Pointers for beginners regarding Total Parenteral Nutrition or commonly, TPN.

2. Enteral nutrition
• the delivery of nutrients in liquid form directly into
the stomach, duodenum, or jejunum.
Parenteral nutrition
• administration of nutriment intravenously.
• nutrition which is delivered through a system other
than the digestive system.
Total Parenteral Nutrition (TPN)
• intravenous administration (via a central venous
catheter) of the total nutrient requirements of a
patient with gastrointestinal dysfunction.

3. Total Parenteral Nutrition
 Also called central parenteral nutrition (CPN) or
‘hyperal’ (hyperalimentation).
[The term ‘hyperalimentation’ is a misnomer because it
incorrectly implies that nutrients are supplied in excess
of needs].
 Large amounts of nutrients in a hypertonic solution can
be supplied via TPN. The catheter is surgically placed
into the superior vena cava.
 The reason that larger amounts of nutrients in a
hypertonic solution can be supplied via the superior
vena cava than with peripheral parenteral nutrition is
that the superior vena cava has a much larger diameter
and a higher blood flow rate, both of which quickly
dilute the TPN solution.

4. Definition
 Total parenteral nutrition (TPN) is a way of
supplying all the nutritional needs of the body by
bypassing the digestive system and dripping
nutrient solution/s directly into a vein.
 The administration of a nutritionally adequate
hypertonic solution (consisting of glucose, protein
hydrolysates, minerals, and vitamins) through an
indwelling catheter into the superior vena cava or
other main vein.
 Normally TPN is administered in a hospital, but
under certain conditions and with proper patient
and caregiver education, it may also be used at
home for long-term therapy (HPA).
 Ideally, TPN provides all the nutrients in the
correct quantities to ensure the body functions
normally.

5. Types of PN
 2 types of IV (or parenteral) nutrition.
 Partial parenteral nutrition (PPN) :
- given for short periods of time,
- to replace some of the nutrients required daily and
only supplements a normal diet.
 Total parenteral nutrition (TPN) :
- given to patients who can’t eat anything and must
receive all nutrients required daily through an
intravenous line.
 Home parenteral nutrition (HPN) : usually requires a CVC
(central venous catheter), which must first be inserted in a
fully equipped medical facility. After it is inserted, therapy
can continue at home.

6.  Parenteral nutrition is administered outside the
digestive tract, intravenously.
 Enteral nutrition encompasses oral and tube feedings
into the digestive tract.
 General rule : ‘if the gut works, use it’.
 The GI tract should be used if possible because it tends
to atrophy when not used. Gut bacteria can translocate
to the circulatory system through an atrophied GI tract
and increase the risk of infection.
 Peripheral parenteral nutrition (PPN) or
Peripheral venous nutrition (PVN)
nutrients are supplied via a peripheral vein, usually a
vein in the arm.

7.  PPN feedings usually supplement enteral feedings.
 Large amounts of nutrients cannot be supplied via a
peripheral vein, because these relatively small veins
cannot tolerate the rush of fluid into the vein that
occurs when a hypertonic solution is introduced into the
circulatory system.
 Body fluids have an osmolarity of about 300 mOsm.
The introduction of a hypertonic solution into a body
compartment will cause an osmotic gradient, resulting
in a fluid shift.
WHAT HAPPENS ?
 When a hypertonic solution is introduced into a small
vein with a low blood flow, fluid from the surrounding
tissue moves into the vein due to osmosis. The area
can become inflamed, and thrombosis can occur.

9. Osmolarity of Solutions
 Proteins and carbohydrates both contribute to
hypertonicity.
 Fat being isotonic, can be administered peripherally.
However, if the patient has delayed lipid clearance, the
use of lipids is contraindicated.
Infusion of Peripheral Nutrition
 The catheter is inserted into the arm vein of the
patient.
 Up to 1800-2500 kcal and 90g protein can be supplied
via PPN.
 This relatively high kcalorie/protein amount can be
supported peripherally only for a short period of time.

