Nurse Roy is administering total parenteral nutrition (TPN) through a peripheral I.V. line to a school-age child. What is the smallest amount of glucose that is considered safe and not caustic to small veins, while also providing adequate TPN?
A. 5% glucose
B. 10% glucose
C. 15% glucose
D. 17% glucose
Correct Answer: B. 10% glucose
The amount of glucose that’s considered safe for peripheral veins while still providing adequate parenteral nutrition is 10%. A dextrose solution of 10% is used initially; if it is tolerated and central access is present, a more concentrated dextrose solution of up to 30 to 35% can be used if needed.
Option A: Five percent glucose isn’t sufficient nutritional replacement, although it’s safe for peripheral veins. Most patients receive dextrose concentrations of less than 20%. Once the fat and protein calories have been calculated, the balance of calories is provided as intravenous carbohydrate.
Option C: 15% of glucose through the peripheral veins may put the veins at risk for extravasation. Parenteral nutrition solutions are typically given via central venous catheters due to their high osmolarity and risks with extravasation if delivered peripherally. However, central venous lines are not without risk and consequently, infants requiring them are cared for in intensive care settings.
Option D: Any amount above 10% must be administered via central venous access. Hypertonic dextrose solutions (above approximately 600 mOsmol/liter) may cause thrombosis if infused via a peripheral vein. It is, therefore, advisable to administer such solutions via an intravenous catheter placed in a large central vein, preferably the superior vena cava.