PubMed Health⌕ Search

Biomedical subjects

P O Järnberg

Publications and source records attributed to P O Järnberg.

At least 19 recordsLinked to original sources
PubMed1988

High- and low-dose fentanyl anaesthesia: hormonal and metabolic responses during cholecystectomy.

We have compared two groups of patients given low- or high-dose fentanyl anaesthesia. Arterial blood samples were collected for measurement of glucose, free fatty acids (FFA), glycerol, beta-hydroxy-butyrate, insulin, c-peptide, glucagon, human growth hormone (HGH), cortisol and adrenaline concentrations. After induction of anaesthesia, blood concentrations of most of these substances decreased. After the start of surgery the concentrations of cortisol, glucose, HGH, FFA and beta-hydroxy-butyrate increased significantly in the group anaesthetized with the lower dose of fentanyl. In the group that received high-dose fentanyl anaesthesia the plasma concentrations of almost all the hormones and substances measured remained relatively low. The differences between the two groups during surgery were significant for adrenaline (P less than 0.001) and cortisol (P less than 0.001). High-dose fentanyl appears to block the trauma-induced stress response seen in patients anaesthetized with low dose fentanyl.

Adult↗
PubMed1988

Paravertebral block during cholecystectomy: effects on circulatory and hormonal responses.

Surgical trauma induces a hormonal metabolic response which is partly responsible for postoperative catabolism. In this study 12 patients underwent cholecystectomy during isoflurane anaesthesia, six with a paravertebral block (PVB) in addition. Plasma concentrations of glucose, cortisol and adrenaline, and heart rate and arterial pressure were compared between the two groups. The patients with PVB showed a significantly diminished response to noxious stimuli.

Adult↗
PubMed1988

Effects of adenosine-induced hypotension on myocardial hemodynamics and metabolism in fentanyl anesthetized patients with peripheral vascular disease.

The effects of adenosine on central and myocardial hemodynamics and metabolism were evaluated during fentanyl anesthesia (100 micrograms.kg-1) in six patients with peripheral vascular disease. Adenosine was intravenously infused, at a rate of 90 +/- 20 (SEM) micrograms.kg-1.min-1, to reduce mean arterial blood pressure by approximately 20% (23 +/- 2% SEM, from 82 +/- 3 to 63 +/- 3 SEM mmHg) during a 20-min period. Systemic and pulmonary vascular resistance indices decreased by 36 +/- 3 and 32 +/- 6% (SEM), and cardiac index increased by 18 +/- 5%. Heart rate, ventricular filling pressures, and whole body oxygen consumption were not affected by adenosine. Despite the reduced mean arterial blood pressure, coronary sinus flow increased by 128 +/- 26% (SEM) in parallel with a 96 +/- 11% (SEM) increase in coronary sinus oxygen content. Left and right ventricular stroke work indices, as well as myocardial oxygen consumption, were maintained. ECG (12-lead) demonstrated signs of ischemia in one subject, while myocardial lactate uptake was unchanged in all subjects. In conclusion, adenosine-induced hypotension in patients with peripheral vascular disease increased cardiac index without affecting myocardial work, whole body, and myocardial oxygen consumptions. The marked increase in coronary sinus blood flow, indicating coronary vasodilation, was not related to increased myocardial work. Further information regarding myocardial effect of adenosine in patients with ischemic heart disease is warranted.

Adenosine↗
PubMed1988

Effects of prenalterol on renal function in patients after major vascular surgery.

Hemodynamic and renal effects of prenalterol were studied in 13 mechanically ventilated patients on the first day after major vascular surgery. Prenalterol (1-[4-hydroxyphenoxy]-3-isopropylamino-2 propanol hydro-chloride), a partial beta-agonist with a predominant beta-1 and a weak beta-2-adrenoceptor activity, was infused into seven patients at rates of 0.5 and 1.0 microgram/kg.min (group A), and at a dose of 2.0 micrograms/kg.min in six patients (group B). Although no hemodynamic changes were observed in group A, systolic BP, mean BP, heart rate, and cardiac output increased significantly in group B. Catecholamine levels and plasma renin activity were unaltered in both groups, as was glomerular filtration rate. Renal blood flow did not change in group A but it increased by 25% in group B. Urine flow, fractional free water clearance, fractional sodium excretion, and fractional chloride excretion were unaltered in both groups. Fractional potassium excretion decreased by 20%, 22%, and 26% at the three infusion rates of prenalterol, respectively. We conclude that prenalterol does not directly influence renal function in the postoperative setting.

