FEN: Parenteral Nutrition II Flashcards
1
Q
List six nutritional components of PN formulations
A
- Carbohydrate
- Fat
- AAs
- Electrolytes
- Multivitamins
- Trace elements
2
Q
List two types of carbohydrates used in PN formulations
A
- Dextrose 70% (3.4 kcal/g)
2. Glycerol (or glycerin) 4.3 kcal/g. Used in premixed parenteral products.
3
Q
Give three examples of lipid emulsion products
A
- Intralipid 10-30%
- Smoflipid 20%
- Omegaven 10%
4
Q
Compare smoflipid and omegaven
A
- SMOFlipid contains Soybean, Medium chain triglycerides, Olive Oil, Fish Oil
- Omegaven contains Fish Oil
5
Q
AAs are available at __ to ___% and provide __ kcal/g
A
- 3-20%
2. Provide 4 kcal/g
6
Q
What is the kcal/g content of lipid emulsions?
A
- 10 kcal/g
7
Q
Electrolytes are added to PN to maintain ________ concentrations
A
Electrolytes are added to maintain physiologic serum concentrations
8
Q
___ and ___ are added to PN on the basis of recommended daily amounts
A
- Multivitamins
2. Trace elements
9
Q
List five steps for developing a central PN regimen
A
- Determine caloric requirements
- Determine fluid requirements
- Determine protein (AA) requirements
- Calculate remaining nonprotein calories and administer about 20-30% of total calories as lipid and the remainer as dextrose
- Estimate a daily maintenance amount of electrolytes, vitamins and trace elements
10
Q
What is hypocaloric, high protein feeding in EN and PN?
A
Involves the administration of about 80% of caloric requirements
11
Q
When can hypocaloric, high protein feeding be considered?
A
- Patients with obesity (BMI greater than 30)
EXCEPT in patients with: - Kidney failure requiring hemodialysis
- And patients with hepatic failure, these patients have increased protein and caloric requirements to maintain positive nitrogen balance.
12
Q
List three ways to estimate caloric requirements
A
- Simplified kcal/kg calculations
- Harris-benedict equation
- Indirect calorimetry
13
Q
How is the simplified kcal/kg calculation chosen and what weight is used?
A
- For BMI less than 30 uses actual body weight
2. BMI greater than 30 uses IBW or ABW
14
Q
What is the adjusted body weight equation?
A
Adjusted body weight = [(actual weight - IBW)*0.25) + IBW
In other words, add 1 lb to the IBW for every 4 lb the actual weight exceeds the ideal weight.
15
Q
What is the simplified kcal/kg calculation for BMI less than 30?
A
25-35 kcal/kg/day based on actual body weight
16
Q
What is the simplified kcal/kg calculation for BMI greater than 30?
A
- 11-14 kcal/kg using actual body weight OR
2. 22-25 kcal/kg based on IBW or Adjusted Body weight
17
Q
What is the BMI equation?
A
Weight in KG divided by the square of height in meters. (unit is kg/m2)
18
Q
What is the Harris-Benedict equation for Men?
A
Basal Energy Expenditure (BEE) = 66 + 13.7(Wt in kg) + 5(Ht in cm) - 6.8(age in yrs)
19
Q
What is the Harris-Benedict equation for women?
A
Basal Energy Expenditure (BEE) = 655 + 9.6(Wt in kg) + 1.8 (ht in cm) - 4.7 (age in years)
20
Q
When is indirect calorimetry most commonly used?
A
Critically ill patients
21
Q
Fluid requirements based on simple ml/kg/day calculations are in the range of what? (ml/kg and total fluid) (used for what patients?)
A
- 30-35 mL/kg/day or 2500-3500 mL/day
2. For patients without fluid restriction
22
Q
Daily fluid requirements for patients without fluid restrictions are to maintain urine output in the range of what?
A
0.5-2 mL/kg/hour
23
Q
Fluid requirements for patients with fluid restrictions should be _______
A
Individualized
24
Q
Do not use PN for fluid _____ but for ________ fluid only
A
- Replacement/resuscitation
2. Maintenance
25
List three broad categories of calculations for determining protein (AA) requirements on basis of BMI
1. BMI less than 30
2. BMI of 30-40
3. BMI greater than 40
26
What is AA requirement for BMI less than 30? (hint: 3 categories)
1. 0.8-2 g/kg/day on the basis of actual body weight, based on stress level.
