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Biomedical subjects

L Jorfeldt

Publications and source records attributed to L Jorfeldt.

At least 91 records · Page 5Linked to original sources
PubMed1985

Influence of extradural blockade on serum thyroid hormone concentrations after surgery.

To study the changes in thyroid hormone metabolism after surgery, the influence of neurogenic blockade by extradural local anaesthetics, and possible hormonal interactions, 16 women undergoing cholecystectomy were randomly allocated to two groups of eight each. All patients received general anaesthesia and in addition one group received extradural blockade for 24 h. Preoperatively and at 2, 4, 6, 12 and 24 h after skin incision arterial serum concentrations of thyroid hormones (T3, free T3, rT3, T4, free T4 and TSH), catecholamines (adrenaline and noradrenaline), cortisol and serum proteins (albumin, prealbumin and TBG) were determined. In both groups total T3, free T3, total T4 and TSH decreased significantly whereas free T4 was unchanged and rT3 increased. No differences between the extradural group and the controls regarding thyroid hormones were observed, in spite of suppressed catecholamine and cortisol concentrations in the extradural group as compared to the control group. All serum thyroid hormone binding proteins decreased significantly in both groups. Changes in thyroid hormone metabolism after surgery seem independent of neurogenic blockade by extradural local anaesthetics, and of plasma catecholamine and cortisol concentrations.

Adult↗
PubMed1984

Is the working capacity of Liberian industrial workers increased by regular malaria prophylaxis?

In a study of the impact of malaria prophylaxis upon the physical working capacity of Liberian industrial workers, two groups of men, one with and the other without malaria prophylaxis, were compared over a period of one year. At the beginning and at the end of the study, the haemoglobin concentration, haematocrit, blood volume and physical performance--measured by bicycle ergometry and expressed as work load at heart rate 170--were compared. No significant differences were found, either within or between the two groups. Routinely distributed malaria prophylaxis thus seems to be of little importance with respect to working capacity in this type of community, where malaria is meso-endemic.

Blood Volume↗
PubMed1984

Effects of the extradural administration of morphine, or bupivacaine, on the endocrine response to upper abdominal surgery.

The endocrine response, and the relief of pain, following the extradural administration of morphine or a local anaesthetic agent bupivacaine (0.5%) were studied for 24h after abdominal surgery and compared with a control group given conventional i.v. morphine after operation. Samples were taken before and at 2, 4, 6, 12 and 24 h after skin incision. Pain relief in both extradural groups was significantly better when compared with the control group. In all three groups, the plasma concentration of cortisol was increased immediately after surgery. Thereafter, significantly lower values were seen in the extradural groups. Plasma adrenaline concentration was lower immediately after surgery only in the group given the extradural local anaesthetic. Plasma noradrenaline concentration remained unchanged after extradural local anaesthesia while an intermediate increase occurred after extradural morphine. Plasma noradrenaline concentration was significantly greater in the controls compared with both extradural groups. Our results indicate that extradural analgesia with a local anaesthetic drug can suppress the increases in the plasma concentrations of the catecholamines and cortisol after surgery. In contrast to extradural local anaesthetic extradural morphine cannot suppress the endocrine response immediately after surgery. However, later in the postoperative period, extradural morphine can suppress the endocrine response, thus indicating that postoperative pain is a factor involved in the stress response following surgery.

Adult↗
PubMed1984

Endocrine and metabolic responses after standardized moderate surgical trauma: influence of age and sex.

The endocrine and metabolic responses to elective cholecystectomy and the influence of age and sex on this stress response were investigated in 21 patients, eight men and 13 women. The patients were divided into two groups, older (n=10) and younger (n=11) than 55 years respectively. Arterial plasma concentrations of catecholamines, cortisol and free fatty acids as well as serum insulin and arterial blood concentrations of glucose, lactate, glycerol, alanine and 3-hydroxybutyrate were measured preoperatively and 2, 24, 48, 72 and 96 h after the start of surgery. Oxygen uptake and CO2 production were measured and respiratory quotient (RQ) was calculated. All hormones and metabolites except insulin and alanine were significantly elevated immediately after surgery. At 24 h plasma noradrenaline and blood glucose were still significantly increased. Serum insulin was increased at 24 and 48 h. Oxygen uptake and plasma cortisol were significantly elevated throughout the period studied and blood alanine was decreased from 2 to 72 h after surgery. The older group showed a significantly higher increase in noradrenaline and lactate, whereas women preoperatively as well as postoperatively had higher glycerol levels. At the end of the period studied women had higher FFA-levels. We conclude that cholecystectomy evokes a significant endocrine and metabolic response and that some of the variables studied are still significantly altered up to 4 days postoperatively. The influence of age and sex on this stress response is of minor importance.

