bluuebunny/crossref_metadata_2025 huggingface dataset:
Urinary Ammonia Plus Urinary Urea Nitrogen as an Estimate of Total Urinary Nitrogen in Patients Receiving Parenteral Nutrition Support
Authors: Burge Jean C. , Choban Patricia , Mcknight Tim , Kyler Mary K. , Flancbaum Louis
Published: May 2008

Nitrogen balance has historically been estimated by using urinary urea nitrogen (UUN) multiplied by a factor of 1.25 to account for nonurea nitrogen present in the urine. Recently, the reliability of UUN as an estimate of nitrogen losses has been questioned and the use of total urinary nitrogen (TUN) has been proposed as a more accurate measure of urinary nitrogen losses. However, analysis of TUN losses is not readily available in many hospital laboratories. Because ammonia is the major fluctuating component of urinary nonurea nitrogen and equipment to measure urinary ammonia is available in most hospitals, this study was undertaken to determine whether urinary ammonia plus UUN provides a clinically useful approximation of TUN. Twenty‐four‐hour urine samples acidified with boric acid during collection from 20 patients (a total of 42 samples) receiving total parenteral nutrition were analyzed for UUN, ammonia, and TUN. The UUN values ranged from 4.9 to 42.4 g/24 h. The mean difference between TUN and UUN was 1.99 ± 0.27 g/24 h. The mean difference between TUN and UUN plus ammonia was 0.78 ± 0.27 g/24 h. Thus, UUN alone accounted for 90% and the combination of UUN plus urinary ammonia accounted for 96% of TUN. These data suggest that UUN plus ammonia does provide a greater level of reliability as an estimate of TUN than UUN alone. (Journal of Parenteral and Enteral Nutrition 17:529–531, 1993)
Nasointestinal Tube Placement With a pH Sensor Feeding Tube
Authors: Heiselman Darell E. , Vidovich Robin R. , Milkovich Gary , Black Lisa D.
Published: May 2008

Radiographic confirmation of enteral feeding tube placement is a common practice representing considerable expense and causing delay in the initiation of enteral nutrition therapy. We evaluated an enteral feeding tube with a pH sensor, which allows immediate verification of the location of the tube by assessment of the pH upon insertion. Insertion pHs were obtained for 24 intensive care unit patients requiring feeding tube placement. Placement was verified radiographically and compared with expected location on the basis of the pH profile. The radiograph and the insertion pH profile were in agreement in 87.5% (21 of 24) of the cases. Concomitant use of histamine blockers did not affect the ability of the pH sensor to detect placement accurately (Fisher's Exact Test, p 5.71) Use of these pH measurements eliminates the need for radiographic documentation of placement, provides a savings for the patient, and may be beneficial in promoting enteral feedings in critically ill patients. (Journal of Parenteral and Enteral Nutrition 17:562–565, 1993)
Exit Site Purse‐String Suture to Secure Long‐Term Venous Catheters
Authors: Bond Sheldon J. , Bond Bonna S.
Published: May 2008

A new method for the prevention of accidental dislodgment of long‐term venous catheters involves the use of an exit site purse‐string suture that holds the catheter cuff in place before the ingrowth of fibrous tissue. This method is safe, reliable, easily reproduced, and does not require any additional incisions or anchoring devices. In our clinical practice, it has drastically reduced the number of accidental dislodgments. (Journal of Parenteral and Enteral Nutrition 17:583–584, 1993)
Effect of Protein‐Calorie Malnutrition on Methotrexate Pharmacokinetics
Authors: Charland Scott L. , Bartlett David , Torosian Michael H.
Published: May 2008

Methotrexate toxicity is increased in protein‐calorie malnutrition. The influence of protein‐calorie malnutrition on the pharmacokinetics and binding of methotrexate (MTX) and the formation of its major hepatic metabolite, 7‐hydroxy‐methotrexate was examined in 30 adult, female Lewis rats. Animals were randomized to receive either a standard diet (22.0% protein; 4.20 kcal/g) or a protein‐depleted diet (PD) (0.03% protein; 4.27 kcal/g) ad libitum for 35 days. Animals were then separated into two groups for either methotrexate pharmacokinetics (n = 20) or serum protein binding (n = 10) studies. The mean weight loss in the PD group was 26% of their initial body weight, as compared with a 29% weight gain in the control group. In the protein binding study, a significant decrease in serum albumin (19%), uncorrected creatinine clearance (38%), and free fraction of MTX (15%) was found in the PD group. All animals in the pharmacokinetic study received a single intraperitoneal injection of MTX (10 mg/kg), and serum MTX and 7‐hydroxy‐methotrexate concentrations were determined using a specific, reversed phase, high‐performance liquid chromatography assay. The mean AUC0–3 in the PD group was 43.6 ± 3.9 μg/mL per hour compared with 15.8 ± 1.1 μg/mL per hour in the control group (p <.001). The time to peak and the peak serum concentrations were significantly greater in the PD animals, which indicated delayed absorption and clearance. These results suggest that the increase in MTX toxicity observed in protein‐calorie malnutrition is associated with a decrease in MTX clearance, and is not related to changes in protein binding or formation of 7‐hydroxy‐methotrexate. (Journal of Parenteral and Enteral Nutrition 18:45–49, 1994)
Creatinine Height Index and Lean Body Mass in Adult Patients With Insulin‐Dependent Diabetes Mellitus Followed for 7 Years From Onset
Authors: Rosenfalck A.M. , Snorgaard O. , Almdal T. , Binder C.
Published: May 2008

