Articles: general-anesthesia.
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Monaldi Arch Chest Dis · Sep 1994
ReviewAtelectasis formation and gas exchange impairment during anaesthesia.
Anaesthesia is accompanied by impaired oxygenation of the blood, and sometimes hypoxaemia may develop despite an increased oxygen fraction of the inspired gas. The major cause of this derangement is shunt, an effect of prompt atelectasis formation in dependent lung regions. An additional cause is ventilation/perfusion (V/Q) mismatch, possibly produced by intermittent airway closure. The magnitude of shunt and size of atelectasis are independent of the age of the patient, whereas V/Q mismatch increases with age, explaining the age dependent impairment of oxygenation.
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Journal of anesthesia · Sep 1994
Effects of halothane and enflurane on the peripheral vasoconstriction and shivering induced by internal body cooling in rabbits.
General anesthetic agents have central and peripheral effects on body temperature regulation, and its alterations are related to the depth of anesthesia. To evaluate the effect of halothane and enflurane on thermoregulation, we investigated the threshold of body core temperatures to induce peripheral vasoconstriction and shivering in spontaneously breathing rabbits. Rabbits were anesthetized with halothane or enflurane at 0.0 (control), 0.2, and 0.4 MAC (minimum alveolar concentration). ⋯ The incidence of peripheral vasoconstriction was not significantly affected by halothane or enflurane. However, the incidence of shivering decreased in a dose-dependent fashion with both anesthetic agents. At 0.2 MAC, the incidence of shivering in the enflurane group was significantly higher than that in the halothane group, suggesting that suppression of shivering by halothane is stronger than enflurane.
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Randomized Controlled Trial Comparative Study Clinical Trial
Efficacy of electroconvulsive therapy after propofol and methohexital anesthesia.
Fifty-eight patients with major depression were randomly assigned to receive a hypnotic dose of either propofol or methohexital for their complete treatment series of electroconvulsive therapy (ECT). As expected, seizure duration was significantly shorter with propofol than with methohexital anesthesia. ⋯ However, this was independent of the choice of propofol or methohexital as the anesthetic. This study supports previous reports that seizure duration does not influence recovery from depression.
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A 68-yr-old man presented for pharyngeal biopsy under general anaesthesia. Coincidentally he was found to have a large mediastinal mass. ⋯ The exact risk of catastrophic airway collapse on induction of anaesthesia in patients with mediastinal masses is controversial but probably small. As there is no test to prevent airway collapse, it is suggested that attempts at biopsy be performed with regional anaesthesia after radiotherapy.