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Biomedical subjects

L Jorfeldt

Publications and source records attributed to L Jorfeldt.

At least 73 records · Page 4Linked to original sources

Cryoprecipitate infusion fails to improve organ function in septic shock.

Plasma fibronectin may be of critical importance for the septic patient through its proposed function as the major opsonin for macrophage clearance of circulating, noncellular debris. As a rule, critically ill, septic patients are depleted of fibronectin. In earlier uncontrolled studies, infusion of fibronectin-rich cryoprecipitate had resulted in improved renal and pulmonary functions and changes in peripheral hemodynamics. In this controlled study, 32 septic ICU patients (mean initial fibronectin level = 60% of normal) received cryoprecipitate or control infusions. Although the fibronectin level was significantly elevated to the normal range in the cryoprecipitate group, no effects were seen in hemodynamics, oxygen metabolism, or lung and kidney functions. Our results indicate that this form of fibronectin therapy does not influence the impaired organ function in septic shock.

Adult↗

The influence of epidural analgesia on the splanchnic exchange of amino acids during upper abdominal surgery.

Splanchnic turnover of plasma amino acids was studied in 10 patients given thoracic epidural analgesia combined with general anaesthesia for elective cholecystectomy. Ten other patients given only general anaesthesia for cholecystectomy served as a control group. All patients received an infusion of glucose during the investigation. The total concentration of amino acids in arterial plasma did not change in the patients given epidural analgesia but decreased by approximately 15% in the non-epidural group. In both groups splanchnic uptake of amino acids increased during surgery and was found to be more than doubled in the early postoperative period. The addition of epidural analgesia to general anaesthesia did not modify the splanchnic uptake of amino acids during surgery and in the immediate (2 h) postoperative period.

Abdomen↗

Sympathetic activity and haemodynamic variables during spinal analgesia in man.

At present there is a lack of information concerning haemodynamic changes related to the degree of sympathetic blockade during spinal analgesia. In this investigation, involving 36 patients, changes in haemodynamic parameters were studied in 30 patients receiving spinal analgesia and in six patients having "sham spinal" analgesia. Three local anaesthetic solutions were used: bupivacaine without and with glucose and tetracaine with glucose. Skin conductance responses were used to evaluate changes in provoked sympathetic activity. It was found, as in previous studies, that a complete block of sympathetic activity in the foot was seen in only 60% of patients with an average analgesic level of T4. A partial sympathetic blockade was registered up to and above the level of analgesia. In 25/30 cases only minor alterations in cardiac output, heart rate, stroke volume, mean arterial pressure and systemic vascular resistance were seen in spinal analgesia whose level reached on average T4-5. In five cases in whom analgesia reached T4-3, mean arterial pressure fell greater than or equal to 30% with a well-preserved cardiac output, but with complete sympathetic blockade up to T5 and in two cases also in the hand. Only minor differences were observed between the different anaesthetic solutions.

Analgesia↗

The influence of abdominal surgical trauma on the exchange of blood-borne amino acids in the human leg.

Associated with surgical trauma is an increased release of gluconeogenic substrates from the periphery. The present study was undertaken to investigate the peripheral exchange of blood and plasma amino acids as well as some other gluconeogenic substrates (lactate and glycerol) in connection with abdominal surgery. Measurements of leg blood flow and femoral arterio-venous substrate differences were made before, during and immediately after elective cholecystectomy. Blood and plasma concentrations of most amino acids except alanine decreased during and immediately after surgery. Simultaneously there was an increased release of several of the amino acids as well as lactate and glycerol from the leg. The total release of plasma amino acids from one leg in the immediate postoperative period was about 2.5 times as high as before surgery. The turnover rates of amino acids as well as the changes in turnover rates were comparable whether the calculations were made from plasma or whole blood concentrations. At the end of surgery there was a high peripheral uptake of 3-hydroxybutyrate concomitant with a low release of amino acids.

Journal Article↗

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↗

The exchange of blood-borne amino acids in the leg during abdominal surgical trauma: effects of glucose infusion.

