ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Pulmonary and systemic hemodynamic responses to administration of pentolinium (0.3 mg/kg) were studied in eight patients undergoing total hip replacement during N2O-halothane anesthesia with Paco2maintained at 35–40 mm Hg. Measurements were made prior to induction of anesthesia; 20 minutes after induction; 45 minutes after induction but prior to pentolinium administration; 10, 20, and 60 minutes after administration of pentolinium; 15 minutes after AP recovered to within 10 per cent of baseline values. The reduction in AP produced by pentolinium was associated with significant decreases in both SVR and LVFP (estimated by measuring PA0via a Swan-Ganz catheter). The profound and significant reductions in calculated PVR were more pronounced than those in SVR. Since PVR decreased in the face of reductions in both pulmonary arterial and left atrial pressures despite a significant increase (at 10 minutes) or no change (at 20 and 60 minutes) in pulmonary blood How, the results suggest an active decrease in pulmonary vascular tone, presumably due to autonomic inhibition by pentolinium. Both LVSWI and RVSWI decreased significantly following injection of pentolinium. HR × SAP, an indirect index of MVo2decreased significantly following an initial increase at 10 minutes. Presumably these effects of pentolinium were conspicuous because N2O-halothane anesthesia altered the baseline of pulmonary vascular tone.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effects of an intravenous infusion of nitroglycerin were studied in 20 acutely hypertensive patients during coronary-artery surgery. Eight patients had histories of essential hypertension and six had been treated for it. They were anesthetized with morphine, diazepam. N2-O. O2- pancuronium. and enflurane. Control measurements were obtained after sternotomy. Nitroglycerin was then administered until the blood pressure returned to normal, and the measurements then repeated. The mean dose of nitroglycerin was 80.0 ± 4.7 μg/min. or 0.96 SmUg/kg/min. This produced significant decreases (P> .03) in systolic diastolic. and mean arterial blood pressures, central venous pressure, pulmonary- capillary wedge pressure, systemic vascular resistance, and left ventricular stroke work index. Cardiac index, stroke index. and heart rate were unchanged. Two indices of myocardial oxygen demand (rate-pressure product and tension-time index) were significantly decreased by nitroglycerin (P> .005). Fifty per cent of the patients had improvement in ST-segment depression on the electrocardiogram. These findings demonstrate that nitroglycerin can he safely administered intravenously during operation, and suggest that nitroglycerin decreases myocardial oxygen demand and relieves myocardial ischemia.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

