摘要:

The uptake and distribution of a single dose of intravenously administered sodium pentobarbital-2-14C (5 ethyl-5-[methylbutyl] barbiturate-2-14C) and its effects on function of reflex response to stimuli were studied in mice. Groups of mice given 30, 40, or 50 mg/kg pentobarbital-2-14C intravenously were sacrificed at intervals from 10 seconds to 1 hour after injection; the level of anesthesia was assessed by testing loss and return of righting reflex and loss and return of withdrawal response to pinprick. There was no obvious relationship between whole brain, or specific brain region, concentration of unchanged pentobarbital and the states of these two reflex responses. No metabolite was detected by chromatography in brain or brown fat with any dose at any time. After each dose three metabolites could be detected by chromatography in the liver, kidney, and blood, as early as 1 minute after injection.

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Estimates of anesthetic requirement based on inspired anesthetic gas concentrations assume equilibration with alveolar, and consequently brain, anesthetic gas tensions. This assumption may be rendered invalid by the solubility of the anesthetic agent and its effects on ventilation. To test this assumption, ED50values of anesthesia using halothane and a less soluble anesthetic, isoflurane, were determined in rats with and without tracheostomies. Alveolar ED50or MAC for halothane and isoflurane were 1.11 ± 0.03 per cent and 1.38 ± 0.02 per cent, respectively. Inspired ED50values 2–3 hours after induction in non-tracheostomized rats were 14 and 17 per cent greater, respectively, than alveolar ED50values 2–3 hours following tracheostomy during halothane and isoflurane anesthesia in the same animals. These data demonstrate that previous studies in which the anesthetic requirement for halothane was determined using inspired gas samples are inaccurate. Inspired ED50values for halothane and isoflurane in rats without tracheostomies were 2 and 11 per cent greater, respectively, than inspired ED50values in the same animals with tracheostomies. Even after 3 hours of anesthesia in tracheostomized rats, measurements of inspired-to-alveolar differences in anesthetic gas tension revealed 9 and 3 per cent differences for halothane and isoflurane, respectively. Thus, the use of inspired concentration for this purpose in rats should be limited to inhalation anesthetics with low blood–gas partition coefficients and with minimal effects on ventilation. A moderately or highly soluble anesthetic agent or one which results in significant respiratory depression necessitates the direct measurement of “alveolar” anesthetic gas tension to determine anesthetic requirement.

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

X-rays of human subjects show that the thyroid cartilage can undergo bending in association with several functional states of the larynx. Flexibility of the laminae appears to augment the opening effect of the sternothyroid or the closing effect of the thyrohyoid muscle on the air passage, and produces spring-actuated restitution of the passage when these muscles relax.

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

The metabolism of isoflurane was studied in Fischer 344 rats and man. In both species, ionic fluoride and non-ionic fluoride were detected in urine, with ionic fluoride the principal metabolite in rats and non-ionic fluoride the predominant end-product in man. Thin-layer chromatography indicated that the non-ionic fluoride metabolite was trifluoroacetic acid (TFA).

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Prior research on the treatment of phobias and the psychological preparation of children for operations suggested that the stressfulness of anesthesia induction might be ameliorated by a short motion picture showing children behaving calmly during induction. This was tested in a controlled experiment with 38 children undergoing minor elective operations. The anesthetics employed were standard combinations of halothane, nitrous oxide, cyclopropane and oxygen. Children who saw the film shortly before leaving for the operating room were judged to be significantly less upset than the controls while waiting to enter the operating room and while being readied for induction. The differences between the two groups during the induction itself were negligible.

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Gas chromatographic analysis of helium in nitrous oxide by peak height measurement may produce erroneously high values if the standard peak height is obtained with helium–oxygen mixtures. This results from concentration of helium by the absorption of an appreciable volume of nitrous oxide by the chromatograph column. This error can be eliminated by calibration with standards of helium–nitrous oxide or by measurement of area rather than peak height.

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1974

数据来源: OVID