10. Recommended Rates
IBW
(kg)
Infusion rate
(cc/hr)
40 60 - 80
50 75 - 100
60 90 - 120
70 100 - 140
80 120 - 160
90 130 - 170

11. Purposes
 Used when individuals cannot or should not get
their nutrition through eating.
 Used when the intestines are obstructed, when the
small intestine does not absorb nutrients properly,
or a GI fistula (abnormal connection) is present.
 To ensure ‘Bowel rest’ (food does not pass through
the bowels).
[Bowel rest may be necessary in Crohn's disease,
pancreatitis, ulcerative colitis, and with prolonged
bouts of diarrhea in young children].

12. Purposes (contd’)
 Used for individuals with severe burns, multiple
fractures, and in malnourished individuals to
prepare them for major surgery, chemotherapy, or
radiation therapy.
 Individuals with AIDS or widespread infection
(sepsis) may also benefit from TPN.
 To rehydrate a patient post-viral illness.
 Patients with more serious and long term illnesses
and conditions may require months or even years
of intravenous therapy to meet their nutritional
needs. These patients may require a central
venous access port.

13.  A specialized catheter (Silastic Broviac or Hickman)
is inserted beneath the skin and positioned below
the collarbone. Fluids can then be injected directly
into the bloodstream for long periods of time. X-
rays are taken to ensure that the permanent
catheter is properly positioned.

15. Description
 The hyperalimentation solution is infused through
conventional tubing with an IV filter attached to remove any
contaminates.
 In adults, the catheter is placed directly into the subclavian
vein and threaded through the right innominate vein into the
superior vena cava.
 In infants and small children the catheter is usually threaded
to the central venous location by way of the jugular vein
(which is entered through a subcutaneous tunnel beneath
the scalp). Sometimes, the umbilical vein is used.
 Strict asepsis must be maintained because infection (sepsis
and septicaemia) is the primary risk.
 Once the catheter is in place, a CXR is done to make sure
the placement is correct.
 TPN solution is mixed daily under sterile conditions.

16. Description (contd’)
 Maintaining sterility is essential for preventing infection.
- The outside tubing leading from the bag of solution to
the catheter must be changed daily.
- The special dressings covering the catheter must be
changed every other day.

17. Contents of the TPN solution
 Are determined / individualized, based on the individual
variables (age, weight, height, and the medical
condition/s) .
 All solutions contain
- sugar (dextrose) for energy
- proteins (AA)
- fats (lipids)
- electrolytes (K+
, Na+
, Ca+
, Mg+
, Cl-
and phosphate);
these are essential for normal body functioning.
- trace elements (Zn, Cu, Mn and Cr)
- vitamins
- insulin (helps the body use sugar), may need to be
added.
 The TPN catheter is used only for nutrients;
medications are not added to the solution.

18. Contents of the TPN solution (contd.)
 For Adults: approx. 2 lts of TPN solution daily (varies
with the individual’s age, size and health).
 The solution should be allowed to be warmed to room
temperature before intravenous nutrition begins. The
solution is infused slowly at first to prevent fluid
imbalances, then the rate is gradually increased. The
infusion process takes several hours.
 Successful TPN requires frequent, often daily
monitoring of the individual's parameters [weight,
glucose levels, FBC, blood gasses, fluid balance, urine
output, waste products in the blood (plasma urea);
electrolytes];
 LFT & RFT may also be performed (special cases).

19.  Conventional IV solutions are….
- sterile water with small amounts of sodium (salt) or
dextrose (sugar) supplied in bottles or thick plastic
bags that can hang on a stand mounted next to the
patient's bed.
- Additional minerals, vitamins, or drugs can be added
to the IV solution by injecting them into the bottle or
bag with a needle.
- These simple sugar and salt solutions can provide
fluids, calories, and electrolytes necessary for short
periods of time.
- If a patient requires IV feeding for more than a few
days, additional nutrients like proteins and fats will be
included. The amounts of each of the nutrients to be
added will depend on the patient's age, medical
condition, and particular nutritional requirements.

