Parenteral Nutrition Flashcards
1
Q
Central PN (TPN) Advantages/Disadvantages
A
Advantages
-Provides optimal nutrition (macro and micronutrients)
Disadvantages
- Must be administered through central line due to high osmolarity
- Increased risks with central lines
2
Q
Peripheral PN (PPN) Advantages/Disadvantages
A
Advantages
- Can be run in a peripheral line
- Avoids need for central line if no other IV lines needed
Disadvantages
- Typically not able to provide optimal PN due to limitations with osmolarity
- Max: 900 mOsm/L osmolarity
- Not for long term use
3
Q
Indications for PN
A
- Paralytic ileus
- Mesenteric ischemia
- Small bowel obstruction
- Severe necrotizing pancreatitis
- Radiation or chemo-related enteritis
- Failure of enteral feeding trial through feeding tube placed distally to GI fistula with high input (>500 mL/day)
4
Q
CI for PN
A
- Patients with functioning GI tract who can eat and meet their nutritional needs via EN
- Duration of PN < 5 days
- Advanced directives that do not warrant aggressive nutrition support
5
Q
Delivery of PN
A
Continuous
- Nutritional components delivered over 24 hours
- Generally better tolerated in critically ill patients
Cyclic
- Administer nutrition over less than 24 hours
- Commonly used in patients on long term PN
Specialized delivery methods
-Intradialytic PN: not ideal route and very rare currently
6
Q
PN Components
A
Macronutrients
- Protein source: amino acids
- Non-protein calories: carbs (dextrose), fat (IV lipid emulsion)
Micronutrients
- Electrolytes
- Vitamins
- Trace Elements
Additives
- Additional vitamins
- Medications
7
Q
Amino Acids
A
- Caloric value: 4kcl/g
- Crystalline amino acid solution
- Provide essential, semi-essential, and non-essential amino acids
- Administration usually combined and administered with dextrose and other TPN components
8
Q
Amino Acid Solutions
A
- Multiple products available with range of concentrations: 3-15%
- Contain between 44-50% AA as essential
- Exact AA compositions and buffers to balance pH vary between products
- EX: Clinisol, Aminosyn, Travasol
9
Q
Specialty Amino Acid Solutions
A
-Modified AA to meet disease/age requirements
Neonates/Infants
- Add taurine, decreased methionine
- EX: TrophAmine, Premasol
Hepatic
- Increased branched chain, decreased aromatic AA, and methionine
- EX: HepatAmine
10
Q
AA AE
A
- Azotemia (high nitrogen in blood)
- Phlebitis/thrombosis (vesicant)
- Fluid/electrolyte disturbances
11
Q
Dextrose
A
- Carb Source
- Caloric value: 3.4 kcal/g
- Main source of energy
- Available in 5-70% concentrations
- D70 only used to compound PNs
12
Q
Dextrose Disadvantages
A
- Increased osmolarity of concentrated solutions
- Uptake into cells is insulin dependent
- Limited ability to oxidize glucose for energy (max oxidation rate: 5-7 mg/kg/min)
- Excess glucose converted to fat => lipogenesis
13
Q
Dextrose AE
A
- Hyperglycemia
- Electrolyte disturbances
- Vein irritation: 12.5% max in peds/neonates, <10% in adults
- Increase CO2 production
- Fatty liver
14
Q
IV Lipid emulsions
A
- Fat source, IVLEs
- Caloric value 9kcal/g
- Account for glycerin in calculation of calories (1.1 kcal/mL: 10%, 2.0 kcal/mL:20%, 3.0 kcal/mL: 30%)
- Lipids can be administered piggybacking TPN/PPN or mixing with other PN componenets
- Emulsifier: egg yolk phospholipids: 15 mMol Phos/L, amekes emulsions “milky”
15
Q
IVLE Advantages
A
- Concentrated source of calories
- Reduces requirement for dextrose
- Provides essential fatty acids (EFAs) and long-chain polyunsaturated fatty acids (LC-PUFAs, linoleic acid)
16
Q
IVLE Disadvantages
A
- Cannot meet body’s requirements of glucose, max: 60% (preferred ~30%)
- Compatibility issues
- Oxidative stress: PUFAs => lipid peroxidation
- Inflammation: pro-inflammatory eiconsanoids soybean oil
- Immune system dysfxn/increased risk of infections
- Hepatobiliary complications: worsened liver dysfxn and PN-associated liver disease
17
Q
IVLE Dosing/Administration
A
- Adult: up to 1 g/kg/day
