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Biomedical subjects

H Rutberg

Publications and source records attributed to H Rutberg.

At least 37 records · Page 2Linked to original sources
PubMed1991

Delayed recovery of muscle pH after short duration, high intensity exercise in malignant hyperthermia susceptible subjects.

Six subjects susceptible to malignant hyperthermia (MHS) and seven control subjects exercised for 4 min at 120% of their calculated maximal oxygen uptake on a bicycle ergometer. Mean (SEM) muscle pH, measured with a needle-tipped electrode in the vastus lateralis muscle, decreased from a resting value of 7.16 (0.04) to 6.78 (0.04) after exercise in the control group, and from 7.15 (0.05) to 6.56 (0.05) in the MHS group (P less than 0.01 compared with control group). A further decrease in muscle pH to 6.68 (0.06) by 5 min after exercise occurred in the control group, followed by incomplete recovery to 7.06 (0.04) 30 min after exercise. In the MHS group, however, muscle pH decreased to 6.45 (0.05) 5 min after exercise before recovering slowly to only 6.64 (0.07) after 30 min (P less than 0.01 compared with control group). There was no difference in muscle temperature, venous pH or venous lactate concentrations between the two groups. The results show that there is abnormal recovery of muscle pH after short-duration, high-intensity exercise in MHS subjects.

Adult↗
PubMed1990

Effect of starvation on work capacity and voluntary skeletal muscle function in man.

Post-operative fatigue is a well-known clinical problem even after uncomplicated surgery. In the multifaceted post-operative state, several factors other then the surgical trauma may influence muscular function, such as an insufficient nutritional intake. The aim of this study was to investigate the effect of fasting on work capacity and voluntary skeletal muscle function. Eight healthy lean volunteers, age range 25-43 years, were studied the day before starvation, at the end of the fasting period of 5 days, and after another 3-4 days on a normal diet. Hand grip strength was assessed as maximum voluntary contraction (MVC) and physical working capacity was investigated with successively increased work load on a cycle ergometer until near exhaustion. After 5 days of total starvation, MVC remained unchanged but physical working capacity was reduced from 220 +/- 18 watt to 199 +/- 22 watt (p < 0.05). Corresponding heart rate, estimated effort and leg tiredness were not changed. A poor nutritional intake per se may therefore be a less important factor causing post-operative muscle fatigue than the operation itself.

Journal Article↗
PubMed1990

Comparison of dye-dilution and plethysmographic blood flow measurements: an evaluation of the influence of invasive techniques on blood flow and on arterial and femoral venous substrate variables in man.

1. In eight healthy volunteers we compared leg blood flow, as determined in a calf segment by strain-gauge plethysmography, with the flow measured by a constant-rate infusion of Indocyanine Green dye into the femoral artery. The representativeness of the calf segment was evaluated by complementary measurements with additional strain gauges attached around the proximal and distal crural and the distal thigh segments (n = 6). Furthermore, we investigated the influence of the catheterization procedure and a simulated vascular puncture, as well as repeated venous occlusions, on blood flow and on arterial and femoral venous substrate concentrations and blood gases (n = 8). 2. The leg blood flow measured by dye dilution was 0.31 +/- 0.03 litre/min (mean +/- SEM). The blood flow in the calf segments was 14.8 +/- 1.6 ml min-1 litre-1 and no difference between the legs was observed. Extended to the whole leg the plethysmographic blood flow was 0.17 +/- 0.01 litre/min and thus lower (43 +/- 7%, P less than 0.001) than the flow determined by the indicator-dilution method. Blood flow in the legs was not influenced by catheterization or sham punctures of the vessels or by repeated venous occlusions. 3. The concentrations of glucose, lactate and glycerol, as well as blood gas variables, in arterial and femoral venous blood did not change during the study or decreased so slightly (pH and lactate) that the arteriovenous difference was not influenced. 4. We conclude that the blood flow of the total leg cannot be satisfactorily estimated from strain-gauge plethysmography of a single calf segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Influence of local beta-adrenoceptor blockade on exchange of fat and glucose in the human leg after surgery.