20. 3-in-1 solution : glucose, proteins and lipids
Infusion:
 Medical Infusion pump:
- preferred method (sterile bag of nutrient solution + pump)
- pump infuses a small amount (0.1 to 10 mL/hr)
continuously in order to keep the vein open.
- feeding schedules vary, but normally the regimen ramps
up the nutrition over one hour, levels off the rate for a few
hours, and then ramps it down over a final hour (in order
to simulate a normal metabolic response resembling meal
time). This should be done over 12 to 24 hours rather than
intermittently during the day.
 Chronic PN is performed through a central IV catheter,
usually through the subclavian or jugular vein with the tip of
the catheter at the superior vena cava without entering the
right atrium.

21.  PICC line :
- Peripherally Inserted Central Catheter
- originates in the arm, and extends to one of the
central veins (such as the subclavian with the tip in
the superior vena cava).

22. Preparation
 Preparation to insert the catheter involves creating a sterile
environment. Other special preparations are not normally
necessary.
Aftercare
 During the time the catheter is in place, patients and caregivers
must be alert to any signs of infection (redness, swelling, fever,
drainage or pain).
Risks
 TPN requires close monitoring.
 Two types of complications can develop as a result of inserting
the catheter into a vein …
* Pneumothorax (infection, air in the lung cavities)
* Thrombosis (blood clot formation) subsequent to phlebitis.
 Metabolic and fluid imbalances
* occur if the contents of the nutritional fluid are not properly
balanced and monitored.
* Hypoglycemia – most common metabolic imbalance;
caused by abruptly discontinuing a solution high in sugar.

23. Risks (contd.)
 If the needle becomes dislodged, it is possible that the
solution may flow into tissues around the injection site
rather than into the vein.

25. NUTRITIONAL COMPONENTS
Amino Acid (AA) Solutions
 Protein is provided as a crystalline amino acid solution.
 500 ml bottles are standard.
 Solutions vary in amino acid concentration and
composition.
 The patient's protein needs determine the protein
concentration to use.
 The underlying disease state/s determines the
composition of amino acids to use.

26. Amino Acid Solutions/Concentrations
Amino acid (AA) solutions are generally available in the
following concentrations:
Percent Solution
(%)
AA Content
(g/100 mL)
3.0 3.0
3.5 3.5
5.0 5.0
7.0 7.0
8.5 8.5
10 10

27. Uses of Amino Acids
 AAs do not normally contribute to the kcalorie
requirement of the patient (although they have 4 kcals
per gram).
 Instead of being used for energy, amino acids should
be used for protein synthesis.
 To determine protein needs, a nonprotein kcalorie to
nitrogen ratio of 80:1 to 150:1 is used.
Nonprotein kcal:N ratio
• 80:1 the most severely stressed patients
• 100:1 severely stressed patients
• 150:1 unstressed patient

28. Dextrose Solutions
 Dextrose in solution has 3.4 kcals/gram (rather than 4
kcals/gram as in dietary carbohydrates), because a
noncaloric water molecule is attached to dextrose
molecules.
 Dextrose solutions come in different concentrations,
and the solution is abbreviated D(%solution)W.
Eg.: D50W indicates a 50% dextrose in water solution.

29. Dextrose Solution Concentrations
Dextrose solutions are available in the following
concentrations:
Percent soln.
(%)
Dextrose
(g/100 ml)
Notation
5 5 D5W
10 10 D10W
20 20 D20W
30 30 D30W
40 40 D40W
50 50 D50W
60 60 D60W
70 70 D70W

30. Infusion Rate of Dextrose
 Dextrose solutions should NOT be administered at a
rate higher than 0.36g per kg body weight/hour.
 This is the maximum oxidation rate of glucose.
 Excess glucose is converted to fat (which can result in
fatty liver).
 The conversion of carbohydrate to fat can cause excess
CO2 production (which is undesirable for patients with
respiratory problems).
Calculation Example :
For 60 kgs patient,
0.36 x 60 kg x 24 hr = 518 grams per day
(Dextrose infusion should not be greater than 0.36g/kg/hr).