The exchange of plasma amino acids and glucose, lactate, glycerol and 3-hydroxybutyrate in the leg was studied in otherwise healthy patients undergoing elective cholecystectomy. Seven patients were given a constant intravenous infusion of glucose at a rate of 1.1 mmol/min throughout the study. Seven other patients who received normal saline only served as a control group. Measurement of leg blood flow and arterio-femoral venous differences of amino acids and other energy metabolites were made on four occasions: (I) before surgery, (II) 10 min after skin incision, (III) at the end of surgery, and (IV) 30 min after the end of anaesthesia. The release of amino acids from the leg was comparable in the two groups before and during the early part of surgery. At the end of surgery the release of several individual amino acids, as well as the total release of amino acids, from the leg was higher in the patients given glucose infusion compared with the control patients. The infusion of glucose prevented the intraoperative rise in arterial levels and uptake of 3-hydroxybutyrate in the leg. A high release of amino acids at the end of surgery was thus associated with low arterial levels of 3-hydroxybutyrate while the reverse pattern was seen in the control patients. These effects of glucose infusion were qualitatively different from those seen in uninjured postabsorptive man.

3-Hydroxybutyric Acid↗

Overuse and distorsion soccer injuries related to the player's estimated maximal aerobic work capacity.

Fourty senior male soccer players were selected for this study. Before the season, each subject performed an exercise test, and the maximal capacity of oxygen uptake was estimated according to Astrand and Rhyming. The exercise test was repeated in 25 subjects 6 months later. The subjects were then ranked according to their estimated maximal capacity of oxygen uptake (estimated VO2 max) at the first test and allocated into one of three groups of similar size. During the season, all new injuries were examined and registered by an orthopaedic surgeon, and the subjects were allocated into one of three groups (overuse injuries, distorsion injuries, and other injuries). There were significantly more overuse injuries among subjects with high estimated VO2 max, and the incidence of distorsion injuries tended to be lower among subjects with high estimated VO2 max. No correlation was found regarding the total incidence of injuries and estimated VO2 max. No significant difference in estimated VO2 max was registered between the tests before and after the season.

Athletic Injuries↗

Effect of extradural analgesia on glucose metabolism and gluconeogenesis. Studies in association with upper abdominal surgery.

Concentrations of glucose and gluconeogenic substrates across the splanchnic circulation were studied in 20 patients undergoing cholecystectomy with general anaesthesia. In 10 patients, general anaesthesia was administered alone, and in 10 general anaesthesia was combined with thoracic extradural analgesia. All patients received a constant i.v. infusion of glucose. Blood glucose concentration increased markedly in the general anaesthesia group in contrast to a moderate and shortlived increase in the patients given extradural analgesia, in whom the splanchnic release of glucose tended to be lower. The splanchnic uptake of glycerol was lower in the patients given extradural analgesia, while the uptake of lactate and the increase in alanine uptake was similar in both groups. Plasma catecholamine and serum cortisol concentrations were higher in the group receiving general anaesthesia alone, while serum growth hormone concentration was higher after surgery in the extradural group. The addition of extradural blockade to general anaesthesia suppresses the increase in blood glucose concentration--and this may be related to a reduced splanchnic release of glucose combined with an increased peripheral uptake.

Abdomen↗

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↗

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↗

Primary fibromyalgia. A clinical and laboratory study of 55 patients.

The clinical symptoms of 55 patients with primary fibromyalgia (PF) were studied and compared with 30 patients with rheumatoid arthritis (RA). The PF patients expressed a more intense feeling of illness than did the RA patients. Stiffness occurred just as often in PF as in RA. Trigger points occurred less frequently in RA patients. Muscular fatigue appeared to be one of the most disabling symptoms in PF. Neurophysiological studies indicated that the fatigue was at least partly of central origin. Ischemic forearm exercise test gave no evidence of impaired glycogenolysis. Laboratory investigation revealed normal 25-hydroxyvitamin D, cobalamin, folate, estrogen, testosterone, and myoglobin in the PF patients.

Adult↗

The influence of abdominal surgery on the splanchnic exchange of amino acids.

