Altered fractional excretion of uric acid during total parenteral nutrition

The presence of crystal proven podagra coincident with a 52% decrease in plasma urate after a 3-day course of total parenteral nutrition (TPN) prompted a study of urate excretion in 9 patients with Crohn's disease. By Day 9 in those receiving TPN, plasma urate decreased 58% (p less than 0.001), while fractional urate excretion increased 94% (p less than 0.005). Twenty-four hour urate excretion and serum creatinine were not significantly altered. These findings persisted for the duration of TPN. In 2 patients with ileocolitis, the addition or deletion of either lipid emulsion or multivitamin infusions during TPN had no effect on urate values. Rather, the amino acid load or a specific constituent appears to be the causal factor. These data suggest that hypouricemia due to extensive net urate excretion is common during TPN therapy. Finally, patients with established gout may be at risk for acute gouty attacks during TPN therapy.     

Urinary excretion of carnitine in multiply injured patients on different regimens of total parenteral nutrition

Carnitine derives from intake of preformed exogenous carnitine and synthesis from lysine and methionine, but is absent in parenteral fluids. Urinary excretions of carnitine and its derivatives was measured in 30 patients 2-8 days after severe multiple injuries and compared with controls. The patients received five different isocaloric parenteral nutritional regimens;group 1 glucose and fat, group 2 glucose, fat and amino acids, group 3 glucose and insulin, group 4 glucose and amino acids, and group 5 branched-chain amino acids. The mean total carnitine excretion in healthy men was 420 mumol/24 h +/- 57 (SEM), and in women 266 mumol/24 h +/- 29, 41% of which was free carnitine. Mean excretion of total carnitine during days 2-8 after trauma for the five groups was: 900 +/- 100, 1169 +/- 112, 1251 +/- 102, 1023 +/- 117, and 668 +/- 128 mumol/24 h, being significantly higher in groups 1-4 than in healthy men. The free carnitine fraction in the patients was significantly higher than in controlled healthy subjects. Total carnitine excretion was unaffected by different nutritional regimens in the very first days. During days 6-8, group 5, receiving branched-chain amino acids had lower excretion of total carnitine (compared to groups 2-4) and free carnitine (compared to groups 3-4). Groups 3 and 4 excreted a higher percentage as free carnitine compared to the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Multifactorial low remodeling bone disease during cyclic total parenteral nutrition

The physiopathology of metabolic bone disease described during long term total parenteral nutrition is poorly understood. We therefore prospectively assessed bone status of seven adult patients [mean age, 42 +/- 16 (SD) yr] treated with cyclic total parenteral nutrition for a period of 7 +/- 2 (SD) months. All patients had hypercalciuria (381 +/- 96 mg/day) associated with negative calcium balance in six of seven patients (-49 +/- 120 mg/day). A correlation was found (r = +0.74, P less than 0.01) between protein intake and calciuria. Two patients developed slight transient hypercalcemia. Serum magnesium and phosphate levels remained within the normal range. A high aluminum load due to the added phosphate solution (253 +/- 84 micrograms/day) was associated with increased serum aluminum levels (52 +/- 38 micrograms/liter). Normal serum levels of 25 hydroxyvitamin D (12 +/- 7 ng/ml) and low normal 1,25 dihydroxyvitamin D levels (21 +/- 8 pg/ml) were found. Serum PTH was normal in five and increased in two of the seven patients. However, in these two patients skeletal unresponsiveness to the action of PTH was found. A new histomorphometric picture of bone was observed; it consisted of a markedly reduced bone formation with subnormal osteoclastic activity leading to a low trabecular bone volume. No osteomalacia was found. The aluminum load may have played a role in these bone defects. The hypercalciuria with negative calcium balance was attributed to the cyclic amino-acid delivery during TPN.     

Jejunal motility during cyclic total parenteral nutrition in patients with Crohn's disease.

Our aim was to study the jejunal motility (a) in seven patients receiving longterm (median: 24 days) cyclic total parenteral nutrition (CTPN) for an acute exacerbation of Crohn's disease involving the ileum and/or the colon without any sign of occlusion and (b) in six healthy volunteers undergoing the same parenteral nutrition for one day after an overnight fast. Continuous recordings, lasting 20 hours, were carried out in patients after correction of their nutritional status and significant improvement of the Crohn's disease activity index. In five of the seven patients, we recorded seven to 14 phase III episodes (PIII) (median: 10), both more frequent and slower during the nocturnal part of the recording time as compared with diurnal. Seven to 18 PIIIs (median: 12) were found in controls. The overall duration of the motor activity was not different between these five patients and controls. In the remaining two patients, no PIII episode was recorded and 79% and 57% respectively of the whole recording time consisted of irregular motor activity. Our work therefore, shows that: (a) PIIIs remain and have a circadian variation in their periodicity and propagation velocity, in most of our patients undergoing longterm CTPN (b) CTPN does not determine a longer duration of motor rest of the small bowel in patients than in controls submitted for a short period of time to the same parenteral intake.     

