IC7 Nutritional Support Flashcards
what is one of the immune organs in the GI tract?
gut associated lymphoid tissue (GALT)
- one of the largest immune organ that is found in the GI tract
what hormone is released by the GI tract (that affects gall bladder) and the implications if patient is NIL by mouth?
when food passes through the stomach to the duodenum, the duodenum is stimulated to release cholecystokinin (CCK)
CCK causes gall bladder to release bile and facilitate fat absorption/digestion
if patient is NIL by mouth = gall bladder is not stimulated = impaired bile flow / bile hold up = gall stone formation and cholecystitis
SPECIFIC implications of terminal ileum (final section of small intestine) resection on absorption
VIT B12 is absorbed by the terminal ileum (mostly)
if resected, patient needs to be on vitb12 supplementation.
potential causes of loss of appetite?
taste changes due to chemotherapy or magnesium deficiency
potential causes of early satiety?
ascites = bloating
liver disease
cancers at abdominal areas
what are the effects of disease states on nutrition?
malnutrition can be caused by
- N/V/D
- changes in appetite/early satiety
- malabsorption
- nutrient losses (dialysis)
- impaired metabolism, increased energy expenditure, protein catabolism
- reduced volitional intake
IT IS A LONG TERM PROCESS
potential causes for increased metabolic demand?
stress or trauma
child development
tissue growth during pregnancy
wound healing
what are the components of nutritional assessment?
A: anthropometric measures
- height, weight, BMI
B: biochemical assessment
- electrolytes
- albumin = produced with nutrition
C: clinical assessment
- clinical history: surgery?
- medical conditions (causing hyper metabolism?)
- physical review (muscle stores = calf muscles, hand grip strength)
D: dietary assessment
- how long patient been starved
- normal dietary intake?
process for nutritional screening and assessment?
1) nutritional screening
- first 24-48h on admission
2) refer to dietician / nutrition specialist
3) nutritional assessment (ABCD)
4) formulate nutritional regime
potential causes of reduced volitional intake?
poor dentition
delirium
what is malnutrition associated with complications
1) increased complications
2) poor wound healing (protein and zinc involved in cellular division)
3) compromised immune status (immune cell production)
4) impairment of organ functions
5) increased use of healthcare resources
6) increased mortality
concern with using albumin to measure nutritional status?
albumin is an acute phase reactant and levels also drop with inflammation
what do nutritional screening tools look at
3minNS
- unintentional weight loss
- nutritional intake in the past 1 week
- muscle wastage
SGA (7 pt)
- weight loss,
- dietary intake,
- GI sx (n/v/D),
- functional status,
- disease states affecting nutritional requirement,
- muscle wastage, fat stores, edema
what is the recommended energy intake for GENERALISED hospital patients?
25-35KCAL/KG body weight
total energy expenditure basic equation
TEE =
BMR or REE
x
activity factor
x
stress factor
BMR = basal metabolic rate - energy required for homeostatic function/basic cellular function
REE = resting energy expenditure - energy expended at rest
methods for BMR/REE measurement?
1) indirect calorimetry (gold standard)
- measure gas exchange (o2, co2) during consumption of substrates to produce energy required
2) predictive equation
- Harris Benedict
- Schofield
Schofield uses the age to categorise then uses weight, while Harris Benedict takes into account the height, weight and age altogether
patient protein requirements
units in g/kg/day
healthy adult = 0.8g/kg/day
trauma/surgery/burn = 1.5 -2
sepsis/critical illness = 1.5-2, up to 2.5
CKD
not on dialysis = 0.6-0.8
on HD/PD = 1.2
on CRRT = up to 2
what is enteral nutrition
nutrition provided to the GI tract via a tube, catheter, stoma that delivers nutrients distal to the oral cavity
what are the pre pyloric tubes available
PEG (percutaneous endoscopic gastrostomy)
NG (nasogastric)
what are the advantages of a pre pyloric tube?
1) more physiologic = feeds into stomach, allow gi tract to process nutrients
2) higher tolerance to bolus feeding
= can eat at specific intervals like normal meal times
3) higher tolerance to wide range of enteral products
= enteral feeds have diff pH and osmolarity = can mix with stomach fluid
4) can be used for venting
= withdrawal of contents through the tube (if patient has obstruction in gastric outlet into the duodenum = food stuck/vomiting = aspiration pneumonia )
downsides to pre pyloric tube
not recommended in patients with delayed gastric emptying
= food stuck in stomach
may have increased aspiration risk due to pressure in the stomach causing gastric reflux
what are the post pyloric feeding options available
nasojejunal
percutaneous endoscopic jejunostromy
advantages of post-pyloric feeding
1) smaller bore
= less discomfort (outlet between stomach and duodenum is smaller)
2) for conditions with dysfunction in the proximal GIT
= delayed gastric emptying, partial gastric outlet obstruction
3) less aspiration risk
= bypass through two entry points (have to bypass both stomach outlet and eosophageal sphincter)
when to use stromy vs naso tube?
