Intestinal Failure

Question 1

Definition of intestinal failure and intestinal insufficiency

Answer 1

• IF: the loss of functioning gut mass to the extent that there are macronutrient, energy and/or water and electrolyte deficiencies, such that IV supplementation is needed
• IS: as above, but IV supplementation is NOT needed

Question 2

Classification of intestinal failure: acute, chronic, functional classifications (3), pathophysiological classification (5)

Answer 2

• acute: short-lived IF, may be due to obstruction/fistula
• chronic: long-term IF, may be due to resections/bypass
• functional classifications: type 1 (days, acute onset post-op), type 2 (weeks-months, abdominal sepsis, fistulae, may need surgery to repair), type 3 (lifelong TPN e.g. SBS, CIPO)
• pathophysiological classification: short bowel syndrome, short bowel mucosal disease, mechanical obstruction, dysmotility, fistulae

Question 3

Short bowel syndrome: prevalence, incidence, causes, sub-types (3)

Answer 3

• prevalence: 1-2 per 100,000
• incidence: 1.5 per 1,000,000
• causes: massive or repeated intestinal resections, fistulae, bypass surgery, paediatric causes (jejunal atresia, gastroschisis, necrotising enterocolitis)
• sub-types: 1) jejunostomy 2) jejunocolic anastomosis 3) mid small bowel resection

Question 4

Appearance of jejunostomy and jejunocolic anastomosis

Answer 4

• jejunostomy: patients will appear very unwell after surgery with high output stoma, low levels of GLP2, unlikely to adapt, highly likely to have nutrient and electrolyte deficiencies. Not likely to get kidney stones, but 45% likelihood of having gallstones
• jejunocoloic anastomosis: appear generally well after surgery. Will have diarrhoea, and can have nutrient and electrolyte deficiencies, but this is less common. The colon can salvage 750-900 kcal/day. 25% likelihood of kidney stones (calcium oxalate- from bacteria), and 45% likelihood of gallstones

Question 5

Normal GI secretion volumes, what happens in short bowel syndrome?

Answer 5

• food and drink: 1500 mL
• saliva: 750 mL
• gastric secretions: 1250 mL
• biliary secretions: 1000 mL
• pancreatic secretions: 1000 mL
• jejunal secretions: 2500 mL
• losses in SBS exceed 5L and are proportional to the length of the jejunum. They are net secretors so the more they drink the more fluids the lose

Question 6

Therapeutic aims for short-bowel syndrome (3)

Answer 6

1) slow the transit time
2) reduce secretions
3) replace micronutrient deficiencies

Question 7

Management of short bowel syndrome: assessment

Answer 7

• clarify with the surgeon the anatomy of the bowel missing
• check blood pressure and see if any postural changes
• fluid balance charts
• serum: electrolytes (K, Na, Mg, PO4), trace elements, vitamins, urea, creatinine
• urine: Na (if <20 mmol then dehydrated)
• septic screen

Question 8

Management of short bowel syndrome: fluid restriction

Answer 8

• dehydration managed by RESTRICTING fluids
• max 1L free hypotonic fluid per day
• mx 1L hypertonic solution (St Marks, WHO or Diaoralyte)

Question 9

Management of short bowel syndrome: medical management

Answer 9

• antimotility: codeine phosphate, loperamide
• antisecretory: omeprazole
• magnesium + vitamin D
• low residue diet
• teduglutide: GLP2 analog, promotes proliferation and adaptation of the gut
• STEP/BIANCHI surgical lengthening procedures
• intestinal transplant if meet 1 or more of following: life-threatening CRBSI, lack of venous access, progressive IF-associated liver failure