Concentration of selenium in plasma and erythrocytes during total parenteral nutrition in Crohn's disease.

Plasma- and erythrocyte-selenium concentrations were determined in five consecutive patients with Crohn's disease given preoperative total parenteral nutrition - nil per os - for a mean period of 34 days per patient. No blood components were administered during the total parenteral nutrition. Before the total parenteral nutrition the plasma-selenium level and, to a less extent, the erythrocyte-selenium levels were below the reference values. After three weeks of total parenteral nutrition both concentrations had fallen. There were, however, clinical and biochemical signs of improvement during the total parenteral nutrition, as indicated by an increase in body weight, P-albumin and P-transferrin. In one female patient given 39 days of preoperative total parenteral nutrition containing 0.06 mumol (5 micrograms) selenium per 24 h the decreasing levels of plasma-selenium and erythrocyte-selenium were both correlated to the duration of the total parenteral nutrition (r = 0.87 and 0.96, respectively). The results suggest that total parenteral nutrition patients may be at risk for selenium deficiency, and that a supplementary administration of selenium via total parenteral nutrition may be required.     

Small-intestinal transit during total parenteral nutrition in the rat

This investigation was designed to test the hypothesis that alterations in small-bowel motility are associated with total parenteral nutrition (TPN). Motility, as reflected by intestinal transit, was studied in rats maintained by TPN for 7–10 days and compared to that of rats fed an oral diet isocaloric with the intravenously administered solution. Transit was measured by injecting radioactively labeled chromium (Na₂ ⁵¹CrO₄) into the duodenum via permanently implanted catheters. Fifteen minutes after injection of the label, animals were killed and the linear distribution of the isotope in the gut was determined. The leading edge of radioactivity traversed 75–87% (95% confidence limit) of the gut length in enterally fed rats and 83–97% in rats on TPN. The difference between the average position of these fronts for the two groups was not statistically significant (P>0.05). In addition, the regression of percent radioactivity traversing or present in a given segment on gut length yielded a slope with 95% confidence limits of –10.48 to –15.02 for orally fed control rats and –9.83 to –12.87 for rats on TPN. Differences between these slopes were not statistically significant (P>0.05). Results support the conclusion that factors which regulate small-bowel motility are not altered significantly by TPN during the time that other functional and structural changes reportedly occur.This study was supported by NIH Grants AM 18164, AI 11361, AM 16305. Dr. Castro is the recipient of NIH Research Career Development Award AI 00087. Dr. Weisbrodt is the recipient of PHS Research Scientist Development Award DA 00022.     

Oxalate metabolism in man studied during total parenteral nutrition

The mean urinary excretion of oxalate was 325 micromol/24 h in six patients during total parenteral nutrition (TPN). The urinary excretion of oxalate was considered to be equal to the endogenous oxalate production. A 2-day load of the oxalate precursor glycine given to five patients did not influence the oxalate excretion in spite of increased serum glycine concentrations. A 3-day load of the oxalate precursor ascorbic acid given to four patients increased the oxalate excretion in all patients. In one patient TPN was prolonged for 20 days without any change in the amount of oxalate excreted.     

Ultrasonographic study of gallbladder motility during total parenteral nutrition

Gallbladder sludge during total parenteral nutrition may be related to abnormal gallbladder motility. To test this hypothesis, gallbladder motility was assessed in 15 parenterally fed patients and in 22 controls using ultrasonography. Parenteral infusion was continuous in 10 cases and cyclic in 5 cases (6 PM to 10 AM). Gallbladder was simulated to a cone and gallbladder volume was calculated after ultrasonographic measurement of the greatest length and diameter. Six to 12 gallbladder volume measurements were performed between 8 AM and 11 PM in the parenteral nutrition group. In controls gallbladder volume was measured hourly between 8 AM and 8 PM. Thus maximal diurnal gallbladder volume and maximal diurnal gallbladder emptying, expressed as a percentage of maximum gallbladder volume, were determined. Maximal gallbladder volume was identical in the two groups. Gallbladder emptying was significantly reduced in parenterally fed patients (p less than 10(-9)) during both continuous and cyclic infusion.     