31. Calculate the maximum dextrose tolerance for the
following weights
Weight (kgs)
70
80
90
100

32. LIPID EMULSIONS
 Lipids in PN are used as a source of essential fatty acids
(EFA) and energy.
 Lipid emulsions are composed of soybean and/or
safflower oil, glycerol, and egg phospholipid.
 Approx. 4% of total kcaloric intake should be EFAs to
prevent EFA deficiency.
 IV lipids are a good source of kcalories for
hypermetabolic patients, or patients with volume or
carbohydrate restrictions (as they are isotonic and
calorically dense).
 Lipids can provide upto 60% of non-protein calories.
 Usually composed of long chain triglycerides (LCT).
 In some cases, LCT + medium chain triglycerides
(MCT) may be beneficial.

33. F.Y.I.
Before lipids could be administered intravenously,
EFAs were provided by rubbing vegetable oil into the
patient's skin.
However, the efficacy of this procedure is
controversial, but it might be used in the case of patients
who cannot tolerate a lipid emulsion.

34. Lipid Emulsion Concentrations
 IV lipids come in concentrations of 10% or 20%
emulsions.
 The 10% emulsion contains 1.1 kcal/ml.
 The 20% emulsion contains 2 kcal/ml.
 Bottles come in 100 ml, 200 ml, 250 ml and 500 ml
volumes.
 500 ml of 10% lipids given once or twice a week is
generally enough to prevent EFAs deficiency.
 The lipid emulsion does not have to be mixed with the
AA and dextrose solutions in a single bag.

35. LIPID EMULSION ADMINISTRATION
 Lipid emulsions are not provided continuously (to
prevent hyperlipidemia). This gives the body a chance
to clear lipids from the blood.
 Usually, lipids are administered 1-2 times per week, but
can be provided daily, under stringent monitoring.
 Recommended infusion times are 4-6 hours for 10%
lipids and 8-12 hours for 20% lipids.
 12-24 hour infusions may be better tolerated by some
patients.
 A total of 2.5g lipids /kg per day should not be
exceeded.

36. Calculation example of maximum daily lipids
For a 60 kg patient,
2.5g x 60 kg = 150g lipid per day maximum
Calculate maximum lipid tolerance for the following
weights:
Weight (kgs)
70
80
90
100

37. Evaluation of Lipid Tolerance
There are three methods that can be used for evaluation
of a patient's lipid tolerance:
Test Dose
Serum Triglycerides
Plasma Turbidity

38. Test Dose Method
10% lipid infused @ 1ml/min for 15-30 min; if no
adverse symptoms, the rate can be increased to
80 - 100 ml/h
OR
20% lipid emulsion infused @ 0.5 ml/min for 15 –
30 min; if no adverse symptoms, the rate can be
increased to 40 - 50 ml/h

39. Serum Triglyceride Method
 Determine a baseline serum triglyceride level before
the emulsion is administered.
 Determine the triglyceride level 8 hours after the
infusion has been terminated.
 If serum triglycerides are normal or if they exceed
250 mg/day, lipids should be given at a reduced rate
or should be used only to prevent EFAs deficiency.
Plasma Turbidity Method
 Plasma is observed for turbidity.
 If turbidity is present, the lipid infusion must be
adjusted.
 Not the best method for testing lipid tolerance,
because hyperlipidemia can occur without turbidity.

40. Contraindications for Lipid Emulsions
 Abnormal lipid metabolism
 Lipid nephrosis
 Acute pancreatitis (if concomitant with or caused by
hyperlipidemia)
 Severe egg allergies
Use lipid emulsions with caution if the patient has:
 A blood coagulation disorder
 Moderate to severe liver disease
 Compromised pulmonary function

41. Administration of Lipids
 Lipids are administered in a bottle that is ‘Y-connected’
(‘piggybacked’) to the IV line containing AA/dextrose
mixture.
 Total nutrient admixtures (TNAs) also called ‘3-in-1
systems’, allow for lipids to be administered with AAs
and dextrose.

