Explain parenteral nutrition. Give its indications, contraindications and complications.

How to lay out the answer. Follow the frame, then write it in your own words.

1 · Open in two lines. Parenteral nutrition is the feeding of nutrients directly into a vein. It is used when the gut cannot be used.
2 · TPN and PPN. TPN: central vein, concentrated, all needs. PPN: peripheral vein, dilute, short-term.
3 · Draw the routes. [Sketch: central line into the subclavian vein for TPN; arm vein cannula for PPN]
4 · Components. Dextrose 3.4 kcal/g, amino acids 4 kcal/g, lipid emulsion, electrolytes, vitamins, trace elements, water.
5 · Indications and contraindications.
- Indications: short bowel, obstruction, ileus, fistula, severe malabsorption.
- Contraindications: working gut, need under 5-7 days, unstable patient.
6 · Complications. Catheter (sepsis, thrombosis), metabolic (blood sugar, electrolytes, refeeding, liver), gut atrophy.
7 · At the bedside. Start small oral or tube feeds as soon as possible and wean off PN slowly.
8 · Close in one line. PN saves lives when the gut fails, but enteral feeding is always the first choice.

Scoring tip: End with a short enteral vs parenteral table; it often earns the last two marks.