ISSN:0148-6071    

DOI:10.1177/0148607194018005387

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

ISSN:0148-6071    

DOI:10.1177/0148607194018005396

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Background:Indirect calorimetry is the preferred method for determining caloric requirements of patients, but availability of the device is limited by high cost. A study was therefore conducted to determine whether clinically obtainable variables could be used to predict metabolic rate.Methods:Patients with severe trauma or sepsis who required mechanical ventilation were measured by an open‐circuit indirect calorimeter. Several clinical variables were obtained simultaneously. Measurements were repeated every 12 hours for up to 10 days.Results:Twenty‐six trauma and 30 sepsis patients were measured 423 times. Mean resting energy expenditure was 36 ± 7 kcal/kg (trauma)vs45 ± 8 kcal/kg (sepsis) (p<.0001). The single strongest correlate with resting energy expenditure was minute ventilation (R2= 0.61,p<.0001). Doses of dopamine, dobutamine, morphine, fentanyl, and neuromuscular blocking agents each correlated positively with resting energy expenditure. In the case of the inotropics and neuromuscular blockers, there was a probable covariance with severity of illness. A multiple regression equation was developed using minute ventilation, predicted basal energy expenditure, and the presence or absence of sepsis: resting energy expenditure = —11000 + minute ventilation (100) + basal energy expenditure (1.5) + dobutamine dose (40) + body temperature (250) + diagnosis of sepsis (300) (R2= 0.77,p<.0001).Conclusion:Severe trauma and sepsis patients are hypermetabolic, but energy expenditure is predictable from clinical data. The regression equations probably apply only to severe trauma and sepsis. Other studies should be conducted to predict energy expenditure in other patient types. (Journal of Parenteral and Enteral Nutrition18:398–403, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005398

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Tyrosine and cyst(e)ine are amino acids that are thought to be essential for preterm neonates. These amino acids have low stability (cyst(e)ine) or low solubility (tyrosine) and are therefore usually present only in small amounts in amino acid solutions. Acetylation improves the stability and solubility of amino acids, facilitating a higher concentration in the solution. We compared three commercially available amino acid solutions, Aminovenös‐N‐päd 10%, Vaminolact 6.5%, and Primène 10%, administered to 20 low‐birth‐weight neonates on total parenteral nutrition from postnatal day 2 onward. Aminovenös‐N‐päd 10% contains acetylated tyrosine and acetylated cysteine; the other solutions do not contain acetylated amino acids and differ in the amount of tyrosine and cysteine added. On postnatal day 7, plasma amino acids were measured together with urinary excretion of amino acids and the total nitrogen excretion; 38% of the intake ofN‐acetyl‐L‐tyrosine and 53% of the intake ofN‐acetyl‐L‐cysteine were excreted in urine. Plasma levels ofN‐acetyl‐L‐tyrosine (331 ± 74 μmol/L) andN‐acetyl‐L‐cysteine (18 ± 29 μmol/L) were higher than those of tyrosine (105 ± 108 μmol/L) and cystine (11 ± 9 μmol/L), respectively. Plasma tyrosine levels in the groups receiving small amounts of tyrosine remained just below the reference range. We showed a linear correlation of plasma cystine with the intake of cysteine (r=.75,p= 0.01), but not withN‐acetyl‐L‐cysteine. The estimated intake of cysteine should be 500 μmol·kg−1·d−1in order to obtain levels comparable with those shown in normal term, breast‐fed neonates. Nitrogen retention did not differ among the three groups (247 to 273 mg·kg−1·d−1). We conclude that a large portion of parenterally administered acetylated amino acids is excreted in the urine of 1‐week‐old, preterm neonates, with higher plasma levels of the acetylated amino acids than of the deacetylated amino acids.(Journal of Parenteral and Enteral Nutrition18:404–408, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005404

