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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sepsis is a major catabolic insult resulting in modifications in carbohydrate and fat energy metabolism, and leading to increased muscle breakdown and nitrogen loss. Insulin resistance, which develops in sepsis, decreases glucose utilization, but plasma insulin levels are sufficiently elevated to prevent lipolysis, resulting in a further energy deficit. The availability of fuels in sepsis is therefore limited, and the body resorts to muscle breakdown, gluconeogenesis, and amino acid oxidation for energy supply. Previous work has not defined, however, the exact alterations in amino acid metabolism. Therefore, the following studies were undertaken. Blood samples were drawn from fifteen patients in whom the diagnosis of sepsis was clinically established; the samples were analyzed for amino acid, beta-hydroxyphenylethanolamines, glucose, insulin and glucagon concentrations. The plasma amino acid pattern observed was characterized by an increase in total amino acid content, due mainly to high levels of the aromatic amino acids (phenylalanine and tyrosine) and the sulfur-containing amino acids (taurine, cystine and methionine). Alanine, aspartic acid, glutamic acid and proline were also elevated, but to a lesser degree. The branched chain amino acids (valine, leucine and isoleucine) were within normal limits, as were glycine, serine, threonine, lysine, histidine and tryptophan. Those patients who did not survive sepsis had higher levels of aromatic and sulfur-containing amino acids as compared to those patients surviving sepsis. On the other hand, those patients surviving sepsis had higher levels of alanine and the branched chain amino acids. In a second group of five patients with overwhelming sepsis accompanied by a state of metabolic encephalopathy, a parenteral nutrition solution consisting of 23% dextrose, and an amino acid formulation enriched with branched chain amino acids was administered. In these five patients, normalization of the plasma amino acid pattern and reversal of encephalopathy was observed. The following sequence of events may be postulated: The septic patient develops insulin resistance in the peripheral tissues, primarily muscle, while the adipose tissue is much less affected. The insulin resistance and the inability to utilize fat leads to increased muscle proteolysis. Muscle breakdown results in release into the blood of enormous amounts of various amino acids; the muscle itself is able to oxidize the branched chain amino acids, supplying the muscles' own energy requirements and alanine for gluconeogenesis. The extensive muscle proteolysis coupled with relative hepatic insufficiency occurring early in sepsis results in the appearance in the plasma of high levels of most of the amino acids present in muscle, particularly the aromatic and the sulfur-containing amino acids. The outcome of patients with sepsis might be positively affected by combined therapy with glucose, insulin and branched chain amino acids.
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PMID:Amino acid derangements in patients with sepsis: treatment with branched chain amino acid rich infusions. 9 98

Sepsis is a major catabolic insult resulting in a peripheral energy deficit which is made up in part by increased breakdown of lean body mass and oxidation of amino acids, principally the branched chain amino acids. The prognosis in any given case of sepsis is difficult to predict, but should theoretically be related to the degree of disturbance in peripheral energy deficit, which may in turn, be related to plasma amino acid pattern. In order to study whether this hypothesis was correct, plasma amino acids and some of their metabolic byproducts, the beta-hydroxyphenylethanolamines, were studied in 25 septic patients, and were used as discriminant variables in a series of computer performed discriminant analyses and multiple regressions. The two functions tested were the degree of metabolic septic encephalopathy as a determinant of the severity of sepsis and the final outcome in the septic patient. Plasma amino acid patterns exhibited elevated levels of the aromatic and sulfur containing amino acids, phenylalanine, tryosine, tryptophan, methionine, cysteine, and taurine, normal concentrations of alanine, and low normal concentrations of the branched chain amino acids, valine, leucine and isoleucine. Arginine levels, as previously noted, were very low. Patients not surviving the septic episode exhibited higher concentrations of aromatic and sulfur containing amino acids, while patients surviving sepsis had higher concentrations of the branched chain amino acids and arginine. When the degree of encephalopathy as a determinant of the severity of sepsis and step wise discriminant analysis with multiple crescent techniques were used, the best discriminant function between patients with and without encephalopathy was found to result from the interaction of cysteine, methionine, phenylalanine, isoleucine, leucine, and valine. These amino acids gave a correct classification in 82% of patients with no encephalopathy, and 80% of patients with septic encephalopathy. When the same amino acids were used for the discriminant analysis for patients dying of sepsis and patients surviving, the best discriminant function was achieved by using plasma concentrations of alanine, cysteine, methionine, isoleucine, arginine, tyrosine and phenylalanine resulting in 91% of the nonsurvivors, and 79% of the survivors correctly classified. The results suggest a close and significant relationship between the deranged energy metabolism and muscle protein breakdown in sepsis, and the outcome. This further suggests a central role for certain amino acids in perhaps predicting the severity of sepsis and its outcome.
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PMID:Plasma amino acids as predictors of the severity and outcome of sepsis. 38 83

