Short bowel syndrome and nutritional consequences

1. Short bowel syndrome and nutritional consequences Alastair Forbes University College London

4. Intestinal failure Inadequate functional intestine to allow health to be maintained by ordinary food and drink

5. Intestinal failure • Critical reduction of functional gut mass below the minimum amount necessary for adequate digestion and absorption to satisfy body nutrient and fluid requirements • Jan DM, in Intestinal failure, Ed: Langnas et al

6. Acute intestinal failure • Usually follows major resection • May be exacerbated by coexistent intestinal dysfunction because of severe inflammation or disorders of motility • (Post-operative ileus) • Type 2 intestinal failure

9. Intestinal failure • rare: prevalence 1-2 per 100,000 incidence 1-5 per 1,000,000 • Crohn's, ischaemia, and surgical mishap account for most benign long-term cases • more common if cancer cases included

10. Intestinal failure: adaptation • Mostly in first 6 months • Hyperplasia and hypertrophy • Ileum better at this than jejunum • Possibly responsive to trophic factors

11. Intestinal failure: adaptation • Mostly in first 6 months • Hyperplasia and hypertrophy • Ileum better at this than jejunum • Possibly Responsive to trophic factors

12. Intestinal failure Ileostomy and <200cm small bowel <150cm with colon Stoma or fistula output >1.5L/day

13. Intestinal losses Output proportional to jejunal length Positive fluid balance requires ~1m Concept of net absorber/net secretor If high/normal secretion and poor absorption, output may be dramatic

14. Net absorber/net secretor ? Normal person is net absorber Drink more  absorb more

15. Net absorber/net secretor ? Normal person is net absorber Dehydration  Thirst  Drinking  Increased fluid retention  Resolution

16. Normal physiology Osmosis and sodium gradients Proximal intestinal response is secretory Threshold about 100mmol/L

17. Net absorber/net secretor ? If <1.5m small intestine Normal proximal secretion is not compensated by distal absorption

18. Net absorber/net secretor ? Drink more  absorb LESS

19. Net absorber/net secretor ? Dehydration  Thirst  Drinking  Increased fluid loss  Deterioration

20. Net secretor and fluid restriction Fluid restriction is central challenge Thirst requires LESS drinking severe - iv saline moderate - oral rehydration solutions mild - limit (sodium-free) fluids

21. The colon in short bowel Retained colon (>half) equivalent to ~50cm small intestine Value mainly in fluid balance Some nutritional gain from fermentation

23. Assessment Observations Serum electrolytes Plasma osmolarity Serum urea nitrogen/creatinine Complete blood picture Serum magnesium

25. Urine sodium Marked sodium retention in dehydration Very early feature Simple untimed sample sufficient <20 mmol/L almost diagnostic Unreliable if renal failure or diuretics

26. Short bowel syndrome management Scan for sepsis Skin care Nutritional care Assessment Plan for future surgery

27. Short bowel syndrome management Scan for sepsis Skin care Nutritional care SSNAP Assessment Plan for future surgery

28. Short bowel syndrome management Resuscitate if necessary with iv saline Reduce oral intake of low sodium fluid Increase sodium intake Don’t render nil per os / nil by mouth

29. Food selection Regular food Encourage high energy density Separate food from liquid Avoid fluids (as low Na+) Little and often

30. Enteral fat intake If no colon useful : energy dense If retained colon may give steatorrhoea fat less utilized than carbohydrate less (beneficial) fermentation

31. Formula feeds in SBS NOT elemental - because high osmolality low energy density high volume poor palatability

32. Formula feeds in SBS Polymeric not inferior to semi-digested No advantage to modified/supplemented feeds Regular (1kcal/ml) or high energy (1.5kcal/ml) determined by needs and tolerance of osmolality

33. Simple electrolyte mix 20g glucose 3.5g NaCl 2.5g NaHCO3 (or citrate) Na+ = 90mmol/L

34. glucose or citrate bicarbonate salt

35. SBS: enteral therapy Limit “free” fluid intake to 500ml/day Oral rehydration solution (>60mmol/l) ad libitum Antisecretory regime Encourage oral feeding ± formula feed ± tube feed