Adult↗
PubMed1984

Effect of propranolol and sclerotherapy in bleeding esophageal varices. A case report.

Portal hypertension and variceal bleeding are discussed in relation to the history of a patient with primary biliary cirrhosis. Beta-blockade and sclerotherapy failed to prevent recurrent bleeding and a shunt operation had to be done. In this patient the portal venous pressure increased despite continuous propranolol administration.

Combined Modality Therapy↗
PubMed1984

Thyroid hormones, catecholamine and cortisol concentrations after upper abdominal surgery.

Serum and plasma concentrations of thyroid hormones, catecholamines and cortisol as well as oxygen consumption were measured simultaneously in twenty patients in connection with cholecystectomy. Arterial blood samples were taken before surgery and at 2, 24, 48, 72 and 96 h after skin incision. A marked and prolonged decrease in T3 and free T3 concentrations was seen. A minor decrease in T4 was also observed but free T4 remained unchanged. TSH concentration was increased 2 h after skin incision, but at no other occasion. A marked increase in adrenaline and noradrenaline concentrations was observed 2 h after the start of surgery. This increase lasted 24 h for noradrenaline. There was a marked and prolonged rise in plasma cortisol after surgery. The oxygen uptake was higher than the preoperative value during the entire postoperative period. No correlations between thyroid hormones and catecholamines or cortisol or oxygen uptake were found. It is concluded that the most pronounced changes in thyroid hormones and TSH after upper abdominal surgery occur about 24 h postoperatively but catecholamines demonstrate their maximal increase immediately after surgery. The inverse correlation between T3 and catecholamines previously reported in burned patients, with their severe hypermetabolism, it is not present during the moderate hypermetabolism after abdominal surgery.

Abdomen↗
PubMed1983

Hemodynamics and leg muscle metabolism at rest and during exercise in young healthy men after prenalterol.

In eight young healthy men the effects of short-term treatment with prenalterol, a new beta-adrenergic agonist, on peripheral hemodynamics and leg muscle metabolism were studied at rest and during exercise at a moderate and a heavy workload. At rest prenalterol treatment significantly increased pulmonary oxygen uptake, heart rate, rate pressure product, and leg blood flow and decreased leg arteriovenous oxygen content difference. During exercise fewer hemodynamic effects of prenalterol were observed. At the moderate workload there was a slight increase in heart rate, but at the heavy workload heart rate fell. Prenalterol raised the arterial concentrations of free fatty acids and glycerol at rest by 70% and 40%, but during exercise these alterations were not present. The plasma levels of epinephrine and dopamine in subjects at rest decreased significantly during influence of prenalterol, but these differences were also abolished during exercise. The leg exchange of metabolites and the concentrations of endogenous muscle metabolites were not influenced by prenalterol, although the lactate concentrations in muscle tended to be lower at rest and during exercise. The results at rest demonstrate that prenalterol in this situation acts predominantly as a stimulator of beta 1-adrenoceptors. During heavy exercise, however, when the endogenous sympathetic tone is high, the beta-stimulating effects are no longer overt and instead reduced heart rate indicates a blocking effect on beta-adrenoceptors. The hemodynamic and metabolic results are concordant with the hypothesis that prenalterol acts as a partial beta-receptor agonist.

Adult↗
PubMed1983

Metabolic changes in a case of malignant hyperthermia.

A patient with fulminant MH is presented. The metabolic changes in muscle tissue, whole blood and plasma are compared with those obtained from the porcine model. The samples were taken 1 h after treatment (including dantrolene sodium) had been commenced. Increased concentrations of lactate, pyruvate and citrate were found in muscle, whereas the concentrations of potassium, free inorganic phosphate and glycogen were reduced. The ATP, ADP and phosphoryl creatine concentrations remained unchanged. In blood, increased concentrations of alanine, lactate and glycerol were observed. An increase in carbon dioxide production was found. These changes are similar to those found in the porcine model.