Femoral arteriovenous differences and flux of amino acids across the leg were measured in seven septic patients and compared with those of six nonseptic patients on days 1 and 3 following major surgery. The septic patients were seriously ill and judged clinically to be catabolic. The postoperative patients, although not septic, were expected to have a maximal catabolic response to operation during the first 3 days after operation. Both groups had increased release of phenylalanine from the leg, an index of muscle proteolysis. Septic patients had decreased femoral arteriovenous differences (--20 vs --74 and --60 mumoles/liter) and decreased flux (34 vs 169 and 128 nm/100 gm of calf muscle) of the branched-chain amino acids as compared with the nonseptic postoperative patients on days 1 and 3. The arterial plasmal levels of the branched-chain amino acids and alanine were not different, but phenylalanine was elevated in the septic patients (88 vs 49 and 55 mumoles/liter). The insulin:glucagon molar ratio was lower in the septic patients (2.4 vs 4.4 and 5.5). These findings suggest that in the catabolism of sepsis there is greater oxidation of branched-chain amino acids in muscle than in the catabolism associated with uncomplicated surgery.
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PMID:Femoral arteriovenous amino acid differences in septic patients. 42 6

In order to quantitate the effect of sepsis and skeletal trauma on gluconeogenesis, four septic and five skeletal trauma patients were evaluated for their ability to convert 14C-L-alanine to 14C-glucose while receiving 5% dextrose by peripheral vein. In the septic group, the mean glucose pool size increased by 35% and the glucose turnover rate increased by 85% over normal. The alanine conversion averaged 11.1% of the dose. The skeletal trauma group showed a glucose pool size increase of 61%, a 100% increase in glucose turnover rate and a 11.7% conversion of the alanine dose to glucose. The increased conversion of 14C-alanine to 14C-glucose in both sepsis and skeletal trauma in the face of an exogenous glucose infusion indicates an abnormal unsuppressible response. Each of the above parameters when compared to normal values was found to be significant at levels greater than 97.5%. The percentages of the dose expired as 14CO2 in three hours were not significantly different from the normals.
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PMID:Gluconeogenic response during glucose infusions in patients following skeletal trauma or during sepsis. 57 25

The plasma concentrations of substrates, together with transhepatic and transgut balances, have been studied in six control and eight septic awake fasted dogs. Four severely ill septic dogs (typically fluid in chest and/or abdomen, extensive peritonitis, respiratory difficulties) had high concentrations of threonine, glycine, tyrosine, lysine, histidine, tryptophan, and triglycerides (p less than or equal to 0.05). The other septic dogs (less severely ill) showed fewer and less pronounced alterations in the plasma substrates (aspartate and tryptophan were elevated, p less than or equal to 0.05). The infusion of glucose increased the concentration of glucose, lactate, and pyruvate and depressed the concentrations of most amino acids in both normal and septic dogs. Threonine, asparagine, glutamine, leucine, isoleucine, alpha-aminobutyrate, and tyrosine were significantly depressed in the severely ill septic dogs (p less than or equal to 0.05). In the normal dogs most amino acids were removed by the liver, with alanine accounting for approximately 40% of the total. Glutamine removal was negligible. In the septic dogs hepatic removal of amino acids was variable; livers of two severely ill septic dogs did not remove amino acids. In the control dogs glucose infusion (0.015--0.017 g/kg/min) tended to lower hepatic removal of amino acids. Hepatic dye removal in the septic dogs was always very poor. In the gut glutamine was removed and alanine, glutamate, glycine, and ammonia produced, but the overall sum of amino acid uptake was negligible in both the control and septic dogs. The ratio of tryptophan to the sum of valine, isoleucine, leucine, tyrosine, and phenylalanine concentrations was greatly elevated in all septic dogs in which it was measured. The free concentrations of amino acids in the liver, heart, and muscle tissues were grossly elevated in the low intravenous alimented septic state relative to the fasted normal state, whereas the tissue concentrative ability as measured by nonmetabolizable amino acids, alpha-aminoisobutyrate and cycloleucine, was not similarly increased. Sepsis clearly alters plasma and tissue concentrations, and in some instances hepatic uptake of amino acids.
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PMID:Plasma concentrations and tissue uptake of free amino acids in dogs in sepsis and starvation: effects of glucose infusion--some effects of low alimentation. 65 52