42. Mineral Increase Needs Decrease Needs
Potassium
•Potassium wasting meds
•Diuresis
•Anabolism
•GI losses (vomiting, diarrhea,
suction)
•Potassium sparing meds
•Renal failure
•Massive tissue destruction
Sodium •Diuretic use
•GI losses (above)
•Hepatic failure
•Congestive heart failure
Calcium •Pregnancy
•Pancreatitis
•Hypercalcemia
Phosphorus •Anabolism •Renal failure
Chloride •Metabolic alkalosis
•Nasogastric suction
•Metabolic acidosis
Magnesium
•Anabolism
•Mg wasting meds
•Hypokalemia
•Alcoholism
•GI losses (short bowel syndrome,
diarrhea, intestinal fistula)
•Renal failure

43. Mineral
State of Catabolism
Comments
Normal
(mEq)
Mild-Mod
(mEq)
Severe
(mEq)
Potassium 0.7 - 0.9 2.0 3.0 - 4.0 Give 5 - 6 mEq/g of N infused
Sodium 1.0 - 4.0 2.0 - 3.0 3.0 - 4.0
Calcium 0.22 0.3 0.4
0.25 m Eq/kg needed for calcium
equilibrium. Dependent on
simultaneous administration
of PO and Na, not N retention
Phosphorous 0.3 0.8 1.2 - 2.0
Needs related to nitrogen
retention which is related to
kcal intake. Give 15-25 mEq
PO per 1000 dex kcals.
Magnesium 0.3 0.3 - 0.4 0.6 - 0.8
Give 2 mEq per gram of N
infused.
Mineral needs (Amount per kg body weight)

44. Mineral Needs Based on Laboratory Data
Mineral Lab Value Daily need
Potassium
Above 4.8
4.0 - 4.8
3.5 - 3.9
Below 3.5
None
20 - 30 mEq
40 - 50 mEq
80 - 90 mEq
Sodium
Above 142
136 - 142
Below 136
None
25 - 50 mEq
50 - 100 mEq
Calcium
Above 10.5
8.0 - 10.5
7.0 - 7.9
None
4.5 mEq
9.0 m Eq
Phosphorous
Above 3.5
2.5 - 3.5
Below 2.5
None
15 mM
15 - 30 mM
Chloride
Above 104
101 - 104
98 - 100
Below 90
None
20 - 25 mEq
40 - 50 mEq
90 - 100 mEq
Magnesium 8.1 Eq

45. Trace Elements
 Requirements for standard trace element mixtures are
to be monitored and adjusted based on serum
concentrations.
 Iron can be given intramuscularly as needed.
• When transferrin levels are low, free iron increases and
can increase susceptibility to infections.
• Critically ill or malnourished patients often have no
bone marrow response to iron.
 Copper supplementation must be administered with
caution to avoid toxicity.
 Extra zinc may be needed by some patients to promote
wound healing.

46. Element Dose
Zinc 2.5 - 4.0 mg
Copper 0.5 - 1.5 mg
Iron 1.0 mg
Chromium 10 - 15 mcg
Manganese 0.15 - 1.8 mg
Iodine 1 - 2 mcg
Selenium 20 - 40 mcg

47. Vitamins
 The vitamin requirements for TPN patients are different
from non-TPN patients because absorption is not a
factor with TPN.
 When needs are increased for certain disease states,
single vitamin supplements can be added to the
solution.
 Serum vitamin levels can be monitored and dosage
adjusted accordingly.
 Vitamin preparations should be added to the TPN
solution just prior to administration to avoid losses from
light exposure.

48. Vitamin Supplementation Recommendations
Vitamin Adults Children Under 11 years
A (IU) 3300 3300 3300
D(IU) 200 200 400
E(IU) 10 10 7
Thiamin (mg) 3 3 1-2
Riboflavin (mg) 3.6 3.6 1.4
Pantothenic Acid
(mg)
40 40 17
Folate (mcg) 15 20 -
B-12 (mcg) 0.4 0.4 1.4
Biotin (mg) 5 5 1
C (mg) 100 100 80

49. THE END