Showing papers in "Anesthesiology in 1968"
194 citations
TL;DR: Anesthesiologists appear to have a low incidence of lung cancer, a somewhat lower than average incidence of coronary artery disease in recent years, and a high death rate from suicide and malignancies of the lymphoid and reticuloendothelial tissues.
Abstract: During the years 1947–1966, there were 441 deaths among junior, active and retired members of the American Society of Anesthesiologists living in the United States or Canada. A cause of death was found for each member and death rates calculated for this group. Comparisons of these rates with those for U. S. males and with male policyholders of the Metropolitan Life Insurance Company were made. Anesthesiologists appear to have a low incidence of lung cancer, a somewhat lower than average incidence of coronary artery disease in recent years, and a high death rate from suicide and malignancies of the lymphoid and reticuloendothelial tissues. These data only suggest trends and point to the need for a prospective study of this subject.
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TL;DR: It is shown that the heart has relatively little effect on the normal regulation of cardiac output, but all the physician has to do is to look at his patients, and he will see that this is true.
Abstract: MOST physicians are surprised to learn that the heart has relatively little effect on the normal regulation of cardiac output, but all the physician has to do is to look at his patients, and he will see that this is true. He will see a patient with mitral valvular disease whose heart has a maximum pumping ability no greater than one third normal, but at rest cardiac output is normal or almost normal. He will see a patient who has had a severe heart attack a day earlier but with a cardiac output now almost normal even though the maximum . . .
141 citations
TL;DR: The results suggest that anesthetic requirement may be related in part to changes in norepinephrinc content in the brain.
Abstract: The effects of prior administration of alphamethyldopa, reserpine, and guanethidine on the minimum alveolar concentration (MAC) of halohane were studied in dogs. The effect of iproniazid, a monoamine oxidase inhibitor, on cyclopropane MAC was studied in rats. Prior administration of alpha-methyldopa or reserpine, which reduce both central and peripheral norepinephrine levels, was associated with a reduction in MAC which was dose-related. Conversely, prior administration of iproniazid, which elevates central norepinephrine levels, resulted in an increase in MAC. MAC was not altered by prior administration of guanethidine, which reduces norepinephrine peripherally but not centrally. These results suggest that anesthetic requirement may be related in part to changes in norepinephrinc content in the brain.
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TL;DR: N2O per se is not a cerebral metabolic depressant and that the anesthetic action of N2O is not based on generalized cerebral metabolic depression.
Abstract: Cerebral blood flow and arterial–sagittal differences for oxygen have been measured in unpremedicated dogs maintained at, 37.0 C. All were paralyzed, had received a spinal anesthetic, and were artificially ventilated. In each of a first group, measurements with and without halothane were carried out with 70 per cent N2O in O2 and with 70 per cent N2 in O2. In a second group, either N2O or N2 was used throughout and measurements were made in the absence of halothane and at 0.1, 0.4, and 0.7 per cent halothane (alveolar). In the absence of halothane and at 0.1 per cent halothane, the average rate of consumption of O2 by the brain (CMRo2) was 11 per cent greater with N2O than with N2. At 0.4 and 0.7 per cent halothane, CMRo2 was greater with N2O but the differences were not significant. It is concluded that N2O per se is not a cerebral metabolic depressant and that the anesthetic action of N2O is not based on generalized cerebral metabolic depression.
TL;DR: Normal subjects were unaffected by the solutions administered by the heated nebulizer, but inhalation of solutions nebulized by ultrasound caused an increase in airway resistance in all, and atropine did not modify the responses of patients to the ultrasonic aerosol.
Abstract: The effects of inhalation of aerosols produced by ultrasonic and by heated nebulizers on airway resistance of ten normal subjects and ten patients with chronic bronchitis or asthma were determined with a body plethysmograph. Normal subjects were unaffected by the solutions administered by the heated nebulizer, but inhalation of solutions nebulized by ultrasound caused an increase in airway resistance in all. When isoproterenol was inhaled by patients immediately prior to the inhalation of the ultrasonic aerosol, no change in airway resistance was seen. Atropine did not modify the responses of patients to the ultrasonic aerosol.
TL;DR: Atropine methylbromide and atropine sulfate exerted peripheral parasympathomimetic effects on the heart, infer that atropines in small doses decelerates heart rate and both drugs prolonged P-R intervals.
