Anesthesiology
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The transformation of lymphocytes in response to phytohemagglutinin stimulation was investigated in 77 patients undergoind anesthesia with and without coincident surgical operation. A depression of lymphocyte transformation apparent immediately following major operations was related primarily to the extent of tissue trauma and not to the anesthetic agent or technique. No depression of lymphocyte transformation followed anesthesia for treatment of pain or for minor operations. ⋯ The leukocyte count did not increase after comparable operations performed with regional anesthesia. Postoperative depression of lymphocyte transformation is primarily due to nonspecific stress, perhaps because of associated sympathetic and adrenocortical stimulation. The depressant effect of anesthesia alone is minimal.
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The authors previously showed that cyclopropane-epinephrine-induced bigeminal arrhythmias can best be explained by a re-entrant mechanism. They have now obtained evidence for reentry in bigeminal arrhythmias during infusions of epinephrine (.5-3 mug/kg/min) in dogs anesthetized with .8 per cent halothane. Both a critical level of blood pressure and a critical increase in heart rate were necessary for arrhythmias to be induced in any given animal. ⋯ Under these conditions further acceleration of the heart rate could reinstate a bigeminal arrhythmia that was again sensitive to further increases in the frequency of vagal stimulation, and it is concluded that the vagus acts on the spread of the re-entrant impulse. This is best shown with cyclopropane anesthesia, because AV-nodal block occurs more easily with halothane. In addition, very brief periods of increased heart rate caused prolonged periods of bigeminy, which indicates that changes in heart rate may alter the electrophysiology of the halothane-sensitized myocardium to promote bigeminal arrhythmias by a re-entry mechanism.
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Biography Historical Article
Alexander von Humboldt and his discoveries, drugs and devices of interest to anesthesiologists.