What all doctors should know about nutrition Flashcards
How is feeding of social importance?
A Basic requirement Provides Nurture Is Symbolic Means “Caring” Is a Social Binder Confers psychological benefits
List the routes of nutritional support
Feeding first
Unless it is contraindicated
When may feeding be contraindicated?
Unsafe swallow
Damaged/non-functioning gut
What are the two methods used if feeding via food is unsuccessful?
Enteral
Parenteral
What is enteral feeding?
Using the gut
Nutritionally complete liquid feeds through various tubes which access the gut
What is parenteral feeding?
Bypassing the gut
Nutritionally complete liquid feed which is broken down – to glucose / amino acids / fats & engineered to be safely administered intravenously
When is parenteral feeding used?
If the gut is not functioning
Why might the gut not be functioning?
Aperistaltic Obstructed Too short Too damaged High fistula Inaccessible
Why might enteral feeding be necessary?
The gut is functioning but Unable to swallow Includes unconscious Insufficient oral intake despite supplements Unable to tolerate supplements Patient choice
List the different types of enteral access
To make it easier:
All names are just descriptions of how we are getting food in:
Route of access - Nasal vs. percutaneous
Where the feed is being delivered - Gastric vs. jejunal
How was the access put in - Endoscopic vs. interventional radiology
What are the advantages of nasogastric tube feeding?
Uses the gut → physiological
Fast and easy to pass tube
Can be done at the bedside by most nursing staff
Minimally invasive
Generally well tolerated
Easy to remove if not tolerated / no longer required
Who is nasogastric tube feeding suitable for?
Working gut
Stomach emptying (into duodenum)
Safe to put tube through nose and down oesophagus
Patient must accept / tolerate the tube
Short-term feeding
e.g. whilst unconscious on ITU, post-op, post-stroke, acute illness
What are the risks of nasogastric feeding?
Tube misplaced / displaced / blocked Reflux / aspiration Not tolerated Tube itself or volume of feed infused
How is correct placement of a nasogastric tube confirmed?
The chest x-ray view should be adequate –upper oesophagus down to below the diaphragm
The NG tube should remainin the midline down to the level of the diaphragm
The NG tube shouldbisect the carina (T4)
The tip of the NG tube should be clearly visible and belowthe diaphragm
The tip of the NG tube should be several cm (10) beyond the GOJ to be confident that it’s within the stomach
What are the advantages of naso-jejunal feeding?
As for NG feeding plus
Vomiting / gastroparesis / duodenal obstruction
Minimally invasive – although may need x-ray or endoscopy to place
Less likely to aspirate / get misplaced
What are the risks of naso-jejunal feeding?
Technically difficult Generally needs endoscopy or placement in interventional radiology This can create delay in feeding Risk of mis/displacement May still not be tolerated
What do PEG and RIG stand for?
Percutaneous endoscopic gastrostomy (PEG) or Radiologically Inserted Gastrostomy (RIG)
What are the advantages of a PEG?
Uses the gut / physiological Durable Tubes last up to a couple of years Unlikely to be accidentally displaced No tube in throat / on face Comfort Cosmetic
Who are PEGs and RIGs suitable for?
Patients with:
a functioning gut
Inability to swallow adequate food/fluid
Due to an irreversible or long-lasting cause
In whom nutrition support is thought to be appropriate
Who can tolerate an endoscopy and minor surgical procedure
What are the risks and shortcomings of a PEG or a RIG?
Perforation Sepsis (Peritonitis and skin infection) Bleeding Perforated viscous Attached to a pump 20 hours per day Misplacement Reflux Buried bumper Death (6% at 30 days) Not involved in mealtimes Alteration in body image
What are the advantages of a surgical jejunostomy (PEJ)?
As for PEG plus
Tolerated if gastroparesis/duodenal obstruction
i.e. longterm option for those requiring NJ feeding
What are the risks of a surgical jejunostomy (PEJ)?
As for PEG but higher risk of complication due to position / anatomy of small bowel
Hence existence of PEG-J a PEG with an extension into the jejunum – best of both worlds
What is contained in total parental nutrition?
Fluid Electrolytes Protein – as amino acids Fat Carbohydrate Vitamins Minerals
List some problems with TPN
Line “access” complications Misplaced line Extravasation of TPN Clot on the line (thromboembolism) Line infection Hyperglycaemia Fluid / Electrolyte disturbance Over or under-feeding Liver disease Gut not being used → atrophy and inflammation £££££
How is TPN monitored?
4 hourly: Observations including temperature and Blood glucose
Daily: U&E, Mg, Ca, phosphate, LFT, FBC, Line inspection and Weight
Monthly: Micronutrients, Triglyceride
What is a refeeding syndrome?
Refeeding syndrome is defined as severe electrolyte and fluid shifts associated with metabolic abnormalities in malnourished patients undergoing refeeding –
whether orally, enterally or parenterally.
Describe the pathogenesis of refeeding syndromes
During starvation energy is saved by switching off trans-membrane pumps
Na (& water) drift intra-cellularly
K & Phos drift extra-cellularly (and are excreted to keep plasma levels stable) → total body depletion
As soon as you get any energy these are all switched back on immediately
→ sudden drop in plasma K and Phos → arrhythmias
→ sudden surge in plasma Na and water → overload
How can refeeding syndromes be avoided?
Be aware of the risk Check electrolytes (Na, K, Mg, Ca, Phos) Begin replacement before feeding Rule of thumb: start slow and build up As low as 5-10kcal/kg/24hrs Keep monitoring electrolytes daily (!) and replacing as necessary
Define Wernicke-Korsakoff’s syndrome
Wernicke-Korsakoffsyndrome (WKS) is a neurological disorder. Wernicke’sencephalopathy andKorsakoff’spsychosis are the acute and chronic phases, respectively, of the same disease. WKS is caused by a deficiency in the B vitamin thiamine and is most frequently encountered in alcoholics.
Acute thiamine deficiency
Precipitated by providing calories in the absence of sufficient reserves of thiamine
i.e. by refeeding
Give the symptoms of Wernicke’s
Opthalmoplegia, unsteady gait, nystagmus, confusion
This is reversible – but only if you act very quickly to give IV thiamine
Give the symptoms of Korsakoff’s psychosis
Sudden onset, dramatic, irreversible memory loss, confabulation
How do you avoid/treat Wernicke’s?
Be aware of the risk
Replace thiamine before and during re-feeding
If low risk and able to eat use high dose oral thiamine
If high-risk or not eating then use IV Pabrinex
Describe the ethics surrounding feeding
Feeding and hydration, however provided, is part of basic care & should not be withdrawn, they represent love and care for the helpless.
Withdrawing them = starving someone to death
PEG/ NG feeding
requires medical / nursing skills
has side effects
is medical treatment
And therefore could be withdrawn if thought not to be providing benefit
Where artificial nutrition and hydration is necessary to keep the patient alive, the duty of care will normally require the doctors to supply it…. but…
If feeding requires medical intervention
AND
Is not thought to be providing benefit
Then there may be circumstances in which it should not be done
How could a PEG be of benefit?
Improved life expectancy
Improved quality of life
medication can be given vs. symptoms/pain
Increase / maintenance of weight
improvement of healing e.g. pressure ulcers
Improved daily activities
increased capacity for rehabilitation
