Strategies for parenteral nutrition weaning in adult patients with short bowel syndrome

The development of parenteral nutrition (PN) was an important, life-saving advance in the care of patients with short bowel syndrome (SBS). Nevertheless, its long-term use is often associated with complications. Therefore, it is desirable, when possible, to wean SBS patients to an oral diet. Given the complexity of PN weaning and the lack of published guidelines, the purpose of this article is to describe strategies of PN weaning and illustrate important clinical considerations during the weaning process. Patient education and motivation are key factors in successful PN weaning. The patient should have clearly defined care protocols and understand the importance of each aspect of the weaning program. Other factors likely to influence weaning success include the length and health of the remnant bowel, the presence of a colon, and the degree to which bowel adaptation has occurred. It is imperative that daily oral fluid and caloric intake goals are met prior to initiating PN weaning and that the patient receives an optimized dietary and medication plan. During weaning, the most practical measures for assessing adequate hydration and nutritional status are oral intake, stool and urine output, serum electrolytes and visceral proteins, and body weight. PN reductions can be made by either decreasing the days of PN infusion per week or decreasing the PN infusion volume equally across all days of the week. Use of recombinant human growth hormone, with or without glutamine, may play a role in facilitating the PN weaning process.     

Role of parenteral nutrition in patients with short bowel syndrome.

More patients with extensive resection of the small bowel--secondary to regional enteritis, mesenteric infarction, cancer, etc.--are surviving perioperative treatment. To avoid nutrition-caused malabsorption and to maintain body composition, intravenous nutrition is initiated with a silastic atrial catheter in the immediate postoperative period. The patients are trained in "home hyperalimentation" procedures designed to allow normal nutrition to be maintained during the months required for bowel adaptation to occur. Because bowel adaptation to the absorption and transport of foodstuffs is in part dependent on the intraluminal presence of foodstuffs, elemental and regular diets are ingested during the period of intravenous support which may last for years. By using combined oral and intravenous nutrition, approximately 20 per cent of patients with short bowel syndrome eventually can take sufficient oral nutrients to sustain life.     

Complications associated with total parenteral nutrition in infants with short bowel syndrome.

The use of total parenteral nutrition (TPN) in five out of six infants with short bowel syndrome (SBS) adaptation permitted enteral nutrition. The duration of TPN depended on the extent of the resection, whether it was proximal or distal, and the adaptation of the residual gut. Residual bowel measuring 10 cm required prolonged TPN in the sixth infant and was not compatible with survival. Catheter-related complications were infection, malposition and dislodgement of the catheter. Metabolic complications were easily controlled by regulating the concentration of the infusate and the rate of the infusion. Osteopenia was common in prolonged TPN and was corrected with vitamin D supplementation. Cholestasis was the most common complication. It was demonstrated with elevation of gamma-glutamyl-transpeptidase levels which became evident as early as six weeks after the introduction of TPN. Serum bilirubin and transaminase elevations were later manifestations. One infant died of hepatic decompensation. Late morphological manifestations were those of cholestatic changes with fibrosis. The biochemical abnormalities of cholestasis were reversible provided TPN was discontinued at an early stage.     

Guidelines for pharmacotherapy, nutritional management, and weaning parenteral nutrition in adult patients with short bowel syndrome: introduction

A group of experienced clinicians met to formulate treatment options for the management of short bowel syndrome in adult patients. Their presentations and discussions generated a set of guidelines for the management of these challenging cases.     

Total parenteral nutrition needs in different types of short bowel syndrome

Thirty-nine patients with short bowel syndrome after extensive small bowel resection, with or without associated partial or total colectomy, received continuous total parenteral nutrition followed by discontinuous parenteral nutrition. Home parenteral nutrition was introduced in 16 of these patients; in eight it was permanent. The assessment of nutritional status included body weight; standard urinary and blood studies; albumin, prealbumin, and transferrin serum levels; and both urinary and fecal nitrogen. A statistically significant correlation (P<0.001) was observed between the length of the remaining small bowel and the necessary duration of nutritional support. Multivariate analysis allowed us to classify patients into three groups as a function of remaining gut length and the duration of required nutritional support. This study should help to define the best nutritional support protocol for patients with various short bowel syndromes in order to ensure the best possible intestinal adaptation and to improve their quality of life.     

