Oral, Enteral and Parenteral Nutrition Flashcards
Definiton: malnutrition
Deficiency or excess (or imbalance) of energy, protein and other nutrients (in clinical practise, undernutrition and inadequate intake of energy, protein and nutrients, is the focus
Definition: cachexia?
General weight loss and wasting occurring in the course of a chronic or emotional disease (i.e., cancer, HIV)
Definition: nutrition supplements
Nutritional supplements include vitamins, minerals, herbs, meal supplements, sports nutrition products, natural food supplements, and other related products used to boost the nutritional content of the diet
Definition: nutrition support
The provision of enteral or parenteral nutrients to treat or prevent malnutrition
Definition: enteral nutrition
A feeding tube is placed in the GI tract to deliver liquid formulas containing all essential nutrients
Definition: parenteral nutrition
The infusion of complete nutrient solutions into the bloodstream (via a central or peripheral vein)
What can malnutrition lead to?
Impaired immune responses (increasing risk of infection)
Reduced muscle strength and fatigue
Reduced respiratory muscle function (increasing the risk of chest infection and respiratory failure)
Impaired thermoregulation (predisposition to hypothermia)
Impaired wound healing and delayed recovery from illness
Apathy, depression and self-neglect
Increased risk of admission to hospital and length of stay
Poor libido, fertility, pregnancy outcome and mother child interactions
What are nutrition assessment tools?
Various tools used by dieticians
- malnutrition screening tool
- malnutrition screening tool for cognitively impaired
- nutrition risk assignment for frail elderly
- mini nutrition assessment
- subjective global assessment
Who is a nutritionally high risk patient?
High nutritional risk was determined by nutrition screening
Diagnosis of malnutrition
Evidence of significant weight loss
Diagnosis or conditions requiring increased calories and protein such as pressure ulcers, infections, fractures, and skin breakdown
Low body weight (low BMI)
Oral dietary intake of less than 50% of estimated energy needs for 3 or more days
Poor acceptance of traditional oral nutritional supplement given during or between mealtimes
What are goals of oral nutrition for patients with malnutrition?
Promote intake of nutrient dense diet (high in energy, protein and micronutrition) Liberalize diet Consume preferred foods High energy, high protein shakes/drinks Snacks between meals
Can high energy, high protein shakes/drinks replace meals?
No. They should be taken between meals, not to replace meals
Consume ideally 2 bottles per day
What are indications for oral nutritional supplements?
BMI less than 18.5
Unintential weight loss of over 10%
Eaten less or nothing for more than 5 days or unlikely to for the next 5 dats
Poor absorptive capacity and/or high nutrient losses and/or increased nutritional needs (e.g., catabolism)
How is enteral nutrition classified?
Typically classified by site of insertion and location of the distal tip of the feeding tube (i.e., nasogastric is inserted in the nose and ends in the stomach)
The site of enteral nutrition depends on what?
Concurrent disease/injury
Impaired gastric mobility
Risk of aspiration
Duration of nutrition support
What are the different types of tube feeding?
Continuous (over 24 hours)
Cyclic (over a fixed period, e.g., 8-20 hours)
Bolus feeding (4-6 times/day)
What is the indication for enteral feeding?
Used when oral intake is inadequate or not recommended for a prolonged period of time. The time period varies.
Enteral is the preferred over parenteral route when the GI tract is functioning
Why is enteral preferred over parenteral route when GI tract is functioning?
Greater convenience
Lower cost
Decreased infectious complications
May enhance immune function, maintain gut flora/integrity
Decrease metabolic complications (decreased incidence and severity)
Allows access for medication administration
What are contraindications for enteral nutrition
Perforation of GI tract
GI ischemia (hemodynamically unstable on vasopressors)
Complete mechanical bowel obstruction
Complete non-mechanical bowel obstruction
High output enterocutaneous fistula involving proximal small bowel
Inability to access GI tract
Patient’s/care provider’s right to refuse enteral feeding
What are complications of enteral feeding?
Nausea, vomiting, cramps, distention, diarrhea, constipation, malabsorption
Aspiration (measure high gastric residuals), tube clogging
Refeeding (low PO4, Mg2+ and K+ after standing)
Metabolic complications (electrolytes, liver abnormalities, hyperglycemia, fluid abnormalities)
What does a dietician do with enteral nutrition?
Initial nutritional assessment
Recommendations regarding appropriate enteral formula
Administration and goal rate
Ongoing monitoring of nutritional status
What are the different enteral formulations available?
Polymeric Elemental/semi Diabetes Comprised respiratory function Inflammatory bowel disease Fluid restricted Renal disease
Describe the polymeric enteral formula
Intact milk or soy protein based (i.e., levity, isosource, isource NH fibre, isosource VHP)
Describe the elemental/semi enteral formula
Elemental - free amino acids or short-chain peptides (i.e., peptamen)
Describe the diabetes enteral formula
Low carbohydrate, modified fat (i.e., glucerna, resource diabetic)
Insufficient evidence to support routine use
Describe the compromised respiratory function enteral formula
Low carbohydrate
High fat (i.e., pulmocare)
Insufficient evidence to support routine use
Describe the inflammatory bowel disease enteral formula
I.e., Modulen
Insufficient evidence to support routine use
Describe the fluid restricted enteral formula
More concentrated (hypercaloric, higher protein) formulas (i.e., isosource 1.5)
Describe the renal disease enteral formula
Hypercaloric Low potassium Low phosphate Low vitamin A and D High calcium Low oxalic acid (reduces kidney stones) I.e., Nepro, Novasource renal
What is the choice of formulation based on?
