1. Nutrition Support in Short Bowel Syndrome Patients
Shikha Kapila, Pharm.D.

2. Learning Objectives
Identify the nutritional, fluid, and electrolyte disturbances with short bowel syndrome (SBS)
Discuss the goals of nutrition support to prevent deficiencies and correct abnormalities in SBS patients
Describe the metabolic complications in SBS patients receiving nutrition support
Develop a monitoring plan for SBS patients receiving nutrition support

3. Case Presentation
JA is a 19 year old male transferred to the Hospital after found unarousable. On admission, he was obtunded and unresponsive with mental status changes. Information was obtained from caregiver as follows

4. Case Presentation PMH: Autism SBS: Ligament of Treitz to
ileocecal valve and partial colon
Nutritional: Chronic TPN, 1/2
strength Ensure® tid, 2 slices
of bread q day
Multiple CVC infections
MPTA:
Cholestyramine 500mg po tid
Actigall 250mg po qd
Imodium 1mg po bid

5. Case Presentation Normal liver and renal functions
CSF/blood culture/urine drug screen/serum lead level all negative
Head CAT scan showed no abnormalities
Plasma NH3 = 375 umol/L (9-33 umol/L)
Diagnosis: Hyperammonemic encephalopathy and coma
Initial treatment: Hemodialysis

6. Short Bowel Syndrome Small Bowel Length Pylorus to ileocecal valve
Ligament of Treitz to ileocecal valve
Overall function and length of remaining small intestine determines intensity of support

7. Short Bowel Syndrome Jejunum, Ileum, Colon
Fluid and Electrolyte homeostasis
Nutrient absorption
Intestinal transit time
Intercellular junction tightness

8. Intestinal Transit Time
Jejunum > Ileum > Colon
Ileum with a rate 3 times slower than the jejunum
Ileocecal valve
Rate controlling step
Prevents bacterial overgrowth

9. Intercellular Junction Tightness
Colon > Ileum > Jejunum
The tighter the junction the greater the potential to create an osmotic gradient to allow fluid absorption

10. Jejunum Proximal 2/5 Inefficient fluid absorption
Intact ileum and colon
Supplementation not required
Absorption of water soluble vitamins
Exceptions include Vitamin B12 and Folate
Multivitamin

11. Ileum Distal 3/5 Prolongs transit time
Important in the conservation of fluid and electrolytes
Resections consistent with loss of bile salts
Solubilize dietary fat and fat soluble vitamins
Fat malabsorption
Choleraic diarrhea

12. Ileum Consequences of fat malabsorption
Osmotic gradient   fluid absorption
 Calcium and Magnesium that bind to malabsorbed fat
Trace element deficiencies : zinc, selenium, chromium, iron

13. Ileum Calcium and Zinc Magnesium Trace elements  multivitamin
Oral supplementation if adequate absorption
Magnesium
Oral  diarrhea
Trace elements  multivitamin
Zinc, Chromium, Selenium
 loss in feces, fistula drainage
Vitamin B12
Monthly injections if > 60 cm terminal ileum resected
B12

14. Enzyme Deficiency in SBS
Significant small bowel resections cause enzyme deficiency
Lactase
Pyrolline-5-carboxylate synthase
Patient case
Resection: Ligament of Treitz  ileocecal valve and partial colon
Suspected possible enzyme deficiency

15. Colon Added bowel length Slows transit time
Bacteria ferment unabsorbed complex carbohydrates into short chain fatty acids
Caloric source
Trophic stimuli
Fluid and electrolyte salvage
Nutrients not salvaged

16. Back to the Case...
Ligament of Treitz  ileocecal valve and partial colon
Malabsorption
Depletion of bile salts
Trace element deficiency
Stable on nutritional regimen prior to admit
Mental status changes and  NH3 level
Enzyme deficiency?