- May be less in the critically ill
- Administer: run over 12 hours only
- May be “liver protective”
- Potential concern for bacterial growth in bag if ran >12 hours
18
Q
Soy Lipid Emulsions
A
- Intralipid (20% and 30%) and Nutrilipid (20%)
- 30% only for compounding admixtures
- Clinolipid: 4:1 ratio olive oil:soybean oil
19
Q
SMOFLipid 20% Emulsion
A
- Alternative IVLE to soybean-based
- SMOF stands for fatty acids it contains
- Advantages unclear: some show lower TGAs/LFT elevations, may decrease inflammation/infection, not shown to be better than soybased in morbidity/mortality or overall superiority
20
Q
SMOF
A
S = Soybean oil M = Medium chain Triglycerides (rapidly cleared energy) O = olive oil (omega-9 source) F = Fish oil (EPA/DHA source)
21
Q
Omegaven 10% Emulsion
A
- Approved for treating pediatric patients with PN-associated cholestasis/liver disease
- 10% emulsion only, 1.1 kcal/mL
- Dose: 1 g/kg/day over 12 hours
- Concern for developing EFAD (essential fatty acid deficiency)
UNMH Indications:
Pediatric/Neonate already on SMOF AND
-Direct bilirubin >5 OR
-Direct bilirubi >2.5 AND no surgical procedures/septic events in 1 month
Switch back to SMOF once direct bili <2
22
Q
Calculating Macros/Fluids
A
Start from Scratch
- Determine total fluid volume/rate (goal 30-40 mL/kg/day, minimal to fit macros for critically ill)
- Determine total energy/caloric requirement
- Determine protein requirement
- Determine non-protein requirement (split 70% dextrose and 30% lipids)
* *Typical dietician way**
Given Macros/Fluid
- Total fluid volume/rate/macros in g/g%/mL provided
- Can determine caloric content across the macros
* *Pharmacists situation**
23
Q
Electrolytes
A
Approximate Daily Requirements assuming Normal Baselines
- Sodium: 1-2 mEq/kg/day
- Potassium: 1-2 mEq/kg/day
- Magnesium: 8-20 mEq/day
- Calcium: 10-15 mEq/day
- Phosphorous: 20-40 mMol/day
- Chloride/Acetate PRN to maintain acid/base balance
24
Q
Reasons to Increase Electrolytes
A
- Na/K: diarrhea, vomitting, NG suction, DI losses
- K only: meds, refeeding
- Calcium: high protein intake
- Magnesium: GI losses, meds, low K+, refeeding
- Phosphate: high dextrose intake, refeeding
- Chloride: metabolic alkalosis, volume depletion
- Acetate: renal insufficiency, metabolic acidosis, GI losses of bicarbonate
25
Vitamins
- Needed for appropriate nutrition
- Fat Soluble: A, D, E, K
- Water Soluble multiple B vitamins and C
- Commercial combo multivitamin product: 13 vitamins total, 10 mL dose to adults
- Additional vitamins can be added to PN based on patient's condition/deficiency: Vitamin C, thiamine, folic acid, Vitamin K
26
Trace Elements
- Combo product in US: Tralement
- 3 mg Zinc, 0.3 mg Copper, 55 mcg Magnesium, 60 mcg selenium per 1 mL
- Add additional 2mg on zinc at UNMH
27
Other Potential Additives
- H2 receptor antagonist (famotidine)
- Insulin
- Neonatal PNs only: heparin, iron dextran
28
GI Conditions + PN
- Some conditions impair nutrient absorption like short bowel syndrome, chronic diarrhea (Tufting enteropathy, Microvillus inclusion disease), and chronic pancreatitis
- May require different electrolyte and vitamin needs depending on condition
- Short bowel requires more magnesium and zinc
29
Pediatric Patients + PN
- Improve growth and development rather than meeting baseline needs
- More aggressive macros, more Ca/Phos to promote bone growth
- Higher dextrose and AA per kg than adults (protein in neonates is up to 4 g/kg/day)
- May require different electrolytes amounts
30
PN Component Incompatibilities
Calcium + Phosphate
- Dependent on [AA} and pH
- Use calcium gluconate, NOT chloride
- Separate order of mixing (add phos before calcium)
Bicarbonate
- Forms insoluble carbonates with Ca, Mg, and release CO2 gas
- Use acetate salts instead (Na or K acetate)
31
Drug + PN Interactions
- Ceftriaxone: incompatible with calcium, don't give while PN running in same IV line
- Safest option is to have a dedicated PN and/or IVLE IC line
32