Abstract: Atropine in small doses decelerates heart rate. This parasympathomimetic effect, which has been attributed to a central vagal stimulating action of atropine sulfate, was studied in dogs by measuring heart rate and P-R intervals. The action of atropine sulfate (which has access to the brain) was compared to that of its quaternary derivative, atropine methylbromide, which is believed not to cross the blood-brain barrier. Atropine methylbromide was more potent than atropine sulfate in accelerating heart rate. In unanesthetized dogs, but not in dogs anesthetized with chloralose, atropine sulfate and atropine methylbromide in small doses slowed heart rate. In awake and anesthetized dogs both drugs prolonged P-R intervals. Bilateral cervical vagotomy abolished the drug effect on the P-R interval, but when the distal limb of the vagus was stimulated electrically both atropine sulfate and atropine methylbromide again prolonged the P-R interval. We infer that atropine methylbromide and atropine sulfate exerted peripheral parasympathomimetic effects on the heart. The possibility that atropine sulfate has central vagal stimulating effect was not excluded.
TL;DR: To evaluate the effect of lowered Paco2 on the size of subsequent cerebral infarction in the dog, the middle cerebral artery was occluded at its origin and the internal carotid artery occluding between the posterior communicating artery and the anterior cerebral artery.
Abstract: To evaluate the effect of lowered Paco2 on the size of subsequent cerebral infarction in the dog, the middle cerebral artery was occluded at its origin and the internal carotid artery occluded between the posterior communicating artery and the anterior cerebral artery. Following occlusion, Paco2 was
TL;DR: Diurnal variation in the incidence of resorptions following halothane was noted, more fetal deaths occurring after exposure during the day than during the night, similar to those seen following exposure to nitrous oxide.
Abstract: Rats were exposed to 0.8 per cent halothane for 12-hour periods at different stages of pregnancy. Fetuses near term were suitably prepared and the skeletons examined. Lumbar ribs and separation of normally single ossification centers into paired lateral centers in the lower thoracic vertebral bodies were common. Incidences of these anomalies were compared with those of a control series and found significantly higher following exposure to halothane on day 8 or day 91/2 (or day 10 for ribs only). Diurnal variation in the incidence of resorptions following halothane was noted, more fetal deaths occurring after exposure during the day than during the night. The anomalies found are similar to those seen following exposure to nitrous oxide.
TL;DR: From the combination of knowledge and actions, someone can improve their skill and ability and this will lead them to live and work much better.
Abstract: From the combination of knowledge and actions, someone can improve their skill and ability. It will lead them to live and work much better. This is why, the students, workers, or even employers should have reading habit for books. Any book will give certain knowledge to take all benefits. This is what this individuality in pain and suffering tells you. It will add more knowledge of you to life and work better. Try it and prove it.
TL;DR: Several arrangements of inspiratory and expiratory valves and of overflow location in a circle absorber system were tested to determine which arrangement best conserved fresh gas and preferentially eliminated alveolar gas and proved to be the most economical.
Abstract: Several arrangements of inspiratory and expiratory valves and of overflow location in a circle absorber system were tested to determine which arrangement best conserved fresh gas and preferentially eliminated alveolar gas. The influences of inflow rate, deadspace, tidal volume and alveolar ventilation were also examined. During spontaneous ventilation, the most economical arrangements (most alveolar gas eliminated at a given inflow rate) were those with the overflow close to the patient However, with one exception, when ventilation was controlled, the arrangements with overflow near the patient became least economical. The exception was the arrangement with both inspiratory and expiratory valves close to the patient and the overflow valve immediately downstream from the expiratory valve. This proved to be the most economical of all the arrangements tested. Economy was directly related to inflow rate and indirectly related to alveolar ventilation in all cases. When the overflow valve was distant from the patient, concomitant increases in deadspace and tidal volume (alveolar ventilation unchanged) reduced economy. However, these increases of deadspace and tidal volume had no effect on economy when the overflow was close to the patient.
TL;DR: Autoradiographic studies of the spinal cord in the dog indicate a specific uptake of C-Iabelled lidocaine and procaine by the neuraxis, and Uptake of drug was higher in the grey matter than in the white matter of the cord.
Abstract: Autoradiographic studies of the spinal cord in the dog indicate a specific uptake of C-Iabelled lidocaine and procaine by the neuraxis. The highest concentrations of the intrathecally-adminis-tered drug were found in the posterior and lateral columns, with only small concentrations noted in the anterior columns. Uptake of drug was higher in the grey matter than in the white matter of the cord, and posterior nerve roots had a higher concentration than anterior roots. Biopsies of the cord and scintillation counting of the weighed specimens provided confirmation of the autoradiographic studies. The significance of these findings is discussed, and possible explanations arc considered.
