摘要:

Cardiac output, oxygen uptake and plasma catecholamines were studied in patients both awake and during anaesthesia prior to and during upper abdominal surgery. Two different forms of anaesthesia were used: neurolept‐nitrous oxide (NLA) and halothane (HALO) anaesthesia. Oxygen uptake was determined by using a masspectrometer, and cardiac output was measured according to the Fick principle. Plasma catecholamines were analysed by high performance liquid chromatography. Cardiac output fell by 40% during NLA and by 30% during HALO. Concomitantly, the oxygen uptake fell by 40% and 35%, respectively. A linear relationship between cardiac output and oxygen uptake could be established both in the awake state and during anaesthesia, with no significant change in the slope or position of the regression line when anaesthesia was commenced. Ventricular filling pressures fell during both anaesthetic procedures. Adrenaline fell to half the plasma concentrations seen in normal subjects under resting conditions, while noradrenaline returned to normal from an initially 30–40% increased value. Surgery caused no significant changes in either cardiac output or oxygen uptake, whereas plasma adrenaline increased by 20 times and noradrenaline by 60–90%. The findings suggest that the reduced oxygen uptake during anaesthesia causes the fall in cardiac output rather than any cardiodepressant action of the anaesthetic. It is possible that the anaesthetic depresses whole‐body metabolism by either blocking the effects of catecholamines or interfering with cellular met

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01815.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Total oxygen delivery (cardiac output × arterial oxygen content) and oxygen consumption were determined in 22 patients undergoing one‐lung ventilation (OLV) during thoracotomy. In 11 patients, anaesthesia was maintained with halothane‐oxygen and in another 11 patients with nitrous oxide‐oxygen‐analgesic combination (Fio20.5). During OLV, oxygen delivery was greater in the halothane group and these patients tended to show a decrease in oxygen consumption compared with the patients of the nitrous oxide group. Therefore, as far as total oxygen balance (oxygen delivery/oxygen consumption) during OLV is concerned, halothane‐oxygen maintenance provides a greater margin of safety than nitrous oxide‐oxygen‐analgesic combination. However, in spite of occasional hypoxaemic episodes, none of our patients receiving 50% nitrous oxide in oxygen showed an oxygen delivery coefficient (oxygen delivery/oxygen consumption) significantly smaller than the predicted normal value for an unanaesthetized patient. This finding may explain why this anaesthetic technique has been used without apparent harm during OLV in patients with unimpaired cardiovas

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01816.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Despite extensive and numerous pharmacokinetic studies on benzodiazepines, the published pharmacokinetic data do not adequately explain the clinical differences found between different benzodiazepine derivatives alter intravenous administration. Especially, correlations between initial drug responses and distributional changes of the benzodiazepines are limited. However, during the elimination phase some relationships exist between the kinetic and dynamic phenomena. Age, sex, diseases and concomitantly given drugs cause clinically important alterations in the pharmacokinetics of benzodiazepines. Generally these anxiolytics and sedatives should be considered as adjuvants to general anaesthesia, but not primarily as routine induction agents. The major reasons for this limitation are a high variability in drug response, a relatively slow onset of action and long‐lasting residual effects. However, benzodiazepines have many important advantages (see Table 5) when used as intravenous inducing agents of general anaesthesi

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01817.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Twenty‐six patients on chronic (>3 months) β‐receptor blocking therapy due to ischaemic heart disease and/or hypertension were randomly distributed to a 4‐day gradual withdrawal (n= 13) or a continuation of ordinary therapy until a planned cholecystectomy under neurolept anaesthesia (n = 13). Plasma‐adrenaline, ‐noradrenaline, ‐potassium, ‐glycerol, ‐FFA, ‐insulin and b‐glucose were determined perioperatively. The metabolic response to surgery was as expected with hyperglycaemia and depressed insulin levels, which did not differ significantly between the two groups of patients. Plasma‐catecholamines showed the highest mean values during emergence from anaesthesia. Plasma‐adrenaline and ‐potassium were constantly highest in the β‐receptor‐blocked patients, who also showed indices of a relatively depressed lipolysis compared to patients in whom β‐receptor blockers had been withdrawn. These discrepancies between withdrawal versus continuation of preoperative β‐receptor blockade seemed to be of small clinical importance and did not oppose the present view that β‐receptor blockers should generally be continued during surgery. However, findings in individual patients suggest that β‐receptor blockade may m

