IC7 feeds Flashcards
considerations of human disgestive system
stomach
GIT
accesorry organs: liver, gallbladder, pancreas
sphincters at outlets to control flow
stomach role and function
- digest food, reservoir to store food
- Pyloric sphincter control rate of release – dumping syndrome (NVD, cramp) because intestines cannot hold
GIT role and function
- digestion, absorption, excretion
- secreions
○ Secretion of fluids: 1-2L lq/d. gastric acids, electrolytes
○ Secretion of enzymes: intrinsic factor (vitB12), enzymes
○ Gut hormones: cholecystokinin - GALT: gut associated lymphoid tissue (Peyer patches eg)
○ Immune cells to protect from infection, luminal mechanical barrier
accessory organs function
duodenum (when food passage in duodenum) –> produce cholecystokinin
- Stimulate pancreatic contraction (pancreatic enzymes)
- stimulate liver to secrete ball and gall bladder to secrete the BILE
- Without this: gall bladder don’t contract, bile not flowing = cholestasis & jaundice may occur (IFALD)
decr intake –> malnuritrion
○ Medications that affect taste/ LoA
○ Ascites (accumulate of fluid, press onto GI –> stomach cannot expand, satiety)
○ Chemo (NV)
○ Malabsorption (major surgery resection of intestine, less nutrition absorption)
incr expenditure –> malabsorption
○ Stress (trauma, surgery, infection, burns, sepsis) more expenditure so more resources for wound healing
○ Dialysis (protein loss)
effects of malnutrition
○ Incr complications
○ Poor wound healing
○ Compromised immune status
○ Impairment of organ function
○ Incr mortality
○ Incr use of healthcare resource
nutritional screening and assessment steps
1) nutritional screening at admission (quick 3mins of nutrition risk pt)
2) Refer to dietitian/ nutritional specialist
for nutritional assessment
3) Formulation of nutritional regime
2) Refer to dietitian/ nutritional specialist
for nutritional assessment
In depth, systematic process of pt data to identify nutrition-related problems
(7 point subjective global assessment) Scale 7 – 1 (severely malnourished)
- Anthropometric (height and weight)
- Biochemical (electrolytes, serum Albumin: liver function, not accurate for malnutrition (affected by fluid overload, infection)
- Clinical (PMH, med, PE)
- Diet history
3) Formulation of nutritional regime includes ___ + ___
- Energy requirements (kcal)
Total energy expenditure dependent on resting/ basal metabolic rate, physical activity, stress factor - protein requirements
3 method to calc energy requirements
1) indirect calorimetry
2) weight base
3) predictive eqns
Indirect calorimetry (*GOLD STANDARD)
- Measurement of gas exchange (CO2, O2) during consumption of substrates to produce required energy
- But difficult to measure accurately gas collected
C6H12O6 + 6O2 —> ATP + 6CO2 + 6 H20
weight based
25-35kcal/kg for general hospitalized pts (ESPEN)
Predictive equations – Scofield eqn, Harris-Benedict eqn
- Only estimate basal metabolic rate
- Need x1.2 for activity and x1.2 for stress factor
* Less accurate than calorimetry
protein requirements (g)
- dependent on medical conditions
healthy: 0.8 g/kg/d
trauma/surgery/burn/ sepsis/ critical ill: 1.5 - 2g/kg/d
CKD:
(not on HD 0.6 - 0.8)
(HD 1.2)
CRRT (2g)
enteral nutrition
For pts who are unable to receive/ tolerate adequate nutrition by oral route
(swallowing impairment, mechanical ventilation, altered mental status, motility disorders)
- pre-pyloric (NG, PEG)
- post-pyloric (NJ, PEJ)
- nasal vs stomy tubes
pre-pyloric EN pros and cons
- More physiologic, maximise function of GIT
- Stomach still acts as reservoir
- Higher tolerance to bolus feeding
- Higher tolerance to wide range of enteral pdts
- Pdt with high osmolarity, less SE of diarrhea as stomach can hold pdts first
- May be used for venting
- Remove gastric fluids (when obstruction occurs, reduce Vol, but risk of ASPIRATION PNEUMONIA)
cons: NOT for feeding in pts with delayed gastric emptying
post-pyloric EN pros and cons
- Smaller bore, less discomfort
- May be used in conditions that result in dysfunctionality in proximal GIT
- Minimize ASPIRATION risk
cons: higher risk of tube clogging due to smaller diameter
modes of EN admin
Bolus (3 main meals)
continuous EN
bolus EN admin
Bolus (3 main meals)