Carbon Dioxide↗
PubMed1983

Lung uptake of lidocaine in man as influenced by anaesthesia, mepivacaine infusion or lung insufficiency.

Pulmonary uptake of lidocaine was investigated in patients before surgery, and aimed at elucidating the influence of general anaesthesia, the presence of another local anaesthetic agent in the blood, or the possible impact of lung insufficiency. When the lung uptake of lidocaine, injected as a bolus together with indocyanine green dye, was calculated as uptake at 95% pass of the dye, there were no statistically significant differences between the four groups. When the extraction in each of the arterial blood samples was calculated on the basis of the relation between relative concentrations, there were statistically significant differences, with a general tendency towards higher extraction of lidocaine in the awake, healthy volunteers, not given mepivacaine, compared to the other groups. In the group in whom mepivacaine was infused, the arterial concentration of mepivacaine increased transiently after the injection of lidocaine. This probably reflects a displacement of mepivacaine from binding sites for both agents. From this study, it is postulated that the ability of the pulmonary circulation to clear the blood of lidocaine is high, and that it is not affected markedly by those situations studied in the present investigation.

Adult↗
PubMed1983

Tissue oxygenation and muscular substrate turnover in two subjects with high hemoglobin oxygen affinity.

Oxygen transport to and substrate turnover in leg muscle were studied at rest and during light and heavy upright bicycle exercise in two brothers with a hereditary hemoglobinopathy associated with high oxygen affinity (P50 = 13 mmHg). Femoral venous oxygen tension was below normal and femoral venous oxygen saturation above normal at rest and during exercise. Thus, the arterial-femoral venous oxygen saturation difference was decreased. Despite a compensatory increase in hemoglobin concentration, the arterial-femoral venous oxygen content difference tended to be below normal at heavy exercise. Approximately 25% of the oxygen was delivered via the abnormal hemoglobin at relative heavy exercise. Arterial lactate levels, lactate release, and muscle lactate concentration were not increased at any level of exercise. Glucose, alanine, pyruvate, and glycerol turnover were essentially normal, but the glycogen and creatine phosphate stores were abnormally depleted at the termination of heavy exercise. The exercise electrocardiogram (ECG) was normal, indicating that myocardial oxygenation was adequate. Muscle-surface oxygen pressure fields were normal at rest (not investigated during exercise). It is concluded that the high oxygen affinity of the hemoglobin in our two subjects did not lead to heart or skeletal muscle hypoxia during heavy exercise, as judged from the ECG and from the leg lactate turnover. Despite the lack of evidence for muscle hypoxia, the subjects experienced leg muscle fatigue and the creatine phosphate and glycogen stores were depleted more than normally.

Adenosine Triphosphate↗
PubMed1982

Hyperinflation on hyperventilation-a simple test to detect early airway disease.

The hypothesis was raised that an increased end-expiratory lung volume when switching over from normal to hyperventilation (positive delta FRC) can be used as a criterion of early obstructive lung disease. In 20 normal subjects and in 24 patients with suspect or manifest lung disease delta FRC at breathing frequencies of 40, 60 and 80 min-1, forced expiratory volume in one second (FEV1), vital capacity (VC), maximal expiratory flow at 50 and 25% of VC (MEF50 and MEF25) and closing volume (CV) were determined. FEV% (FEV1 X VC-1 X 100) and CV% (CV X VC-1 X 100) were calculated. delta FRC40 correlated negatively with FEV%, MEF50 and MEF25 for normals and patients separately with no difference between the groups. The residual standard deviation of delta FRC40 on FEV% was significantly reduced when MEF50 and MEF25 was included. delta FRC40 did not correlate with CV or CV%. delta FRC60 and delta FRC80 did not correlate with MEF50 and MEF25. The reproducibility of delta FRC40 was of the same order as the other variables studied. A delta FRC40 of +0.31 corresponded to MEF50 and MEF25 values 2 SD below the reference value. This suggests that a positive delta FRC40 of more than 0.31 indicates airway obstruction.

Adolescent↗
PubMed1981

Metabolic effects in muscle during antihypertensive therapy with beta 1- and beta 1/beta 2-adrenoceptor blockers.

