2- intestinal failure Flashcards
what absorption type processes occur in the stomach?
- intrinsic factor binds to b12
- pepsin begins digestion of protein
- Fe3+ to Fe2+
what absorption occurs in duodenum?
- iron absorbed (Fe2+)
pancreatic digestive enzymes like lipases, proteases, amylase help: - break proteins down to amino acids that are then absorbed
- break polysaccharides to disaccharides
- along with bile salts emulsify triglycerides to break down to fatty acids + monoglycerides
what absorption occurs in jejunum?
- brush border disaccharides broken down to monosaccharides which are absorbed
absorbed:
- calcium
- folate
- fat soluble vitamins
- free fatty acids
- monoglycerides
- small amount of b12 a
- moderate amount of water
- small amount of sodium
what absorption and processes occur in ileum?
- b12 absorbed
- moderate amount of water + sodium absorbed
- intrinsic factor absorbed for reuse
- bile acids reabsorbed for recycling to liver
what absorption and processes occur in colon?
small amount is absorbed of:
- water
- electrolytes
- bile acids
describe the whole fluid secretion & absorption of GI tract
*hint = start with dietary input and end with what’s lost in faeces
- 2L (dietary input) + 1.5L (digestive secretions)
- +1.5L (gastric secretions) = 5L
- +1L (liver) and 1L (pancreas) + 2L (intestine) = 9L
- small intestine reabsorbs 7.8L so 1.2L left
- colonic mucous secretions = 0.2L = 1.4L
- 0.15L lost in faeces and colonic reabsorbs 1.25L
what are things absorbed in colon?
- bile acids
- electrolytes (sodium, potassium, calcium)
- water
what are the GI tract transit times
10 seconds from mouth →oesophagus
3hrs →get to stomach
7-9 hours →through small bowel
25-30 hours →large intestine/colon
30-120 hours →excretion in rectum
what is intestinal failure?
= inability to maintain adequate nutrition or fluid status via the intestines
= reduction in function below the min necessary for absorption of macronutrients and / or water and electrolytes such that intravenous supplementation is required to maintain health and / or growth
what are causes of TYPE 1 intestinal failure?
type 1= short term
- surgical ileus (bowel can stop functioning straight after surgery making build up in stomach and lack of absorption)
- critical illness
GI problems that can cause:
- vomiting
- dysphagia
- pancreatitis (inflamed so no exocrine function for digestive enzymes to break down food)
- GI obstruction
- diarrhoea
- oncology (chemo or radiotherapy cause inflammation making pain, loss appetite)
what are causes of TYPE 2 intestinal failure?
type 2 = unable to absorb enough nutrients and fluids to maintain adequate nutrition and hydration over the long term
= occurs as a result of structural or functional abnormalities within GI tract
- vascular embolism
- crohns disease
- narrowing of superior mesenteric artery compromising blood suppply - causing pain
- radiation (no absorb, can be unpleasant, painful)
- adhesions (bowels loops + don’t function)
- fistulae (abnormal connections forming between e.g small bowel and colon which skips areas of absorption)
what are causes of TYPE 3 intestinal failure?
chronic = because of disease process have developed short bowel syndrome
- crohns
- radiation
- dysmotility
- malabsorption
- inoperable obstruction e.g. cancer
- volvulus = bowel twists cutting off supply
- vascular disaster
briefly describe differences between 3 types of intestinal failure?
type 1 = self limiting
type 2 = significant & prolonged parenteral nutrition support (>28 days)
type 3= chronic IF (long term parenteral nutrition) = can be at home
what is support/treatment for type 1 IF?
- replace fluid, correct electrolytes (e.g. if losing magnesium or sodium, boost where needed)
- can sometimes supply short term IV nutrition if unable to tolerate food
- acid suppression with proton pump inhibitors to prevent developing stress ulcers
- allow some oral diet feeding e.g. build up from soups + custards
what is support/treatment for type 2 IF?
