Basics
Description
Malnutrition, malabsorption, and/or fluid and electrolyte loss after extensive small-bowel resection ‚
Pathophysiology
- Markedly decreased mucosal surface area due to resection
- Loss of trophic hormones
- Loss of peptide hormones that regulate motility
- Abnormal transit
- Malabsorption of protein, fat, carbohydrate, vitamins, electrolytes, and trace elements, depending on site of resected intestine
- Patient can lose as much as half of intestine if the duodenum, distal ileum, and ileocecal valve (ICV) are present.
- If the ICV is gone, patients may not be able to tolerate even a 25% loss of intestine without the help of parenteral nutrition (PN).
- Normal bowel length: 150 " “200 cm, 26 weeks ' gestation; 200 " “300 cm at birth in full-term infant; 600 " “800 cm, adult
- Infants have low intestinal reserve; do not tolerate resection as well as do adults.
- However, long-term prognosis is often better because of hypertrophy and hyperplasia of the intestine.
- Gastric acid hypersecretion occurs soon after intestinal resection but is transient.
- Bowel adaptation can occur over time. Increased surface area due to bowel dilatation, villous hypertrophy, and bowel lengthening can occur. Stimulation of luminal contents is needed for bowel growth, and factors such as glutamine, short-chain fatty acids, tropic hormones, and growth factors may be important for bowel growth.
Etiology
- Infants: intestinal resection for necrotizing enterocolitis
- Congenital anomalies include intestinal atresias, gastroschisis, omphalocele, and meconium ileus.
- Malrotation may result in volvulus with bowel resection secondary to ischemic injury.
- Older children: neoplasms and radiation enteritis
- Intestinal resection secondary to Crohn disease, trauma, pseudoobstruction syndrome
Diagnosis
History
- Defecation pattern: number, size, nature (watery, bulky, foul smelling), presence of blood and mucus
- Ostomy output: consistency (watery, viscous, thick), volume ( ≥50 mL/kg/day often leads to dehydration and electrolyte imbalance)
- Weight loss or gain; gaining length/height
- Abdominal distention and flatulence
- Intense perianal rashes related to stool acidity and malabsorption of carbohydrates
- Abdominal pain and characteristics
- Vomiting and characteristics
- Diet history: appetite, oral intake, tube feeds, PN
- Central line " “associated bloodstream infection (CLABSI) history (if receiving PN)
- Medication history
- Surgical history
Physical Exam
- Weight, length, and head circumference measurements (if applicable); obtain previous growth chart if available
- Signs of vitamin deficiencies in exam of mouth, lips, skin, hair, and skeleton and in assessment of healing difficulties
- Signs of liver disease (icterus, hepatomegaly, splenomegaly, dilated abdominal veins)
- Signs of vascular thrombosis (extremity swelling, dilated veins in neck region)
- Abdominal exam: surgical scars, ostomies, distention, bowel sounds
- Rectal exam: consistency of stool, heme positivity, perianal rash
Diagnostic Tests & Interpretation
Lab
- Blood tests
- CBC: Check for anemia, mean corpuscular volume.
- Electrolytes: Check for losses and adequacy of replacement.
- Minerals: calcium, phosphorus, magnesium, iron, zinc; check for losses and adequacy of replacement therapy
- Albumin and prealbumin: Check for protein stores and nutritional status.
- Liver evaluation: Alanine aminotransferase (ALT), Ž ³-glutamyl transpeptidase (GGT), and bilirubin may be elevated in PN-associated liver disease (PNALD).
- Vitamin levels
- Vitamin A, 25-hydroxy vitamin D, vitamin E, RBC folate, and vitamin B12; check for adequacy
- An elevated methylmalonic acid (MMA) level is a more sensitive marker of B12 deficiency but may also be elevated in small-bowel bacterial overgrowth.
- Prothrombin time/international normalized ratio (PT/INR) indirectly measures vitamin K deficiency. PIVKa (the protein induced in vitamin K absence) is a more sensitive marker of vitamin K deficiency.
- Carnitine: Check status if on long-term PN and presence of liver disease.
- Breath tests: lactose and lactulose breath test to check for lactase deficiency and bacterial overgrowth, respectively
- Stool tests
- Stool for pH and reducing substances: Check for carbohydrate malabsorption.
- Stool smear for fat (Sudan stain " ”qualitative): Check for excessive fat loss.
- Stool for blood: Check for mucosal damage.
- Stool elastase: measure of pancreatic insufficiency. May be falsely depressed if watery stools (dilutional effect)
- Tests of absorption
- D-xylose absorption test and lactose breath test to check for carbohydrate malabsorption
- 72-hour quantitative fecal fat collection along with concomitant diet record
- Carotene levels to check for fat absorption
- 24-hour stool collection forα-1-antitrypsin clearance to check for protein absorption
Imaging
Upper GI series with small-bowel follow-through and barium enema to evaluate length, caliber, and location of remaining bowel ‚
Diagnostic Procedures/Other
Endoscopy ‚
- Upper endoscopy: Look for presence of inflammation that may be contributing to malabsorption; obtain and culture duodenal aspirates to assess for bacterial overgrowth.
