Fundamentals of Nursing Q 531
The two blood vessels most commonly used for TPN infusion are the:
A. Subclavian and jugular veins
B. Brachial and subclavian veins
C. Femoral and subclavian veins
D. Brachial and femoral veins
Correct Answer: A. Subclavian and jugular veins
Total Parenteral Nutrition (TPN) requires the use of a large vessel, such as the subclavian or jugular vein, to ensure the rapid dilution of the solution and thereby prevent complications, such as hyperglycemia. TPN is a mixture of separate components that contain lipid emulsions, dextrose, amino acids, vitamins, electrolytes, minerals, and trace elements. TPN composition should be adjusted to fulfill individual patients’ needs. The main three macronutrients are lipids, emulsions, proteins, and dextrose.
Option B: Total parenteral nutrition is not administered through a peripheral intravenous catheter (Peripheral Parenteral Nutrition, PPN) because it has high osmolarity. PPN osmolarity needs to be less than 900 mOsm. The lower concentration necessitates larger volume feedings, and high-fat content is necessary. High osmolarity irritates peripheral veins; hence TPN is given through central venous access. PPN is used to provide additional nutrition to patients with functional gut and enteral feedings.
Option C: Historically, total parenteral nutrition (TPN) has been administered by the central venous route because of the rapid development of thrombophlebitis when TPN solutions are administered into peripheral veins. The insertion and placement of central venous catheters are, however, associated with morbidity and mortality and is the main cause of TPN-related complications.
Option D: The brachial and femoral veins usually are contraindicated because they pose an increased risk of thrombophlebitis. By avoiding central venous catheterization, TPN can be made safer. Current awareness about the pathophysiology of peripheral vein thrombophlebitis and the use of a number of techniques that prevent or delay the onset of peripheral vein thrombophlebitis means it is now possible to administer TPN via the peripheral route.