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

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 cardiovascular effects of Forane, a new inhalation anesthetic, were examined in seven un-medicated volunteers under conditions of constant arterial carbon dioxide tension and body temperature. Comparison of results during anesthesia with awake values demonstrated maintenance of myocardial function but progressive vasodilatation as anesthesia deepened. No significant changes in the cardiac output, ballistocardiogram I-J wave amplitude, ejection time, mean rate of ventricular ejection, or pre-ejection period occurred with onset or deepening of anesthesia. Arterial pressure decreased, as did total peripheral resistance. Increased muscle and skin blood flow and forearm venous compliance suggested that the loss of resistance was due in part to dilatation of vessels in the skin and muscles. Cardiac output was maintained by an increased heart rate which compensated for the decreased stroke volume. Comparisons of results during the first and fifth hours of anesthesia demonstrated only minor changes with increased duration of anesthesia. These included further increases in forearm blood flow and an increase in base excess.

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 new inhalation anesthetic, Forane, has been shown to produce only minimal depression of cardiac output during controlled ventilation, but a significant decrease in arterial pressure and profound respiratory depression. This study was undertaken to determine whether spontaneous ventilation, with the consequent elevations in CO2, would alter the cardiovascular responses to Forane, and whether Forane alters the cardiovascular response to imposed increases in CO2(CO2challenge). During controlled ventilation Forane maintains cardiac output, primarily through an increase in heart rate at the expense of stroke volume. Spontaneous ventilation alters the cardiovascular response to Forane, in that heart rate and cardiac output are further increased. These changes can be explained by the increase in Paco2secondary to spontaneous ventilation. Cardiovascular CO2response slopes reveal that Forane decreases the response of the cardiovascular system to increases in Pco2As in previous studies with Forane, the authors did not find any stimulation of the cardiovascular system with time.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The ventilatory effects of Forane were studied in ten volunteers and compared with values obtained in eight volunteers anesthetized with halothane. Paco2averaged 60 torr with both 1.9 per cent alveolar Forane (approximately 1.45 X MAC) and 1.6 per cent halothane (1.9 X MAC). The slopes of the CO2response curves were depressed to 30 ± 6 per cent (Mean ± SE) of awake control values by 1.28 per cent Forane (approximately 1.0 X MAC) and to 45 ± 7 per cent of controls with 1.05 per cent halothane (1.25 X MAC). Therefore, when equivalent anesthetic doses are considered, less Forane than halothane was needed to increase Paco2and depress the slope of the CO2response curve. In contrast to halothane, Forane in increasing concentrations did not cause progressive increases in respiratory frequency. At equal multiples of MAC, Forane produces more profound respiratory depression than halothane, and this depression results from a unique failure of respiratory frequency to increase with increasing depth of anesthesia.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Apneic thresholds in man anesthetized with diethyl ether, halothane, and Forane were compared. Assisted ventilation to apnea lowered Paco2by an average of 4.6 torr from Paco2during spontaneous respiration. There was no difference between anesthetics or depths of anesthesia in the reduction of Paco2needed to achieve apnea Apneic thresholds were lower in subjects anesthetized with ether than in those anesthetized with halothane or Forane because Paco2with spontaneous respiration was lower with ether than with either of the other two anesthetics. During ether anesthesia apneic threshold did not change significantly as end-tidal ether concentration was increased from 3.0 to 6.0 per cent. During halothane anesthesia apneic threshold and Paco2during spontaneous ventilation increased by 9 torr as end-tidal halothane increased from 1.0 to 1.5 per cent. We conclude from these results that: 1) assisted ventilation can produce only a minor reduction in Paco2; 2) ether does not stimulate respiration independent of CO2.

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