The metabolic effects of the local administration of propranolol were determined in seven patients undergoing cholecystectomy. Measurements were carried out in the early postoperative period before and after infusion of 2 mg of intraarterial propranolol into the femoral artery of one leg using the other leg as control. Blood flow and arterio-venous concentration differences for oxygen, glucose, lactate, alanine, glycerol and total FFAs were determined. Uptake and release of FFAs were determined by using a tracer technique. The statistical analyses were based on differences between the test and the control leg in changes following the blockade. Glycerol release was significantly more suppressed in the test leg than in the control leg. No difference between the legs was seen in the uptake of oxygen, FFA and glucose or the release of lactate and alanine. The arterial concentration of propranolol was 6.07 +/- 0.72 ng ml-1 (mean +/- SEM). This study indicates that a local beta-blockade by intra-arterial propranolol infusion after surgery slightly reduces the postoperative lipolysis in leg tissues but does not influence or only marginally influences leg blood flow and oxygen uptake or the exchange of glucose, lactate and alanine after moderate surgical trauma.

Adult↗
PubMed1989

Epidural morphine by the thoracic or lumbar routes in cholecystectomy. Effect on postoperative pain and respiratory variables.

Thirty-seven women undergoing elective cholecystectomy were randomised into two groups, receiving either lumbar epidural morphine (group L) or epidural morphine via the thoracic route (group T). The effect on pain relief was assessed by a visual analogue scale and included both resting pain and 'provoked' pain. Respiratory parameters (PEF, FEVI and FVC) were also studied. The patients were investigated preoperatively, and 4, 6, 12 and 24 hours after the start of surgery. No significant difference was observed between the groups concerning pain relief or respiratory performance. We conclude that after cholecystectomy lumbar epidural morphine is as effective as thoracic epidural morphine in relieving postoperative pain.

Adult↗
PubMed1988

Skeletal muscle contraction characteristics in vivo in malignant hyperthermia susceptible subjects.

Ten malignant hyperthermia susceptible (MHS) subjects were investigated, all of them positive in in vitro tests. As a control group 12 healthy subjects were investigated. The investigation was done in a blind fashion during strictly standardized conditions. Electromechanical delay of contraction and half contraction time to tetanus were faster (P less than 0.05) while half relaxation time was shorter in the MHS subjects (P less than 0.05). Skin and intramuscular temperature were significantly higher in the MHS subjects (P less than 0.05). This indicates that MHS subjects differ in various skeletal muscle characteristics during "normal" conditions. Further studies to define the temperature level at which the test of muscle function is most discriminating are needed before it can be used for diagnostic purposes.

Adolescent↗
PubMed1988

Spinal haematoma following epidural analgesia. Report of a patient with ankylosing spondylitis and a bleeding diathesis.

A patient who developed an epidural haematoma with multifactorial aetiology (bleeding diathesis, ankylosing spondylitis, chronic alcoholism and acute pancreatitis) after epidural analgesia for pain relief is described. Our conclusion is that adequate laboratory screening of blood coagulation, including platelet count, should be carried out in this category of patient before attempted epidural blockade, the risks of which must be weighed against the benefits. The block should be allowed to wear off intermittently and repeated neurological assessment performed if an epidural catheter is used for repeated injections or for a continuous infusion of local anaesthetic. Neuroradiological examination should be carried out promptly if an epidural haematoma is suspected and surgical decompression performed without delay if the diagnosis is confirmed.

Anesthesia, Epidural↗
PubMed1987

Effects of graded exercise on leg exchange of energy substrates in malignant hyperthermia susceptible subjects.

It has been speculated that, in malignant hyperthermia-susceptible (MHS) individuals, an abnormality of sympathetic activity is seen during stressful situations, such as exercise. The authors investigated whether muscle metabolism in eight MHS subjects, at rest and during moderate and heavy short-term exercise, is different then that in normals. Leg exchange of energy substrates (glucose, lactate, and glycerol) was quantified by measuring leg blood flow and arterial-venous concentration differences. Muscle biopsies were also performed, and ATP, glycogen, and lactate were analyzed. Catecholamines and oxygen uptake were also measured. The study was performed at rest with subjects in the supine position and during two periods (40% and 80% of the subjects maximal oxygen uptake, respectively) on a bicycle ergometer. The principal finding of the study was that there was no major difference in oxygen uptake or leg exchange of glucose, lactate, and glycerol between MHS-subjects and previously standard normals during different grades of exercise. Furthermore, muscle metabolites and plasma catecholamines did not differ between the groups. This study indicates a normal sympathetic activity and muscle metabolism in MHS subjects during rest, as well as during moderate and severe exercise. The authors' results do not support the opinion that persons with positive in vitro tests for MH should restrict their physical activity.

Adult↗
PubMed1987

Abnormal relaxation rates in subjects susceptible to malignant hyperthermia.

