TOTAL PARENTERAL NUTRITION (TPN) ADMINISTRATION

TOTAL PARENTERAL NUTRITION (TPN)

 TPN is administered through central access when the client requires a large concentration of carbohydrates ( higher than 10% glucose concentration)

The subclavian or internal jugular veins are used when TPN is a short term intervention (shorter than 4 weeks)

When TPN is anticipated for an extended period ( longer than 4 weeks ), a more permanent catheter, such as peripherally inserted central catheter (PICC) line, a tunnelled catheter, or an implanted vascular access device is used.

Peripheral parenteral nutrition (PPN)

• Peripheral parenteral nutrition is administered through a peripheral vein, typically in the arm
• Peripheral parenteral nutrition is used for short periods ( 5 to 7 days ) and when the client needs only small concentrations of carbohydrate, fats and proteins.
• Peripheral parenteral nutrition is used to deliver isotonic or mildly hypertonic solutions: the delivery of highly hypertonic solutions into peripheral veins can cause sclerosis, phlebitis, or swelling.

COMPONENTS OF PARENTERAL NUTRITION 

1. Carbohydrates

• Mainly in the form of dextrose (glucose) with concentrations ranging from 5% to 70%
• The strength of the dextrose solution prescribed depends on the client"s nutritional needs and on protocols.
• Typically provide 60% to 70% of caloric (energy) needs.
• Dextrose provides 3.4 kcal/g

2. Amino acids 

• concentrations range from 3.5% to 20%; lower concentrations are most commonly used for PPN and higher concentration are most often administered through a central vein.
• Amino acid solutions provide approximately 4 kcal/g of protein
• About 15% to 20% of total energy needs should come from protein 

3. Fat emulsion (lipids)

• Provide up to 30% of caloric (energy) needs
• Available in concentration of 10% , 20% and 30% providing 1:1, 2.0, 3.0, kacal/mL, respectively
• Provides non-protein calories   and prevents or corrects fatty acids deficiency
• Lipid solutions are isotonic and therefore can be administered through a peripheral or central vein.
• Most fat emulsions are prepared from soybean or safflower oil with egg yolk to provide emulsification; the primary components are linoleic, oleic, palmitic, linolenic, and stearic acids.
• Lipids contain egg yolk phospholipids,  and should not be given to clients with egg allergies.
• Glucose intolerant clients with diabetes mellitus may benefit from receiving a large percentage of their PN from lipids: this can help control blood glucose levels and lower insulin requirements caused by infused dextrose.
• Examine the bottle for separation of an emulsion into globules or for the accumulation of froth; if observed, do not use and return the solution to the pharmacy.
• Additives should not be put into the fat emulsion solution 
• Infuse solution initially at 1 mL/min, monitor vital signs every 10 minutes, and observe for adverse reaction for the first 30 minutes of the infusion; if signs of an adverse reaction occur, stop the infusion and inform the physician 
• If no adverse reaction occurs, adjust the flow rate to the prescribed rate.
• Monitor the serum lipids 4 hours after discontinuing the infusion.

Signs of an adverse reaction to lipids

• Chest and back pain
• Chills
• Cyanosis
• Diaphoresis  
• Dyspnea
• Fever
• Flushing
• Headache
• Nausea and vomiting
• Thrombophlebitis
• Vertigo

4. Vitamins

• PN solutions usually contain a standard multivitamin preparation to meet most vitamin needs and prevent deficiencies.
• Individual vitamin preparations can be added, as needed.

5. Minerals and trace elements: Commercial mineral and trace elements preparations are available in different concentration to promote normal metabolism.

6. Water: The amount of water needed in a PN solution is determined by electrolyte balance and fluid requirements.

7. Electrolytes: Electrolyte requirements for individuals receiving PN therapy vary, depending on body weight, presence of malnutrition or catabolism, degree of electrolyte depletion, changes in organ function, ongoing electrolyte losses, and the disease process.

8. Insulin: May be added to control the blood glucose level because of the high concentration of the glucose in the PN solution

9. Heparin: May be added to reduce the buildup of fibrinous clot at the catheter tip.

ADMINISTRATION

1. Types of solution

• Continuous PN
• Infused continuously over 24 hours
• Most commonly used in a hospital setting
• Less risk of complications
• Cyclic PN 
• Generally are 8 to 16 hours infusions that are usually given in night
• Allows clients requiring PN on long term basis to participate in activities of daily living without inconvenience of IV bag and pump set
• Monitor glucose levels closely
• preferable for use in home settings

2. Types of PN solutions 

• 2 in 1 solution
• Combines dextrose and amino acids in one solution
• An in-line filter (0.22 um)  is placed in the dextrose- amino acid line to ensure sterility 
• Lipids administered peripherally or central line
• Lipids are administered through separate tubing attached below the filter of the main IV administration because particles in the fat emulsion are too large to pass through the filter 
• Total nutrient admixture(TNA), 3- in - 1 solutions
• Combines dextrose, amino acids, and lipids in one solution 
• A 1.2 um filter or large should be used because the lipid particles are too large to pass through a 0.22- um filter

3. Discontinuing PN therapy 

• Gradually decrease the flow rate for 1 to 2 hours while increasing oral intake 
• Encourage oral nourishment.
• Record oral intake, body weight, laboratory results of serum electrolytes and glucose level

COMPLICATIONS

• Air embolism 
• Hyperglycemia
• Hypervolemia   
• Hypoglycemia
• Infection
• Pneumothorax