Based on the patient’s medical condition, nutritional status and digestive/absorptive capabilities
Incorrect administration of medications with tube feeds can result in what?
Clog feeding tubes
Decrease drug effectiveness
Increased adverse effects
Drug-formula incompatibilities
What are some considerations when administering medicaments with tube feeding?
Use liquid dosage form when possible (elixirs and suspensions are usually favoured over syrups)
Dilute hypertonic medications with 10-30 mL of water
Crush tablets (if allowed) to a fine powder and mix with 30 ml water unless otherwise instructed
Each drug must be administered separately
Flush tube with 15-30 ml warm water before giving drug, with 5-10 ml between each drug and 15-30 ml water after last medication
Which tablets cannot be crushed?
Do not crush or split cytotoxic/hazardous medications, pantoprazole, alendronate, dabigatran, sustained release/enteric coated products (i.e., medications labeled SR, CR, MR, TR, XL, EC)
How can liquid ciprofloxacin affect tube feeding? What is recommended?
High risk of feeding tube blockage with a suspension, plus it binds to divalent ions in the tube
Use tablet formulation and disperse tablets in water prior to dosing OR hold tube feeds 1 hours before and 1-2 hours after dose OR IV formulation
How can phenytoin (dilantin) affect tube feeding? What is recommended?
Reduction in absorption (variable)
Administer the parenteral solution enterally and dilute it was 30 ml of water OR hold feeds 1-2 hours pre and post administration OR IV formulation
How can parenteral nutrition be infused?
Central line (PICC, tunnelled catheter, port) Peripheral line (osmolarity
What are indications for parenteral nutrition?
Patients where the GI tract is not functional or cannot be accessed
Patients who cannot be adequately nourished by oral diets or enteral nutrition
Patients with inadequate oral intake for 7-14 days or in patients in whom inadequate oral intake is expected over 7-14 day period
What are conditions that might indicate parenteral nutrition?
Paralytic ileus Mesenteric/GI ischemia Small bowel/intestinal obstruction GI fistula (except when enteral route is available distal) Intractable vomiting or diarrhea Diffuse peritonitis GI perforation Short bowel syndrome Severe pancreatitis with intolerance of enteral nutrition
What are components of TPN?
Dextrose
Amino acids
Lipids
Electrolytes (sodium, potassium, chloride, calcium, phosphate, magnesium)
Trace elements (zinc, copper, manganese, chromium, selenium, iodide)
Multivitamins
+/- vitamin K
What are the energy requirements of parenteral nutrition?
Usually calculated by the dietician
Various equations to calculate
Total energy expenditure is 25-30 kcal/kg (chronically ill - less basal energy 20-25 kcal/kg)
What are the fluid requirements of parenteral nutrition?
Normal (around 30 ml/kg)
Plus abnormal losses from osmotic diuresis, nasogastric drainage, wound output, diarrheal/ostomy losses
What is dextrose? Why is it important in parenteral nutrition?
It is a source of energy. Not a necessary building block for other molecules
Dextrose requirements: 70-85% of calories
Final dextrose concentration is usually 15-25%
What are amino acids? Why are they important in parenteral nutrition?
Building blocks of protein
Metabolic intermediates in the biosynthesis of other molecules (serotonin, dopamine, GABA, nucleotides, etc.)
Amino acid requirements: 1-15. g/kg
Needed for tissue repair/synthesis (ideally used as an energy source)
What are lipids?
Source of energy
Structural components of cell membranes
Important signalling molecules
Precursors to formation of other molecules (i.e., steroid hormones)
What are the lipid requirements in parenteral nutrition?
15-30% of calories
Provides 10 kcal/g of energy
Prevents essential fatty acid deficiency
What are the 3 lipids available in Canada for parenteral nutrition?
Intralipid
SMOFLipid
Clinoleic
What is a pharmacists role in parenteral nutrition and electrolytes?
They are involved in monitoring and adjusting electrolytes to maintain in therapeutic range
Try to identify reason for electrolyte imbalance and correct underlying cause
Considerations:
-amount of electrolytes given over a 24 hour period
-rate of electrolytes
-concentration of electrolytes
What are multivitamins used in parenteral nutrition?
Multi-12 (vitamins A, Bs, C, D, E)
half dose in renal dysfunction
What are the tract elements used in parenteral nutrition?
Multiple products (zinc, copper, chromium, selenium, iodine, magnesium) Caution in liver disease - eliminate copper and manganese or give half doses of trace elements
What is vitamin K?
Cofactor in production of factors VII, IX and X and protein C and S
Traditional vitamin K dosing in TPN patient: 10 mg/week
Intralipid (not other lipids) is a significant source of vitamin K and further vitamin K supplementation in patients may not be necessary
What needs to be considered with calcium and phosphate?