- Lower endoscopy: Look for presence of colitis, especially eosinophilic colitis. Evaluate caliber and quality of anastomosis site if in colon.
Differential Diagnosis
- Infants: necrotizing enterocolitis, volvulus, atresia (jejunal and ileal), gastroschisis, perforated meconium ileus, congenital short-bowel syndrome, aganglionosis of the intestine
- Older children: midgut volvulus (due to malrotation), Crohn disease, adhesions causing intestinal obstruction, strictures, trauma
Treatment
Medication
- Supplementation of deficient vitamins (E, D, K, B12, folic acid) calcium, magnesium, iron, and zinc
- H2-receptor antagonists and proton pump inhibitors decrease gastric acid hypersecretion and reduce gastric secretory volume (particularly in the postoperative period).
- Antidiarrheal drugs codeine, diphenoxylate, and anticholinergic drugs (e.g., loperamide) to decrease motility (caution in patients with slow transit or bacterial overgrowth)
- Ion-exchange resins: Cholestyramine binds intraluminal dihydroxy bile acids to prevent bile acid " “induced diarrhea.
- Octreotide/somatostatin: decreases gastric, pancreatic, and intestinal secretions; slows GI motility. Use with caution, though, as may reduce splanchnic blood flow.
- Bacterial overgrowth: Commonly used oral antibiotics are metronidazole, trimethoprim-sulfamethoxazole, ciprofloxacin, vancomycin, and gentamicin.
- Prokinetic agents: Reglan to treat delayed gastric emptying. Use with caution given potential side effects.
- Ethanol lock therapy has demonstrated some preliminary success in reducing CLABSI. Therapy may be associated with an increased risk of venous thrombosis. Randomized control trials in the pediatric short-bowel population are needed.
- Miscellaneous
- Sucralfate to treat bile reflux
- Probiotics to treat bacterial overgrowth
- Ursodiol for cholestasis
- Polycitra for electrolyte losses
- Dietary fiber to enhance absorption; caution in infancy and in patients with bacterial overgrowth
Surgery/Other Procedures
- Surgery is useful in patients who develop strictures and partial obstruction or in those who have very short intestine length with one or more significantly dilated segments distal to the duodenum.
- Intestinal interpositions (isoperistaltic or antiperistaltic) historically are used to delay gastric emptying, slow intestinal transit, and increase absorption but have largely fallen out of favor.
- Intestinal lengthening and tapering procedures, including the Bianchi and serial transverse enteroplasty (STEP) procedures, increase absorptive surface area.
- In patients with extremely short intestines and PN dependency, small-bowel transplantation or multivisceral transplantation is considered. Factors favoring consideration: advanced liver disease, recurrent prolonged hospitalizations, life-threatening bloodstream infections, and loss of central venous access sites.
Ongoing Care
Follow-up Recommendations
Patient Monitoring
- Signs to watch for:
- Vomiting, diarrhea, weight loss, severe fluid and electrolyte abnormalities, sepsis, bowel dilatation, intestinal obstruction
- Major cause of death: sepsis and cholestatic liver disease
Diet
- Fluid and electrolyte therapy: extremely important in the acute phase immediately after bowel resection. In the chronic phase, it is important to keep up with ongoing losses, especially when enteral feeds are started.
- Oral diet
- For patients who are able to avoid PN or tube feeds, a low-lactose diet may be well tolerated.
- Low-oxalate diets are helpful in preventing oxalate stones.
- In general, a high-calorie diet regardless of carbohydrate and fat composition should be the mainstay of treatment.
- Enteral feeds: more successful in the patient with less extensive resection, intact ICV, and colon in continuity. In extensive loss, feeds are initiated after electrolytes are stabilized.
- Feeds started very slowly, often started with elemental diet to facilitate absorption and for concern for allergic injury.
- Enteral feeds stimulate intestinal adaptation. Before 1 year of age, formula should have low osmolality: higher fat content than carbohydrate.
- After 1 year of age, there is no advantage of elemental formulas over intact formulas with respect to tolerance, unless small-bowel damage is present.
- Development of oral skills and oral feeding should be encouraged when possible, as introduction of solid foods with maturity slows transit and improves enteral capacity.
- PN: important in the acute phase postoperatively, when nutrition must be maintained in the face of paralytic ileus; indispensable in the chronic phase when full enteral feeds cannot be instituted.
- Balanced solutions of protein, glucose, and fat should be administered.
- Prophylactic measures to prevent PN-induced liver damage should be instituted (e.g., prevention of overfeeding, early introduction of enteral feeds, cycling of PN when patient is stable, limitation of IV fat emulsion).
