Nutrition
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Randomized Controlled Trial Comparative Study Clinical Trial
Response of severely malnourished patients to preoperative parenteral nutrition: a randomized clinical trial of water and sodium restriction.
Preoperative parenteral nutrition (PPN) may be beneficial for severely malnourished patients who are candidates for a major elective surgical procedure. The response to PPN, however, has not been thoroughly investigated. Expansion of the extracellular water compartment may occur in some patients, producing a further decrease in the serum albumin concentration and increasing the postoperative complications. ⋯ Weight changes correlated with water (r2 = 0.46, P = 0.001) and sodium (r2 = 0.62, P = 0.0001) balances. Inappropriate responses to PPN in both groups (expansion or depletion of the extracellular water compartment) were associated with a significant increase in pulmonary postoperative complications. During PPN, extracellular water expansion--as determined by increasing weight and lowering of the serum albumin concentration--and aggressive fluid therapy to treat water and sodium depletion seem crucial to the development of postoperative respiratory complications.
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Glutamine (Gln) has been one of the most intensively studied nutrients in the field of nutrition support in recent years. Interest in provision of Gln derives from animal studies in models of catabolic stress, primarily in rats. Enteral or parenteral Gln supplementation improved organ function and/or survival in most of these investigations. ⋯ Intravenous Gln (either as the L-amino acid or as Gln-dipeptides) has been shown to increase plasma Gln levels, exert protein anabolic effects, improve gut structure and/or function and reduce important indices of morbidity, including infection rates and length of hospital stay in selected patients subgroups. Additional blinded studies of Gln administration in catabolic patients and increasing clinical experience with Gln-enriched nutrient products will determine whether routine Gln supplementation should be given in nutrition support, and to whom. Taken together, the data obtained over the past decade or so of intensive research on Gln nutrition demonstrate that this amino acid is an important dietary nutrient and is probably conditionally essential in humans in certain catabolic conditions.
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Randomized Controlled Trial Clinical Trial
Integrated nutritional, hormonal, and metabolic effects of recombinant human growth hormone (rhGH) supplementation in trauma patients.
An anabolic stimulus is needed in addition to conventional nutritional support in the catabolic "flow" phase of severe trauma. One promising therapy appears to be rhGH infusion which has direct as well as hormonal mediated substrate effects. We investigated on a whole-body level, the basic metabolic effects of trauma within 48-60 h after injury in 20 severely injured (injury severity score [ISS] = 31 +/- 2), highly catabolic (N loss = 19 +/- 2 g/d), hypermetabolic (resting energy expenditure [REE] = 141 +/- 5% basal energy expenditure [BEE]), adult (age 46 +/- 5 y) multiple-trauma victims, before starting nutrition therapy and its modification after 1 wk of rhGH supplementation with TPN (1.1 x REE calories, 250 mg N.kg-1.d-1). ⋯ The hyperglycemic, hyperinsulinemia observed during rhGH supplementation may be due to defective nonoxidative glucose disposal, as well as inhibition of glucose transport activity into tissue cells. The simultaneous operation of increased lipolytic and reesterification processes may allow the adipocyte to respond rapidly to changes in peripheral metabolic fuel requirements during injury. This integral approach helps us to better understand the mechanism of the metabolic effects of rhGH.
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Comparative Study
Increased contribution by myofibrillar protein to whole-body protein breakdown according to severity of surgical stress.
A study was conducted to clarify the contribution by myofibrillar protein to whole-body protein breakdown in surgically stressed patients. Thirteen patients who underwent esophagectomy (group E) and 22 who underwent gastric or colorectal operation (group GC) were studied. Patients were all male and younger than 65 y old. ⋯ On the other hand, femoral-arteriovenous differences of BCAA, Ala, Gln, Tyr, and Phe correlated significantly with the urinary excretion of 3-MH. These data suggest that skeletal muscle protein degradation is proportional to the breakdown of total myofibrillar proteins and both correlate with the severity of stress. From these data, it may be suggested that the contribution of skeletal muscle to whole-body protein catabolism is increased postoperatively, and that the increase is correlated with the severity of surgical stress.