The acute malignant hyperthermia crisis appears to be mediated by a sudden and sustained rise in the concentration of sarcoplasmic calcium, leading to a prolonged muscle contraction. It is not known whether calcium metabolism in skeletal muscle is abnormal in malignant hyperthermia susceptible (MHS) subjects under normal conditions. A hypermetabolic state in skeletal muscle can be assessed in vivo by measuring relaxation rate. In the present study the relaxation rate was measured in the adductor pollicis muscle after electrical stimulation of the ulnar nerve. Ten MHS subjects with no clinical symptoms of muscle disease were investigated. Relaxation rates were found to be significantly higher in the MH-susceptible subjects compared with controls even under normal conditions (p less than 0.001). Determination of relaxation rate could thus be considered a possible addition to those methods currently available for the diagnosis of MHS.

Adolescent↗
PubMed1987

Influence of epidural blockade on postoperative plasma fibronectin concentrations.

To investigate the influence of neurogenic and hormonal stimuli during and after surgery on plasma fibronectin levels, 16 females undergoing cholecystectomy were studied. Eight patients received general anaesthesia, and eight also received a thoracic epidural block with local anaesthetic, which was maintained for 24 h postoperatively. The epidural group had significantly lower plasma levels of adrenaline and cortisol than the general anaesthesia group in the postoperative period. The previously well-documented early decrease in plasma fibronectin concentration following surgery was observed, and was essentially parallel with that of albumin, pre-albumin and thyroid hormones, with no differences between the groups. However, the restoration of the fibronectin level was slower in the epidural group, with significantly lower values as compared with controls at 48 and 72 h after surgery (p less than 0.01-0.001). It was concluded that the post-traumatic plasma fibronectin decrease is not mediated by neurogenic or adrenal stimuli. Such stimuli may, however, influence the subsequent restoration of the plasma fibronectin concentration.

Adult↗
PubMed1986

Exchange of free fatty acids and glucose in leg tissues before and immediately after surgery.

The present study was undertaken to investigate whether there is an augmented uptake of free fatty acids (FFA) in the leg tissues immediately after surgery when the energy expenditure of the leg is increased considerably. Eight patients were studied before and after cholecystectomy. Blood and plasma flow were determined in one leg, as well as arterio-venous concentration differences for oxygen, glycose, lactate and the total fraction of FFA. To determine uptake and release of FFA, 1-(14C)-oleic acid was infused intravenously and the arterio-venous differences for (14C)-FFA were determined. The mean oxygen uptake in the leg increased from 0.72+/-0.06 mmol/min to 1.78+/-0.41 mmol/min. The uptake of free fatty acids in the leg did not increase significantly after cholecystectomy when compared to before operation in spite of the marked increase in oxygen uptake. Postoperatively there was, however, a positive linear relationship between the uptake of FFA and that of oxygen in the leg. The glucose uptake, after correction for released lactate, corresponded to 7% of the oxygen uptake before surgery and 13% after surgery. The arterial FFA concentration did not change. This study indicates that the combined possible contribution of glucose and free fatty acids to the oxidative energy metabolism of the leg tissues exceeded the oxygen uptake before, but not after surgery. In the postoperative state there was a positive correlation between oxygen uptake and FFA uptake in the leg.

Journal Article↗
PubMed1986

Malignant hyperthermia: clinical course and metabolic changes in two patients.

Two cases of malignant hyperthermia (MH) are presented. One patient was treated symptomatically for the first 6 h until she was given dantrolene. Her clinical course was complicated and the catecholamine and cortisol concentrations were still elevated 24 h after start of treatment. In the second patient an early diagnosis was made and treatment promptly instituted. Only minor endocrine-metabolic changes were seen in this patient. However, in spite of the early successful treatment with dantrolene the MH reaction recurred 12 h after the initial symptoms. These two cases demonstrate the importance of early treatment including dantrolene. Successful treatment with dantrolene does not, however, preclude a recurrence of MH, and thus subsequent doses of dantrolene should be given.

Catecholamines↗
PubMed1986

Effect of adrenaline on exchange of glucose in leg tissues and splanchnic area. A comparison with the metabolic response to surgical stress.