Exclusive enteral nutrition in children with crohn's disease

Exclusive enteral nutrition involves the use of a complete liquid diet, with the exclusion of normal dietary components for a defined period of time,as a therapeutic measure to induce remission in active Crohn's disease(CD). This very efficacious approach leads to high rates of remission, especially in children and adolescents newly diagnosed with CD. This intervention also results in mucosal healing,nutritional improvements and enhanced bone health.Whilst several recent studies have provided further elaboration of the roles of exclusive enteral nutrition in the management of CD, other reports have provided new understanding of the mechanisms by which this intervention acts.     

Preoperative total parenteral nutrition for bowel resection in Crohn's disease

To examine the effect of preoperative total parenteral nutrition (TPN) on patients with Crohn's disease undergoing bowel resection, an historical cohort was assembled of 103 patients resected between 1982 and 1984 by a single surgical team. Preoperative, perioperative, and postoperative variables were compared between patients receiving TPN and patients not receiving TPN. Analysis was stratified for three surgical procedures: segmental small bowel resection, ileocecectomy, and segmental or total colectomy. The effect of TPN was most pronounced in patients having small bowel surgery. For segmental small bowel resection, 12 of 17 patients had TPN, and these patients had 20.4 ±14.3 cm less bowel resected than did those in the non-TPN group, an effect not dependent on duration of TPN. For ileocectomy patients, 31 of 62 patients received TPN, and these patients had 11.2±4.2 cm less small bowel resected than the non-TPN group, an effect not dependent on the duration of TPN. For large bowel resection patients, 6 of 24 patients had TPN, and there was no difference in length of bowel resection, preoperative and perioperative variables, or recurrence. The total hospital stay was 13.5±2.6 days longer for those having TPN;3.5±1.9 days of the longer stay was postoperative. In conclusion, TPN was associated with reduced length of small bowel resection at the expense of longer hospital stay.This research supported in part by the Gastrointestinal Research Foundation Junior Board.     

Trace metal and essential fatty acid deficiency during total parenteral nutrition

While deficiencies of trace metals and essential fatty acids are rare in humans fed orally, the widespread use of total parenteral nutrition (TPN) has increased the likelihood of encountering these deficiencies. A 14-year-old boy, with total villous atrophy of the small intestine, suffered from severe malnutrition and was placed on a conventional TPN regimen. Although not immediately recognized, he rapidly developed deficiencies of zinc, copper and essential fatty acids. Careful monitoring of the course of the illness and the responses to sequential treatments with zinc, lipid, and copper given intravenously allowed examination of the effects of the deficiencies on skin, intestine, liver, and hemopoietic systems and helped to establish normal requirements for the metals. The progress of the illness suggested that patients with intestinal malabsorption may be especially at risk of developing some of these lesser known complications of TPN.     

Acute pancreatitis associated with high-concentration lipid emulsion during total parenteral nutrition therapy for Crohn's disease

A 17-yr-old boy with Crohn's disease and growth retardation developed an acute abdominal crisis while receiving total parenteral nutritional support. Acute pancreatitis was confirmed surgically. After recovery, in an attempt to provide adequate calories and to elucidate the inciting agent, he was rechallenged with his original total parenteral nutritional solution which contained 500 ml/day of a 20% fat emulsion. Symptoms and signs of acute pancreatitis quickly returned. Total parenteral nutrition was continued without the fat emulsion and symptoms and signs disappeared. This case suggests that acute pancreatitis was due to intolerance of high-concentration lipid emulsion.     

Hepatic complications of total parenteral nutrition

Total parenteral nutrition is now widely used in the treatment of nutritional depletion. Among problems that persist in the use of this technique, the development of hepatic abnormalities has received increasing attention. In this review, the current understanding of the pathogenesis and management of liver injury during short-term total parenteral nutrition is summarized. These complications include fatty liver, cholestasis, and nonspecific triaditis. The experience with hepatic complications during long-term total parenteral nutrition is also reviewed. Evidence that progressive liver injury develops in some patients requiring lifelong total parenteral nutrition raises a serious dilemma for both patients and physicians. Better understanding of the pathogenesis is required before appropriate treatment can be prescribed.     

Recent developments in home total parenteral nutrition

Home parenteral nutrition (HPN) support has been an advancing therapy in the past 30 years. Patients who previously had no options to sustain their lives are now able to live at home, maintain employment, and continue with most daily activities. Although this therapy has been innovative and successful, it requires great financial and professional resources. The expense of HPN makes most patients dependent on third-party payment, and the complications can result in frequent hospitalizations and may be life-threatening. For these reasons, extensive training of the patient and caregivers is necessary. Thorough and time-consuming monitoring by a multidisciplinary team of professionals is also essential. Home care and supply companies offer services that make the process of home TPN easier for the patient and the healthcare team. Advances in the area of home nutrition support are expected to continue as the demand for this therapy rises.