The 24‐hour urinary creatinine excretion value can be used as an index of protein nutrition; the creatinine height index and lean body mass can be estimated from this value. On the basis of longitudinally measured 24‐hour urinary creatinine excretions during the initial 7 years of type 1 diabetes in an incidence cohort of 147 adult patients, we studied creatinine height index and lean body mass and possible relationships to sequential measurements of glycated hemoglobin (HbA1c). The patients were divided into four groups according to their glycemic control during these 7 years: I, HbA1c < 7.4% (n = 37); II, HbA1c 7.4% to 8.2% (n = 37); III, HbA1c 8.3% to 8.9% (n= 38); IV, HbA1c > 8.9% (n = 35). One year after the onset of diabetes, height indices were as follows (% of normal values, median and quartiles): I, 104% (90 to 116); II, 101% (78 to 105); III, 121% (92 to 128); IV, 87% (78 to 109) ([IV] < [I to III]; p <.05). During the following 6 years no significant differences in height index were observed among the four groups of patients at any point in time. Slightly higher calculated lean body mass values were found in the most well‐controlled patients, but otherwise no differences were found in lean body mass. It is concluded that, apart from the first year, indices of protein nutrition remain normal during the initial 7 years of type 1 diabetes, even in patients with poor glycemic control. (Journal of Parenteral and Enteral Nutrition 18:50–54, 1994)
Nutritional and Metabolic Characterization of a Thiamine‐Deficient Rat Model
Authors: Molina Patricia E. , Myers Nicollete , Smith Rita M. , Lang Charles H. , Yousef Khalil A. , Tepper Patrick G. , Abumrad Naji N.
Published: May 2008

The effects of a thiamine‐deficient diet on plasma and tissue vitamin concentrations and on whole‐body glucose metabolism were assessed. Male Sprague‐Dawley rats (175 to 200 g body weight) fed a thiamine‐deficient (TD) or nutritionally complete purified diet were used for plasma thiamine mononitrate and monophosphate and for red blood cell and tissue thiamine pyrophosphate (TPP) determinations weekly for up to 5 weeks. Additional rats were used for assessment of basal glucose kinetics by using a primed constant infusion of [3‐3H]glucose. Plasma thiamine mononitrate levels decreased 60% at 1 week and were undetectable after 5 weeks on the diet. Plasma thiamine monophosphate decreased 80% after 1 week on the TD diet, and levels were undetectable after 4 weeks on the diet. Red blood cell TPP in the TD group decreased progressively with time: 54% at 1 week, 86% at 3 weeks, and 92% at 5 weeks. At 1 and 4 weeks, the decrease in tissue TPP was significant in the liver (65% and 89%, respectively), gut (52% and 94%, respectively), spleen (40% and 60%, respectively), and skeletal muscle (37% and 76%, respectively), with the brain (7% and 84%, respectively) showing the slowest initial rate of depletion. The TD diet did not alter plasma glucose concentrations, but it increased plasma lactate by 75% and plasma pyruvate by 50% to 75%. Rates of hepatic glucose production and peripheral glucose utilization were not different between the control and TD rats at 2 weeks, but they were 25% higher in the TD rats after 6 weeks on the diet. Plasma hormone concentrations were not different between the control and TD animals at 2 weeks. However, after 6 weeks on the diet, plasma insulin levels were 37% lower in the TD group, and glucagon and corticosterone levels were 85% to 97% higher than in the control animals. In general, these changes in whole‐body glucose flux induced by the TD diet could not be explained simply by the reduction in food consumption in the deficient animals In summary, TD resulted in (1) marked reductions in plasma thiamine levels, (2) a progressive decrease in red blood cell TPP content that paralleled that seen for both thiamine monophosphate and TPP in most peripheral tissues, and (3) multiple changes in whole‐body carbohydrate metabolism and glucoregulatory hormone concentrations. These changes were documented before any neurologic manifestations of a TD state. (Journal of Parenteral and Enteral Nutrition 18:104–111, 1993)
Assessing the Validity of Adjusted Urinary Urea Nitrogen as an Estimate of Total Urinary Nitrogen in Three Pediatric Populations
Authors: Boehm Kristi A. , Helms Richard A. , Storm Michael C.
Published: May 2008

Nitrogen excretion is a useful measurement for determining efficiency of protein utilization. Knowledge of nitrogen losses is especially important in the treatment of stressed, postsurgical, or catabolic patients, in whom optimizing the amount of nitrogen intake in the diet may spare visceral and somatic proteins and encourage anabolism. Many methods have been used to estimate total urinary nitrogen (TUN) in different patient populations. Urinary urea nitrogen (UUN) values are routinely adjusted and used by investigators who are not able to measure TUN directly by either Kjeldahl or pyrochemoluminescent methods. The rationale for the use of adjusted UUN concentrations to predict TUN is based on adult experiences. No similar experience in pediatrics has been published. We have compared TUN with adjusted UUN in a study of 250 urine samples from pediatric patients (n = 34) and normal pediatric volunteers (n = 109). Our findings suggest that adjusted UUN (determined by previously established formulas) may be of limited use in estimating TUN in neonates, infants, and critically ill pediatric patients; however, adjusted UUN may be useful in approximating TUN in healthy school‐aged children. Good correlations were found between UUN and TUN for critically ill children and postsurgical neonates and infants, suggesting that these newly described regression equations (once validated) may be useful in predicting TUN from a measured UUN. (Journal of Parenteral and Enteral Nutrition 18:172–176, 1994)
Central Line Occlusion With Three‐in‐One Nutrition Admixtures Administered at Home
Authors: Erdman Steven H. , Mcelwee Carol L. , Kramer Jan M. , Zuppan Craig W. , White John J. , Grill Bruce B.
Published: May 2008