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01818.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Forty‐eight chronically (>3 months) β‐receptor‐blocked patients with ischaemic heart disease and/or hypertension were studied on 49 occasions after random distribution to a 4‐day, gradual preoperative withdrawal (n = 26) or a continuation (n = 23) of β‐receptor blockers. The patients were scheduled for either a cholecystectomy (n = 28) or a carotid thrombendarterectomy (n = 21) under neurolept anaesthesia. Three patients were excluded from the randomized part of the study due to complications (tachycardia, hypertension, severe angina) after therapy withdrawal. In subgroups, central haemodynamics (β‐receptor blockers withdrawn n = 6, continued n = 8) and creatinine‐kinase B (β‐receptor blockers withdrawn n = 9, continued n= 11) were studied. Withdrawal of β‐receptor blockers was associated with high heart rates, supraventricular tachyarrhythmias and a hyperkinetic circulation during pain stimuli. Significantly more postoperative ECG changes (p<0.02) indicative of myocardial ischaemia were found than in β‐receptor blocked patients. These patients had low heart rates but also pronounced increases in pulmonary capillary wedge pressures, which in single patients could be associated with myocardial damage. These results imply that β‐receptor blockers should be continued before surgery and that a concomitant vasodilatatory therapy is likely to avoid the drawbacks of an

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01819.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Myocardial blood flow, oxygen consumption and carbon dioxide release were studied before and during hemodilution in man. Dextran 70 was used as the dilutional agent to reduce hematocrit values from 37 to 28% (mean). The decrease of oxygen content in arterial blood after hemodilution was compensated by an increase of cardiac output. The myocardial blood flow increased proportionally more than the cardiac output, resulting in a virtually unchanged oxygen tension in coronary sinus blood. The metabolism of the heart was not affected as the respiratory quotient remained unchanged. This investigation suggests that blood losses up to 20% of the total blood volume can be replaced by dextran solutions, without a significant decrease of myocardial oxygen supply.

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01820.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

This investigation was performed to evaluate the effect of ketamine anesthesia on non‐pregnant uterine activity. Seven healthy non‐pregnant women took part in the study. Anesthesia was induced with an i.v. bolus injection of ketamine 2 mg/kg and maintained with a continuous i.v. ketamine infusion, mean dosage 39 μg/kg/min. Before induction of anesthesia, each patient was placed in the lithotomy position, and a catheter fitted with two microtransducers for monitoring of intra‐uterine pressures was fed through the cervix into the uterine cavity. For determination of plasma concentrations of ketamine and norketamine, venous blood samples were collected. The assay was based on a gas‐liquid chromatographic technique. It was found that ketamine induced an increased uterine activity, both in basal tone and intensity of contractions. Only minor effects on the frequency were observed. This stimulatory effect was simultaneous with a hemodynamic stimulation with increases in heart rate and arterial blood pressure, and with the peak plasma concentration of

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01821.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

A new topical anaesthetic formulation, EMLA, consisting of a eutectic mixture of the two local anaesthetics, prilocaine and lidocaine, was used in an attempt to reduce the pain associated with venous cannulation in children. The formulation of the local anaesthetic cream yields a high concentration (approximately 80%) of active substance compared with previous formulations (approximately 20%). A highly statistically significant difference in the experience of pain due to venous cannulation in favour of EMLA compared with placebo was found in this study (p<0.001) in 60 children from 6 to 15 years of age. Stimulus of C fibre endings in the subcutaneous tissue and/or the vascular wall seems to be the mechanism behind the slight to moderate discomfort experienced by about one third of the children treated with EMLA. Local side effects of EMLA were negligible.

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01822.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Circulatory responses to laryngoscopy and endotracheal intubation were compared between throe groups of patients, two of which were subjected to a procedure of topical anaesthesia before induction of general anaesthesia. Topical anaesthesia, achieved with either a lidocaine dose aerosol or by gargling with viscous lidocaine, attenuated the magnitude of the pressor response to laryngoscopy and intubation but had no effect on the heart rate response. Lidocaine aerosol had some advantages over viscous lidocaine; these were the significantly smaller haemodynamic response to the local anaesthetic procedure itself and probably shorter duration of the circulatory changes produced by intubation. It is concluded that both of these simple methods are relatively ineffective in preventing haemodynamic changes associated with laryngoscopy and intubation and should probably be combined with another preventive method.

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01823.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The effects of prenalterol infusion, 0.5 μg/kg/min, on renal function were studied in 10 male volunteers. Systolic blood pressure increased by 22 mmHg(P<0.01) and diastolic pressure decreased by 11 mmHg (P<0.01). Heart rate increased by 11 beats/min (P<0.01). Plasma catecholamine levels and plasma renin activity were not altered. Renal haemodynamics were unchanged. Urine flow rate and fractional free water excretion decreased by 29% and 45%, respectively (P<0.01). Fractional sodium excretion increased by 19% (P<0.01) and fractional potassium excretion fell by 33% (P<0.05)

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1982.tb01824.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY