摘要:

The excretion of methoxyflurane in end-expired air has been studied in patients after methoxyflurane anesthesia and in anesthesiologists after they have administered methoxyflurane anesthsia. Methoxyflurane is detectable in the end-expired air of patients for 10–18 days after anesthesia and in anesthesiologists for as long as 30 hours after exposure. Concentrations in patients' end-expired air could be related to a time-and-concentration measure, methoxyflurane per cent hours (MFPH), for as long as 120 hours after exposure. Samples of air collected in the area in the operating room from which the anesthesiologist inspired air contained 1.3–9.8 ppm methoxyflurane, depending on the concentration of anesthetic being delivered to the patient. A significant decrease in the methoxyflurane concentration in operating room air was obtained using a gas trap. Due to the potential hazards of chronic exposure to anesthetic gases, protection of the anesthesiologist and other operating room personnel seems advisable.

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 kinetics of disposition of lidocaine after intravenous regional anesthesia of the arm and direct intravenous infusion were studied in volunteers. Plasma levels of the drug in blood samples from a contralateral artery and in some cases also from the pulmonary artery and a contralateral vein were determined by gas chromatography. Peak plasma levels of lidocaine after cuff release (iv regional anesthesia) were 20 to 80 per cent lower than those found when the same dose was given directly into a vein over three minutes. Peak levels after cuff release were inversely proportional to tourniquet-application time; they also tended to be lower (by about 40 per cent) when the same dose was given in 0.5 per cent instead of 1.0 per cent solution. During the first few minutes after cuff release, distribution of lidocaine within the pulmonary system buffers the vital organs against high blood levels of the drug. Computer analysis of the data afforded estimates of the amount of drug remaining in the arm as a function of time after cuff release. Release of drug into the systemic circulation was found to be biphasic, an initial fast release of about 30 per cent of the dose, followed by a gradual washout of the remainder. Calculations indicated that even 30 minutes after cuff release about 50 per cent of the dose still remained in the arm. If anesthesia is to be re-established following cuff release this may be possible 10 to 30 minutes after initial release by injection of about half of the original dose following reinflation of the cuff.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

The neuromuscular effects of pancuronium were studied in 65 patients anesthetized with nitrous oxide supplemented by thiopental and/or meperidine. There was a marked variation among patients in their responses to pancuronium. A dose of 0.02 mg/kg depressed twitch height 44 per cent. Recovery to 90 per cent of control twitch height took 16 minutes. With repeated doses a cumulative effect was observed. A dose of 0.04 mg/kg produced an 88 per cent block. Twitch height recovered to 90 per cent of control in 58 minutes. After a dose of 0.08 mg/kg the twitch response was markedly depressed (>98 per cent) or abolished, and the trachea could be intubated with ease. Recoveries to 10 and 25 per cent of control took 65 and 86 minutes, respectively. During a partial block, tetanus was usually poorly sustained and posttetanic facilitation was observed.

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 purpose of this experiment was to determine whether halothane interferes with the utilization of lipid as a source of fuel for the contractile process by the isolated rat atria. Rats were starved 24 hours in order to increase the lipid content of the heart. Atria from starved rats were better able to maintain their contractility in the absence of exogenous substrate and also were more resistant to depression by halothane than atria from fed rats. Approximately 11 mg/100 ml (1.41 vol per cent) halothane were necessary to achieve 50 per cent depression of the force of contraction of atria from starved rats whether glucose was present in the bathing medium or not. To achieve the same degree of depression in the presence or absence of glucose in atria from fed rats required about 6.5 mg/100 ml (0.83 vol per cent). Atria from starved rats behaved like atria from fed rats in that the depressant action of halothane was independent of external glucose. The site of action of halothane in either case cannot be related to the uptake or phosphorylation of glucose, but may involve the glucose phosphate isomerase step, as previously suggested. The greater halothane requirement for atria from starved rats suggests that endogenous lipid accumulates during starvation and is used as an energy source for the contractile process in the face of a halothane-induced block in glycolysis. Other possible reasons for the resistance of atria from starved rats to halothane's depressant action are discussed.

ISSN:0003-3022    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

In an intact closed-chest dog preparation, 2–3 MAC (0.44 per cent alveolar) methoxyflurane markedly decreased left ventricular function and myocardial blood flow, efficiency, and oxygen uptake A negative myocardial excess lactate and unchanged cardiac output–myocardial blood flow ratio suggested adequate myocardial oxygenation. The significant correlation between myocardial blood flow and mean aortic blood pressure in the depressed heart may indicate a loss of metabolic control of coronary perfusion. Myocardial uptake of nonesterified fatty acids, lactate, and pyruvate decreased with myocardial depression. Although there was little glucose utilization in the depressed hearts, arterial glucose was low in contrast to the arterial level with halothane. Consequently, altered myocardial glucose metabolism cannot be postulated as a mechanism in the cardiac depression produced by methoxyflurane.

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