* Usually by gravity, mimics oral intake
* More physiologic
* No pump required
* Greater freedom for ambulation
Continuous EN
Continuous (many small meals)
* Pump assisted delivery at a constant rate
* Better tolerated, less bloating
* Lower risk of ASPIRATION
types of EN formula
Modular
(semi) elemental - oligomeric
elemental - monomeric
Polymeric
Immune-modulating Disease-specific
Modular
- Single nutrient
- Used as fortifier to enhance a specific nutritional component/ augment oral diet
- Used in acute setting, short period (renal/ resp/ liver fail)
protein powder, MTG (bypass lymphatic system)
[oligomeric]
(semi) elemental
- Contains PARTIALLY hydrolysed nutrients
Proteins –> peptides (semi) - For pts with impaired GI function
- Impaired tolerance to standard feeds
- Meal replacement as well, protein is partially hydrolysed into peptides
[monomeric] elemental
completely hydrolysed to improve digestion, lactose free, aa based, elemental formula
polymeric
- Contains intact macronutrients
- Require sufficiently functional GIT for digestion
- Meal replacement with pt with intact GIT
isocal (clear feed): easily digested, more tolerable
Immune-modulating
Disease-specific
- Contains additions/ restrictions of specific nutrients to meet needs for disease management
- Can be for other disease not marketed
- Caloric dense + fluid restricted: CKD & HF
- May or may not meet indiv full nutritional needs
glucerna
fresubin protein energy
nepro HP
nepro LP
nutrifriend
all are caloric dense 1 - 1.8kcal/ml
glucerna - low GI
fresubin protein energy - high protein 20g/serving
nepro HP - high protein 18g
nepro LP - low protein, K, Phosphate
nutrifriend - omega-3 FA EPA/DHA
Drug-nutrient interaction in EN
- Not an issue with bolus/ intermittent feeding
- Administration of incompatible drugs may cause:
□ Ppt
□ curdling, clamping of proteins
□ Alteration of DF (sustained/ PR/ EC)
prevent drug-nutrient interaction
- Prevention and mitigation
□ Stop feeding, flush access device before and after drug admin
□ Use therapeutic alternatives available in appropriate DF (suitable for crushing)
Complications of EN
○ Occlusion of feeding tubes (jejunal > gastric tube) , med admin, formula (concentrated/ high protein/ fibre will adhere to tube walls)
○ Tube migration
○ Infection 2nd to microbial contamination (water encourage microbial growth)
* Do not dilute feeds, just flush water separately
○ Aspiration
○ NVCD
○ Refeeding syndrome!!
Strategies to maximise tolerance to EN
○ Continuous > bolus
○ Prokinetic agents (metoclopramide, domperidone, IV erthromycin)
○ Post-pyloric feeding (if gastric feeding not tolerated)
○ Isotonic formula (boost isocal)
○ Semi-elemental/ elemental feeds in pt with malabsorptive issue (short bowel syndrome)
if the gut works, use it
- maintain functional integrity of the gut
- undergo 1st pass metabolism, promote efficient nutrient utilisaion
- maintain normal gallbladder function
- maintain gut-associated and mucosal-associated lymphoid tissues
- less complications than PN – line sepsis, IFALD
- less expensive
PARENTERAL NUTRITION
- For patients who are unable to receive or tolerate adequate nutrition by enteral route (paralytic ileus, small bowel obstruction, high output/ proximal fistula, mesenteric ischemia)
- Parenteral access devices
○ Peripheral
○ Central
peripheral pros and cons
PICC, midlines
pros
- Tip is located outside of central vessels. Small tube
- No fluid restriction
- <2 weeks use
cons
- Requires frequent re-site ~72hrs
- Nutrient delivery limited by osmolarity and conc
- Burning, welling, pain
- 900mOsmol
central pros and cons
Post-a-cath > peripheral central > tunnelled central > Non-tunneled central
pros
- Position of catheter tip is large bore blood vessel
- Distal superior vena cava, inferior vena cava, right atrium)
- Dilutes high osmolarity, more tolerable
- Used for longer term care (less re-site >2wks)
cons
* Larger tube
* Fluid restricted, can use hypertonic sol
Post-a-cath > peripheral central > tunnelled central > Non-tunneled central
Post-a-cath, sc port: implant port, near clavicle, for chemo pts
peripheral central PICC: arm to large vessel
tunnelled central veous catheter: lower infection risk