17. Complication: D-Lactic Acidosis
Mental status changes
Confusion, lethargy, aggressive behavior, visual changes
Fermentation of malabsorbed carbohydrates in the colon
 disaccharide enzyme (lactase)   D-Lactic acid
Patient case:  oral carbohydrate intake prior to admit not to mention D-Lactic acidosis does not explain increased NH3

18. Complication: Peptic Ulcerations
Acute condition
First 3-6 months
Gastric acid hypersecretion
Treatment
H2RAs (famotidine, ranitidine)
PPIs (omeprazole, pantoprazole)

19. Complication: Nephrolithiasis
Consequence of fat malabsorption secondary to ileal resection
Calcium  malabsorbed fat
Decreased calcium levels
Free oxalate
Oxalate stones  renal impairment  kidney stone formation

20. Complication: Nephrolithiasis
Treatment
Low oxalate diet
Increase fluid intake
Calcium supplementation
Citrate and intravenous magnesium
Cholestyramine
Separate by 2 hours from other medications

21. Complication: Cholelithiasis
Precipitation of cholesterol as a result of malabsorption of bile salts 
Cholesterol gallstones
Patients at risk
Chronic TPN
Absence of gut stimulation

22. Complication: Cholestasis
Complete or partial obstruction of bile flow
Chronic TPN,  gut stimulation, SBS, Sepsis
Non-pharmacologic treatment
Trophic enteral feeds
Obstacle: diarrhea

23. Complication: Cholestasis
Pharmacologic Approach to cholestasis
Cholecystokinin-Octapeptide (CCK)
Increases gallbladder contraction
Ursodiol (Actigall)
Solubilizes gallstones and increases bile flow secretion

24. Complication: Bacterial Overgrowth
Bacterial translocation a result of disrupted intestinal barrier and bacterial overgrowth
Ileocecal valve important in prevention
Deconjugation of bile salts  fat malabsorption
Treatment:
Oral antibiotics: aminoglycosides, metronidazole

25. Complication: Diarrhea
Benefits of oral feeds > diarrhea
Choleraic diarrhea
Bile salt-induced diarrhea
< 100 cm ileal resection
Treatment includes a bile salt binder
Cholestyramine

26. Complication: Diarrhea
Diarrhea in relation to massive small bowel resection
Fatty acid diarrhea (steatorrhea)
Pharmacological therapy
Codeine
Immodium
Octreotide: benefit in patients with output approaching ~ 1.5 L/day

27. Case Summary
Diagnosis: Hyperammonemic encephalopathy and coma due to  NH3
Massive resection from Ligament of Treitz to ileocecal valve and partial colon
Nutrition: TPN-dependent  1/2 Ensure  2 slices bread/day
 oral intake c/w excessive diarrhea
TPN c/w hepatic dysfunction

28. Case Summary
MPTA
Cholestyramine 500mg po tid
Actigall 250mg po qd
Imodium 1mg po bid
D-Lactic acidosis ruled out secondary to  carbohydrate intake and  NH3 level
Hemodialysis decreased NH3 to 78umol/L (9-33 umol/L)

29. Case Summary Etiology: Urea cycle enzyme deficiency
Plasma aminogram results:
 Glutamine 1370 umol/L ( umol/L )
 Ornithine 17 umol/L ( umol/L )
 Citrulline trace (16-55 umol/L )
 Arginine trace ( umol/L )
Etiology: Urea cycle enzyme deficiency

30. Case Summary: Urea Cycle
Ammonia (NH3) a byproduct of protein degradation  urea
Ornithine and Citrulline act as precursors to arginine to convert NH3 to urea
Ornithine and enzymes Pyrolline-5-carboxylate synthase exclusive to the small intestine

31. Case Summary: Urea Cycle
Lack of small intestine 
Enzyme deficiency
Arginine deficiency
 NH3 due to a ‘break down’ in the urea cycle

33. Conclusion to the Case Day 2 of admission Hemodialysis repeated
Post dialysis NH3 = 51 umol/L
Continuous infusion of arginine initiated
Ammonia levels returned to baseline
Discharged: outpatient follow up
Continued on medications prior to admit as well as nutritional regimen from prior to admit

34. Urea cycle enzyme deficiency versus lack of arginine?
Conclusion to the Case
Readmitted within < 24 hours!
Identical clinical presentation
Plasma NH3 = 513 umol/L (9-33 umol/L)
Returned to baseline post arginine infusion
Urea cycle enzyme deficiency versus lack of arginine?

35. Laboratory Monitoring of Stable Parenteral Nutrition PatientsX
Blood cultures
Ammonia
Chemsticks
Vitamin concentrations
TIBC, Ferritin
Cu, Zn, Mn, Se, Cr, Fe
Hgb, Hct, CBC, Platelets, PT
Triglycerides
Albumin, Prealbumin, Total protein
Mg, Ca, phosphorus
AST, ALT, LDH, Alkaline Phosphatase, Total and Direct Bilirubin
Na, K, Cl, CO2
BUN, Creatinine
Glucose
As indicated
Weekly
Biweekly
Initial