The use of single‐container parenteral nutrition admixtures can be cost effective and can simplify home administration. Three‐in‐one admixtures (dextrose, amino acids, lipid emulsion, and other additives in a single bag) were in use when a marked increase in catheter occlusions was seen in the pediatric home parenteral nutrition population. Insoluble laminar deposits were found in the removed catheters. In all subsequently placed catheters, separate (SPLIT) infusions of lipid and parenteral nutrition solution were used rather than three‐in‐one admixtures. This was associated with an obvious decrease in catheter occlusions. Catheter life‐span was retrospectively determined for 15 catheters of identical size and style that were used in eight patients who had received either infusions of three‐in‐one admixtures or SPLIT infusions. Life table survival analysis revealed a median survival time of 70 days for the three‐in‐one group (n = 8) and 290 days for the SPLIT group (n = 7). Survival distributions for the two groups were significantly different (p =.025). During the period of clustered catheter occlusion, the use of three‐in‐one admixtures that were stored in the home for up to 7 days was associated with a shortened catheter life‐span. Occlusion or deposit development was not seen in catheters used for inpatient parenteral nutrition support when admixtures were prepared and infused within 28 hours. Catheter deposits were implicated as sanctuary sites for pathogenic bacteria in two patients. Failure to retrieve and inspect occluded catheters delayed the identification of the deposits. All occluded nutrition support catheters that cannot be cleared by standard methods should be retrieved for inspection of the lumen as part of routine surveillance. (Jouynal of Parenteral and Enteral Nutrition 18:177–181, 1994)
Efficacy of Hypocaloric Total Parenteral Nutrition in Hospitalized Obese Patients: A Prospective, Double‐Blind Randomized Trial
Authors: Burge Jean C. , Goon Ann , Choban Patricia S. , Flancbaum Louis
Published: May 2008

Obesity is a major health problem in the United States today. Traditionally, management of obese hospitalized patients has not differed from that of normal‐weight patients, with calorie and protein needs based on current body weight and weight loss postponed until the acute illness has subsided. This study was undertaken to determine whether obese hospitalized patients (> 130% ideal body weight) requiring total parenteral nutrition and given hypocaloric (HC) feedings with adequate protein intake could achieve nitrogen balance comparable with that of controls (C) given isonitrogenous normocaloric formulas. Sixteen obese patients (HC = 9, C = 7) were randomized to either HC (50% resting metabolic energy expenditure, plus protein; calories:nitrogen = 75:1) or C (100% resting metabolic energy expenditure, plus protein; calories:nitrogen = 150:1) formulas. Resting metabolic energy expenditure was determined by indirect calorimetry on day 0 and weekly, and nitrogen balance was determined daily. The two groups were similar in Harris‐Benedict predicted energy expenditure and metabolic energy expenditure, initial and final serum albumin, total iron‐binding capacity, and weight loss. Total daily calorie and nonprotein calorie intake per kilogram body weight were 14 ± 4.1 (HC) vs 25 ± 4 (C) and 7 ± 1.9 (HC) vs 20 ± 3 (C), respectively. Protein intake was 1.23 ± 0.4 (HC) vs 1.31 ± 0.2 (C) g/kg per day. Initial respiratory quotients were similar and consistent with fasting (HC = 0.7 ± 0.09 vs C = 0.66 ± 0.09); final respiratory quotients in C patients reflected mixed fuel use (C = 0.82 ± 0.11 vs HC = 0.7 ± 0.12). Mean net nitrogen balance was similar (HC = 1.3 ± 3.6 g of nitrogen per day compared with C = 2.8 ± 6.9 g/d). Eight of nine HC patients achieved positive nitrogen balance as did six of seven C patients. Duration of treatment averaged 9.6 ± 3.0 days. These data indicate that HC feedings can be effectively administered to mildly‐to‐moderately stressed hospitalized obese patients and can achieve nitrogen balance comparable with that of patients given conventional total parenteral nutrition formulas. (Journal of Parenteral and Enteral Nutrition 18:203–207, 1994)
Pharmacokinetic Profile of Dodecanedioic Acid, a Proposed Alternative Fuel Substrate
Authors: Mingrone G. , Greco A.V. , De Gaetano A. , Tataranni A. , Raguso C. , Castagneto M.
Published: May 2008