36. Intestinal failure: pharmacological therapy Proton pump inhibitors reduce gastric secretion Loperamide reduces speed of transit

37. Intestinal failure: pharmacological therapy Proton pump inhibitors reduce gastric secretion Loperamide reduces speed of transit Codeine less favored – sedative Anticholinergics less favored – dry mouth Somatostatin and derivatives disappointing Teduglutide (GLP-2) great promise Citrulline - interesting

38. Intestinal failure parenteral nutrition Continue all components of enterally based regime (but less rigidly) Always aim for maximal possible enterally Usually give more nutrition than estimated or measured because of malabsorption

39. Intestinal failure: parenteral nutrition Usually give more nutrition than predicted Example: patient needs 2000 kcal/day But has SBS and absorption of 50% Eats 2000kcal - absorbs 1000kcal Needs 1000kcal parenterally Total 3000kcal administered Correct 2000kcal received

40. Intestinal failure: parenteral nutrition Usually give more nutrition than predicted Example: patient needs 2000 kcal/day But has SBS and absorption of 50% Eats 2000kcal - absorbs 1000kcal Needs 1000kcal parenterally Total 3000kcal administered Correct 2000kcal received Same applies to other nutrients

41. Intestinal failure research • New forms of assessment • Modified parenteral feeds • Drugs and trophic factors • Surgical options • The artificial intestine?

42. Growth hormone • Uniquely approved by the FDA for use in SBS • Mediates its trophic effects through IGF-1 • Increases serum IGF-1 and IGF-1 in intestine • Increases crypt cell proliferation • inhibits apoptosis in intestine • Enhances intestinal absorption of nutrients • Best in combination with a optimal SBS care

43. Glucagon-like peptide 2 • Intestinal trophic activities recognized 1996 • From intestinal L cells exposed to luminal nutrients • Degraded by DPP IV, t½ 7 min • Increases crypt cell proliferation • Inhibits villous apoptosis • Enhanced digestive and absorptive function • Reduces gastric secretion and slows emptying • Increases intestinal blood flow • Rapidly reversible changes

44. Teduglutide • Longer acting analogue of GLP-2 • 1 amino acid alteration • enzyme resistant • More effective than native ? • growth of juvenile primate small bowel • Particular benefit for fluid balance • Mean of 800mL/d reduction in Phase II Jeppesen Gut 2005

45. Teduglutide Phase 3 study – 24 week evaluation • n=83 • End-point = 20% reduction in PN • Placebo, 0.05/kg, 0.1/kg • 15/16; 27/35 & 29/32 completed • AEs few - 1, 5 and 2 drop-outs Jeppesen 2009

46. Teduglutide Weight change • Placebo: 61.5  61.6 • Low dose: 57.2  59.7 • High dose: 59.5  61.4

47. Teduglutide Weight change • Placebo: 61.5  61.6 • Low dose: 57.2  59.7 • High dose: 59.5  61.4 Response • Placebo: 1/16 6% • Low dose: 16/35 46% p=0.005 • High dose: 8/32 25% • Combined: 24/67 36% p=0.077

48. Citrulline in intestinal failure • Produced by intestine (only) • Degraded/excreted by kidneys • Excellent marker of intestinal integrity Paris group

49. Citrulline in intestinal failure • Produced by intestine (only) • Degraded/excreted by kidneys • Excellent marker of intestinal integrity • In various conditions and independent of inflammation • Clinically predictive Paris group London/Parma/Zambia group

50. Therapeutic citrulline in intestinal failure ? • A “safer” arginine donor • Preserves nitrogen balance in resected rats (Gut 2004) • Reduces splanchnic sequestration of amino acids • Treatment for sarcopenia in rats (AJPEM 2006) • Prevents TPN muscle atrophy (Clin Sci 2008) Paris/Warsaw group Osowska et al