Aged↗
PubMed1988

Effects of ephedrine on renal function in patients after major vascular surgery.

The haemodynamic and renal effects of ephedrine were studied in 11 mechanically ventilated patients on the first day after major vascular surgery. Ephedrine, a sympathomimetic agent with alpha-1, beta-1, and beta-2 agonistic activity, was infused into 11 patients to achieve a 20% rise in systolic blood pressure. The doses used were 2-6 micrograms/kg/min, and in six of these 11 patients the dose was then doubled, 4-12 micrograms/kg/min for another renal function test. Blood pressure, heart rate, and cardiac output increased at both dose-ranges. Systolic pulmonary arterial pressure increased by 10% at the first dose-range. Systemic vascular resistance was unchanged and plasma catecholamine levels were unaltered in the present study. Plasma renin activity diminished by 18% and 6%, respectively. Clearance of para-aminohippuric acid increased by 20% and 6%, at the two dose-ranges, while clearance of inulin and urine flow rate increased by 24% and 29%, respectively, at the first dose-range, without further increase during the second dose-range. Fractional chloride excretion, and fractional osmolar clearance were unaltered. Fractional Na+ clearance rose by 30% and 36%, respectively. Fractional free water clearance diminished by 8% at the second dose-range. When comparing the two dose-ranges, HR, systolic and mean BP rose by 8%, 13% and 11%, respectively. Fractional K+ excretion diminished by 30%. We conclude that ephedrine given as a continuous infusion seems to have beneficial effects on renal function in patients after elective major vascular surgery.

Aged↗
PubMed1987

High- and low-dose fentanyl anaesthesia: circulatory and plasma catecholamine responses during cholecystectomy.

The cardiovascular and neuroendocrine effects of a high-dose fentanyl anaesthesia (100 micrograms/kg body weight) were compared with those of a balanced type of fentanyl anaesthesia (5 micrograms kg-1) during upper abdominal surgery. High-dose fentanyl anaesthesia prevented the increase in catecholamine concentrations and attenuated the circulatory response to surgical stress seen in the group anaesthetized with the balanced technique of anaesthesia.

Adult↗
PubMed1987

Effects of dobutamine on haemodynamics and renal function in patients after major vascular surgery.

Eight mechanically ventilated patients were studied, before and during a dobutamine infusion the day after major vascular surgery. During infusion of three different doses of dobutamine (2.5, 5, 10 micrograms/kg/min) increases were found in heart rate of 13%, 21% and 47%, systolic blood pressure of 17%, 27% and 35%, and cardiac output of 11%, 22% and 45%, respectively. Right atrial pressure decreased by 20% at the highest dosage. Pulmonary arterial pressure and pulmonary capillary wedge pressure remained unchanged. There were no changes in plasma catecholamine concentrations and plasma renin activity. Fractional potassium excretion decreased by 23%, 33% and 43%, respectively, at the three dosages, while renal blood flow, glomerular filtration rate, urine flow, fractional sodium, chloride, osmolar and free water clearances were unchanged.

Aged↗
PubMed1986

Effects of dobutamine on renal function in normal man.

The effects of graded doses of dobutamine on renal function were studied in eight male volunteers. The infusion rates were 2.5, 5 and 10 micrograms/kg/min. Systolic blood pressure increased by 19% (P less than 0.01), 31% (P less than 0.01), and 44% (P less than 0.01), respectively, while diastolic blood pressure decreased by 17% (P less than 0.02), 17% (P less than 0.02) and 25% (P less than 0.01), respectively. Heart rate increased at the highest dosage by 32% (P less than 0.01). Glomerular filtration rate (GFR) diminished at all three infusion speeds by 10% (P less than 0.02), 9% (P less than 0.05) and 14% (P less than 0.02), respectively, while renal blood flow (RBF) was unchanged. Urine flow rate (UF) decreased by 36% (P less than 0.05) and fractional free water clearance (CH2O/CIn) diminished by 37% (P less than 0.05) at the rate of 10 micrograms/kg/min. Fractional potassium excretion (CK/CIn) decreased by 34% (P less than 0.01) and 44% (P less than 0.01) at the two highest rates. Fractional sodium excretion (CNa/CIn) and fractional chloride excretion (CCl/CIn) were unchanged. Catecholamine levels were unaltered. Plasma renin activity (PRA) rose significantly (P less than 0.05) at the highest infusion rate of dobutamine. It is concluded that dobutamine influences GFR, the clinical significance of which, however, is difficult to evaluate.

