ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Dynamic pulmonary compliance was measured in adult patients, first awake and then during halothane anesthesia under various conditions. Patients were free from respiratory obstruction and excessive inflation of the lungs during all measurements. Compliance decreased approximately one-third during deep anesthesia. During light anesthesia and emergence when tidal exchange approximated control values, there was less decrease in compliance. The occurrence of pulmonary atelectasis during deep anesthesia in spontaneously breathing patients is suggested. This may be the primary reason for decreased compliance during anesthesia. Compliance decreased in the conscious state in changing from the sitting to supine position. Men had higher measurements both awake and anesthetized than women, and greater decreases during anesthesia. A thiopental induction was associated with more of a decreased compliance than an inhalation induction. Thin patients encountered little change during anesthesia compared with normal and obese patients. During positive-pressure breathing compliance was lower than measurements during spontaneous respiration.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Cardiac arrhythmias were produced in the cat by the injection of epinephrine, norepinephrine, ethylnorepinephrine or isoproterenol during the inhalation of 25 per cent cyclopropane in oxygen. The injection of dibenamine, an alpha adrenergic blocking agent, produced epinephrine reversal, decreased the pressor response to norepinephrine and increased the depressor response to isoproterenol. Dibenamine did not consistently increase the threshold doses of catecholamines required to produce cardiac arrhythmias. In those instances where the arrhythmia threshold doses of the catecholamines were increased, usually to twice control, this result often was attributable to a modification by dibenamine of the pressor effects of the catecholamines. The beta adrenergic blocking agent pronethalol produced ethylnorepinephrine reversal, increased the pressor response to epinephrine and markedly reduced or abolished the depressor response to isoproterenol. The arrhythmia threshold doses of the catecholamines were increased to 8 times those of controls. Large doses of isoproterenol (3 mg./kg.) produced beta adrenergic blockade and increased the arrhythmia threshold doses of the catecholamines to 4 times those of controls. The results suggest that cyclopropane-catecholamine arrhythmias are blocked by specific beta adrenergic blockade and that myocardial ectopic excitation may be attributable to the beta adrenergic receptors.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Fit volunteers were given three doses of 1.5 μg./kg. of the bases of scopolamine or atropine intravenously over a period of 20 minutes. Heart rates fell at first, then rose greater after scopolamine than atropine. Within 30 minutes after the third dose of scopolamine, a striking secondary bradycardia developed, which lasted for three hours. Secondary bradycardia was not seen after atropine. In one experiment with scopolamine, cardiac output was measured and peripheral vascular resistance was calculated. Output varied directly, and resistance inversely in proportion to heart rate.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Uptake of 1 per cent ethylene was studied in eight healthy, awake, unpremedicated adults. End-expiratory concentrations of ethylene were measured by gas chromatography, and CO2by infrared analysis. In all subjects, end-tidal concentration of ethylene was at least 95 per cent of equilibrium at the end of five minutes, 97 per cent by 10 minutes and 99 per cent at the end of 20 minutes. Studies were terminated at 30 minutes because of inability to detect differences between inspired and expired ethylene concentrations. It was unlikely that total body saturation had occurred in that time. Ordinate-derivative analysis of the individual experimental curves yielded two exponentials of the general formae−kt. Neither exponential could be related to a specific body compartment. Comparison of two separate studies done on the same subject, measuring “wet” end-tidal samples in one and “dry” samples in the other, showed no essential differences between the two uptake curves, indicating that the diluting effect of pulmonary water vapor on the dry inspired gas mixture could be ignored.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

In ten normal adult male subjects the administration of cyclopropane caused significant alterations in splanchnic hemodynamics which could not be attributed to hypoxia, hypercarbia, hypothermia, or surgical stimulation. Cyclopropane caused a moderate increase in splanchnic perfusion pressure but a much larger increase in splanchnic vascular resistance, with the result that splanchnic blood flow diminished. The intravenous administration of a small dose (10–12 mg.) of hexa-methonium reversed all of these changes. Splanchnic blood volume was diminished in two of five individuals in whom the measurement was made. The results of this study suggest that cyclopropane causes an increase in the activity of sympathetic vasoconstrictor fibers supplying the liver and intestine. The degree of vasoconstriction produced may be enhanced by the fact that cyclopropane sensitizes vascular smooth muscle to the actions of norepinephrine.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Experiments with five narcotics, (morphine 0.3 mg./kg., oxymorphone 20 μg./kg., levorphan 50 μg./kg., meperidine 1.5 μg./kg. and fentanyl 1.5 μ./kg.) and three narcotic antagonists (nalorphine 150 μg./kg., naloxone 5 μg./kg., and levallorphan 20 μg./kg. were designed, to investigate whether or not the various antagonists exhibit a more pronounced effect against the pharmacological actions of their parent compounds, than against those of structurally less closely related narcotics. No such specificity of action was found. Naloxone appeared more effective than nalorphine or Ieval-lorphan. With all three antagonists there was a direct relation between the degree of narcotic-induced respiratory depression and the efficacy of the antagonist.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

Studies of cerebral circulation and gaseous metabolism were performed in six healthy young volunteers during anesthesia induced with thiopental and maintained with nitrous oxide andd-tubocurarine. The blood thiopental level was very low when measurements were made, and intravenousd-tubocurarine has been shown not to affect cerebral flow or metabolism. Therefore 70 per cent nitrous oxide was probably the agent chiefly responsible for the changes observed. When Paco2was normal, cerebral blood flow remained normal, but cerebral oxygen uptake decreased 23 per cent. About one third of this decrease was caused by a small decline in body temperature, with the remainder most likely owing to nitrous oxide. When mean arterial Pco2was decreased to 18.3 mm. of mercury, cerebral blood flow was halved, and mean jugular venous Pco2declined to 19.8 mm. of mercury, a level generally assumed to be associated with suboptimal cerebral oxygenation. However, cerebral metabolic rate for oxygen did not decrease further at this low Paco2.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID

摘要:

In 30 healthy obstetrical patients, determinations of serum cholinesterase were performed during labor, one day and three days postpartum. Ten patients were studied late in pregnancy and 6 weeks postpartum. Compared to nonpregnant values as determined 6 weeks postpartum, there was a 27.7 per cent reduction of enzyme activity during late pregnancy, a 15.6 per cent decrease during labor, a 24.6 per cent decrease one day postpartum, and a 32.3 per cent decrease two days later. Compared to values during labor, over 90 per cent had falls of cholinesterase activity three days postpartum.Low cholinesterase values (below 55 units per ml.) were found in 10 per cent of patients in late pregnancy and during labor, in 20 per cent of patients one day postpartum, and in 60 per cent of patients two days later.A case is presented of prolonged paralysis following the use of 400 mg. succinylcholine during cesarean section. Subsequent studies disclosed abnormally low serum cholinesterase activity, but a qualitatively normal enzyme.

ISSN:0003-3022    

出版商:OVID    

年代:1965

数据来源: OVID