1) stromy tubes for more long term feeding
= done surgically through skin.
2) appearance
= nasal need to insert through nose
3) durability
= only change once a year vs /month
disadvantages of post pyloric feeding
1) high risk of tube clogging
due to smaller size
what are the modes of admin for enteral feeding
1) continuous
- need pump
- better tolerated (spread over longer hours = trickle feeding = less distension)
- lower aspiration risk
2) bolus
- more physiologic (mimic oral intake)
- no pump needed
- more freedom for ambulation (IMPT!)
types of enteral formulas
1) modular
= single nutrient
= fortifier to enhance specific nutritional component
2) semi elemental
= partially hydrolysed or completely hydrolysed
= for patients with impaired GI function (surgical resection) / tolerance to standard feeds
3) polymeric
= macronutrient
= need sufficiently functional GIT
4) immune modulation/disease specific
= addition/restriction of certain nutrients to meet disease management needs
examples of semi elemental nutrition
peptamen
- powdered peptides
examples of modular nutrition
1) MCT oil
= for patient with chyles leakage
2) myotin
= protein
examples of polymeric nutrition
BOOST
- isotonic feed to reduce diarrhoea (not high osmolarity to draw water)
RESOURCE FRUIT
- clear feed without lipids so more easily digestible = see if gut has resumed function
GLUCERNA
DISEASE specific formulas
diabetes
= glucerna (low GI)
increased protein needs
= fresubin protein energy
about 20g of protein per serving
CKD
(dialysis)
= nephro HP (18g/per serving)
also suitable for patients on fluid restriction due to cardiac failure or poor heart function as it is caloric dense
(no dialysis)
= nephro LP (low protein, k, phosphate)
inflammatory disease/cancer
= nutrifriend
high in omega 3 fatty acids EPA/DHA
what are some drug nutrient interactions with enteral feeds?
1) binding of medication on tube
= phenytoin bind irreversibly to tube
2) medication feed interaction
= eg fluroquinolones to space apart
3) alteration of dosage form
= tablet fed through tube needs to be crushed, affecting dosage forms with enteric coating or sustained release
how to prevent drug nutrient interactions with enteral feeds?
1) sufficient flushing between feeds
- stop feed and flush access device before and after drug administration
2) use therapeutic alternatives in appropriate dosage form
- eg SR = IR formulation
common complications with EN
1) refeeding syndrome
2) occlusion of feeding tube
- jeju > gastro
- meds
- high fibre / high protein / concentrated feeds may adhere to tube = need to flus
3) tube displacement
- vigorous cough = increase intra abdo pressure
4) aspiration
5) infections secondary to microbial contamination (of the feed eg adding water)
6) n/v, diarrhoea, constiaption
- constiapiton = lack of fibre
- diarrhoea = jeju feeds because stomach acts as a holding site
monitoring parameters for EN
1) signs of intolerance (N/V/D)
2) gastric residual volume
= indicator for ability to process food normally, taken 30-60min after
= pH, color, consistency of aspirate also noted (pH of gastric contents usually 1-2, higher pH = more mixing with feeds = unable to tolerate)
3) BG
4) electrolytes (refeeding syndrome)
5) fluid balance (renal/cardiac pt)
6) weight (LONG TERM)
- SHORT TERM = fluid retention (no)
how to maximise EN tolerance
1) continuous > bolus
2) pro kinetic agents (meto, domperidone, IV erythromycin)
3) post pyloric if intolerant to gastric feed
4) use of isotonic formula (boost isocal)
5) semi elemental for pts with malabsorption (short bowel syndrome)
advantages of enteral nutrition vs parenteral nutrition
1) maintain functional integrity of the gut (prevent gut atrophy)
2) undergo first pass metabolism and promote efficient nutrient utilisation
- glucose > glycogen
- conversion of inactive –> active vit D (vs giving activated vitD = risk of hypercalcaemia)
3) maintain normal gall bladder function
4) maintain gut associated and mucosal associated lymphoid tissues
5) less complications vs parenteral
6) less expensive
reasons for parenteral nutrition (disease states)
for patients who cannot tolerate adequate nutrition via enteral feeds
examples
1) paralytic ileus (gut dysmotilty due to trauma or surgery)
2) small bowel obstruction
3) high output/proximal fistula (food will come out of the hole)
4) mesenteric ischemia (insufficient oxygen = necrosis)
differences between available parenteral nutrition?