Non-Soybean Compatibility Issues
- SMOF incompatible with hydrocortisone and dopamine
- Long list of SMOF compatible
- Omegaven: compatible with PN only
- Treat unknowns as incompatible
33
Serious PN Complications
Metabolic
- Hyper/hypoglycemia from abruptly stopping PN, starting with too high dextrose when patient hasn't been eating or NPO, ramping the rates up/down
- Refeeding syndrome: K, Phos, Mg
Hepatotoxicity
- Intestinal failure-associated liver disease (IFALD)
- Steatosis and cholestasis
- More common in long term PN, especially short bowel patients
34
Refeeding Syndrome
- Potential severe shifts in fluids and electrolytes in malnourished patients receiving EN/PN
- Help prevent by slowly initiating/advancing PN
- Signs/symptoms: Hypophosphatemia**, hypokalemia, hypomagnesemia
- Also changes in glucose, protein, and fat metabolism
- Monitor: glucose, K, Mg, and Phos (replete electrolytes as needed)
35
IFALD
-Direct bili > 2 for 2 consecutive weeks without other cause
Risk Factors
- PN > 2 weeks
- Low gestational age and birth weight in neonates
- Short bowel syndrome
- Recurrent episodes of sepsis
- Excessive caloric intake
- Intralipid use (soybean based)
- Inability to tolerate EN or lack of EN
36
Additional TPN Complications
- HyperTGA: related to lipids, decrease rate or hold
- Acid/base disorders and electrolyte disturbances: monitor and adjust as needed
- Central line infection: important to keep clean
- Thrombosis: increased risk with central line and if patient is < 1 y.o.
37
EFAD
- Essential Fatty Acid Deficiency
- Dry thick, desquamating skin, alopecia, decreased wound healing, hepatic dysfxn, growth retardation
- Prevent be giving adults minimum of 100g of IVLE per week (250 mL 20% IVLE 2x/week)
- Triene:Tetraene ratio to evaluate for EFAD (>0.2 consider EFAD)
38
Starting/Stopping PN
- Increase dextrose and lipid amounts over several days and assess tolerance (glucose < 180, TGA < 250)
- Do not abruptly D/C: could lead to hypoglycemia and other electrolyte shifts
39
Cycling PN
- Provide same PN content over a shorter duration
- Common in long-term of home TPNs
- Typically goal to run over 12-14 hours (initiate on continuous to transition to goal cycle rate)
- Titrate up/down over first and last hours to prevent hypo/hyperglycemia
40
PN Administration Pearls
- When D/C continuous TPNs, run 1/2 of prior rate for 2 hours before stopping
- Do not administer other drugs through PN IV line if possible (check compatibilities if necessary)
- Max hang PN for 24 hours and lipids for 12
- Filter PN with 0.2 micron filter, lipids with 1.2 micron filter
41
Monitoring PN Initially
- Daily weights and "ins and outs"
- Capillary glucose every 4-6 hours (can space out more when/if stable)
- electrolytes at baseline then daily of QoD (2x per week once past 1-2 weeks of PNs)
- LFTs and TGAs at baseline, then after 1-2 days of TPNs, then weekly
42
2-in-1 Products
- Dextrose and AA in same PN bag
- EX: Clinimix bags, Clinimix E has electrolytes
- [Peripherally run]: 4.25/5 %
- [Centrally run]: 4.25/10 or 5/15%
43
3-in-1 Products
-Dextrose, AA, and lipids all in same bag
| Ex: Kabiven
44
Combination Product Requirements/Limitations
-Require activation to mix the components together before infusing
- Limitations
- Macro/micro contents must be appropriate for patient to use
- Not appropriate for patients with abnormal electrolytes or large/small macro needs
45
Outpatient PNs
- More common to go home on PN with home infusion companies
- Can do 3 or 2-in-1,, 3 is easier but many require custom formulations and use 2-in-1
- Cyclic PN over short duration is easier at home and often run overnight
46
Pharmacist/Dietician Roles in Hospital
Pharmacist
- Work with dietician to manage PN
- Understand malnutrition implications
- Monitor fluid and electrolyte status
- Manage PN ingredient shortages
Dietician (RD)
- Complete nutrition assessments
- Aid in diagnosis of malnutrition'
- Manage EN
- Work with PharmDs to manage PN