1. Hepatic carbohydrate metabolism was studied by an intravenous galactose test in control patients, malnourished non-septic patients, patients with prolonged severe sepsis and patients after recovery from sepsis. 2. Blood galactose half-life was not significantly increased in the septic group despite abnormal liver-function tests, whereas it was approximately doubled in the malnourished patients. 3. The rise in blood glucose after galactose injection was less in both the septic and malnourished groups, as compared with that in the control subjects. 4. Fasting blood glucose, lactate and pyruvate concentrations were similar in all groups, whereas blood ketone bodies were increased in the malnourished and septic groups, and blood alanine was decreased only in the septic group. 5. The changes in hepatic metabolism and function were reversible on recovery from sepsis. 6. It is suggested that alterations in hepatic blood flow and the metabolic fate of galactose within the liver may explain the changes in the metabolic response to galactose observed in malnourished or septic patients.
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PMID:Galactose and hepatic metabolism in malnutrition and sepsis in man. 67 28

Indirect calorimetry and nitrogen measurements suggest that uncomplicated abdominal surgery produces no significnat change in resting metabolic expenditure and only a slight loss of urinary nitrogen. More severe injury and infections produce larger increases in resting metabolic expenditure and nitrogen loss. Severe injuries can result in a 15 to 30% loss of body weight, but the protein contribution to caloric expenditure does not exceed 20% and is less than expected. The provision of calories and nitrogen can change the course of the septic patient. A continual conversion of alanine carbon to glucose occurs in septic patients, including those who are receiving exogenous glucose at the normal hepatic production rate. In sepsis, the release of glucogenic substrates from peripheral tissues may determine the rate of hepatic gluconeogenesis.
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PMID:Energy balance and carbohydrate metabolism in infection and sepsis. 88 81

The protein catabolic response to sepsis has been measured in three patients and in two normal subjects using a pulse injections of L-[15N]alanine. In addition, the urea kinetics were measured using a pulse administration of [15N]urea. Several nitrogen models which simulated the metabolic pathways of nitrogen-labeled compounds were tried. Best curve fits and acceptable confidence limits were obtained with a four-pool model containing two metabolic pools and two urea pools. Using this model, synthesis and catabolism rates were calculated for a fast and slow protein turnover pool. The mean daily total protein synthesis rate in the normal was 3.695 g/kg compared to 4.479 g/kg in sepsis. Because all subjects were in negative nitrogen balance, the mean total protein catabolic rate in the normal was 4.379 g/kg, compared to 5.298 g/kg in sepsis. These data suggest an increase in both protein synthesis and catabolism during sepsis.
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PMID:Whole body protein synthesis and catabolism in septic man. 88 84

Sixteen seriously septic patients were studied to determine whether proteolysis occurred to satisfy a deficit of peripheral fuel, as suggested by out previous experimental observations. Concentrations of glucose, lactate, free fatty acids,and alanine were measured in blood samples from the femoral artery and vein to determine extraction (+) and release (-) by the leg. Simultaneously, cardiac index (CI) was determined by thermal dilution, so that an estimate of uptake or production of fuel substrates could be made from the proportional relationship of cardiac index to peripheral blood flow. Due to the antilipolytic effect of elevated levels of insulin (42 +/- 4 muM per milliliter) in those patients with elevated cardiac indices (4.38 +/- 0.33 L. per square meter per minute), free fatty acid uptake (-0.59 +/- 0.021 mM.) was reduced. In low-flow septic shock (CI, 1.66 +/- .41 L. per square meter per minute), the majority of glucose taken up by the limb was converted to lactate (arterial lactate, 3.14 +/- 0.7 mM.; deltaA-V 0.68 +/- 0.17). Free fatty acid uptake also was impaired in low-flow sepsis. As opposed to fasting, arterial levels and uptake of ketone bodies were insignificant in sepsis. These findings suggest that there is a deficit of peripheral fuel with respect to glucose and fat. That protein is oxidized to fill this deficit is substantiated by the increased alanine release (-0.13 +/- 0.01, -0.33 +/- 0.12 mM.) in the high-flow and low-flow septic groups, respectively, whereas alanine production was three- and fourfold greater than that observed in fasting patients. Enhanced release of alanine reflects the magnitude of oxidation of branched-chain amino acids and accounts for the high rates of gluconeogenesis and proteolysis observed in sepsis.
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PMID:Proteolysis associated with a deficit of peripheral energy fuel substrates in septic man. 94 Oct 92

Fifteen thermally injured patients with positive blood stream cultures for gram-negative organisms demonstrated a decreased mass flow of glucose through the glucose space when compared with 17 patients without sepsis studied at a comparable time after injury. Amino acid concentrations determined in ten burned patients with sepsis and nine burned patients without sepsis revealed an increase in the gluconeogenic precursors alanine, glycine, methionine and phenylalanine in those patients with sepsis. The administration of alanine consistently increased serum glucose in seven patients without sepsis but exerted no effect on glucose concentrations in six person with sepsis. These data, taken together, indicate that gram-negative sepsis in burned patients impairs the increased rate of glucose production and flow to peripheral tissue which characteristically occurs after thermal injury.
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PMID:Impaired glucose flow in burned patients with gram-negative sepsis. 98 49


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