d-Tubocurarinc (dTe) was administered intravenously to six healthy unanesthetized volunteers to assess the effects of partial paralysis on ventilatory response to CO2. Each subject received during a −40-minute period 0.2 mg/kg. consisting of five incremental doses at intervals 10 minutes apart. Isohypereapnia with PETCO26–7 torr above each subject's resting level was maintained throughout>dTc administration. Ventilation at this level of stimulus was 23.8 ± 1.1 I/min (mean ± SE) before administration of>dTc. about three times resting levels. Steady-state minute ventilation measured during the period 4–6 minutes after each dose of>dTc failed to decrease significantly; the levels of ventilation were maintained principally by increased respiratory frequency, since tidal volumes declined significantly from an average of 1,550 ml to 1,050 ml (P> 0.025). Changes in the slope of the CO2-response curve varied widely among subjects. Although the control slope of 2.65± 0.76 1/min/torr (mean ± SE) was reduced to 1.50 ± 0.36 1/min/torr after partial curarization. the change was not significant (P< 0.10). Ventilation was maintained at a time when grip strength was 6 per cent of control, vital capacity was 52 per cent of control, and maximum static respiratory pressures were 35–40 per cent of control. Nevertheless, the results suggest significant impairment of vital respiratory functions such as coughing, deep breathing, and the ability to maintain a patent airway in the absence of endotracheal intubation.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A 12-year follow-up study of children who had had operations with general anesthesia in infancy and of nonhospitalized children of the same age showed almost identical incidences of respiratory allergy in the test and control groups. General anesthesia in infancy does not predispose to respiratory allergies in childhood.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Isolated strips of mid-pregnant and postpartum rat myometrium were rendered functionally Ca2-free by exposure to a Ca2-free modified Krebs-bicarbonate solution containing 1 mM ECTA. The muscle strips were then exposed to 2.25 mM Ca2for periods of 15 to 600 seconds for the mid-pregnant tissues and one 120-second period for the postpartum tissues. At the end of each exposure. Ca2was removed and simultaneously each muscle was depolarized with 125 mM K2SO2. Isometric tension changes in the muscles were measured with and without 0.5 per cent halothane. In the mid-pregnant muscles, halothane diminished the initial tension development in response to Ca2by approximately 50 per cent, regardless of the duration of Ca2exposure. The contractile response of these muscles to depolarization with K2SO4was reduced 10 per cent by 0.5 per cent halothane; this was probably due to reduction in transmembrane influx of Ca2. In the postpartum muscles, the initial tension development in response to Ca2was threefold greater than in mid-preguaut muscles and was reduced 25 per cent by halothane. These tissues failed to develop any tension in response to K2SO4. The most likely explanation for the effect of halothane is that it reduces the transmembrane influx of Ca2in both types of tissues, but that the postpartum sarcoplasmic reticulum presents less competition for intracellular Ca2than pregnant sarcoplasmic reticulum.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Arterial and peripheral venous plasma levels of huptvacaine were determined in 30 patients following epidural anesthesia using 150 and 225 mg, as well as following intercostal nerve block with 400 mg. Arterial levels were consistently higher than levels in simultaneously sampled venous blood, and the highest levels occurred with bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine may have a wider margin of safety in man than is now stated.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Peripheral vascular and direct cardiac effects of calcium chloride were determined in a new animal model, the unanesthetized calf, before and after replacement of its natural heart (NH) with a pneumatically driven artificial heart (AH). Calcium (5 and 10 mg/kg) significantly increased cardiac output (Q1) and reduced systemic vascular resistance (SVR) before and after AH implantation. Increases in Q1in AH calves and reductions in SVR in both NH and AH calves were, however, transient, being present 5 minutes but not 15 minutes after both doses of calcium. Increases in Q1and reductions in SVR were significantly (P<.05) greater after 10 mg/kg than after 5 mg/kg calcium in NH and AH calves. Both doses of calcium produced greater (P<.05) increases of Q1in NH than in AH animals but similar reductions in SVR. Pulmonary vascular resistance, heart rate and pulmonary arterial and right atrial pressures were not significantly altered by either dose of calcium in NH or AH calves. Mean aortic pressure was influenced by 10 mg/kg calcium only, being transiently reduced in AH calves and increased in NH animals. Pulmonary shunt (Qs/Qt) was increased by both doses of calcium in NH calves but only by 10 mg/kg in AH animals. Correlations of mean change in Qs/Qtwith mean change in Qtwere high both before (r = .99) and after (r = .97) AH implantation. These data demonstrate that calcium significantly reduces SVR in a dose-related manner as well as exerting a positive inotropic effect on the myocardium.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Tracheal mucociliary flow rates in dogs were measured with a radioactive droplet technique during thiopental anesthesia, and subsequently during halothane anesthesia. Body temperature and inspired gas temperature and humidity were held constant. Ventilation was controlled with 25 per cent oxygen in nitrogen to produce PaCo230 torr Mucociliary flow rate remained constant when halothane concentration was held constant at 1.2 MAC halothane. Mucociliary flow rates at 0.6 MAC halothane were comparable to those after thiopental. 25 mg/kg. Increases in concentration from 0.6 to 1.2 to l.8 to 2.4 MAC halothane progressively depressed mucociliary How. Flow at 2.4 MAC halothane was 27 per cent of the control (thiopental) value. Flow returned to previous values as end-tidal halothane concentration was reduced. The depression produced by halothane may represent impairment of an important pulmonary defense mechanism.

ISSN:0003-3022    

出版商:OVID    

年代:1976

数据来源: OVID