Dodecanedioic acid (C12), a saturated, aliphatic dicarboxylic acid with 12 carbon atoms, was given as an intravenous bolus (800 μmol/kg of body weight [kgBW]) in male Wistar rats to study its pharmacokinetic profile. Because total plasma C12, which results from the sum of both free and albumin binding fractions, was measured by high‐performance liquid chromatography, an in vitro experimental session was carried out to determine the binding curve of C12 in rat plasma. These data were then used to calculate the plasma C12 free fraction in in vivo experiments. The best fit obtained for the experimental data of albumin binding was obtained with the equation of reversible, saturable binding to one, two, or three classes of noninteracting equivalent sites. Only a single binding site was clearly identified with a dissociation constant of 147 μmol/L and a maximal predicted binding of 1.57 mol/mol albumin. The urinary excretion of C12 was 3.90 ± 1.62% of the administered dose. The pharmacokinetic analysis was performed by one‐compartment model with linear transfer to the tissues, taking into account simultaneously both plasma concentration and urine excretion data. The apparent volume of distribution of C12 was 0.248 ± 0.035 L/kgBW, the apparent first order rate constant to the tissues was 0.0535 ± 0.0123 min−1 and that from plasma to urine was 0.00206 ± 0.00051 min−1. The C12 plasma half‐life was 12.47 minutes. Renal clearance was 0.00051 L/kgBW per minute, whereas the systemic clearance was 0.0138 L/kgBW per minute. Because the renal clearance was much less than the rat inulin clearance reported in literature, the presence of C12 passive back‐diffusion was hypothesized. (Journal of Parenteral and Enteral Nutrition 18:225–230, 1994)
Immunoregulation by Parenteral Lipids: Impact of the n‐3 to n‐6 Fatty Acid Ratio
Authors: Grimm Helmut , Tibell Avnika , Norrlind Bjorn , Blecher Christoph , Wilker Sigrid , Schwemmle Konrad
Published: May 2008

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 an in vivo model. 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/106 PBMCs vs 40.7 ± 8.3 pg/106 PBMCs [controls], p <.002) and the safflower‐oil group (28.4 ± 6.9 pg/106 PBMCs, p <.002). Conclusions: The n‐3 to n‐6 fatty acid ratio determined the immunoregulatory potential of intravenous fat emulsions in 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 Nutrition 18:417–421, 1994)
Effects of Total Parenteral Nutrition on Lipid Metabolism in Rats
Authors: Ekelund M. , Roth B. , Trelde H. , Ekstrom U. , Nilsson‐Ehle P.
Published: May 2008

Background: The pathophysiologic mechanisms behind the development of liver steatosis during total parenteral nutrition (TPN) and the possible relationship to alterations of lipoprotein lipase activities in different tissues are not fully known. It is also unknown whether continuous and discontinuous administration of TPN affect lipid metabolism differently. Methods: TPN, including 8.4 g of triglycerides per kilogram per day, was given for 10 days to two groups of male Sprague‐Dawley rats that received the infusions discontinuously and continuously, respectively. Freely fed rats were used as controls. Results: TPN led to hyperlipidemia and accumulation of triglycerides in the liver. High‐density lipoproteins were enriched in triglycerides, whereas high‐density lipoprotein cholesterol and phospholipid levels were low. The activities of hepatic lipase were markedly decreased, and lipoprotein lipase activities in adipose tissue and in cardiac muscle were both up‐regulated. The increased levels of cholesterol and phospholipids in the serum of TPN animals were more pronounced after discontinuous administration. Conclusions: TPN including lipids interferes with the normal regulation of lipid metabolism. Although the mechanisms remain obscure, the elevation of lipoprotein lipase activities seems functionally important to accommodate the increased input of triglycerides during TPN. Possibly, the observed alterations in lipase activities may be attributed to a state of hypothyroidism. (Journal of Parenteral and Enteral Nutrition 18:503–509, 1994)
Metabolic Rate in Severe Head Trauma
Authors: Raurich Joan M. , Ibáñez Jordi
Published: May 2008

Background: The metabolic rate of patients suffering severe head trauma (HT) is not well defined, and large variations of resting energy expenditure (REE) have been reported, suggesting an important nonuniformity of REE distribution in HT patients. The purpose of this clinical study was to assess the metabolic rate in mechanically ventilated patients suffering from severe isolated HT, or HT associated with other injuries, in the absence of gross motor activity. Methods: Eighty HT patients undergoing mechanical ventilation were studied between 48 and 72 hours after injury. Three groups of patients were studied in the following clinical settings: (group A) isolated HT, not receiving morphine (n = 34); (group B) isolated HT, receiving an intravenous perfusion of morphine (n = 26) to control gross motor activity; and (group C) HT associated with other serious injuries, receiving intravenous morphine (n = 20) to induce sedation and analgesia. REE was measured with the open‐Douglas‐bag method. Results: No significant differences among the three groups were found in the metabolic rate expressed as the percentage of measured REE from predicted REE and REE expressed in terms of body weight. The mean percent measured REE was 123 ± 16, and REE expressed in terms of body weight was 30 ± 5 kcal/kg per day. Severe hypermetabolism was diagnosed if mean percent measured REE was greater than 130 and was present in 25 of 80 (31%) patients. Conclusions: Severe HT treated with or without morphine was characterized by a moderate state of hypermetabolism after the first days of trauma, but an important proportion of HT patients showed considerably elevated metabolic rates. (Journal of Parenteral and Enteral Nutrition 18:521–524, 1994)
Antipyrine Clearance in Surgical Patients Maintained on Hypocaloric Peripheral Parenteral Nutrition
Authors: Jorquera Francisco , Almar Mar , Martinez Carlos , Gonzalez‐Sastre Manuela , Culebras Jesus M. , Gonzmel‐Gmiego Javier
Published: May 2008