Adult↗
PubMed1984

Plasma catecholamine and free fatty acid levels during infusion of lipid emulsion in critically ill patients.

The fractional elimination rate of exogenous fat, and fat-mobilizing lipolysis in relation to plasma catecholamine (CA) levels were studied in seven ventilator-treated ICU patients. Blood levels of CA, triglycerides, cholesterol and free fatty acids (FFA) were also analyzed before and during constant infusion of a soybean oil emulsion (Intralipid). Triglyceride concentrations rose significantly during the infusion. FFA levels also increased significantly within 30 min after the infusion was begun, reflecting fatty acids derived from Intralipid triglycerides. Plasma norepinephrine levels showed large interindividual variations and were inversely related to FFA concentrations. No correlation was found between plasma CA levels and the fractional removal rate of fat. These data suggest a deficiency of substrate in these critically ill patients.

Adult↗
PubMed1984

Anesthetic agents and sympatho-adrenal response to hemorrhage in the rat.

The sympatho-adrenal activity as reflected in plasma catecholamine levels was studied in rats subjected to a standardized hemorrhage. A comparison was performed between awake rats and rats anesthetized with diethylether, enflurane, barbiturate or ketamine. As expected diethylether increased sympathoadrenal activity. Enflurane induction increased adrenaline and decreased noradrenaline levels. Upon hemorrhage the sympatho-adrenal activity was depressed compared to the awake state. Barbiturate anesthesia depressed sympatho-adrenal activity. Ketamine increased noradrenaline levels and a relative hypertension was noticed during bleeding. The results focus attention on important differences in sympatho-adrenal activity between awake rats and rats anesthetized with different agents.

Anesthetics↗
PubMed1983

Renal excretion of fluoride during water diuresis and induced urinary pH-changes in man.

Fluoride renal clearance (CF) was studied in young healthy subjects with standard clearance technique following administration of 3 mg F as a 30-min constant infusion. High urinary flow rates were induced and experiments were performed under both urinary alkaline and acidic conditions. The data showed that a high urinary flow resulted in maximum fluoride clearance. High water diuresis may therefore be an important part in the treatment of acute fluoride intoxication.

Adult↗
PubMed1983

Plasma catecholamines during surgical stress: differences between neurolept and enflurane anaesthesia.

To evaluate the influence of enflurane and neurolept anaesthesia on the sympatho-adrenal response to surgery, arterial plasma concentrations of adrenaline and noradrenaline were measured at 11 carefully defined events before, during and after cholecystectomy in two groups of five patients. During steady-state anaesthesia prior to operation and after cholangiography, when the operative procedure had been interrupted for 10 min, adrenaline concentrations were similar in the two groups. During periods of stress such as intubation, skin incision and abdominal exploration, adrenaline levels were 4-6 times higher in the neurolept patients compared to the enflurane patients (P less than 0.01), in whom adrenaline levels were very stable. Noradrenaline levels also varied with stress but without difference between the two groups. Systolic blood pressure was approximately 20 mmHg higher during operation in the neurolept group than in the enflurane group (P less than 0.05). It is concluded that enflurane blocks the sympatho-adrenal response to surgical stress more effectively than conventional neurolept anaesthesia.

Adult↗
PubMed1983

Esophageal elastance in anesthetized humans.