1) peripheral
- requires frequent re-site (72h or when inflammation)
- delivery limited by osmolarity and concentration = cannot be used long term because cannot meet demands
2) central
- for longer term care (tolerate higher osmolarity due to larger volume of blood
composition of MACRONUTRIENTS in PN bag and why each is needed
amino acids (4kcal/g)
- essential + non essential
dextrose (glucose; 3.4kcal/g)
- to avoid excessive ketone production
lipid (10kcal/g)
- source of essential fatty acids (linolenic and alpha linolenic acid)
when are conditionally essential amino acids required
essential amino acids are provided by external sources
conditional EAA = normally non-essential, but become essential under specific circumstances like illness, injury, or infancy, because body cannot produce enough
- paediatrics may contain taurine and cysteine because lack enzymatic system to produce them
- both are required for fat absorption + bile secretion
micronutrients in PN bag include:
1) electrolytes
- ca, mg, k, phosphate
- acetate, chloride for acid base balance
2) multivitamins
- fat soluble (A,D,E, K)
- water soluble (B, C)
3) trace elements
- zinc, selenium, iron, iodide
- copper, manganese
concerns with copper and manganese in PN
IF patient has liver or gall bladder impairment = impaired bile flow (may be due to lack of CCK) = copper and manganese cannot be properly excreted without bile production
intestinal failure associated liver disease (IFALD) is a complication of impaired bile flow.
drug nutrient interactions for PN
incompatible drugs
1) precipitation
2) loss of drug activity
3) phase separation of lipid emulsions (due to pH/electrolyte changes)
4) toxicity
preventing drug nutrient interactions for PN
1) administer via separate peripheral IV cannula
- if using TPN = can use central line only
2) if needed, pause PN and flush access device before + after drug admin
- if pause, may enter hypoglycaemia
3) use access devices with multiple lumens
- esp if poor peripheral access
4) avoid admixture or y site
device-related complications for pN
1) OCCLUSION in IV catheter
= thrombus/clot
= inappropriate flushing
= precipitate from drug incompatibility/crystalisation
= lipid residues
2) mal positioning (wrong location)
3) catheter related bloodstream infection (CRBSI)
reasons and how to prevent CRBSI in PN
ensure sterile catheter bag
hand hygiene when handling
catheter enters bloodstream without additional defence from gut
metabolic complications for PN
1) refeeding syndrome
2) hyper/hypoglycaemia
3) fluid overload
4) intestinal failure associated with liver disease
5) metabolic bone disease
how to prevent occlusion of PN
1) LIPID RESIDUES
change administration tubing every 24h and flush out lipids if there is lipid residues
2) CLOT/THROMBOSIS
for clotting, can flush with push pause technique
cause of metabolic bone disease in pN
aluminium contamination causing osteomalacia / osteoporosis
vit D insufficient supplementation
monitoring parameters for PN
1) BG
2) electrolytes
3) fluid balance
4) weight
5) renal function test (creatinine, BUN, chloride, O2)
6) LFT
7) triglycerides
8) signs of infection (e.g., differential blood count, fever, redness/pus around access site)
pathophysiology of refeeding syndrome
1) starvation / malnutrition
= catabolism (break down glycogen, muscle, fats)
= decreased insulin, increased glucagon
= electrolytes drawn from intracellular stores (k, p, mg)
2) refeeding = switches to anabolism
3) insulin increased
= drive glucose uptake for energy production
= drive shift of electrolytes into cells
= utilisation of thiamine
4) plunge in electrolyte levels
= hypo- mg, p, k
= edema, fluid retention & potential disruption in electrochemical membrane potential = arrhythmia, cardiac failure, neuromuscular complications
+
thiamine deficiency
management of refeeding syndrome
1) identify high risk
2) check serum electrolytes at baseline
3) correct deficiencies prior to feeding OR defer feeding if electrolytes critically low
4) administer thiamine vit B1 supplément
5) initiate feeding slowly (initiate at 50%) and gradually increase to meet nutritional requirements
6) continue monitoring electrolytes and adjust feed as needed
how to identify high risk patients for refeeding syndrome
patient has one of the following
- bmi <16
- unintentional weight loss > 15% in past 3-6 months
- little / no nutrition intake last 10 days
- low P, K, Mg before feeding
patient has two or more of:
- bmi <18.5
- unintentional weight loss > 10% in past 3-6 months
- little / no nutrition intake last 5 days
- History of alcohol misuse or drugs, including insulin, chemotherapy, antacids, or diuretics
how much b1 supplementation to give
100-200mg per day for 7 to 10 days
guiding principles for artificial nutrition (ethics) + palliative considerations
autonomy,
beneficence (do good),
non-maleficence,
justice (equality)
considerations
- end of life patients may nt be able to process feeds/ remove feeds = is it improving QOL or force feeding?
