Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1982
Comparative StudyDifferential sensitivity of fast and slow fibers in mammalian nerve. III. Effect of etidocaine and bupivacaine on fast/slow fibers.
Etidocaine and bupivacaine are long acting local anesthetics with contrasting effects on motor and sensory function. The effect of these drugs on fast-conducting (large, motor) and slow-conducting nerve fibers (small, pain) in the isolated rabbit vagus nerve was examined. Both drugs had an equivalent effect on slow fibers. ⋯ During this long latency of effect by bupivacaine on fast fibers, only the slow fibers were blocked. This period of differential effect on fast and slow fibers is believed to be the explanation for the early effect of bupivacaine on pain fibers followed by a later block of motor function. This difference is believed to be due to the lower lipid solubility solubility and greater ionization of bupivacaine, which impedes diffusion across the permeability barriers present in fast-conducting A fiber.
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Anesthesia and analgesia · Jul 1982
Pharmacokinetics of inhalation anesthetics: a three-compartment linear model.
The evolution of mathematical models of the uptake of the inhaled anesthetic agents has produced increasingly complex models in which researchers have attempted to incorporate more and more data on the effects of anesthetics on the processes of respiration, circulation, and metabolism. One result of this evolution has been to limit the application of these models due to the large amount of data required by the model and the need for a large digital computer to generate a solution. ⋯ Only a programmable hand calculator is needed for the solution. Due to the simplicity of this model, compared with previously described models, it should prove useful in understanding the kinetics of gas uptake by the body.
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Anesthesia and analgesia · Jun 1982
Comparative StudyChanging specialties: do anesthesiologists differ from other physicians?
Career choices of physicians frequently change after senior year in medical school. Although previous studies have documented the magnitude of these changes, they contain no information concerning anesthesiologists. Changes in specialties of 1151 physicians, graduates from the same medical school, between the years 1968 and 1976 were studied. ⋯ Of 31 physicians who planned careers in anesthesiology as seniors, 26 (84%) remained in anesthesiology. Nine physicians changed from other specialties to anesthesiology. The ability of anesthesiology to retain physicians who originally planned to specialize in it, or to gain physicians from other fields, was not different from that found in other specialties studied.
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Anesthesia and analgesia · Jun 1982
Continuous monitoring of mixed venous oxygen saturation in critically ill patients.
A new pulmonary artery balloon flow-directed catheter combines a fiberoptic photometric system for continuous display of mixed venous blood oxygen saturation (SvO2) with the capacity for hemodynamic measurements including thermodilution cardiac output estimation. This oximetry system was studied to determine its accuracy, reliability, and usefulness in the surgical intensive care unit (ICU). ⋯ The catheter values for SvO2 were closely related (r = 0.9516) to those obtained from a laboratory Co-oximeter. Continuous monitoring of SvO2 is accurate and valuable as a warning system for deterioration in cardiopulmonary function and as an indicator of the effects of various therapeutic maneuvers in critically ill patients.
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Anesthesia and analgesia · May 1982
Epinephrine-induced arrhythmias during halothane anesthesia with the addition of nitrous oxide, nitrogen, or helium in dogs.
The arrhythmogenicity of epinephrine was examined in 34 male mongrel dogs awake and during 1.1 MAC steady state halothane-O2 anesthesia with the addition of 50% N2O, nitrogen, or helium. All anesthetized dogs required more epinephrine than did awake dogs to produce ventricular extrasystoles. ⋯ The dogs given halothane-N2O also showed a small, but statistically significant difference from dogs given halothane-O2. These results suggest that the addition of N2O to halothane increases the cardiac arrhythmic potential of epinephrine in the dog.