Esophageal elastance (Ees) was measured in 13 human subjects, awake and anesthetized by halothane, in the supine and left lateral postures. Static esophageal pressure was measured by an esophageal balloon catheter, respiratory volumes by pneumotachography, and functional residual capacity (FRC) by body plethysmography. In the supine awake subject, Ees averaged 3 cmH2O/ml at FRC and increased significantly with lung volume. Ees remained unaltered at FRC during anesthesia in the supine position, but lung volume dependence was no longer observed. In the left lateral position the awake subject displayed the same Ees at FRC as in the supine position and lung volume exerted only a small influence on Ees. The latter was reduced during anesthesia and tended to diminish with increasing lung volume. All variations in Ees caused by posture, anesthesia, and lung volume were small and affected the shape of the pressure-volume curve of the lung to only a minor degree.

Adult↗
PubMed1982

Effects of prenalterol on renal function in normal man.

The effects of prenalterol infusion, 0.5 microgram/kg/min, on renal function were studied in 10 male volunteers. Systolic blood pressure increased by 22 mmHg (P less than 0.01) and diastolic pressure decreased by 11 mmHg (P less than 0.01). Heart rate increased by 11 beats/min (P less than 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 less than 0.01). Fractional sodium excretion increased by 19% (P less than 0.01) and fractional potassium excretion fell by 33% (P less than 0.05).

Adrenergic beta-Agonists↗
PubMed1981

Renal fluoride excretion and plasma fluoride levels during and after enflurane anesthesia are dependent on urinary pH.

To determine the effects of urinary pH on fluoride ion excretion and the resulting plasma fluoride concentration during and after enflurane anesthesia, renal function, plasma inorganic fluoride levels, and fluoride excretion were studied in two groups of patients pretreated with either NH4Cl or acetazolamide to produce acidic or alkaline urine, respectively. During anesthesia, urinary flow rate, inulin clearance (Cin) and para-aminohippurate (PAH) clearance (CPAH) were 7, 61, and 43 per cent of control values in the acidic-urine group and 22, 74, and 57 per cent of control values in the alkaline-urine group, respectively. Fractional fluoride clearances (CF/CIN) during anesthesia and operation were 0.06 +/- 0.05 in the acidic-urine group (urinary pH 5.08) and 0.68 +/- 0.23 in the alkaline-urine group (urinary pH 8.16). Values of total fluoride excretion during the same period were 0.06 +/- 0.04 mg and 0.87 +/- 0.29 mg, respectively. Mean maximal plasma levels of fluoride were 26.3 +/- 7.3 microM in the acidic-urine group and 13.5 +/- 2.4 microM in the alkaline-urine group. The differences between groups in fluoride clearance, fluoride excretion, and plasma fluoride levels were all statistically significant. The data clearly show that renal fluoride clearance is closely related to urinary pH.

Acetazolamide↗
PubMed1981

Thoracic gas volume measured by body plethysmography during anesthesia and muscle paralysis: description and validation of a method.

A method based on body plethysmography for the assessment of thoracic gas volume (TGV) in the anesthetized, paralyzed subject is presented. The compression of thoracic gas following inflation is detected by measuring the difference between the inflation volume and the "box volume" change caused by the expansion of the chest. Model experiments showed good agreement between true and measured volumes with a residual standard deviation of 2 per cent. In studies on human subjects with healthy lungs during halothane anesthesia, the coefficient of variation of repeated measurements was 5 per cent. Comparative measurements with resting lung volume (FRC) determined by multiple breath nitrogen washout disclosed a larger volume by the box technique, a difference which was reduced but not eliminated by deep breathing during the nitrogen washout. This difference, amounting to 0.2 liters on the average, may be explained by abdominal gas and by the detection of trapped gas by the box technique but not by the nitrogen washout.

Adult↗
PubMed1981

Lipid infusion in critically ill patients. Acute effects on hemodynamics and pulmonary gas exchange.

Hemodynamics, pulmonary diffusing capacity (DLCO) blood gases, oxygen consumption (VO2) and carbon dioxide excretion (VCO2) were studied in healthy volunteers and ventilator-treated, critically ill patients before and during infusion of lipid emulsion for 4 h. Triglyceride levels rose from 1.0 mmole/L to 8.5 mmole/L in the volunteers and from 1.4 mmole/L to 6.3 mmole/L in the patients after h. No adverse effects on cardiovascular performance were observed. Increases in VO2, and VCO2 and cardiac output were found in both groups, while RQ remained constant. No changes in DLCO and blood gases occurred.

Adolescent↗