Backgyound: Antipyrine clearance (CL AP) constitutes a sensitive indicator of hepatic microsomal enzyme activity providing specific information on hepatic function. The purpose of this study was to evaluate the influence of hypocaloric peripheral parenteral nutrition on CL AP in patients receiving nutrition support after elective surgery. Methods: CL AP was measured in 15 patients before elective gastrointestinal surgery and 6 days after the surgery. Antipyrine (1 g) was administered orally, and CL AP was determined by the one‐sample method. Subjects received a postoperative 786 kcal/d regimen providing 66 g of amino acid per day and 133 g of glucose per day for 5 days. Nutritional status was evaluated by anthropometric parameters. A control group of 15 patients received no postoperative hypocaloric peripheral parenteral nutrition but received conventional fluid therapy. Results: Mean CL AP was increased by 61% (0.66 ± 0.06 mL/min·kg−1 body wt vs 0.41 ± 0.05 mL/min·kg−1 body wt in the preoperative period; p <.001), and antipyrine half‐life was reduced by 42% (10.9 ± 1.0 hours vs 18.9 ± 2.0 hours; p <.001) after 5 days of hypocaloric peripheral parenteral nutrition. No significant modification was shown among control patients in CL AP (0.54 ± 0.07 mL/min·kg−1 body wt vs 0.46 ± 0.05 mL/min·kg−1 body wt in the preoperative period) or in antipyrine half‐life (14.0 ± 1.4 hours vs 16.5 ± 1.8 hours). No significant correlation was observed between CL AP changes and those for the nutritional status of the patients. Conclusions: The results of our study indicate that oxidative drug‐metabolizing capacity is increased in surgical patients maintained on hypocaloric peripheral parenteral nutrition. Clinicians should be conscious of the potential of this effect for altering the efficacy or toxicity of many therapeutic agents. (Journal of Parenteral and Enteral Nutrition 18:544–548, 1994)
Heart Rate and Metabolic Response to Burn Injury in Humans
Authors: Giantin Valter , Ceccon Anna , Enzi Giuliano , Sergi Giuseppe , Perini Paola , Bussolotto Mauro , Schiavon Mauro , Casadei Alessandro , Mazzoleni Francesco , Nardo Sartori Leo , Zurlo Francesco
Published: May 2008

Background: Although frequently done, estimating the energy requirements of individual burn patients without measuring their resting metabolic rate is a less than satisfactory method of evaluation. Methods: We tested whether heart rate, which relates to the energy expenditure during physical activity, is also associated with postburn hypermetabolism (calculated as percentage increase of resting metabolic rate above the predicted normal fasting resting metabolic rate). Twenty‐three patients [12 men and 11 women, aged 38 ± 13 years (mean ± SD); weight, 71.6 ± 14.8 kg; body mass index, 25.4 ± 3.6; total burn surface area, 35.3 ± 17.8% (percentage of body surface)] were studied weekly for 3 weeks after an overnight fast. Results: Measured resting metabolic rates and heart rates were 2016 ± 497 kcal/d, 101 ± 13 bpm (n = 19); 2231 ± 485 kcal/d, 107 ± 13 bpm (n = 18); and 1903 ± 598 kcal/d, 99 ± 14 bpm (n = 11) for weeks 1, 2, and 3, respectively. Postburn hypermetabolism was +36% ± 19%, +55% ± 27%, and +36% ± 35% in the first, second, and third week, respectively. In each week postburn hypermetabolism correlated with heart rate (r = 0.65, p =.003; r = 0.69, p =.001; and r = 0.80, p =.002, respectively). Only in the second week did postburn hypermetabolism correlate with total burn surface area (r = 0.52, p =.02); there was no correlation with body temperature. In a multiple regression analysis, predicted resting metabolic rate, heart rate, and total burn surface area together explained 77% of all of the variance observed in the 48 fasting resting metabolic rates that were measured in the study (r2 = 0.77, p <.0001), and each of these variables also had a significant partial correlation with fasting resting metabolic rates (r2 = 0.45, p <.0001; r2 = 0.29, p <.0001; and r2 = 0.03, p <.03, respectively). Conclusions: In burn patients, variability in heart rate is associated with a significant part of postburn hypermetabolism variability. Therefore, heart rate may be considered a useful variable to be used for the evaluation of the energy requirements of severely burned patients. (Journal of Parenteral and Enteral Nutrition 19:55–62, 1995)
Effect of Fiber and Its Fermentation on Colonic Adaptation After Cecal Resection in the Rat
Authors: Kelberman Ira , Cheetham Brian C. , Rosenthal Jerome , Levine Gary M.
Published: May 2008

Background: The role of fiber in postresection adaptation is poorly understood. We examined the significance of short‐chain fatty acids produced by intracolonic fiber fermentation during colonic adaptation. Methods: Rats underwent one of three surgeries: control laparotomy, cecal resection, or cecal resection with placement of perfusion catheter. Rats of each surgical group were randomly assigned to receive treatment regimens of standard fiber diet (with or without fermentation‐suppressing antibiotics), fiber‐free diet, or diet plus intracolonic perfusion of short‐chain fatty acids. Adaptation parameters of mucosal weight, mucosal DNA and protein content, water absorption, and butyrate absorption were measured. Results: Compared with controls, postresection rats that were fed fiber had 65% greater basal and 112% greater butyrate‐stimulated water absorption as well as 140% greater butyrate absorption. Fiber‐fed rats exhibited significantly greater colonic weight and colonic mucosal protein after cecal resection. These changes were absent in postresection rats fed a fiber‐free diet. Inhibition of fermentation by neomycin and metronidazole added to a standard fiber diet also prevented postresection adaptation. All adaptive changes were restored when the cecal‐resection rats that were fed the fiber diet with antibiotics received an intracolonic infusion of short‐chain fatty acids. Adaptation did not occur when short‐chain fatty acids were infused into colons of postresection rats that were fed a fiber‐free diet. Conclusions: Cecal resection leads to significant functional and structural changes in the adapting residual colon. Fermentation of dietary fiber by colonic flora to short‐chain fatty acids is necessary, but it alone is not sufficient to mediate adaptation. (Journal of Parenteral and Enteral Nutrition 19:100–106, 1995)
Intravenous Iron Administration to Very‐Low‐Birth‐Weight Newborns Receiving Total and Partial Parenteral Nutrition
Authors: Friel James K. , Andrews Wayne L. , Hall Michael S. , Rodway Merlee S. , Keith Mary , McCloy Ursula C. , Matthew J. Derek , Long David R.
Published: May 2008