Indications and recommendations for the use of recombinant human growth hormone in adult short bowel syndrome patients dependent on parenteral nutrition

Given the lack of published guidelines regarding the use of trophic factors to treat patients with short bowel syndrome (SBS), a group of experts in the field convened to discuss best-practice strategies. Trophic factors, such as recombinant human growth hormone (r-hGH) and glucagon-like peptide-2 (GLP-2), may enhance intestinal adaptation and decrease parenteral nutrition (PN) requirements; therefore, their utility in treating SBS patients was evaluated. Available clinical data on use of r-hGH therapy in SBS patients were discussed, as were the utility of r-hGH in the PN weaning process, the optimal timing of r-hGH therapy, and how to select appropriate patients for r-hGH therapy. In addition, contraindications and precautions as well as adverse effects of r-hGH treatment were discussed. The meeting culminated with the development of a treatment algorithm to summarize best-practice recommendations for the management of SBS in adult patients. This algorithm involves attempting to wean patients off PN without the use of trophic factors. If this is unsuccessful, it is recommended that patients be treated with an r-hGH regimen or participate in investigational studies using other trophic factors.     

Cholesterol metabolism in pediatric short bowel syndrome after weaning off parenteral nutrition

BackgroundSmall intestine essentially regulates cholesterol homeostasis.AimsTo evaluate cholesterol metabolism in short bowel syndrome (SBS).MethodsCholesterol precursors (e.g., cholestenol, desmosterol and lathosterol) and plant sterols (campesterol and sitosterol), respective markers of cholesterol synthesis and absorption, were determined in SBS patients (n = 12) an average of 31 months after weaning off parenteral nutrition and in age-matched controls (n = 80).ResultsAmong patients, serum cholesterol precursor sterol to cholesterol ratios were 2–10 times higher (P < 0.0001 for each). Those without any remaining ileum had 1.2–2.8 times higher precursor sterol to cholesterol ratios than those with an ileal remnant (P < 0.05 for each). Serum cholesterol concentration, campesterol/cholesterol and campesterol/sitosterol were 34–39% lower (P < 0.05 for each) in relation to controls. Bile acid absorption was markedly impaired (2.4 (0.2–3.2)%). Plant sterol ratios reflected the absolute length of remaining jejunum (r = 0.625–0.663), and precursor sterol ratios inversely that of ileum (r = −0.589 to 0.750, P < 0.05 for all).ConclusionAfter weaning off parenteral nutrition, patients with pediatric onset SBS continue to have marked intestinal malabsorption of bile acids and moderate cholesterol malabsorption resulting in decreased serum cholesterol despite a marked compensatory increase in cholesterol synthesis.     

Low-dose growth hormone in adult home parenteral nutrition-dependent short bowel syndrome patients: a positive study

BACKGROUND & AIMS: Controversy surrounds a 3-week treatment with a high-dose (0.14 mg. kg(-1). day(-1)) growth hormone (GH), glutamine, and high carbohydrate diet in home parenteral nutrition (HPN)-dependent patients with short-bowel syndrome (SBS). This study assessed treatment with low-dose GH in these patients. METHODS: Twelve adult HPN-dependent (duration, 7 +/- 1 years; mean +/- SEM) patients with SBS (small-bowel remnant length, 48 +/- 11 cm) who were on an unrestricted hyperphagic diet were randomized in a double-blind, placebo-controlled, crossover study. Patients received daily low-dose GH (0.05 mg. kg(-1). day(-1)) and placebo for two 3-week periods separated by a 1-week washout period. Net intestinal absorption of macronutrients was assessed using a duplicate diet; nutritional assessment and blood tests were performed. Data from each group were compared using Wilcoxon rank sum test. RESULTS: Treatment with GH increased intestinal absorption of energy (15% +/- 5%, P < 0.002), nitrogen (14% +/- 6%, P < 0.04), carbohydrates (10% +/- 4%, P < 0.04), and fat (12% +/- 8%, NS). The increased food absorption represented 37% +/- 16% of total parenteral energy delivery. Body weight (P < 0.003), lean body mass (P < 0.006), D-xylose absorption (P < 0.02), insulin-like growth factor 1 (P < 0.002), and insulin-like growth factor binding protein 3 (P < 0.002) increased, whereas uptake of GH binding protein decreased (P < 0.01), without any major adverse effect. CONCLUSIONS: Three weeks of low-dose GH significantly improved intestinal absorption in HPN-dependent SBS patients who were on a hyperphagic western diet.     

Emerging treatments for short bowel syndrome in adult patients

Introduction: Short bowel syndrome (SBS) is the major cause of chronic intestinal failure (IF), defined as ‘the reduction of gut function below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth’.

Areas covered: Spontaneous intestinal adaptation, including increased hormonal secretion, development of hyperphagia and gut microbiota dysbiosis, occurs 2 years after resection, improving intestinal absorption and decreasing PN dependency. Hormonal treatments, promoting intestinal hyperadaptation, have been proposed in patients with SBS with chronic IF. Clinical studies showed teduglutide to increase urine production and reduce the need for parenteral support volume in these patients. According to the latest ESPEN Guidelines, if a growth factor treatment is considered, the GPL2 analog, teduglutide, should be the first-choice treatment.

