Acta anaesthesiologica Scandinavica
-
Acta Anaesthesiol Scand · Nov 1989
Atelectasis and gas exchange impairment during enflurane/nitrous oxide anaesthesia.
The development of atelectasis and effects on gas exchange during enflurane anaesthesia in nitrogen/oxygen or nitrous oxide/oxygen (inspired oxygen fraction 0.4) were studied in 16 lung-healthy patients (mean age 49 years). Awake, no subject displayed atelectasis as assessed by computed x-ray tomography of the thorax. Pulmonary gas exchange, studied by multiple inert gas elimination technique, and blood gases were normal. ⋯ Perfusion of poorly ventilated lung regions (low VA/Q) averaged 4-5% and did not vary significantly during the anaesthesia. In the nitrous oxide group, shunt increased to 6.3% after 90 min of anaesthesia, and there was a parallel decrease in perfusion of low VA/Q regions. The findings suggest that besides prompt collapse of lung tissue during induction of anaesthesia, absorption of gas from closed-off or poorly ventilated regions takes place and further increases the atelectatic area.
-
Acta Anaesthesiol Scand · Nov 1989
Comparative StudyThe association between the neuroleptic malignant syndrome and malignant hyperthermia.
The neuroleptic malignant syndrome (NMS) is an uncommon but dangerous complication of treatment with neuroleptic drugs. A primary defect in skeletal muscle has been suggested in view of similarities in the clinical presentations of NMS and anaesthetic-induced malignant hyperthermia (MH). The in vitro halothane-caffeine contracture tests are the most reliable method of identifying individuals susceptible to MH. ⋯ The response to halothane and caffeine exposure of skeletal muscle from NMS and control subjects was the same and significantly different from that of muscle from patients susceptible to MH. Furthermore, muscle from subjects in NMS and control group responded similarly to increasing concentrations of chlorpromazine. These results do not point towards an association between NMS and MH.
-
Acta Anaesthesiol Scand · Nov 1989
Reversal of postoperative somnolence using a two-rate infusion of physostigmine.
In order to antagonize immediate postoperative somnolence, 24 surgical patients were given a two-rate infusion of physostigmine, aiming at a constant plasma concentration in the range of 1 to 10 ng/ml. Plasma concentrations of physostigmine were determined during infusion and after infusion and the effects of physostigmine on analgesia and postoperative sedation, and its side effects were monitored throughout. On the 1st postoperative day some of the patients (n = 8) were given 5 mg physostigmine orally, after which plasma concentrations as well as effects were measured. ⋯ After oral physostigmine administration the following morning, the majority of patients experienced side effects such as nausea and abdominal pain. In conclusion, physostigmine given as infusion antagonizes postoperative somnolence. However, the arousal effect was considered not better than that resulting from a bolus dose of the drug, although the infusion regimen allowed a prolonged clinical effect duration.
-
Acta Anaesthesiol Scand · Oct 1989
Randomized Controlled Trial Comparative Study Clinical TrialComparison of the effects of continuous intrapleural vs epidural administration of 0.5% bupivacaine on pain, metabolic response and pulmonary function following cholecystectomy.
Twenty patients undergoing elective cholecystectomy were prospectively randomised to receive either intrapleural (bolus 20 ml followed by 10 ml/h) or thoracic epidural (bolus 9 ml followed by 5 ml/h) bupivacaine 0.5% for 8 h postoperatively to assess the effect of these two techniques on pain, pulmonary function and the surgical stress response. As assessed by the visual analogue scale (VAS), both groups received good but not total pain relief. Both groups had a 50% reduction in forced expiratory volume (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) after operation, and there was no observed effect on the stress response as measured by plasma glucose and cortisol. It is concluded that while both techniques provide good analgesia, the degree and extent of nerve blockade are not sufficient to affect the afferent neurogenic stimuli responsible for the observed effects on pulmonary function and the stress response.