Lecture 15 Flashcards
Define enteral and parenteral
ENTERAL = using the gut PARENTERAL = bypassing the gut
Describe enteral route of nutrition
Nutritionally complete liquid feeds through various tubes which access the gut
Use IF GUT FUNCTIONING Unable to swallow Includes unconscious Insufficient oral intake despite supplements Unable to tolerate supplements Patient choice
Describe parenteral route of nutrition
Nutritionally complete liquid feed which is broken down – to glucose / amino acids / fats & engineered to be safely administered intravenously
Use IF GUT NOT FUNCTIONING Aperistaltic Obstructed Too short Too damaged High fistula Inaccessible
Discuss nano-gastric tube feeding in terms of advantages, suitability and risks
Advantages
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 it 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? Tube misplaced / displaced / blocked Reflux / aspiration Not tolerated Tube itself or volume of feed infused
How do we confirm correct placement?
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
Discuss nano-jejunal feeding in terms of advantages and risks
Advantages
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? 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
Discuss Peg and rig in terms of advantages, suitability and risks
Advantages 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 is it 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
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
Discuss Percutaneous Jejunal access in terms of advantages and risks
Advantages
As for PEG plus
Tolerated if gastroparesis/duodenal obstruction
i.e. longterm option for those requiring NJ feeding
What are the risks?
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 does total parenteral nutrition
Fluid Electrolytes Protein – as amino acids Fat Carbohydrate Vitamins Minerals
Discuss the 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
Discuss Monitoring TPN
4 hourly: Observations including temperature Blood glucose Daily: U&E, Mg, Ca, phosphate, LFT, FBC Line inspection Weight Monthly: Micronutrients Triglycerides
Define 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 re-feeding syndrome
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
What does a sudden drop in plasma K and Phos and a sudden surge in plasma Na and water
arrhythmias and overload
How do you avoid/treat re-feeding
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 - wks
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.
Discuss WKS
Acute thiamine deficiency
Precipitated by providing calories in the absence of sufficient reserves of thiamine
i.e. by refeeding
Wernicke’s: opthalmoplegia, unsteady gait, nystagmus, confusion
This is reversible – but only if you act very quickly to give IV thiamine
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
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