Background: Intravenous iron supplements are not routinely administered to very‐low‐birth‐weight newborns receiving total parenteral nutrition because of the possible increased risk of infection and because iron needs may be met with blood transfusions. Methods: To assess the benefits of a prudent IV iron supplement (200 to 250 μg/kg/d), 26 very‐low‐birth‐weight newborns (birth weight, 1005 ± 302 g; gestational age, 28 ± 2.3 weeks; mean ± SD) were randomly allocated to receive total parenteral nutrition without iron (No‐Iron) or with iron supplied as iron dextran (Iron). These newborns were followed at baseline (2 to 3 days after birth) and at weeks 1 to 4 thereafter. At each sampling time, urine samples, fecal samples (rarely), unused total parenteral nutrition solutions, blood products, and a blood sample (1 mL) were collected. Results: There were no differences between the two groups in anthropometric measurements, hematologic or biochemical parameters, number or amount of blood transfusions (2.3 ± 1.9), amount of blood removed for diagnostic purposes (44 ± 16 mL), or number of septic events (n = 16). There was no difference between the groups for the total iron excreted; however, the Iron group retained more iron. Iron balance was negative for all but 10 newborns (No‐Iron, 3; Iron, 7) throughout the study. Conclusions: A total iron intake of 400 μg/kg/d, half of which was provided by IV iron, is not sufficient to maintain iron balance or to meet fetal accretion rates (1000 μg/kg/d) in very‐low‐birth‐weight newborns receiving total parenteral nutrition. Furthermore, endogenous iron from blood transfusions does not provide an adequate supply of iron. (Journal of Parenteral and Enteral Nutrition 19:114–118, 1995)
Seldinger Technique as an Alternative Approach for Percutaneous Insertion of Hydrophilic Polyurethane Central Venous Catheters in Newborns
Authors: Valk W.J.C. , Liem K.D. , Geven W.B.
Published: May 2008

The use of hydrophilic central venous catheters, percutaneously inserted by means of the Seldinger technique, was evaluated in this prospective study. Between 1988 and 1991, 138 catheters were inserted in newborns who were admitted to our neonatal intensive care unit. An adequate position of the tip, evaluated radiographically, was achieved in 130 (94.2%) of these insertions. The side effects associated with these 130 catheters and the duration of their use were recorded. Results were compared with those of percutaneously inserted Silastic catheters described in the literature. The rate of adequate catheter placement seems comparable. Because of a high rate of minor mechanical complications, the mean catheter duration was rather short (8.3 days). However, the incidence of serious complications, especially infectious complications, was low. (Journal of Parenteral and Enteral Nutrition 19:151–155, 1995)
Total Enteral Nutrition Support Improves Body Composition of Patients With Active Crohn's Disease
Authors: Royall Dawna , Greenberg Gordon R. , Allard Johane P. , Baker Jeffrey P. , Jeejeebhoy Khursheed N.
Published: May 2008

Background: Previous studies using indirect calorimetry in Crohn's disease have suggested that with weight loss there is a proportionally greater decrease in body fat along with a sparing of lean mass. This study analyzed body composition (compared with that of controls) by direct methods in a group of 30 patients with active Crohn's disease and further evaluated the effects of nutrition support on body composition. Methods: Total body protein was assessed by neutron activation, fat was assessed by dual energy x‐ray absorptiometry, water was assessed by bioelectric impedance analysis, and potassium was assessed by γ‐ray technique. These measurements were repeated in patients with Crohn's disease after 3 weeks of enteral nutrition by feeding tube that provided 35 nonprotein kcal/kg of ideal body weight. Results: Compared with age‐ and sex‐matched controls, patients had lost (on average) 11.3 kg (16%) of body weight (p <.0005), including 5.1 kg (30%) of fat (p <.0005), 2.2 kg (19%) of protein (p <.025), 3.7 kg (10%) of water (p = NS), and 24.9 g (21%) of total body potassium (p <.01). After enteral feeding, body weight increased by 1.9 ± 0.3 kg (p <.0005). Weight gain was accompanied by an increase in body protein (0.3 ± 0.1 kg), fat (0.3 ± 0.1 kg), and water (1.1 ± 0.4 kg) (all p <.025), and by a nonsignificant increase in total body potassium. The weight gain of approximately 2 kg consisted of 65% water, 18% fat, and 18% protein, thus comprising a normal proportion of body composition. Conclusions: Reduced body weight in patients with Crohn's disease compared with that in controls was due to less fat tissue. With modest nutritional repletion, proportionate gains in all body compartments are possible. (Journal of Parenteral and Enteral Nutrition 19:95–99, 1995)
The Effect of Selenium Supplementation on Skeletal and Cardiac Muscle in Selenium‐Depleted Patients
Authors: Rannem Terje , Ladefoged Karin , Hylander Ellinor , Christiansen Jette , Laursen Henning , Kristensen Jens Halkjær , Linstow Michael , Beyer Nina , Liguori Rocco , Dige‐Petersen Harriet , Jensen Birte Hjort , Jarnum Stig
Published: May 2008

