occupational exposure to nitrous oxide.
Despite evacuation of excess anaesthetic gases at the expiratory valve of the anaesthetic circuit and a general ventilation system producing 17-20 air changes per hour, mask anaesthesia often causes occupational exposure to anaesthetic gases exceeding the threshold limit values. The effect of a local air exhaust system, a local scavenger, on occupational exposure to nitrous oxide during paediatric mask anaesthesia was studied. ⋯ The experiences from the installation and clinical use are discussed. Local scavenging is an excellent complement to the scavenging of excess gases at the expiratory valve, and it may be considered an alternative to expensive, high-capacity ventilation systems.
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Acta Anaesthesiol Scand · Dec 1983
Clinical effects of regional intravenous guanethidine (Ismelin) in reflex sympathetic dystrophy.
Twenty patients with documented reflex sympathetic dystrophy were treated with a series of regional intravenous guanethidine blocks. The mean delay between the first clinical symptoms and the start of guanethidine blocks was 3.6 months. The overall result was good in 11 patients, moderate in two patients and poor in seven patients. ⋯ Side effects, except pain after the injection, were few and of minor importance. The tolerance of the procedure may be improved by preceding the injection of guanethidine by an injection of a local anaesthetic agent. It may be concluded that with correct diagnosis and indication, guanethidine injections may play an important part in the treatment of reflex sympathetic dystrophy and may replace sympathetic blocks with local anaesthetics because of the longer duration of action and lower incidence of serious side-effects.
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Acta Anaesthesiol Scand · Dec 1983
Comparative StudyCardiac arrhythmias in intubated children during adenoidectomy. A comparison between enflurane and halothane anaesthesia.
In 75 children undergoing adenoidectomy, occurrence of cardiac arrhythmias and influence of anaesthesia on respiration were studied during halothane and enflurane anaesthesia. All the children were intubated orally. In 25 children halothane, and in another 25 children enflurane was used during spontaneous ventilation. ⋯ During enflurane anaesthesia the incidence of ventricular arrhythmias was lower (8%) in spite of higher end-tidal CO2 tensions and an anaesthetic depth that was only just the level needed to allow intubation. The incidence of ventricular arrhythmia during halothane anaesthesia was shown to be influenced by the anaesthetic technique used, which was not found with enflurane anaesthesia. The greater stability in cardiac rhythm with enflurane indicates a more favourable effect of this agent on the myocardium as well as a decreased sympathetic response to anaesthesia and surgery as compared with halothane anaesthesia.
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Acta Anaesthesiol Scand · Dec 1983
Clinical Trial Controlled Clinical TrialTopical anaesthesia with EMLA, a new lidocaine-prilocaine cream and the Cusum technique for detection of minimal application time.
The minimal effective onset time of the new topical anaesthetic formulation EMLA (a eutectic mixture of lidocaine and prilocaine), was evaluated by the double-blind technique in 53 female and 66 male patients (median age 40 and 36 years, respectively) subjected to intravenous cannulation. Conventional plotting and regression analysis failed to answer the question. The Cusum technique, originally designed for industrial production control, could successfully be applied to solve the problem. It demonstrated a minimal effective EMLA application time of 45 min in adults.