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

The present study examined the hemodynamic and metabolic effects of nutrition support in patients with malnutrition secondary to severe mitral valve disease and congestive heart failure. Pulmonary artery pressure measurements, echocardiographic studies, gas exchange measurements, immune function tests, and clinical evaluations were made on hospitalized patients 2 weeks before and 3 weeks after surgery for valve replacement or annuloplasty. All patients received a total daily energy intake of 20 to 30 kcal/kg, four of the patients preoperatively as a combination of oral food plus parenteral nutrition and these four patients plus two additional patients as only parenteral nutrition in the early postoperative period. All six patients received nutrition support as oral food plus parenteral nutrition in the late postoperative period. Compared with baseline, nutrition support was associated with stable hemodynamic function, unchanged whole‐body oxygen consumption and carbon dioxide production, and improved clinical indices both before and after surgery. Comprehensive hemodynamic, metabolic, and clinical studies thus indicate that acceptable levels of nutrition support can be provided to malnourished patients with severe congestive heart failure, which improves their clinical status and does not adversely influence cardiac function.(Journal of Parenteral and Enteral Nutrition18:409–416, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005409

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Background:The immune system is reported to be influenced by polyunsaturated fatty acids. Therefore, immunoregulation caused by intravenous fat emulsions with different n‐3 to n‐6 fatty acid ratios was studied in anin vivomodel.Methods:Experimental rat heart allotransplantation served as a defined immunologic challenge. Twenty percent emulsions of safflower oil (n‐3 to n‐6 = 1:370), fish oil (n‐3 to n‐6 = 7.6:1), and soybean oil (n‐3 to n‐6 = 1:6.5), and a 1:1 mixture of safflower oil and fish oil (n‐3 to n‐6 = 1:2.1) were continuously infused (9 g of fat per kg of body weight per day) after transplantation until complete rejection. The prolongation of graft survival, an accepted parameter of immunosuppression, was assessed. Beyond that, cytokine release by mitogen‐stimulated peripheral‐blood mononuclear cells (PBMCs) from animals exsanguinated on day 4 after transplantation was evaluated.Results:The mean rejection time was 7.8 days in the sham‐infused saline control group and 6.7 days in the safflower‐ and fish‐oil‐mixture group (oil control group). Continuous infusion of soybean oil prolonged the graft survival time to 10.4 days, fish oil to 12.3 days, and safflower oil to 13.3 days. PBMC α‐tumor necrosis factor release was significantly reduced in the fish‐oil group (51.9 ± 13.0 pg/106 PBMCs vs 70.8 ± 10.9 pg/106 PBMCs [controls],p<.004). Interleukin‐6 release was diminished in both the fish‐oil group (22.2 ± 13.6 pg/106PBMCsvs40.7 ± 8.3 pg/106 PBMCs [controls],p<.002) and the safflower‐oil group (28.4 ± 6.9 pg/106PBMCs,p<.002).Conclusions:The n‐3 to n‐6 fatty acid ratio determined the immunoregulatory potential of intravenous fat emulsionsin vivo.Both n‐3 and n‐6 fatty acids were immunosuppressive when applied as the main polyunsaturated fatty acid sources. PBMC cytokine release was significantly reduced in these groups. The more balanced the n‐3 to n‐6 ratios, the less immunosuppressive the fat emulsion. There was no immunosuppressive effect at an n‐3 to n‐6 ratio of 1:2.1. (journal of Parenteral and Enteral Nutrition18:417–421, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005417

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Background:Arginine (Arg) is generated in the kidney by the conversion of circulating citrulline. The most important source for circulating citrulline is the metabolism of glutamine (Gln) by the gut. In this study, we investigated the influence of an enteral diet enriched with Gln on renal Arg synthesis in the rat.Methods:Rats were fed a 12.5% Gln‐enriched diet or an isocaloric, isonitrogenous control diet for 14 days. Kidney plasma flow and arterial and renal venous plasma levels of a number of amino acids were measured, and kidney amino acid fluxes were calculated.Results:Compared with the control diet, Gln enrichment resulted in significantly higher arterial plasma levels of circulating citrulline (30%,p<.0001) and Arg (31%,p<.0005). The uptake of circulating citrulline and the subsequent production of Arg by the kidneys were significantly higher in the Gln‐enriched group (40% and 38%, respectively) and showed an equimolar relationship in both the control (r=.84,p<.0001) and the Gln‐enriched group (r=.83,p<.0001).Conclusions:The findings indicate that enteral Gln supplementation caused significantly increased arterial plasma levels of Arg as a result of increased renal Arg production from circulating citrulline. Considering the multiple important biologic properties of Arg, the reported beneficial effects of Gln in catabolic states might be explained in part by increased renal Arg production.(Jouynal of Parenteral and Enteral Nutrition18:422–426, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005422