If mixed in too high a concentration, calcium and phosphate can form an insoluble precipitate of calcium phosphate
Separate addition of calcium and phosphate to TPN when preparing TPN
Try to keep combined calcium and phosphate less than 30 mmol/L
What is osmolarity?
Measure of solute concentration (mOsm/L)
Determines route of administration (central vs. peripheral)
Osmolarity above 900 mOsm/L increases risk of phlebitis (chemical irritation of the vein)
Influenced by dextrose, amino acid and electrolyte concentration
What is total nutrient admixture?
Mixture of dextrose, amino acids and lipids
May decrease the risk of infection (fewer line manipulations) and lipids mixed with dextrose and amino acids do not support bacterial growth as well as lipids alone
Electrolyte limitations - excessive electrolytes can cause the emulsion to destabilize (crack)
What is 2 in 1 parenteral nutrition?
Mixture of dextrose and amino acids +/- lipids infused separately
More flexibility in dosing where an IV compounder is not available
What are additives?
A limited number of medications can be added to TPN or mixed via "Y" site Insulin Ranitidine Supplemental zinc Iron
Additives: insulin
Regular insulin is compatible with TPN (via Y-site)
Not routinely added to TPN (difficult to adjust insulin dose)
Additives: iron
Not part of routine trace elements
Consider for iron deficient patients +/- long term TPN
Do NOT add 3 in 1 (TNA) solutions
What are complications due to parenteral nutrition?
Infections (catheter related, comorbid disease, contaminated TPN) - in case of infection, remove IV line and culture Blood clots (foreign body in the vasculature increases the risk of clots) Hyperglycaemia (requires frequent monitoring of blood sugar)
What are the risk factors for hyperglycaemia?
Introducing dextrose (carbohydrate) load Comorbid disease (diabetes) Insuline resistance, increased gluconeogensis and decreases glucose utilization
How hyperglycaemia in parenteral nutrition managed?
Addition of insulin
Decrease of dextrose concentration or infusion rate
What is refeeding?
Provides calories to a malnourished patient (leads to intracellular shift of serum phosphorous as metabolism gets started)
What does refeeding result in?
Decreased muscle contraction of diaphragm (respiratory failure)
Altered oxygen delivery to peripheral tissues
Decreased contractility of the heart/CHF
Cardiac arrhythmias
Encephalophathy
Rhabdomyolysis
How common is high triglycerides in parenteral nutrition?
Common in TPN (especially long term or underlying liver disease)
Coincides with hepatic steatosis (may develop in week)
Often precedes liver abnormalities (cholestasis and hepatocellular damage, which can progress to cirrhosis and failure)
Reduction or withdrawal of lipid emulsions or change to alternative lipid lower in omega-6 fatty acids
What are the different types of hepatotoxicity?
Steatosis, steatohepatitis, cholestasis, choleithliasis and fulminant liver disease
Steatosis is more common in adults
Primarily diagnosed by high LFTs or high bilirubin
What are potential causes of hepatoxicity?
Excess caloric intake (dextrose)
Impaired hepatic secretion of triglycerides
What causes fluid overload?
Several sources of fluids (IV medication flushes)
Increased insulin (anti-natriuretic, anti-diuretic properties) causes fluid retention
Underlying cardiac, renal and liver issues
What should be done in the case of fluid overload?
TPN solutions may be concentrated to decrease fluid volume
Use lower sodium and glucose concentrations
What should be done in the case of metabolic acidosis?
Minimize chloride (use acetate)
What should be done in the metabolic alkalosis?
Maximize chloride and restrict acetate
What is osteomalacia? What causes it?
Softening of bones
Caused by calcium and phosphate deficiency
Low levels of PTH, vitamin D, high urinary calcium excretion
Aluminum has been detected in some long-term TPHN patients (could be contributing factor)
What are some considerations when starting TPN?
Start at lower rates and increase gradually to target
Try to avoid “refeeding” and hyperglycaemia
Correct phosphorus, magnesium and potassium deficiencies
What are some considerations when discontinuing TPN?
Abrupt discontinuation may result in rebound hypoglyecmia
During last hour of infusion, decrease to half infusion rate for 30 minutes then one quarter rate for 30 minutes OR run D10W at some rate as the TPN for 6 hours
Check blood sugar 30 minutes after discontinuation
May require supplemental electrolytes to replace those that the patient was getting in the TPN
What is cycling TPN?
Administration of full TPN over the shortest tolerable time (usually 10-12 hours at night)
Facilitates ambulation in stable patients
May benefit with hepatobiliary dysfunction
Taper over last hour to prevent rebound hypoglycemia
Watch for hypo and hyperglycemia
What is the role of a pharmacist in parenteral nutrition?
Assess patient’s nutritional status and comorbid disease states and medications which may affect TPN
Work with team to assess if TPN is appropriate
Review the following clinical parameters and make recommendations to the TPN team (electrolytes, fluid status, iron status in long term patients, zinc status)
Work with team to assess/manage patients with TPN complications