Background:The purpose of the present study was to evaluate the effect of sodium selenite on skeletal and cardiac muscular function in patients with severe Se deficiency.Methods:Skeletal and cardiac muscular function was investigated in 10 selenium depleted patients on long‐term home parenteral nutrition because of short bowel syndrome. The following examinations were applied: Skeletal muscle biopsy, muscular force test (Kin‐Com dynamometer test), electromyography (EMG) and radionuclide ventriculography. The patients were blindly randomized to intravenous supplementation with selenium 200 μg 5 to 7 times per week or placebo for 4 months. Hereafter the examinations were repeated. The patients randomized to placebo received selenium in an open study for a further 4 months and hereafter their skeletal and cardiac function was reevaluated.Results:Plasma selenium increased to normal levels from median.21 μmol/l (range 0 ‐.69) to 1.25 μmol/l (range.9 ‐ 2.27) following selenium repletion. The muscle biopsies showed only minor abnormalities. The only change after selenium supplementation was a small but statistically significant increase of the mean diameter of fiber type 1. The muscle strength of the quadriceps muscle was unchanged after selenium substitution. EMG did not reveal signs of myopathy. The cardiac function was normal and remained unchanged.Conclusion:Despite severe selenium depletion ten patients on long term home parenteral nutrition had normal cardiac function, and no clinically significant signs of skeletal myopathy. The only change after selenium supplementation was a small but statistically significant increase of the mean diameter of muscle fiber type 1.(Journal of Parenteral and Enteral Nutrition19:351–355, 1995)
Morphometric Changes in Microvasculature in Rat Myocardium During Malnutrition
Authors: Vandewoude Maurits F.J.
Published: May 2008

Background: Because the interrelationship between the parenchymal cell population and the microvasculature is critical in normal organ function, the effects of starvation on rat myocardium were studied morphometrically with respect to the microvasculature. Methods: Morphometric analytical studies were performed on myocardium of adult, female Wistar rats (groups of 5–7 rats) on fasting days 0, 1, 2, 4, 6, 8 and 10. Since cardiac muscle is a tissue with a high level of anisotropy, methods based on the concept of vertical planes were used to describe quantitative alterations in the rat myocardium both at the cellular and ultrastructural level. Results: Morphometric analysis of electromicrographs of myocardium showed an increase in capillary density together with a decrease in capillary lumen cross‐sectional area during starvation (p<.05). There was no significant change in volume fraction of the capillaries but surface density of the myocytes increased significantly (p<.01) and the diffusion distance for oxygen from the capillary lumen to the mitochondrion decreased (P<.01). Conclusions: Malnutrition alters the interrelationship between parenchyma and vascularization in the heart. This leads to a significant decrease of the diffusion distance for metabolites. This decrease of diffusion distance may improve cellular energy supply and offers a relative protection of the metabolism in the malnourished myocyte. (journal of Parenteral and Enteral Nutrition 19:376–380, 1995)
Osmolarity Does Not Affect the Gastric Emptying Rate of Oral Rehydration Solutions
Authors: Brouns Fred , Senden Joan , Beckers J. , Saris Wim H.M.
Published: May 2008

Background: The objective of this study was to determine the effect of either carbohydrate content or osmolarity on gastric emptying rate in normal healthy subjects. Methods: In total 12 test drinks were ingested as a single 8 mL/kg per body weight bolus on an empty stomach. Six of these drinks had a different carbohydrate content, increasing stepwise from 45 to 90 g/ L, but all with the same osmolarity (330 mOsm/kg). The other six drinks all contained 60 g carbohydrate/L but differed stepwise in osmolarity because of the use of maltodextrins with a difference in chain length (243 to 374 mOsm/kg). Results: The results show a significant negative relation between carbohydrate content and gastric emptying in the six drinks with a uniform osmolarity but progressively increasing carbohydrate content. The six drinks, which had the same carbohydrate‐energy content but different osmolarities, emptied all at the same rate from the stomach. The delivery of carbohydrate‐energy per minute from the stomach to the small intestine was the same for all drinks. Conclusions: From these data we conclude that the rate of gastric emptying of carbohydrate‐containing solutions is triggered by the carbohydrate‐energy drink content or by the delivery rate of carbohydrate‐energy to the gut. Osmolarity in the range studied here had no effect. (Journal of Parenteral and Enteral Nutrition 19:403–406 1995)
Inhibition of Pulmonary Microvascular Endothelial Glutamine Transport by Glucocorticoids and Endotoxin
Authors: Ming Pan  , Wasa Masafumi , Ryan Una , Souba Wiley
Published: May 2008