Expert opinion: These therapies underline the importance of patient monitoring at home and the complexity for HPN adaptation. A multidisciplinary approach should be a gold standard.     

Modern treatment of adult short bowel syndrome patients

By definition, intestinal failure prevails when oral compensation is no longer feasible and parenteral support is necessary to maintain nutritional equilibrium. In the past, conventional treatment has mainly focused on "making the most of what the short bowel syndrome patient still had" by optimizing remnant intestinal function through dietary interventions, antidiarrheals and antisecretory agents. However, modern treatment options are in the near horizon, and the increased understanding of the mediators for intestinal adaptation will lead to the expansion of the limited treatment armamentarium in short bowel syndrome patients with intestinal failure. The clinical meaningfulness and implications of the observed effects of growth hormone, glutamine, glucagon-like peptide 2 (GLP-2) and the dipeptidyl peptidase-4 degradation resistant analog, teduglutide, is presented in this review and balanced against treatment related adverse events and possible unfavourable effects of long-term, possibly lifelong, treatments.     

Dietary and medical management of short bowel syndrome in adult patients

Resection of the small bowel can lead to malabsorption of fluid, electrolytes, minerals, and other essential nutrients, resulting in malnutrition and dehydration. Individualized and tailored nutritional management for patients with short bowel syndrome (SBS) helps to optimize intestinal absorption, leading to nutritional independence such that a patient can resume as normal a lifestyle as possible. Parenteral nutrition (PN), used to supply the required nutrients following resection, is associated with a number of complications affecting patient morbidity and mortality. Attempts should be made to wean patients from PN to an oral diet as soon as possible. Dietary management is complex and needs to be individualized for each patient on the basis of his or her specific gastrointestinal anatomy, underlying disease, and lifestyle. In addition to nutrient intake, management of SBS also requires appropriate oral rehydration, vitamin and mineral supplementation, and pharmacotherapy. Several medications provide a useful adjunctive function to dietary intervention, including antidiarrheal agents, H2 antagonists and proton pump inhibitors, pancreatic enzymes, somatostatin analogs, antimicrobials, and trophic factors.     

Intestinal adaptation in patients with short bowel syndrome

Functional adaptation of remaining intestine was evaluated in 30 patients with extensive small bowel resection. Calcium and xylose absorption tests were compared. Calcium absorption was measured by a double-radiotracer technique. Serum xylosemia was measured 2 hr after D-xylose ingestion. Patients were divided into two groups according to the time interval between surgery and evaluation: less (group I) or more (group II) than two years. A statistically significant correlation was found between xylosemia and remaining small bowel length (r = 0.71; P less than 0.001) and between calcium absorption and remaining small bowel length (r = 0.75; P less than 0.001) in group I. A significant correlation was also observed between calcium absorption and time after surgery (r = 0.65; P = 0.001) but not for xylose absorption. Calcium absorption value was significantly increased in group II patients compared with group I patients matched for remaining small bowel length (36.2 +/- 12.5% vs 14.5 +/- 9.1%; P less than 0.001) while no difference was observed between the two groups concerning xylose absorption. These data indicate that intestinal calcium absorption continues to increase for more than two years after a major bowel resection in man. The intestine does not seem to recover all its functions at the same time.     

Enteral and parenteral nutrition in the care of patients with short-bowel syndrome

Short-bowel syndrome is a challenging entity for the gastroenterologist, requiring integration of medical, nutritional, surgical and psychological therapies. Treatment must be based on the patient's age, remaining gastrointestinal anatomy, baseline nutritional status and underlying general health as well as the numerous complications which may arise. This chapter reviews physiological alterations that occur with short-bowel syndrome and how therapies can be tailored to most adequately meet the needs of these patients. Emphasis on early stages of therapy to enhance intestinal adaptation is focused on as management during this time has a significant impact on the long-term outcome of these patients.     

The management of patients with the short bowel syndrome

The surgeon is invariably the primary specialist involved in managing patients with short bowel syndrome. Because of this they will play an important role in co-ordinating the management of these patients. The principal aims at the initial surgery are to preserve life, then to preserve gut length, and maintain its continuity. In the immediate postoperative period, there needs to be a balance between keeping the patient alive through the use of TPN and antisecretory agents and promoting gut adaptation with the use of oral nutrition. If the gut fails to adapt during this period, then the patient may require therapy with more specific agents to promote gut adaptation such as growth factors and glutamine. If following this, the patient still has a short gut syndrome, then the principal options remain either long term TPN, or intestinal transplantation which remains a difficult and challenging procedure with a high mortality and morbidity due to rejection.