what doctors should know nutrition Flashcards
enteral vs parenteral feed
and reasons why for each (3 enteral, 4 parenteral)
enteral: using the gut use if gut is functioning, reasons for enteral feed: - unable to swallow (Eg unconscious) - unable to tolerate supplements - patient choice
parenteral: bypassing gut use if got is not functioning, reasons for parenteral feed: -aperistaltic gut -obstructed gut -gut too damaged -high fistula
Naso-gastric (NG) tube
when is it used?
3 advantages and 3 risks
used for short term feeding eg ITU, post-op, post-stroke.
advantages:
- uses gut (physiological)
- fast and easy to insert/remove
- minimally invasive
risks:
- tube misplaced/ blocked/displaced
- reflux/aspiration
- not tolerated either by tube itself or volume of feed infused
How to ensure NG tube is inserted correctly
if obtained aspirate has pH between 1 and 5.5 = inserted correctly
if not, chest x-ray: tube should remain in midline, bisect carina at T4. be below diaphragm, and approx 10cm past GOJ into stomach
Naso-jejunal feed 5 advantages and 4 risks
advantages:
- uses the gut (physiological)
- fast and easy to insert/ remove
- minimally invasive
- less likely to aspirate/ get misplaced
- can be used if pt vomiting/ gastroparesis/ duodenal obstruction
risks:
- technically difficult
- generally needs endoscopy/ interventional radiology to place therefore delay in feeding
- still risk of mis/displacement
- may not be tolerated
PEG and RIG stands for
3 advantages, 4 disadvantages
Percutaneous Endoscopic Gastrostomy
Radiologically Inserted Gastrostomy
3 advantages:
- uses gut (physiological)
- no tube in throat/on face therefore comfort/cosmetic better
- unlikely to displaced
risks:
- perforation
- sepsis (peritonitis and skin infection)
- misplacement
- reflux
example of percutaneous jejunal access
advantages and risks
advantages:
same as PEG + also tolerated if gastroparesis/ duodenal obstruction
risks:
same as PEG + higher risk of complication due to anatomy, therefore PEG-J exists which is a PEG with an extension to jejunum (best of both)
what does total parenteral nutrition (TPN) contain ?
what are the line access complications and what are 5 other problems with it?
how do we monitor TPN hourly, daily and monthly?
TPN contains fluid, electrolytes, amino acids, fat, carbohydrates, vit and mins
line access complications:
misplaced line, extravasation of TPN, clot on line, line infection
other problems: liver disease, hyperglycaemia, fluid/electrolyte disturbance, over/under feeding, gut not being used= atrophy/ inflammation
monitoring:
- 4 hourly obs including temp and glucose levels
- daily U&E, Mg, Ca, LFT, phosphate, FBC, line inspection, weight
- monthly: micronutrients, triglycerides
refeeding syndrome
a) when does it occur?
b) explain the pathophysiology in terms of Na+ water and /K+ and phosphate
c) how to treat/avoid
a) when someone who is malnourished begins to eat again (orally, enterally or parenterally)
b) pathophysiology: during starvation transmembrane pumps switch off which results in na+ and water drift into cells, and k+ and phos move to plasma.
when refeeding begins, pumps switch on immediately. sudden drop in k+ and phosphate = arrythmias
sudden inc in na+ and water = overload
c) reintroduce feed slow and build up
monitor electrolytes daily
wernicke-korsakoff’s syndrome
a) what is it and is it caused by (+ who is it found in the most)
b) what are the 2 parts and what are symptoms
c) how to avoid/ treat
a) neurological disorder caused by refeeding when there’s thiamine deficiency, most commonly found in alcoholics
b) wernicke’s: opthalmoplegia, unsteady gait, nystagmus, confusion (reversible if give IV thiamine quickly)
korsakoff’s psychosis: sudden onset, irreversible, memory loss
c) - replace thiamine before/ during refeeding
- if low risk give high dose oral thiamine
- if high risk give IV pabrinex (banana bags)
