Management of Short Bowel Syndrome By:- Dawit Mesfin (Medical Intern) The likelihood of successful transition to enteral feeding in short bowel syndrome depends upon several factors: The length of remaining small bowel The remaining segments of small bowel Presence of the colon and an intact ileocecal valve Intestinal adaptation Early Management During the early period after lengthy intestinal resection, the predominant goals are The administration of parenteral nutrition and Prevention of fluid and electrolyte abnormalities. Most patients are kept fasting and supported with a standard parenteral nutrition solution, which can be administered at home if long-term therapy is anticipated. Large volume gastric or proximal small bowel fluid losses are relatively common in the early phase. As a result, fluid replacement protocols with Sodium, Potassium Choride, and magnesium are important during this phase. Stomal and fecal losses should be measured and replaced every two hours with a solution separate from the nutrition solution. An H2 blocker should be given intravenously to suppress gastric hypersecretion, which may improve nutrient absorption, and reduce fluid losses. Patients with SBS often develop gastric acid hypersecretion, which may be associated with deactivation of pancreatic enzymes, a reduction in the optimal pH needed for fat absorption, and increased intestinal fluid losses. fish oil-based intravenous lipid emulsion in the treatment of parenteral nutrition-associated liver disease shown to reduce mortality and need for liver transplantation in children with SBS. ENTERAL FEEDING Slow introduction of enteral feeding is indicated once the patient stabilizes. Complex diets are known to enhance greater adaptation than elemental diets; however, elemental diets have a role when intestinal inflammation is present. Continuous tube feeding (exclusively or in conjunction with oral feeding) in the postoperative period has been shown to significantly increase net absorption of lipids, proteins, and energy compared with oral feeding Composition Many enteral feeding formulations, especially amino acid solutions, are high in carbohydrate content. This is often a disadvantage in short bowel syndrome because carbohydrates create a much higher osmotic load in the small intestine than fats or proteins. Children, especially infants, are more likely to be intolerant of large concentrations of carbohydrates and do much better on a formula higher in fat content. The negative effects of dietary carbohydrates are less apparent in adults, especially those with large segments of retained colon who are more capable of fermenting malabsorbed carbohydrates to short-chain fatty acids, which can be absorbed and serve as a calorie source Protein hydrolysate diets often contain a higher, more physiologic percentage of fat and are frequently better tolerated . Fiber supplementation also may be helpful by enhancing adaptation via increased short-chain fatty acid production and providing an additional calorie source in patients with a reasonable amount of colon. In addition, fiber supplementation may decrease the watery nature of the stools by adsorbing stool water. This can be helpful if frequent stooling causes perineal skin breakdown. Other additions to the enteral regimen are less useful. As an example, medium-chain triglycerides are frequently given because they are more water soluble than long-chain triglycerides and better absorbed in the presence of bile acid or pancreatic insufficiency. However, they have a slightly lower caloric density, exert a greater osmotic load in the small intestine, and, since patients with short bowel syndrome typically have normal pancreatic and biliary function, are of limited value. Lactose restriction is often not necessary in patients with short bowel syndrome. Many such patients tolerate lactose well as it is absorbed in the proximal small bowel, and dairy products are good sources of fat, calories, and calcium. Oxalate restriction is important in those with an intact colon and fat malabsorption to avoid stone formation. Frequency of feeding Continuous enteral feeding via a nasogastric or gastrostomy feeding tube is initially advantageous. Continuous feeding permits constant saturation of carrier transport proteins, taking full advantage of the absorptive surface area available. For the same reason, small frequent feedings are preferable to infrequent large feedings. The primary benefit of continuous enteral feeding is that it facilitates intestinal adaptation, thereby accelerating the progression to oral feeding in patients in whom a transition to oral feeding is expected. Tapering of parenteral nutrition Enteral feedings should be advanced slowly, and parenteral calories concomitantly and isocalorically decreased to maintain nutritional status, control fluid losses, and ensure gut adaptation. It is important not to be overly aggressive, and to make small frequent increases in enteric feeding as the small intestine adapts to increased nutrient administration. The success of enteral feeding can be assessed by measurement of enteral fluid loss, which reflects the degree of carbohydrate malabsorption. Carbohydrate malabsorption can be estimated directly by testing the stool or ostomy fluid for glucose (eg, with a Clinitest tablet). The important elements of chronic enteral nutrition are: Small frequent feedings (every two to three hours in adults). A reasonable mixture of protein, carbohydrates and fats; ideally, 40 percent of the patient's caloric intake should be provided in the form of fat. Avoidance of hypertonic beverages (eg, sodas and fruit juices). Avoidance of high carbohydrate feedings; those with simple carbohydrates often result in sudden osmotic fluid losses and dehydration and all forms of carbohydrate increase bacterial proliferation. Pharmacologic therapy A number of pharmacologic agents have been used to reduce secretory losses in patients whose intake is exceeded by output. H2 blockers, proton pump inhibitors, and octreotide inhibit excessive gastric or pancreatic secretion with varying success. Loperamide Thickening agents Growth factors — have been tried to hasten adaptation and to enhance mucosal growth beyond the normal limits of adaptation Glutamine and growth hormone Glucagon-like peptide-2 - Teduglutide SMALL BOWEL TRANSPLANTATION Small bowel transplantation has been advocated for certain patients with Short bowel syndrome who are not candidates or Patients who have developed complications from long-term parenteral nutrition and In whom adequate adaptation cannot occur. NONTRANSPLANTATION PROCEDURES The goal of these operations is to increase nutrient and fluid absorption by either Slowing intestinal transit or Increasing intestinal length. Operations designed to slow intestinal transit include Segmental reversal of the small bowel, Interposition of a segment of colon between segments of small bowel, Construction of small intestinal valves, and Electrical pacing of the small intestine The intestinal lengthening operation for which there is the greatest experience is the longitudinal intestinal lengthening and tailoring procedure Serial transverse enteroplasty Serial transverse enteroplasty procedure. This illustration depicts the serial transverse enteroplasty procedure. Lengthening of dilated small intestine is accomplished by serial applications of an intestinal stapling device, with firings oriented perpendicular to the long axis of the intestine. Clinical issue Assess likelihood of resuming an oral diet Management/comments Increased likelihood with jejunal length greater than 200 cm and intact colon May take months to years Anticipate consequences based upon remaining intestinal segments Proximal small intestine primarily responsible for absorption of proteins, carbohydrates but ileum able to compensate Ileum responsible for vitamin B12 and bile salts. >100 cm resected leads to loss of bile salts leading to fat malabsorption. <100 cm resected leads to bile salt malabsoprtion and secretory diarrhea Loss of colon and extensive small bowel resection is poorly tolerated Early management Fluid and electrolyte replacement predominates Begin enteral feeding once patient stabilizes Antidiarrheals may help Octreotide (recommended by some authorities) can reduce digestive secretions but increases the risk of gallstones and tachyphylaxis develops. Thus, it should be used with caution and only in late stages of therapy (after approximately two years when intestinal adaption has been achieved) Cholereic enteropathy Use bile salt sequestering agents Gastric acid hypersecretion H2 blocker or PPI (efficacy can be determined by measuring fecal pH and aiming for pH ≥7) Enteral nutrition Continuous enteral feeding or small frequent feedings is preferred Continuous takes full advantage of absorptive surface area and may facilitate intestinal adaption Advance slowly, taper parenteral nutrition. It is reasonable to initiate by providing approximately 5 percent of total daily caloric need, making slow incremental advances every three to seven days as tolerated Carbohydrate malabsorption can be estimated by testing stool for glucose (eg, Clinitest tablet) but it is usually apparent clinically with develoment of increased fluid losses Fat malabsorption Reduce fat intake Protein malabsorption Use protein hydrosylates Fat soluble vitamin malabsorption Monitor and replace; Avoid excessive concurrent dietary intake Vitamin and mineral malabsorption (K+, Cl-, Mg++, Ca++, Zn++, Fe++, selenium, Monitor and replace Chronic complications of the Short Bowel Syndrome in adults Chronic complications of short bowel syndrome In Adults, Liver and biliary disease associated with parenteral nutrition, Malabsorptive nutritional abnormalities including metabolic bone disease, small bowel bacterial overgrowth induced arthritis and colitis, Enteric hyperoxaluria, and D-lactic acidosis. Other complications related to parenteral nutrition such as central line sepsis and catheter breakage also are common until the parenteral nutrition phase has ceased . Patients with intractable complications may be candidates for small bowel transplantation. In Children Acute complications that can occur anytime include watery diarrhea, electrolyte disturbances, and catheter-related complications. More chronic complications are the same with adults include liver and biliary disease associated with parenteral nutrition, bacterial overgrowth-induced arthritis, colitis, and D-lactic acidosis, nutritional deficiencies, and enteric hyperoxaluria.