The hemodynamic and metabolic consequences of long-term antihypertensive treatment with beta 1- and beta 1/beta 2-adrenoceptor blockade was investigated in five young men with mild essential arterial hypertension (World Health Organization stages I and II) at rest and during submaximal exercise in a single-blind crossover study. The drugs (atenolol and alprenolol) were given in equipotent doses as estimated from their effects on blood pressure. Leg blood flow and oxygen uptake were the same during both treatment periods. Muscle glycogen decreased by 40% during exercise, irrespective of the drug. There was a positive relationship between muscle lactate release and concentration, but for a given muscle lactate concentration the release tended to be lower during treatment with alprenolol. A negative correlation was observed between the percentage of slow-twitch fibers versus lactate release and muscle lactate concentration. The results demonstrate that during exercise muscle glycogen breaks down despite beta blockade and is neither reduced when both beta 1- and beta 2-receptors are blocked, nor when only the beta 1-receptors are blocked. It is also shown that beta blockade impairs the translocation of lactate from the muscle cell to the blood and this is greater with alprenolol than with atenolol, probably due to a membrane effect.

Adrenergic beta-Antagonists↗
PubMed1981

Splanchnic turn-over of some energy metabolites and acid-base balance during intravenous infusion of lidocaine, bupivacaine or etidocaine.

The splanchnic turn-over of energy metabolites in circulating blood has been studied in four groups of young, healthy volunteers, receiving intravenous infusions of physiological saline (n = 5), lidocaine 4 mg/min (n = 7), bupivacaine 2 mg/min (n = 7) and etidocaine 2 mg/min (n = 8). The results showed that the local anaesthetic agents increased the splanchnic blood flow and oxygen consumption, the uptake of glycerol and lactate, and the release of 3-hydroxybutyrate. These effects are adrenaline-like but cannot be explained by one single mechanism involving increased activity of the sympathetic nervous system. Only a minor part of the increased oxygen uptake could be attributed to the energy cost of drug metabolism.

3-Hydroxybutyric Acid↗
PubMed1981

Central haemodynamics during halothane and enflurane anaesthesia in vascular surgery.

Central haemodynamics were studied before and during reconstructive vascular surgery in 18 patients receiving halothane or enflurane anaesthesia (nine patients in each group). In both groups cardiac output (CO), stroke volume (SV), oxygen uptake (VO2) and arterial blood pressure fell significantly after induction of anaesthesia, whereas the arterio-venous oxygen difference (AVD) and the total peripheral resistance (TPR) remained unchanged. In spite of an average intraoperative blood loss of 600 ml, which had not been substituted for, surgery brought about an increase in CO, SV and VO2, while the AVD and TPR remained unchanged. Following transfusion of 900 ml of blood, CO and SV showed a further significant increase in both groups, whereas VO2 was unchanged and the AVD and TPR fell significantly. The pulmonary capillary venous pressure (PPCV) was stable during induction of anaesthesia and surgery but increased after blood transfusion. The changes in SV and PPCV were analyzed in relation to the concept of ventricular function curves. It is concluded that there were no fundamental differences in central haemodynamics between halothane and enflurane anaesthesia either before or during surgery. In both groups the changes in CO and SV were due mainly to a reduced demand of oxygen transport and expected changes in sympatho-adrenergic tone rather than to myocardial depression.

Aged↗
PubMed1981

Influence of abdominal surgical trauma upon some energy metabolites in the quadriceps muscle in man.

Thirteen patients with gallbladder disease but otherwise healthy were studied in connection with cholecystectomy. Specimens of the lateral vastus muscle were taken by the percutaneous needle biopsy technique during anesthesia before surgery, on two occasions during surgery and 30 min after discontinuation of anaesthesia. The muscle samples were analysed for glycogen, lactate, citrate, ATP, phosphoryl creatine, creatine and water content. Citrate and lactate concentrations in muscle increased continuously throughout the study. There were no significant changes in the concentration of glycogen, phosphoryl creatine, and ATP in muscle tissue. The increase in citrate concentration is probably related to an augmented uptake and combustion of free fatty acids and 3-hydroxybutyrate in this situation. The data suggest that during anaesthesia and abdominal surgery an increase in the muscle citrate concentration may contribute to the modulation of carbohydrate utilization in skeletal muscle.

Abdomen↗