- > 4 weeks (ICU/HDU)
- Parenteral nutrition +/- some enteral feeding (oral or naso-gastric tube)
what is support for type 3 IF?
total parenteral nutrition = can be from months to years - can also do at home
- intestinal transplantations but only specific cases (long term survival lower than HPN)
- glucagon like peptide-2 can lengthen gut but increases risk for developing malignancy and expensive
- bowel lengthening procedures (yet to be validated in adults)
what is short bowel syndrome?
it’s when small intestine from jejunum to ileum too small - normally it’s 6-7m long
<200cm = short bowel
<50cm = ultra short bowel
→means insufficient length of small bowel to meet nutritional needs without artificial nutritional support
short bowel can lead from conditions that then means type 3 IF
what are 4 types of short bowel?
- jejunostomy
- ileostomy
- jejuno-colic anastomosis
- ileo-colic anastomosis
what is the significance about where bowel left in short bowel?
depending on where stoma is makes different implications for treatment
what is jejunostomy?
→due to gastroparesis, obstruction in duodenum/stomach, malabsorption disorders, gastric surgery
= surgical operation to allow stoma (artificial opening) which means direct access for nutritional and fluid
what is ileostomy?
= usually done when the colon is removed or bypassed due to disease or injury, such as in cases of ulcerative colitis or Crohn’s disease
= surgical operation to allow stoma, but this time for a bag to be filled with waste directly from small intestine bypassing colon - absorption can still occur in rest of small intestine
what is jejunocolic anastomosis?
→done if short bowel syndrome, colon resection = as bowel rehabilitation →done to make flow through GI tract (usually done if block/insufficient absorption)
= surgically connecting jejunum + transverse colon, by creating anastomosis, the nutrient absorption enhanced as colon can aborb water + electrolytes
what is ileocolic anastomosis?
= done when problem with small intestine (especially ileum)
= involves surgically connecting ileum to ascending colon, anastomosis optimises nutrient absorption
what is parenteral nutrition?
delivering nutrients directly into the bloodstream through intravenous (IV) access, bypassing the digestive system.
what is enteral nutrition?
delivering nutrients directly into the gastrointestinal tract, typically through a feeding tube that enters the stomach or small intestine
what nutrition + fluid is required for jejunostomy where left is:
a) 0-50 cm
b) 51-100 cm
c) 101-150 cm
d) 151-200 cm
a) parenteral nutrition + saline
b) parenteral nutrition + saline
c) oral/enteral + oral (enteral) glucose
d) oral + oral (enteral) glucose
what is peripheral parenteral nutrition?
Peripheral (lipid free = reduced calories)
= via peripheral venous access, IV line
- lipid containing usually avoided to prevent irritation of small blood vessels
what is central parenteral nutrition?
= delivery through central vein access which allows higher nutrient concentrations + inclusions of lipids in parenteral nutrition solution
what are complications of central parenteral nutrition?
pneumothorax / arterial puncture/misplacement
what are types of catheter for peripheral parenteral nutrition and types of central parenteral nutrition?
peripheral = blue 22G PVC
types of central venous:
- PICC (peripherally inserted central catheter)
- Tunnelled catheter (Subclavian / Hickman line)
- Vascuport / Portacath
- Ultrasound guided insertion by Radiology
what is a portacath?
= central venous access device that consists of thin membrane(port) placed under the skin, connected to catheter that is inserted into large vein (usually subclavian or jugular)
- you can teach patients to insert themselves to allow them to administer medication, fluid, nutrition - complete nutrition can be given with these long line
what are complications of portacath?
- number of complications like extreme risk of developing sepsis through endocarditis as putting growth medium into heart
- also can get catheter blockage, displacement or malfunction
- liver problems, gallbladder problems, neurological problems (memory disturbance), skeletal, kidney, intestinal problems
what usually happens in small bowel transplant - what is their life like after?
5 year survival 60%
- stoma remains but eating + drinking normally
→most people get liver along with pancreas and small intestine
what is important to never underestimate in the role of eating?
Never underestimate the psycho-social role of eating
how long can it take to be ready to leave hospital for home parenteral nutrition?
can take up to 2 months to be ready when everyone is comfortable in how to do it