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Both skinfold anthropometry and bioelectrical impedance are indirect, simple bedside methods to assess body composition. It is not clear, however, whether the results of these methods are comparable. In this study, body composition was determined in 449 subjects by skinfold anthropometry and by bioelectrical impedance. Percentage of body fat ranged from 8.0% to 47.5% with the skinfold technique and from 0.6% to 78.5% with bioelectrical impedance. Linear regression analysis showed a significant positive correlation (r =.84;p<.0001) between the results of both techniques. However, plot analysis showed that, in comparison with bioelectrical impedance, skinfold measurements overestimate fat mass in the lower weight range and underestimate it in obese subjects. We conclude that the results of skinfold anthropometry and bioelectrical impedance are not comparable, especially in the extreme ranges of body fat. At the present time, other, more rigorous techniques are necessary to assess body composition accurately, in the extreme ranges of body fat in particular. (Journalof ParenteralandEnteral Nutrition18:427–429, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005427

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

Background: Patients who have undergone ileal resection are at risk for developing magnesium depletion/deficiency because of poor absorption and decreased intake as well as increased endogenous losses. Magnesium repletion is difficult to accomplish because of the cathartic action of most oral magnesium supplements at therapeutic doses. The results of in vitro and insitustudies show that magnesium diglycinate (chelate) represents a highly available form of magnesium that is absorbed in part as an intact dipeptide in the proximal small intestine. Methods: We conducted a double‐blind, randomized crossover trial with 12 patients who had ileal resections in order to compare the bioavailability of a 100‐mg dose of26Mg‐labeled chelate with MgO in this patient population. Results: For the patient group as a whole,26Mg absorption was low but was not different for the two supplements (23.5% vs 22.8% for magnesium chelate and MgO, respectively). However,26Mg absorption was substantially greater from the chelate (23.5%vs11.8%;p<.05) in the four patients who showed the greatest impairment of magnesium absorption with MgO and was better tolerated by all patients. Peak isotope enrichment also occurred significantly earlier after26Mg chelate than after26MgO ingestion (mean difference 3.2 ± 1.3 hours;p<.05), and the area under the enrichmentvstime curve was greater after chelate ingestion (p<.05). Conclusions: Data from this study support the suggestion that some portion of magnesium diglycinate is absorbed intact, probably via a dipeptide transport pathway. Magnesium diglycinate may be a good alternative to commonly used magnesium supplements in patients with intestinal resection. (Journalof Parenteraland EnteralNutrition 18:430–435, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005430

出版商:SAGE Publications    

年代:1994

数据来源: WILEY

摘要:

To investigate whether increased availability of lipids affects glucose metabolism in healthy postabsorptive men when lipid and glucose are infused in amounts used in parenteral nutrition, we infused glucose (4 mg/kg·min−1) for 6 hours and clamped plasma glucose at basal level during the first 3 hours. After 3 hours, either long‐chain triglycerides (LCTs) (0.07 g/kg·h−1) (n = 7) or a mixture of LCTs and medium‐chain triglycerides (MCTs) (MCTs/LCTs, 50/50%, 0.07 g/kg·h−1) (n = 7) was administered, and the infusion rates of glucose and insulin were unchanged compared with the first 3 hours. In a control study, glucose was infused for a period of 6 hours without the lipid infusion (n = 5). After 6 hours, the plasma glucose concentration and glucose tissue uptake were not affected by LCT or MCT/LCT infusion. Nonetheless, glucose oxidation decreased in the LCT group (from 6.42 ± 1.04 to 2.31 ± 0.85 μmol/kg·min−1,p<.001) and in the MCT/LCT group (from 7.62 ± 1.50 to 5.50 ± 0.76 μmol/kg·min−1,p<.01) but not in the control group. Concentrations of the glucoregulatory hormones were not different among the three groups. In conclusion, MCTs/LCTs administered concomitantly with glucose infusion, in amounts similar to those used in total parenteral nutrition, inhibit glucose oxidation without affecting glucose tissue uptake, just as LCTs do. (Journalof Parenteral andEnteralNutrition 18:436–441, 1994)

ISSN:0148-6071    

DOI:10.1177/0148607194018005436

出版商:SAGE Publications    

年代:1994

数据来源: WILEY