2. Maintenance 0.8-1 g/kg/day
3. Moderate stress 1.3-1.5 g/kg/day
4. Severe stress 1.5-2 g/kg/day
27
What is AA requirement for BMI 30-40?
2 g/kg/day based on IBW
28
What is AA requirement for BMI greater than 40?
1. 2.5 g/kg/day based on IBW
29
What is AA protein restriction level for patients with kidney dysfunction without dialysis?
1 g/kg/day
30
What is AA protein restriction level for patients with kidney failure with dialysis? (intermittent hemodialysis and continuous renal replacement therapy)
1. Intermittent hemodialysis: 1.2-1.5 g/kg/day
| 2. CRRT 1.5-2.5 g/kg/day
31
Calories from protein (___ kcal/g) should be included in the _____ to prevent overfeeding
1. 4 kcal/g
| 2. Should be included in total caloric provisions to prevent overfeeding
32
For 3-in-1 formulations, the final AA concentration should be around __% to provide _____ and ______
1. 4%
2. Adequate buffering capacity (e.g. pH)
3. And prevent lipid emulsion destabilization
33
Complete protein requirements can be provided on day ___ of PN
1. day 1 of PN
| 2. There is no need to slowly titrate up to recommended amount
34
After calculating nonprotein calories, administer about __% to __% of total calories as lipid and the remainder as ____
1. 20-30%
| 2. dextrose
35
Make sure the ____ rate of administration does not exceed the maximum rate of _____ rate of ____
1. Make sure the dextrose rate of administration does not exceed the maximum rate of
2. Hepatic oxidation rate of 4-5 mg/kg/minute
36
Hepatic oxidation of dextrose rate may be lower in _____ patients, so monitor for ___ and adjust amount of _____ provided.
1. Critically ill patients
2. Hyperglycemia
3. Adjust amount of dextrose provided if needed
37
If rate of dextrose rate needs to be lowered due to impaired hepatic oxidation, what is the maximum amount of lipid that can be administered?
A higher percentage of calories from lipid (up to 50-60% or 2.5 g/kg/day) can be provided for a short time in certain cases (e.g. hyperglycemia, hypercapnia)
38
Initial dextrose amounts can be in the range of ___ to ___ g/day
150-200 g/day
39
You may need to reduce dextrose to ___ to ___ g/day initially in patients with diabetes or stress-induced hyperglycemia
1. 100-150 g/day
40
In patients requiring reduced initial dextrose amounts, increase gradually during the first _ to __ days to goals if BG values are less than ____ to ___ mg/dL
1. 3-4 days
| 2. 140-180 mg/dL
41
Describe essential fatty acid deficiency and its prevention with PN (which fatty acids are essential, how much to supplement, how often to supplement)
1. The fatty acids linoleic acid (LA) and alpha-linolenic acid (ALA) must be supplied to the body
2. EFAD can be prevented by supplying 2-4% of total calories as lipid
3. Can administer lipid emulsion every 1-2 weeks.
4. This was a bigger problem in the past, as lipid emulsions did not become available in the US until the 70s.
42
Typical maintenance electrolytes range for central PN: Sodium
60-150 mEq/day (1-2 mEq/kg/day)
43
Typical maintenance electrolytes range for central PN: Potassium
40-80 mEq/day (1 mEq/kg/day)
44
Typical maintenance electrolytes range for central PN: Phosphate
10-40 mmol/day (or 15 mmol/1000 kcal)
45
Typical maintenance electrolytes range for central PN: Ca2+
10-15 mEq/day
46
Which calcium salt is preferred for addition to PN to prevent incompatibilities?
Gluconate preferred over chloride
47
Typical maintenance electrolytes range for central PN: Mg2+
8-20 mEq/day
48
Which magnesium salt is preferred for addition to PN to prevent incompatibilities?
Sulfate preferred over chloride
49
Typically, greater amounts of ___, ____ and ____ will be needed during the first few days of PN because of ___ shifts
1. Magnesium, phosphorus and K+
| 2. Because of IC shifts
50
__ and ___ salt forms can be adjusted as needed to maintain____ balance
1. Chloride and acetate salt forms
| 2. Can be adjusted as needed to maintain acid/base balance
51
There are commercial products containing standard trace elements. What are those elements? What is an example of that product?
1. Selenium
2. Chromium
3. Copper
4. Manganese
5. Zinc
6. MTE-5
52
What two trace elements may be indicated for additional supplementation in certain conditions?
1. Zinc
| 2. Selenium
53
What two trace elements may be indicated for restriction under certain conditions? Why?