The splanchnic exchange of amino acids was studied during and immediately after elective cholecystectomy in 10 patients given a constant infusion of glucose (1.1 mmol/min). Measurements of splanchnic blood flow and arteriohepatic venous differences of plasma amino acids, glucose, lactate and glycerol were made preoperatively, intraoperatively and twice in the immediate postoperative period. The arterial plasma concentration of most amino acids declined during and after surgery but the arterial concentration of alanine was highest in the postoperative period. The total splanchnic uptake of amino acids increased from 140.3 +/- 36.0 mumol/min preoperatively to 338.2 +/- 51.7 mumol/min postoperatively (p less than 0.05). Alanine and glutamine accounted for 65-70% of the total splanchnic uptake of amino acids throughout the investigation. The fractional extraction of methionine increased in the immediate postoperative period, while the fractional extraction of the remaining amino acids was stable. The splanchnic uptake of gluconeogenic substrates exceeded the splanchnic glucose release. The splanchnic uptake of amino acids had already increased intraoperatively and further increased postoperatively despite a net splanchnic glucose uptake in this period.

Abdomen↗

Clinical buffering of metabolic acidosis: problems and a solution.

Traditionally sodium bicarbonate has been the buffer of first choice in the treatment of metabolic acidosis. This treatment, however, involves risks of developing a hyperosmolar state, a high sodium concentration in the blood, increased arterial carbon dioxide tension and, as a result of the latter, intracellular and intracerebral acidosis and also cerebral oedema. The buffering effect occurs slowly and as a consequence of this, and of the titration curve of sodium bicarbonate, overcorrection of metabolic acidosis is often seen. Tris buffer was introduced as an alternative and has been claimed to solve most of these problems, but on the other hand it entails a very high risk of peripheral venous thrombosis and thrombophlebitic lesions owing to its local irritative effect. In order to overcome these disadvantages a new mixture of Tris, acetate, bicarbonate and phosphate has been designed. In the studies described it was shown to have an adequate buffering effect and to provide a solution to most of the problems connected with buffering of metabolic acidosis. The new Tris buffer mixture has a buffering effect in blood equivalent to 0.5 mol/l sodium bicarbonate, although its sodium content has been decreased to one-third of pure sodium bicarbonate. Its administration also results in predictable buffering in cerebrospinal fluid and skeletal muscle. In a clinical study it was demonstrated that the new Tris buffer mixture results in sufficient and adequate buffering without significant side-effects.

Acetates↗

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↗

A hemodynamic profile diagram and its application in septic patients.

A physiologic profile is presented in the form of a circular diagram, in which hemodynamic parameters, oxygen uptake and arterial lactate are displayed on 12 radial spokes. Results are presented as per cent of reference values. In the normal state the profile will be evenly circular, while different circulatory disturbances present typical patterns. This is shown in serial measurements on 12 septic patients, who displayed increases in cardiac output, oxygen metabolism, stroke volume, heart rate, pulmonary artery pressure, right atrial pressure, pulmonary capillary wedge pressure and arterial lactate, while pulmonary and systemic vascular resistances were decreased. Stepwise multiple regression analysis indicated that systemic vascular resistance was the best early discriminator between survivors and non-survivors. The hemodynamogram offers a compact and easily understood presentation of data, which makes it possible to follow the course of the disease and provides a diagnostic and didactic tool.

Adult↗

Gas exchange during mechanical ventilation.

In an experimental model using a Servo-ventilator (Siemens-Elema, Sweden) oxygen consumption (V'O2) and carbon dioxide production (V'CO2) were measured at varying FIO2. Gas exchange was simulated by adding N2 or CO2 to the inspiratory line of the ventilator. Inspiratory and expiratory gases were collected in Douglas bags for analyses by a mass spectrometer. The residual standard deviation for the regression of measured V'O2 on predicted V'O2 was 14 ml/min and did not significantly differ from the line of identity. For V'CO2 the corresponding residual standard deviation was 3 ml/min. This regression line deviated by -3% from the line of identity.

Carbon Dioxide↗

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↗