Transcript Parenteral Nutrition

Parenteral Nutrition
NFSC 370
McCafferty
Definition
• TPN = Total Parenteral Nutrition
• Provision of nutrients intravenously
– Central
– Peripheral
• For patients who are already malnourished
or have the potential for developing
malnutrition and who are not candidates
for enteral nutrition
Advantage:
Potentially life-saving when GI tract
cannot be used or when oral/parenteral
nutrition cannot meet nutrient requirements
of patient.
Disadvantages:
• Costly
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• Long term risk of liver dysfunction,
kidney and bone disease, and nutrient
deficiencies
• .
Routes for Parenteral Nutrition
Central Venous Access
Central Parenteral Nutrition (CPN): Central Venous
Access
– Utilization of large central veins for the
administration of a patient’s complete nutrient
needs
– Preferred Route
– .
– Can deliver daily requirement for kcals,
protein, micronutrients in concentrated
volumes
Routes for Parenteral Nutrition
Central Venous Access
• PICC Line
– Peripherally inserted central catheter
– Benefits
• Access to central vein
• Can accommodate hypertonic fluids
• Lower risk of phlebitis than PPN
• Easier to insert than central line
Indications for TPN
– NPO for extended period
– Enteral nutrition support projected to
be inadequate for
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– Severe acute pancreatitis
– High output enterocutaneous fistulas
B. Contraindications
1.
2.
C. TPN Solution
1. Carbohydrate: Dextrose
a.
b. Most common concentrations: 50% and 70%
2. Protein: AAs
a.
b. Most common concentrations: 8.5% and 15%.
3. Lipid: IV emulsion
a. 10% solution =
b. 20% solution =
c. Concentrated source of kcals
d.
Lipid, cont.
e. Helps minimize hyperglycemia
f. Helps prevent respiratory acidosis (in
respiratory failure)
g. Need at least 10% of kcals from lipid to
prevent EFA deficiency
h. Excessive lipid administration may
suppress immune fx.
i. Often hung separately
j. Admixtures (3:1) becoming more
common
k. Potential source of vit. K: potential
problem if anticoagulants used
4. Vitamins
Daily MV in formula is standard
5. Electrolytes
– Start with standard amounts
– Adjust as needed
6. Common Medications
– Insulin
– H2 antagonists
– heparin
Peripheral Parenteral Nutrition
(PPN)
Utilization of peripheral veins for the
administration of nutrients
A. Indications for use:
1. PN necessary but no access to central vein
2.
3. Malnourished patients with frequent NPO for
procedures/tests
B. Contraindications:
1. Patient can be fed enterally
2. Pt. has weak peripheral veins
3.
C. Limitations
1. Peripheral site more prone to
inflammation/infection
2. Catheter may need to be repeatedly inserted
Poor choice for long-term nutrition
D. PPN Solution
1. Typically delivers 1400-2500 kcals/day
2. Carbohydrate: Dextrose (glucose)
3. Protein: AAs
4. Lipid: IV lipid emulsion
a. Concentrated source of kcals
b. Isotonic
c. Administered every day to protect
vein
Intravenous Solutions
Abbreviations:
D: dextrose
W: water
NS: normal saline (0.9% sodium chloride
solution)
D5W:
D10W:
D50W:
D70W:
Calculations
• Dextrose =
• AA =
• Lipid
– 10% lipid provides
– 20% lipid provides
– Lipid can be infused separately or with
dextrose and amino acid (admixture)
• TPN Orders – Several ways they can be
written. Examples:
– Per liter
• Example: 500 ml 70% dextrose, 500 ml 15% AA
@ 50 ml per hour, plus 250 ml 20% lipid/d
– Final concentration
• Example: 20% dextrose, 6% AA at 85 ml/hr plus
500 ml 10% lipid/d
– Per Day:
• 960ml 8.5% Aas, 960ml D50W at 80ml/hr, plus
250 ml 20% lipids q day
Example1: Figure out total kcalories and
protein grams per day from this per
liter order:
500 ml 8.5% AA/L
= 1 liter ‘admixture’
500 ml D50W/L
to be run@83ml/hr.
In this example, lipids
plus 500ml 10% lipid are hung separately
Protein Grams (per 500 mL):
Kcalories (per L):
Total volume:
Example 2:
Calculate total kcals and protein grams
provided in this per-day formula
960ml 8.5% AAs
960ml D50W
to run @ 80ml/hr (X 24h = 1920ml)
plus 250 ml 20% lipids q day
D50W:
8.5% AAs:
Lipids:
TPN Administration
A. Rate
1. Start slowly, especially w/dextrose. Allows
blood to adapt to increased
glucose/osmolality
2. Infusion pump is used to ensure proper
rate.
3. Example: Start at 40ml/hr x 24hr. Then
progress to 80ml/hr x 24h (equivalent to
increasing TPN by 1 liter per day), etc.
until goal rate has been reached or patient
intolerance is noted.
a. If rate is increased too quickly, hyperglycemia may result
b. Monitor tolerance: electrolytes, blood glucose,
triglycerides, ammonia, etc.
4. Introduce lipids gradually to avoid adverse reactions (fever,
chills, backache, chest pain, allergic reactions, palpitations,
rapid breathing, wheezing, cyanosis, nausea, and unpleasant
taste in the mouth)
5. When pt. is taken off TPN, rate must be tapered off
gradually to prevent hypoglycemia.
6. ( TPN by ½ X 2 hrs, then DC – usually sufficient to
prevent hypoglycemia)
7. PPN doesn’t need to be tapered off (uses more dilute
solution w/less dextrose)
B. Cyclic Infusion
1. TPN infused at a constant rate for only <24
hours/day (e.g. 12-14hr overnight)
2. Allows more freedom/normal daytime activity
3. Can be used to reverse fatty liver resulting from
continuous infusion
(Chronically high insulin levels may inhibit fat mobilization
 fatty liver)
4. Fewer kcals may be necessary to maintain N
balance (body fat better mobilized for energy)
5. Requires higher infusion rate: not all patients can
tolerate it.
Potential TPN Complications
A. Catheter or Care-Related Complications:
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Fluid in the chest (hydrothorax)
Air or gas in the chest (pneumothorax)
Blood in the chest (hemothorax)
Sepsis
Blood clot (thrombosis)
Infusion pump malfunctions
Myocardial or arterial puncture
B. Metabolic or Nutrition-related
Complications
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Hyperglycemia/Hypoglycemia
Dehydration/Fluid overload
Electrolyte imbalances
Hyperammonemia
Acid-base imbalance
Fatty liver
Bone demineralization
Transitional Feedings -- moving
from parenteral to enteral nutrition
A. Begin oral diet while tapering off TPN
1.
2.
B. Tube feeding while tapering off TPN
1. Rate of TF gradually increases as TPN rate
decreases
2. Remember that long term TPN without enteral
nutrients  atrophy of intestinal villi
C. Discontinue TPN when oral/enteral intake
provides
1. Consider possible apprehension to begin oral
intake
2. Poor appetite possible at first
3. Team members should provide support and
reassurance