1. Copper
2. Manganese
3. Prevent accumulation and toxicity because both undergo biliary elimination
54
Under what conditions is additional zinc supplementation warranted?
1. High-output fistulas
2. Diarrhea
3. Burns
4. Large open wounds
(acute, traumatic conditions)
55
Under what conditions is additional selenium supplementation warranted?
1. Chronic diarrhea
2. Malabsorption
3. Short-gut syndrome
4. Chronic illness
(chronic conditions)
56
Under what conditions are copper and manganese restricted? Why?
Severe cholestasis should have copper and manganese restricted to prevent accumulation and toxicity because both undergo biliary elimination
57
Parenteral multivitamin added ___ to PN
Daily
58
During shortages of parenteral vitamins, can reduce frequency of administration to ____ or can administer ___ vitamins daily
1. 3 times per week
| 2. Administer individual vitamin entities
59
What vitamin can be supplemented in patients with history of alcohol abuse? What is the supplement amount? What amount is typically contained in parenteral multivitamin?
1. Thiamine 25-100 mg
| 2. Normal MVI only contains 6 mg.
60
Why must you calculate the dextrose administration mg/kg/min?
To ensure it does not exceed hepatic oxidation
61
Why must you calculate the final concentration of macronutrients?
Final PN admixture should have certain final concentrations, which depends on total volume.
62
List the 8 steps in the order of mixing for manual compounding of PN
1. Add dextrose, AAs, sterile water
2. Add phosphate
3. Add other electrolytes (except Ca2+) and trace minerals
4. Mix well
5. Add Ca2+
6. Observe for precipitates or contaminates
7. Add lipid if 3-in-1 formulation
8. Add vitamins last
63
Why do you not mix dextrose and lipids directly?
Do not mix dextrose and lipids directly because the low pH of dextrose can destabilize the lipid emulsion
64
Why do you not add Calcium at the same time as the other electrolytes when compounding PN?
You need to mix phosphate well with other ingredients first to ensure phosphate is evenly distributed and to prevent precipitated with calcium
65
Why do you add vitamins last to PN?
To maintain potency
66
____ pH is associated with greater risk of Ca2+ and phosphate precipitation
Increasing pH (more basic)
67
If Ca2+ concentration is __ mEq/L or less and phosphate concentration is ___ mmol/L or less, the risk of precipitation is low.
1. Ca2+ concentration 6 mEq/L or less
| 2. Phosphate concentration is 30 mmol/L or less
68
Calcium ___ is more likely to precipitate with phosphate than calcium ____
Chloride is more likely to precipitate than gluconate.
69
The final concentration of AA should be at least ___ or greater to prevent Ca2+ and phosphate precipitation
2.5% or greater
70
List two ways AAs prevent Ca2+ and phosphate precipitation
1. AAs form soluble complexes with Ca2+ and phosphate
2. AAs provide a buffer system to maintain a lower pH of the PN in an acceptable range to prevent Ca2+ or phosphate precipitation
71
As the temperature ____, the risk of precipitation of Ca2+ and phosphate increases.
Increases
72
Describe the time frame of use between refrigerating and rewarming PN
1. PN should be refrigerated if not administered within 24 hours of compounding
2. If refrigerated, PN should be administered within 24 hours of rewarming.
73
In general, medications should/should not be added to PN?
Should not
74
List two ways to administer medications incompatible with PN
1. Separate IV catheter
| 2. Separate lumen of a central venous catheter
75
What medication is incompatible with PN because it precipitates with Ca2+?
Ceftriaxone
76
What medication is incompatible with PN because it can change the pH of PN?
Phenytoin
77
What medication is incompatible with PN because it destabilizes the lipid emulsion in 3-in-1 PN formulations?
Iron dextran. Trivalent cation destabilize the lipid emulsion in 3-in-1 PN formulations.
78
Medications containing ____ or ____ as diluents cannot be added to PN
1. Propylene glycol
| 2. Ethanol
79
List six medications which contain propylene glycol or ethanol as diluents
1. furosemide
2. diazepam
3. lorazepam
4. digoxin
5. phenytoin
6. etoposide
80
Only ____ insulin is compatible with being added to PN
regular insulin
81
What should you do if an incompatible IV drug is to be administered through the same IV catheter as the PN? (hint: what to do and how much to use)
1. PN should be stopped
2. Followed by a compatible flush before AND after drug administration
3. Volume of flush should be sufficient to clear the entire catheter of PN and of drug (about 10 mL)
