ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The authors previously reported thatd-tubo-curarinc (dTc) had a negative inotropic effect on isolated perfused rabbit hearts; the effect was concentration-dependent and related to myocardial calcium exchange. This paper reports results of a concentration–response study of die effects of crystalline dTc, various commercial preparations of dTc, and their preservatives on the contractile amplitude of stimulated rabbit atrial strips. Crystalline dTc produced a slight positive inotropic effect which was significantly different from control, while the commercial preparation, Tubarinc (used in previous studies), produced depression with 43 ± 10-5to 5.4 X 10-4[M]. This depression closely paralleled that produced by antibacterial preservative, p-chloro-m-cresol, while the antioxidant preservative, K mctabisulfite, produced minor depression. Other commercial preparations containing antibacterial preservatives also produced depression similar to the depression produced by their antibacterial preservatives. The commercial preparations dispensed without antibacterial preservatives produced relatively little depression. The authors conclude that their previous results were due to the preservative, p-chloro-m-cresol, and not to dTc

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The authors studied the effects of halothane on the simulated diving reflex and the Valsalva maneuver in man. Arterial blood pressure, heart rate, cardiac output by ballistocardiogram and other measurements of cardiovascular function were recorded. Diving was simulated by application of a wet cloth at 0 C to the face with simultaneous apnea. The Valsalva maneuver was effected by raising the airway pressure to 25–30 torr for 25–30 sec. Simulated diving in the conscious subject decreased heart rates as much as 29 per cent from the lowest control heart rate, compared with a 3.G per cent decrease during halothane anesthesia. Bradycardia was associated with increases in systolic and diastolic blood pressures in conscious and anesthetized subjects. The decrease in cardiac output observed in conscious subjects did not occur during anesthesia. Anesthesia apparently abolishes the parasympathetic component of the simulated diving reflex and interferes with the sympathetic component of this reflex. During phases II, III, and IV of the Valsalva maneuver greater decreases in blood pressure and increases in heart rate were observed during anesthesia. Halothane reduces or abolishes the circulatory reflex responses to diving and to the Valsalva maneuver in man.

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 amounts of cyclopropane, diethyl ether, halothane and methoxyflurane absorbed by rubber were determined by measuring the rates of infusion of anesthetic liquid or gas required to maintain a constant circuit concentration within a closed breathing system. Rates of absorption were directly proportional to the circuit concentration, the rubber-gas partition coefficients, the areas of exposed rubber, and the square roots of the diffusion coefficients. The observed uptake of each anesthetic was identical to that calculated from diffusion equations. The calculated diffusion coefficients of the above agents in rubber were 14, 1.7, 2.3, and 2.64 ± 10-5cmz/min, respectively. At equipotcnt anesthetic concentrations, the absolute amounts of anesthetic vapor absorbed by the breathing circuit are nearly the same for all agents. Absorption and elimination of these agents arc linear functions of the square root of time and cannot be accelerated by rapid flushing of the circuit. As a consequence, as much as 300 ml of anesthetic vapor may be routinely transferred from one case to a subsequent patient when agents are switched between cases.

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