Background: During septic states, the lungs produce increased amounts of glutamine, an event that is mediated by both endotoxin and the glucocorticoid hormones and is presumed to be due to accelerated intracellular glutamine biosynthesis. Because enhanced net glutamine release in vivo could also be due to a decrease in cellular uptake, we assayed glutamine transport in cultured rat microvascular pulmonary endothelial cells. Methods: The effect of Escherichia coli endotoxin (LPS, 1 μg/mL), various cytokines, and dexamethasone (DEX, 0.1 μmol/L) on glutamine transport activity was studied in rat lung microvascular endothelial cells grown in varying glutamine concentrations (0, 0.1, 0.5, and 2 mmol/L). Experiments were also performed in cells treated with cycloheximide, actinomycin D, or chelerythrine chloride. Results: More than 90% of glutamine transport was mediated by the Na+‐dependent transport system ASC. DEX and LPS inhibited endothelial glutamine uptake in a time‐ and dose‐dependent manner, a response that was only observed when incubation medium contained the lower concentrations of glutamine. Neither DEX nor LPS altered transport activity in cells cultured in medium containing 2 mmol glutamine/L. There was no synergistic or additive effect when both compounds were added together. The cytokines tumor necrosis factor α, interleukin (IL) 1, IL‐2, and IL‐6 did not alter glutamine transport. Both DEX and LPS inhibited glutamine transport by decreasing transporter maximal transport velocity (Vmax) without affecting transporter affinity (Km). Cycloheximide and actinomycin D abrogated the inhibition of transport activity that was observed in DEX‐ or LPStreated cells, whereas the protein kinase C inhibitor chelerythrine chloride had no effect on either control or stimulated glutamine transport. Conclusions: These data suggest that DEX and LPS “down‐regulate” glutamine uptake by lung microvascular endothelial cells by inducing the synthesis of an inhibitory protein that modulates the activity of the System ASC protein. This response in vitro appears to be influenced by the extracellular glutamine concentration. This decrease in microvascular endothelial glutamine transport may be one mechanism by which net lung glutamine release is enhanced during critical illness. (Journal of Parenteral and Enteral Nutrition 19:477–481, 1995)
1995 Jonathan E. Rhoads Lecture. The Nutrition Management of the Patient With Acute Renal Failure
Authors: Kopple Joel D.
Published: May 2008

The clinical status of patients with acute renal failure (ARF) varies greatly. Some individuals have only mild or moderate ARF or may have only mild perturbations of their metabolic status. Other patients exhibit a severe reduction in renal function with oliguria or anuria. Depending upon their comorbid conditions, ARF patients may be among the most hypercatabolic patients in the hospital. Clinical trials have not clearly shown a beneficial effect of nutrition support on morbidity or mortality in patients with ARF, although limitations in sample size and experimental design and inclusion of patients with widely disparate clinical conditions may have contributed to the difficulty in demonstrating benefits. Several recent therapeutic approaches that have been studied either in experimental animals with ARF or in small numbers of humans with ARF hold promise for improving clinical outcome. Continuous arteriovenous or venovenous hemofiltration with or without dialysis is such a therapy. In comparison to intermittent hemodialysis this former treatment more safely removes large quantities of water and solutes from critically ill patients with unstable hemodynamics and allows them to receive rather large quantities of nutrients, including amino acids. Also promising are studies in experimental animals with ARF which indicate that several growth factors may accelerate the recovery of renal function. In rats with ARF, insulin‐like growth factor 1 both enhances recovery of renal function and suppresses their enhanced catabolism. For most patients with ARF requiring nutrition support, evidence suggests that both essential and nonessential amino acids should be employed. However, there appears to be a therapeutic role for small quantities of essential amino acids, without nonessential amino acids, in selected patients. Data support the importance of proactive measures to prevent fluid and electrolyte imbalances in patients with ARF. (Journal of Parenteral and Enteral Nutrition 20:3–12, 1996)
Observations on the Patterns of 24‐Hour Energy Expenditure Changes in Body Composition and Gastric Emptying in Head‐Injured Patients Receiving Nasogastric Tube Feeding
Authors: Weekes Elizabeth , Elia M.
Published: May 2008

Background: Although intolerance to nasogastric feeding is commonly observed after head injury, quantitative measurements of gastric emptying are lacking. Concepts about energy requirements are limited by the lack of long‐term measurements of total energy expenditure. Methods: Six male subjects with severe head injury had their gastric emptying measured by the phenol red technique. N and energy balances were measured by classic balance techniques, which included continuous indirect calorimetry for up to 24 hours (days 3 to 5). Measurements of body composition were made on days 3 to 5 and 12 to 19 (4 subjects only). Results: The subjects lost a mean of 9.8 kg of which 2.3 kg was estimated to be due to fat (equivalent to — 14 g N/d and —1690 kcal/d). On days 3 to 5, basal metabolic rate (BMR) was 130% to 135% of predicted. The low dietary intake (650 kcal and 4.2g N/d) was associated with negative energy (— 1710 ± 520 kcal/d) and N balances (‐19 ± 5 g N/d). Gastric emptying was delayed twofold (days 3 to 5) compared with controls (p <.001) and was associated with significant regurgitation of feed into the mouth (16 of 31 saliva samples contained glucose at a concentration of >0.5 mmol/L compared with control values of <0.2 mmol/L. Conclusions: The large negative energy balance in the subjects studied was largely due to the inadequate nasogastric feeding, which was associated with a twofold reduction in the rate of gastric emptying and frequent regurgitation of feed. The large negative N balance and the high contribution of protein oxidation to total energy expenditure (25% to 28%) was predominantly due to the injury sustained and immobility. An increase in BMR is not necessarily associated with increased total energy expenditure or energy requirements. (Journal of Parenteral and Enteral Nutrition 20:31–37, 1996)