Non-tunneled central venous catheter: short live for 2wks, high risk infection
commercial vs customised formulation
Commercial (can add more of specific electrolytes) vs customised formula ( adjust ratio of macromolecules for pt tolerability)
Composition of PN
(concern for ___)
- Nutrition in simplest, most elemental form [stored in separate components]
○ Dextrose solution/ AA + electrolytes / Lipid emulsion - Admixture of multiple components
Concern: stability, compatibility especially for
□ Ca, P – high conc will ppt
□ Lipid – pH unstable
□ Dextrose – acidic, pH 2-
Drug-nutrient interaction in PN considerations
- Not problem if administer via separate lumens of same access device
- Admixture vs Y site compatibility
- TPN (total parenteral nutrition) vs TNA (total nutrition admixture)
Admin of incompatible drugs may cause (ppt, loss of drug activity, phase separation of lipid emulsion, toxicity)
Admixture vs Y site compatibility
- Admix: mix in the bag, more likely to have interaction
- Y site: single lumen but no interaction between lines (separate), still need check for potential DNI
* Can consider dual/ triple lumen catheter (only mix in venous large vein is highly diluted)*
TPN (total parenteral nutrition) vs TNA (total nutrition admixture)
TPN: nutrient fat w/o fat — lipid is more incompatible with more drugs
TNA: every component inside
Prevention and mitigation of DNI in PN
- Admin via separate peripheral IV cannula
- If need: pause PN admin, flush access device before and after drug admin before resume PN infusion
device related complications for PN
- Occlusion in IV catheter
○ Thrombosis/ clotting
○ Inapp flushing techniques
○ Ppt from drug incompatibility, crystallization (Ca, P)
○ Lipid residues - Mal-position
- Catheter-related bloodstream infection (need aseptic infusion technique)
metabolic complications with PN
○ Refeeding syndrome
○ Hyper/hypogly (as glucose injected directly into blood stream)
○ Fluid overload (direct into blood stream)
○ Intestinal failure associated liver disease (IFALD)
○ Metabolic bone disease (osteomalacia, soteoporosis in LT)
Intestinal failure associated liver disease (IFALD) 3 main causes
associated with long nil-by-mouth.
- Lack of CCK (no stimulation of gallbladder –> cholestasis)
- Oversuppl fats and dextrose accumulate in liver –> fatty liver
- Type of TG administered (MCT, LCT oils – provide essential FA).
- LCT is pro-inflammatory marker –> lead to liver damage
- Consider using fish oil based (anti-inflamm but insuff essential oils so not given solely) > olive oil based > soybean based (LCT)
refeeding syndrome pathophysiology
- Starvation, malnutrition
a. Body breaks down protein, fat, mineral, electrolytes, vitamin. Depletion from intracellular stores (muscles, fats).
b. Salt and water intolerance from reduction in renal excretion
c. Serum electrolytes may appear normal - Refeeding (body switch to anabolism)
a. Insulin secretion to incr glucose, K, Mg, PO4 uptake.
b. Increase protein and glycogen synthesis for storage - Imbalance
a. Cells will produce energy (use up thiamine) and take back what was depleted (K, Mg, PO4) from bloodstream
□ Drastic drop
□ 1 ATP produced = 3 mmol PO4 used (hallmark)
refeeding syndrome markers
hypoK (3.5 - 5.0mmol/L)
hypoMg (0.75 - 1.07 mmol/L)
hypoPHOSPHATASEMIA (0.85 - 1.45mmol/L)
thiamine deficiency (vit B1)
- Salt and water retention –> oedema
management
- Identify high risk pts
- Check serum electrolytes at baseline
- Correct deficiencies prior to feeding. DEFER if critically low
- Administer vit B1, thiamine supplement
- Initiate feeding slowly, gradual increase next few days to meet nutritional requirements
- Continue monitor electrolytes as feeding progresses, adjust amount of replacements needed
high risk pts for refeeding syndrome
≥1
- BMI< 16kg/m2
- intentional weight loss >15% in past 3-6m
- little or no nutritional intake > 10d
- low level K, Mg, Phosphate before feed
≥2
- BMI <18.5 kg/m3
- unintentional weight loss >10% in past 3-6mnths
- little or no nutritional intake >5d
- hx of alc misuse of drugs, insulin, antacids, chemo, diuretics
thiamine suppl
between 25mg and 100mg, taken once a day.
Severe thiamine deficiency. The usual dose for adults is 100mg, taken 2 or 3 times a day.
