ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The relation between receptor occlusion by a competitive neuromuscular blocking agent and fade of an indirectly elicited tetanus at frequencies of 30, 100 and 200/sec has been determined. Tetanic fade at 30/sec returned to normal when one-fifth to one-quarter of the receptors became available, and thus recovery approximated closely that of the single twitch response. The tetanic fade at 100/sec was not normal unless half the receptor pool was available, and a normal response at 200/sec required two-thirds of the pool. It is suggested that recovery of the response to tetanic stimulation at 100/sec would provide a practical index of adequate recovery from curarization

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Halothane in concentrations used clinically produces contracture in isolated frog sartorius muscle previously treated with caffeine, 0.5 to 1 mM. Contracture produced by caffeine in muscles previously exposed to halothane can be prevented by procainamide but is increased by lidocaine. Similarly, contracture produced by halothane in muscles pretreated with caffeine can be increased by lidocaine, but not by procainamide. However, procainamide added after development of contracture will not produce relaxation. The underlying abnormality in anesthetic malignant hyperpyrexia may be a deficit in the ability of sarcoplasmic reticulum to reaccumulate calcium, allowing a sustained active state of contracture, a situation which can be pharmacologically mimicked by the use of caffeine. If so, it may be that in treatment of malignant hyperpyrexia in man, procainamide rather than lidocaine may be the better drug for attempting alleviation of the abnormal contracture and hypermetabolic state.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Six EEG levels of Ethrane anesthesia, similar to those of ether, were observed in cats with chronically implanted recording electrodes. With the onset of surgical anesthesia (EEG level III and deeper), high-amplitude spikes and/or spike-wave-complexes invariably appeared in all leads. In three cats faint twitching of the muscles of the face and tongue synchronous with spike discharges appeared at levels III and IV. Deepening or lightening the level of anesthesia stopped the twitching. As anesthesia deepened and the duration of burst suppression lengthened, spiking became more rhythmic Bursts of single or grouped high-voltage spikes arising from a nearly flat baseline commonly were the only major ongoing electrical activity observed in deep level V and in level VI. Noise increased the frequency of spike-like discharges in two deeply anesthetized (level V) animals

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The EEG patterns of increasing depths of Ēthrane-O2anesthesia and the alterations in the patterns produced by changing Paco2and by addition of 60 per cent nitrous oxide have been evaluated in 30 individuals. Increasing depth of anesthesia was characterized by the appearance of high-voltage spikes, with the subsequent development of spike waves and burst suppression. Maximum depth was marked by a predominance of spike waves and burst suppression. The anesthetic depth and Paco2at which changes occurred have been defined. With elevation of Paco2, indices of cerebral irritability appeared to be reduced, while reduction of Paco2increased their occurrence. The greatest CO2effect was seen at inspired Ethrane concentrations of 2.5 per cent or more. The addition of nitrous oxide did not alter the predominant EEG patterns.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The effect of epinephrine on the venous absorption of a local anesthetic (mepivacaine) from the epidural space of the dog was investigated by comparing the concentrations of mepivacaine in the azygos vein after epidural injection of 100 mg of 2 per cent mepivacaine with and without epinephrine 1:200,000. Blood flow in the azygos vein averaged 100 ml per minute. Concentrations of mepivacaine in the azygos vein reached a maximum of 10 μg/ml. At least 9 per cent of the dose of local anesthetic was removed in 30 min via the azygos vein; this was reduced to 3 per cent when epinephrine 1:200,000 was added to the anesthetic solution. It is concluded that die addition of small amounts of epinephrine to epidural local anesthetics is valuable to reduce venous absorption and favor neural blockade

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Trifluoroethanol has been postulated to be an intermediate in the formation of trifluoroacetate during the biotransformation of halothane. As much as 80 per cent of injected C-labeled trifluoroethanol could be recovered as trifluoroacetate in the urine of two volunteers. Excretion of radioactivity lasted seven to nine days after administration of trifluoroethanol. It is unlikely that trifluoroethanol is an endproduct of halothane metabolism in man.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Administration of 22 μg/kg pancuronium to 11 conscious subjects decreased grip strength to 23.6± 5.4 per cent of control within 5 minutes. Grip strength returned to 86.0± 4.7 per cent of control in 25 minutes and vital capacity to 97.0±2.0 per cent of control in 15 minutes. Exercising at a fast rate during partial block caused rapid fatigue. Administration of edrophonium or neostigmine at the height of the block caused rapid but incomplete return of grip strength. In 11 lightly anesthetized subjects 40 μg/kg pancuronium decreased the twitch tension of the indirectly stimulated adductor pollicis muscle to 11.5 ±2.8 per cent and tidal volume to 71.4± 7.4 per cent of control by 5 minutes. Tidal volume recovered by 15 minutes, but twitch tension was only 66.9 ± 6.0 per cent of control at 60 minutes. The administration of edrophonium or neostigmine at this time had little or no effect on twitch tension. Tetanic stimulation applied 10 to 15 minutes later showed well-maintained tetanus, which was followed by significant posttetanic facilitation and maintenance of the twitch tension above the pre-drug control level for the remainder of the 10- to 15-minute observation period. Moderate elevation of pulse rate was the only significant circulatory change.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Electroencephalograms (EEC) of seven healthy male volunteers anesthetized with Forane were studied. Body temperature and Paco2were maintained at normal levels except that hypocapnia was transiently induced once or twice during each study. Increasing doses of Forane produced increasing periods of burst suppression, with complete electrical silence appearing at approximately 2½ per cent end-tidal Forane. At light levels of anesthesia, the frequency of electrical activity was 14 to 17 Hz at a maximum voltage of 120-180 microvolts. At subanesthetic concentrations (below 1.2 per cent) frequency increased and voltage decreased slightly. Hypocapnia did not alter these EEC findings. Audiostimulation could sometimes provoke an EEG response during an electrical silence. In no case was a convulsive EEC pattern (high-frequency, high-voltage spiging activity) seen. Forane-induced EEG changes can be distinguished from those seen with other anesthetics by the maintenance of high-frequency activity at any level where EEG activity is present. Depth of anesthesia can be monitored with the EEG.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID