The clinical management of short bowel syndrome: steps to avoid parenteral nutrition

Nutritional Care for Patients with Intestinal Failure

Intestinal failure is a debilitating, complex disorder associated with loss of portions of intestine or loss of intestinal function. Short bowel syndrome is the most common form of intestinal failure and results in inability to maintain nutritional, fluid, and electrolyte status while consuming a regular diet. Nutrition interventions to treat short bowel syndrome include enteral and parenteral nutrition, intestinal rehabilitation techniques to enhance absorptive capacity of remnant bowel, and surgical reconstruction designed to provide more surface area for absorption. These therapies are interrelated services to restore nutritional status through the safest most effective therapy consistent with patient lifestyle and wishes.

Intestinal Rehabilitation: A Management Program for Short-Bowel Syndrome

Over the last 3 decades, there has been significant improvement in the survival and quality of life of patients who require home parenteral nutrition; however, parenteral nutrition remains costly, is associated with multiple complications, and does not promote the function of the remaining bowel. Intestinal rehabilitation refers to the process of restoring enteral autonomy and decreasing dependence on parenteral nutrition by utilizing dietary, pharmacological, and, occasionally, surgical interventions. A major focus of research has been to identify a trophic factor that will enhance adaptation of the remaining gastrointestinal tract following massive gut resection and allow enteral autonomy. Whether intestinal rehabilitation occurs as the result of increased intestinal adaptation or as the result of a comprehensive approach to care has yet to be determined. This article reviews intestinal failure as the result of short-bowel syndrome and the management strategy of an intestinal rehabilitation program in the care of these patients.

Spectrum of short bowel syndrome in adults: intestinal insufficiency to intestinal failure

Short bowel syndrome (SBS) refers to the malabsorptive state caused by physical or functional loss of portions of the small intestine, most commonly following extensive intestinal resection. Such resections hinder absorption of adequate amounts of macronutrients, micronutrients, electrolytes, and water, resulting in malnutrition, diarrhea, and dehydration. Clinical features of SBS vary along a continuum, depending on the extent and anatomy of intestine lost and the ability of the patient and the remaining intestine to compensate for the loss. The impact of SBS can be extensive, leading to diminished health-related quality of life because of its many physical and psychological effects on patients. SBS is associated with decreased survival; risk factors for SBS-related mortality include very short remnant small bowel, end-jejunal remnant anatomy, and arterial mesenteric infarction as primary cause. Although parenteral nutrition and/or intravenous fluid (PN/IV) is a life-saving measure for many patients with SBS, patients with the most severe malabsorption (ie, dependent on PN/IV) are at risk for severe, chronic complications and death. Patients' treatment needs vary depending on disease severity and resection type; thus, each patient should be individually managed. This review discusses the spectrum of disease in patients with SBS and presents common complications encountered by these patients to highlight the importance of individualized management and treatment.

Morphological and functional changes in the colon after massive small bowel resection

PURPOSE

Anecdotal evidence suggests that the colon plays an important role after small bowel resection (SBR). However, colonic changes have not previously been studied. The aim of this study was to characterize morphological and functional changes within the colon after SBR and elucidate the influence of diet complexity on adaptation.

METHOD

In study 1, 4-week-old piglets underwent a 75% SBR or sham operation and were studied at 2, 4, and 6 weeks postoperation to allow analysis of early and late adaptation responses. Piglets received a polymeric infant formula (PIF). In study 2, SBR piglets received an elemental diet and were studied at 6 weeks postoperation and compared with SBR + PIF piglets from study 1. For both studies, immunohistochemistry was used to quantitate intestinal cell types. Changes in functional proteins were measured by Western blot, enteroendocrine/peptide YY (PYY), enterocyte/liver fatty acid binding protein (L-FABP), and goblet cells/trefoil factor 3 (TFF3).

RESULTS

In study 1, early and late adaptation-related changes were observed after SBR. Early adaptation included increased numbers of enterocytes (P = .0001), whereas late adaptation included increased proliferative cell numbers (P = .02). Enteroendocrine, goblet, and apoptotic cells numbers were significantly elevated in the resected group at all time-points studied (P < .05). Functional changes included increased levels of L-FABP (P = .04) and PYY (P = .03). There was no change in TFF3 expression. In study 2, feeding with an elemental diet resulted in suboptimal adaptation as evidenced by reduced rate of weight gain and significant reductions in total cell numbers (P = .0001), proliferative (P = .0001) and apoptotic cells (P = .04), enteroendocrine cells (P = .001), and PYY expression (P .004).

CONCLUSION

These findings indicate that significant morphological and functional changes occur in the colon after massive SBR and that these occur as early and late adaptation responses. Elemental diet was associated with suboptimal adaptation suggesting an effect of diet complexity on colonic adaptation.

Clonidine reduces diarrhea and sodium loss in patients with proximal jejunostomy: a controlled study

BACKGROUND

Patients with short bowel syndrome have significant fluid losses. This represents a significant management problem, especially in patients with minimal residual intestine. We determined whether clonidine, an alpha2-adrenergic agonist, is effective in decreasing fecal water and sodium (Na) losses in patients with proximal jejunostomy. Eight parenteral nutrition (PN)-dependent subjects (3 men, 5 women), aged 49.9+/-10.2 years, with a residual small bowel length of 71.8+/-152.0 cm that ended in a jejunostomy, were studied.

METHODS

Subjects were admitted to the North-western General Clinical Research Center (GCRC) for a 2-day equilibrium period while receiving a self-selected 100 g fat diet with protein 1.5 g/kg/d and 30 kcal/kg/d and 1 L/d of oral rehydration solution. A D-xylose test was performed after an overnight fast. On days 3-5, all stool and urine were collected for volume, weight, fat, nitrogen, energy, sodium, magnesium, potassium, and calcium. Meals were provided in duplicate and the equivalent portions consumed by each patient were analyzed for fluid volume, fat, nitrogen, energy, sodium, magnesium, calcium, and potassium in order to calculate nutrient balances. At the conclusion of the stool and urine collections (day 6), a clonidine (0.3 mg) patch was applied to the shoulder. Subjects were restudied after 1 week.

RESULTS

Daily fecal volume and weight were 4.514+/-1.769 L/d and 4394+/-1727 g/d, respectively, at baseline. Five subjects were net "secretors" in that excreted fecal volume exceeded oral intake. Fecal volume decreased by 427+/-562 mL/d (8.9%, p=.07). Fecal weight decreased by 438+/-527 g/d (9.4%, p=.05). Urine volume correspondingly increased by 747+/-1934 mL (18.9%, p=not significant [NS]). The increase in urine output was weakly and negatively correlated with the decrease in fecal volume and weight (r=-0.37 and -0.41, respectively, p=NS). Oral fluid intake decreased slightly from 3.328+/-1.246 L/d baseline to 3.203+/-1.119 L/d with clonidine therapy (-3.8%, p=NS). Fecal Na loss was significantly decreased from baseline (887+/-996 mg/d, 11.2+/-12.3%; p=.036). This was not related to decreased oral Na intake, which actually increased from baseline (3.799+/-2.271 g/d) to 3.933+/-1.314 g/d after clonidine therapy (p=NS). No patient developed hypotension.

CONCLUSIONS

Our results show the transdermal administration of clonidine is associated with a modest but clinically significant decrease in fecal output in patients with short bowel syndrome and high-output proximal jejunostomy that require chronic parenteral fluid infusion. This is accompanied by decreased fecal Na loss.

Enteric-coated cholylsarcosine microgranules for the treatment of short bowel syndrome

Cholylsarcosine (CS) is a semisynthetic bile salt that may be useful in bile salt replacement therapy of short bowel syndrome (SBS). In SBS the bile salt pool becomes depleted, disturbing the uptake of dietary lipids and resulting in weight loss. Previous studies showed that CS in a simple capsule formulation of 1.5-12 g day(-1) can increase the uptake of lipids but often results in gastric irritation. In this work a microgranule dosage form was developed to protect the gastric mucosa while facilitating rapid generation of CS levels in the duodenum. CS microgranules were produced by wet granulation and coated with Eudragit L30D-55 in a fluidized-bed coater. The in-vitro dissolution rate of CS from the microgranules was investigated with USP apparatus under fasted- and fed-state conditions. CS release was delayed under simulated gastric conditions (pH 1.2 and 4.5) but was very fast at higher pH values (5.5, 5.8 and 6.5) more typical of the duodenum. In a pilot clinical trial, four patients received 4 g CS with meals (1.5 g with lunch, 2.5 g with dinner) for 1 week. The parameters investigated were fat absorption coefficient (FAC%), serum beta-carotene level and faecal weight. Although study numbers were too small to achieve statistical significance, the serum beta-carotene level and FAC% increased in the three patients who completed the trial. As expected, the fecal weight did not change. The results indicate that the CS microgranules are promising for the treatment of the intraluminal bile salt deficiency in patients with SBS.

Effects of bowel rehabilitation and combined trophic therapy on intestinal adaptation in short bowel patients

AIM: To evaluate the effects of bowel rehabilitation and combined trophic therapy on intestinal adaptation in short bowel patients.

METHODS: Thirty-eight patients with severe short-bowel syndrome (SBS) were employed in the present study, whose average length of jejunum-ileum was 35.8 ± 21.2 cm. The TPN treatment was initiated early to attain positive nitrogen balance and prevent severe weight loss. The TPN composition was designated to be individualized and altered when necessary. Enteral feeding was given as soon as possible after resection and increased gradually. Meals were distributed throughout the day. Eight patients received treatment of growth hormone (0.14 mg/kg•d) and glutamine (0.3 g/kg•d) for 3 wk. D-xylose test, ¹⁵N-Gly trace test and ¹³C-palmitic acid breath test were done to determine the patients' absorption capability.

RESULTS: Thirty-three patients maintained well body weight and serum albumin concentration. The average time of follow-up for 33 survival patients was 5.9 ± 4.3 years. Twenty-two patients weaned from TPN with an average TPN time of 9.5 ± 6.6 mo. Two patients, whose whole small bowel, ascending and transverse colon were resected received home TPN. An other 9 patients received parenteral or enteral nutritional support partly as well as oral diet. Three week rhGH + GLN therapy increased nutrients absorption but the effects were transient.

CONCLUSION: By rehabilitation therapy, most short bowel patients could wean from parenteral nutrition. Dietary manipulation is an integral part of the treatment of SBS. Treatment with growth hormone and glutamine may increase nutrients absorption but the effects are not sustained beyond the treatment period.

Nutritional management of short bowel syndrome in adults

Short bowel syndrome (SBS) comprises the sequelae of nutrient, fluid, and weight loss that occurs subsequent to greatly reduced functional surface area of the small intestine. Signs and symptoms of SBS include electrolyte disturbances; deficiencies of calcium, magnesium, zinc, iron, vitamin B12, or fat-soluble vitamin deficiency; malabsorption of carbohydrates, lactose, and protein; metabolic acidosis, gastric acid hypersecretion; formation of cholesterol biliary calculi and renal oxalate calculi; and dehydration, steatorrhea, diarrhea, and weight loss. Thorough nutritional management is the key factor in achieving an optimal outcome in SBS. Total parenteral nutrition is necessary in the early stages, as is replacement of excess fluid and electrolyte losses. Nutritional management of SBS has traditionally been divided into three phases: an acute phase when total parenteral nutrition is usually begun, an adaptation phase, and a maintenance phase. Recommendations regarding the need for parenteral nutrition vary depending on the presence or absence of certain factors: the ileocecal valve, jejunum, and functional colon. Patients with residual small bowel length of 100 cm or less usually require the administration of parenteral nutrition at home with good results. The total parenteral nutrition diet should consist of a majority of calories from fat, followed by protein, and the remaining as carbohydrates. Vitamins, minerals, and trace elements should also be added accordingly. Although total parenteral nutrition is initially necessary, treatment goals should focus on early transition to enteral nutrition followed by oral feeds. Other recent advances in the medical management of SBS include pharmacologic treatment and the use of specific nutrients and growth factors to stimulate intestinal absorption and adaptation. Both animal studies and clinical trials in humans have shown much promise in supplementation with growth factors and hormones. This strategy is likely to play a greater role in the treatment of SBS in the future.

Total-body-water measurement with 18O-labeled water in short-bowel patients with an ileostomy

The aim of this study was to evaluate the use of H(2)(18)O for total-body-water (TBW) determination in patients with short bowel because ileostomy losses of labeled water can falsify TBW. Thirteen adult short-bowel patients were studied after an overnight fast. Saliva, blood, urine and ileostomy output were collected before and 30, 60, 90, 120, 240, and 360 min after oral ingestion of 0.88 g/kg of 2.5% H(2)(18)O to measure (18)O abundance by isotope-ratio mass spectrometry. TBW was calculated from the dilution of the isotopic water in saliva and plasma. The quantity of labeled water lost in the ileostomy was calculated from the isotopic enrichment of the ileostomy output from T0 to T360. The values obtained from saliva or plasma with (corrected) and without (uncorrected) considering H(2)(18)O lost in the ileostomy output were compared with a paired t test. Agreement was evaluated using the Bland-Altman method. From T0 to T360, the ileostomy output and the percentage of lost labeled water were 490 +/- 314 mL and 6.38 +/- 8.52%, respectively. TBW calculated from plasma or saliva isotopic enrichment was different, and a significant difference was also observed between corrected and uncorrected TBW values (saliva: uncorrected TBW = 32.35 +/- 7.52 L, corrected TBW = 30.29 +/- 6.09 L; plasma; uncorrected TBW = 30.80 +/- 7.29 L, corrected TBW = 28.79 +/- 5.79 L). The agreement between the values obtained from the two dilution spaces or between the two calculation methods was poor. Because of the large discrepancies between calculation methods, determination of TBW from oral ingestion of (18)O-labeled water in patients with short bowel should be calculated only from plasma (18)O space dilution and should consider ileostomy losses.

Serum leptin concentrations in patients with short-bowel syndrome

BACKGROUND

Short-bowel syndrome is a state of severe malabsorption resulting from absence or removal of the small bowel for several causes. A number of short-bowel patients develop hyperphagia. Leptin, a protein secreted from adipose tissue, signals the amount of energy stores to the brain.

OBJECTIVE

To study body composition and leptin regulation in short-bowel patients and to determine whether or not leptin concentrations are linked with hyperphagia.

DESIGN

We studied 25 short-bowel patients (remnant bowel less than 150 cm) and 31 controls and 10 oral nutrition. Fifteen patients received total parenteral nutrition and 10 oral nutrition. Anthropometric measurements, body composition (by bioelectrical impedance), and cholesterol, triacylglycerol and leptin concentrations were studied in all subjects.

RESULTS

There were no differences between short-bowel patients and controls in anthropometric variables, body composition, or leptin concentrations. Leptin concentrations were higher in short-bowel women than men (9.21+/-8.54 vs. 3.22+/-1.86 ng/ml, P=0.01). Leptin concentrations correlated positively with age (r=0.4, P=0.045), body mass index (r=0.52, P=0.007), fat mass (r=0.67, P=0.001) and body fat (r=0.68, P=0.0001); there were no correlations with other body composition parameters. We found no correlations between parenteral or oral nutrition and body composition parameters, or between leptin concentrations and the presence of hyperphagia. Logistic regression analysis showed that body fat correctly identified leptin concentrations in 60% of patients.

CONCLUSIONS

Body composition, leptin concentrations and leptin regulation in patients with short-bowel syndrome are similar to those of controls. Leptin concentrations do not correlate with hyperphagia in short bowel-patients.