- If cholestasis is present, it may be necessary to modify amount of trace elements in PN.
- Need permanent central access to deliver concentrated PN solutions
- IV fish-based oil emulsion (composed of omega-3 polyunsaturated fatty acids) has been studied as a preventive measure against PN-associated liver disease with promising results.
Prognosis
- Contingent on site and amount of bowel resected
- Adaptation is better after jejunal resection than after ileal resection.
- More extensive resection (<40 cm of residual bowel in neonatal period) and loss of the ICV portend a worse prognosis.
- Duration of PN is inversely related to prognosis.
- Most progress is made in the 1st year after bowel resection. Children who are PN dependent at 5 years of age may be unlikely to wean from PN.
- Severe PN-associated liver disease portends a poor prognosis.
Complications
- Fluid and electrolyte loss, resulting in diarrhea, dehydration, and metabolic acidosis
- Calcium and magnesium deficiency, resulting in bone disease and osteoporosis
- Carbohydrate malabsorption
- Fat malabsorption
- Vitamin A deficiency: increased susceptibility to infections
- Vitamin D deficiency: rickets
- Vitamin E deficiency: peripheral neuropathy, hemolysis
- Vitamin K deficiency: prolonged clotting time, bruising
- Vitamin B12: macrocytic anemia and leukopenia
- Folic acid: macrocytic anemia
- Iron deficiency: microcytic anemia
- Copper deficiency: pancytopenia
- Zinc deficiency: poor wound healing, diarrhea, poor vertical growth
- Essential fatty acid deficiency: increased susceptibility to infection, decreased energy stores
- Gallstones: due to disturbed enterohepatic circulation of bile salts and lithogenic bile formation
- Renal stones: due to fat malabsorption and increased oxalate absorption
- Failure to thrive
- TPN-dependent liver disease: cholestasis, end-stage cirrhosis, and portal hypertension
- Carnitine deficiency: contributes to development of steatosis
- Sepsis
- Small-bowel bacterial overgrowth and D-lactic acidosis due to stasis, causing encephalopathy, ataxia, and other neurologic symptoms
Additional Reading
- Cober ‚ PM, Killu ‚ G, Brattain ‚ A, et al. Intravenous fat emulsions reduction for patients with parenteral nutrition-associated liver disease. J Pediatr. 2012;160(3):421 " “427. ‚ [View Abstract]
- Cole ‚ CR, Kocoshis ‚ SA. Nutrition management in infants with surgical short bowel syndrome and intestinal failure. Nutr Clin Pract. 2013;28(4):421 " “428. ‚ [View Abstract]
- Duro ‚ D, Kamin ‚ D, Duggan ‚ C. Overview of pediatric short bowel syndrome. J Pediatr Gastroenterol Nutr. 2008;47(Suppl 1):S33 " “S36. ‚ [View Abstract]
- Mercer ‚ DF, Hobson ‚ BD, Gerhardt ‚ BK, et al. Serial transverse enteroplasty allows children with short bowel syndrome to wean from parenteral nutrition. J Pediatr. 2014;164(1):93 " “98. ‚ [View Abstract]
- Pieroni ‚ KP, Nespor ‚ C, Ng ‚ M, et al. Evaluation of ethanol lock therapy in pediatric patients in long-term parenteral nutrition. Nutr Clin Pract. 2013;28(2):226 " “231. ‚ [View Abstract]
- Puder ‚ M, Valim ‚ C, Meisel ‚ JA, et al. Parenteral fish oil improves outcomes in patients with parenteral nutrition associated liver injury. Ann Surg. 2009;250(3):395 " “402. ‚ [View Abstract]
- Rudolph ‚ JA, Squires ‚ R. Current concepts in the management of pediatric intestinal failure. Curr Opin Organ Transplant. 2010;15(3):324 " “329. ‚ [View Abstract]
Codes
ICD09
- 579.3 Other and unspecified postsurgical nonabsorption
ICD10
- K91.2 Postsurgical malabsorption, not elsewhere classified
SNOMED
- 26629001 Short bowel syndrome (disorder)
FAQ
- Q: What are the favorable prognostic factors in short-bowel syndrome?
- A: Greater length of residual small bowel, jejunal versus ileal resection, maintenance of the ICV, and lack of PN-associated liver disease. Neonates demonstrate better bowel adaptation than do adults.
- Q: Are elemental formulas better than intact formulas in the management of patients with short-bowel syndrome?
- A: Limited case series suggest that elemental formulas may be associated with a shorter duration of PN dependence than intact formula, which may be related to a higher incidence of food allergy in the short bowel population. However, elemental formulas have a higher cost and higher osmolarity, which may exacerbate diarrhea. Animal studies suggest that intestinal adaptation is improved with nutrient complexity, suggesting that elemental formula may be inferior to intact protein formula in this regard.