TL;DR: Compound 347 (CHF2-O-CF2-CHFCl), a new non-explosive fluorinated ether, was administered with nitrous oxide–oxygen to 100 patients for major elective abdominal operations and provided rapid, pleasant induction and emergence and adequate hypnosis, analgesia and muscular relaxation, with minimal alterations in the vital signs.
Abstract: Compound 347 (CHF2-O-CF2-CHFCl), a new non-explosive fluorinated ether, was administered with nitrous oxide–oxygen to 100 patients for major elective abdominal operations. This agent provided rapid, pleasant induction and emergence and adequate hypnosis, analgesia and muscular relaxation, with minim
TL;DR: Clinical use of the drug in association with mechanical ventilation in the treatment of chronic hypereapnia appears justified, and the effect of acetazolamide on cerebrovascular tone remains unexplained.
Abstract: An experiment was designed to rule out bypoxia of cerebral tissue as a mediator of increased cerebral blood flow (CBF) due to acetazolamide (Diamox). Hypoxia might be produced by carbonic anhydrase inhibition by delaying the acidification of the red blood cell until it left the tissue capillary. Fifteen dogs were studied under pentobarbital anesthesia. CBF was estimated from the arteriovenous oxygen content difference across the brain. Cerebral tissue oxygen tension (Paco2) was measured directly on the cortical surface. CBF was altered by altering arterial Pco2 (Paco2) before and after the intravenous administration of 25 mg./kg. acetazolamide. At Paco2 = 30 mm. Hg, acetazolamide increased CBF by 69 per cent; at Paco2 = 40 mm. Hg, by 64 per cent; at Paco2 = 50 mm. Hg, by 55 per cent. This was accompanied by an increase in Po2 of 20 mm. Hg at Paco2 = 30 mm. Hg; 19 mm. Hg at Paco2 = 40 mm. Hg; 16 mm. Hg at Paco2 = 50 mm. Hg. Since Po2 increased, clinical use of the drug in association with mechanical ventilation in the treatment of chronic hypereapnia appears justified. The effect of acetazolamide on cerebrovascular tone remains unexplained.
TL;DR: The effect of postoperative pain relief on cardiopulmonary function was examined quantitatively in 36 patients who underwent upper abdominal surgery and arterial oxygen tensoin increased in the epidural group and decreased in the meperidine group.
Abstract: The effect of postoperative pain relief on cardiopulmonary function was examined quantitatively in 36 patients who underwent upper abdominal surgery. Postoperative pain relief was obtained by intravenous meperidine or by mepivacaine epidurally. Expiratory volumes increased during analgesia, despite decreases in respiratory rate and minute volume, especially in the epidural group. The reduction of respiratory rate and minute volume did not result in respiratory acidosis. A reduction of 7 or 8 per cent in oxygen consumption was observed in both groups during analgesia without significant changes in metabolic factors. Differences between decreased &OV0422;s/&OV0422;T in the epidural group and increased &OV0422;s/&OV0422;Tin the meperidine group were statistically significant, After the establishment of analgesia, arterial oxygen tensoin increased in the epidural group and decreased in the meperidine group. The implications of these findings for the problems of postoperative pain relief are discussed.
TL;DR: It is concluded that halothane is a direct cerebral metabolic depressant and not based on an impaired oxygen supply nor associated with alteration of cerebral metabolic pathways.
Abstract: Cerebral blood flow (CBF) and arterial-sagittal sinus differences for oxygen, glucose, and lactate have been measured in ten unpremedicated dogs maintained at 37.0° C and ventilated with 0 to 2 per cent halothane in N2O (70 per cent) and O2. Flows were determined by a direct method which collects the venous drainage of portions of both cerebral hemispheres. With halothane, the rate of consumption of O2 by the brain (CMRo2) was reduced 17 per cent (mean) while CBF and sagittal sinus Po2 increased. Oxygen/glucose and lactate/glucose indices were unchanged. Since the reduction in CMRo2 with halothane was apparently neither based on an impaired oxygen supply nor associated with alteration of cerebral metabolic pathways, it is concluded that halothane is a direct cerebral metabolic depressant.