TPN on the NCLEX
Central line requirements, glucose monitoring, never stopping abruptly, lipids, and infection risk.
TPN is IV nutrition with two built-in exam traps: sugar and sepsis.
Line requirements
Standard TPN is hypertonic (dextrose above 10%) and requires a central line with the tip in a large central vein; peripheral veins scar and thrombose. Lower-concentration peripheral parenteral nutrition exists for short-term partial support. Use a dedicated lumen: no meds, no blood draws, no piggybacks through the TPN line. Run it on a pump, always.
Glucose control
Monitor blood glucose every 4 to 6 hours when starting, then per policy. Hyperglycemia is expected early; sliding-scale insulin or insulin in the bag manages it. Start TPN at a modest rate and titrate up; sudden full-rate dextrose overwhelms endogenous insulin. Watch for refeeding syndrome in the malnourished: phosphorus, potassium, and magnesium crash as feeding begins.
Never stop it abruptly
Abrupt discontinuation causes rebound hypoglycemia: the pancreas is still secreting insulin matched to a high dextrose load. Taper per orders. If the next bag is delayed or the line is lost, hang dextrose 10% in water (D10W) at the same rate until TPN resumes. If a bag arrives cold, let it reach room temperature; do not microwave it. A bag hangs no more than 24 hours.
Lipids and infection
Lipids: inspect the emulsion; do not hang it if it is cracked, separated, or oily-layered. Egg allergy is a contraindication flag for some emulsions. Lipids support fatty-acid needs and calories; infusion tubing for lipids changes more often per policy because fat feeds microbes. Infection: TPN is a premium bacterial growth medium on a central line. Fever in a TPN patient is a line infection until proven otherwise. Sterile technique for every bag and tubing change; tubing changes every 24 hours.
Frequently asked
TPN bag runs dry and pharmacy is an hour out?
Hang D10W at the ordered rate and notify. Never leave the patient with nothing running, and never bolus the next bag to catch up.
Blood glucose 220 on day 1 of TPN?
Common early. Treat per the sliding scale, report per parameters, and expect insulin adjustments in the bag or subQ.
Can I run antibiotics through the TPN lumen?
No. Dedicated lumen. Use another lumen or a peripheral line.
Quick check
Loading a question…
How ready are you right now?
10 real NCLEX questions, free, in your browser. See how close you are to ready and which subjects are costing you.
Try 10 questions free