Surgical trauma is accompanied by increased energy expenditure and raised arterial concentrations of adrenaline and glucose. In order to study the acute effects of an adrenaline infusion on glucose metabolism and oxygen uptake in the leg and splanchnic bed, adrenaline was administered at a rate giving plasma concentrations of adrenaline similar to those in connection with abdominal surgery. Seven healthy males participated in the study. Adrenaline 40 ng/(min X kg body weight) (0.22 nmol/(min X kg body weight] was infused producing a plasma concentration of 2.77 +/- 0.42 nmol/l (mean +/- SEM). Leg and splanchnic blood flows and the femoral and hepatic arterio-venous differences for oxygen, glucose, lactate and other metabolites were determined. Measurements were made before and between 30 and 40 min after the start of the adrenaline infusion. Following the infusion of adrenaline the leg blood flow increased by 140% and hepatic blood flow by 25%. The leg oxygen uptake increased by 30%, but no significant increase in splanchnic oxygen uptake was observed. The arterial glucose concentration rose by 35%. Splanchnic glucose output increased X 2.5, but no significant increase in leg glucose uptake was observed. Leg release of gluconeogenic substrates increased but only lactate and glycerol uptake increased in the splanchnic bed. Leg blood flow increased more than that usually seen after surgery, whereas leg oxygen uptake and splanchnic oxygen uptake was higher in the immediate postoperative period. Splanchnic glucose release increased more during the infusion than in connection with surgery. It is concluded that adrenaline at a plasma concentration similar to that during and immediately after surgery can induce changes in glucose metabolism which are of the same order or more pronounced than those seen in connection with abdominal surgery.

Adult↗
PubMed1986

Effect of adrenaline on exchange of free fatty acids in leg tissues and splanchnic area. A comparison with the metabolic response to surgical stress.

The present investigation was aimed at studying the acute effects of an adrenaline infusion on the exchange of free fatty acids in the leg and splanchnic bed. Seven healthy males participated in the study. Adrenaline (40 ng/(min X kg body weight)) (0.22 nmol/(min X kg body weight] was infused to produce a plasma concentration similar to that seen in connection with surgery (2.77 +/- 0.42 nmol/l). Leg and splanchnic blood flow were measured and the femoral and hepatic arterio-venous differences for the total fraction of FFA were determined. 1-14C-oleic acid was infused intravenously so as to determine uptake and release of FFA. Measurements were made before and between 30 and 40 min after the start of the adrenaline infusion. The FFA concentration rose by 140% and the FFA uptake in the leg and splanchnic region increased about three fold. For 3-hydroxybutyrate the arterial concentrations as well as leg uptake and splanchnic uptake increased about six fold, four fold and eight fold, respectively. Ketogenesis accounted for a large part of the FFA uptake in the splanchnic bed during adrenaline infusion. We conclude that adrenaline infusion results in pronounced changes in FFA and 3-hydroxybutyrate concentrations and in the exchange of these substrates in leg and splanchnic bed. The adrenaline-induced increases in FFA and 3-hydroxybutyrate metabolism were generally more marked than those seen during and immediately after surgery.

3-Hydroxybutyric Acid↗
PubMed1985

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

The influence of thoracic extradural local anaesthetics (0.5% bupivacaine) or extradural morphine on the metabolic response to upper abdominal surgery was compared with the administration of morphine i.v. in the period after operation. The extradural local anaesthetic group had significantly lower blood glucose and plasma FFA concentrations and consistently, but not significantly, lower blood glycerol and lactate concentrations than both the other groups. At 4 h both extradural groups had significantly lower plasma FFA and blood 3-hydroxybutyrate concentrations than the control group. Blood alanine concentration decreased in all three groups with a minimum at 24 h. There were no differences in serum insulin concentrations between the groups. It is concluded that thoracic extradural morphine differs from thoracic extradural local anaesthetics in being much less able to suppress the metabolic response associated with upper abdominal surgery.

Adult↗
PubMed1985

Factors of importance in the hyperglycaemia induced by upper abdominal surgery.

The variation in the hyperglycaemic response, between different individuals, is large in the immediate postoperative period. In the present study, factors of possible importance in the hyperglycaemic response to standardized elective surgery (cholecystectomy) were determined by stepwise multiple linear regression analysis. The statistical analysis comprised 29 variables which included hormones (catecholamines, cortisol, insulin, thyroid hormones), blood-borne energy metabolites (glucose, lactate, free fatty acids (FFA), glycerol, 3-hydroxybutyrate, alanine) as well as anthropometric data and variables related to surgery and anaesthesia. In linear regression analysis, with one independent variable, the glucose concentration correlated significantly with: the duration of surgery, the dose of pancuronium bromide, the dose of fentanyl, the lactate, adrenaline and cortisol concentrations respectively. The variables which, when successively included in stepwise regression, significantly reduced the residual variance for glucose were, in order of introduction; the duration of surgery and the cortisol and adrenaline concentrations respectively. It is concluded that, in standardized surgical trauma the duration of surgery may influence the metabolic response to surgery. Duration of surgery has, thus, to be taken into account when interpreting results from studies where different treatments are compared. Our results confirm that there is a synergistic effect of cortisol and adrenaline in mediating the hyperglycaemic response to surgery.

Adult↗