How to place a IV catheter in a rat? - briefly
Insert a sterile 24‑G catheter into the lateral tail vein after warming the rat and flushing with heparinized saline, then secure with tissue glue and confirm patency by observing blood return. Maintain the catheter for up to 24 hours, monitoring for thrombosis or infection.
How to place a IV catheter in a rat? - in detail
Inserting an intravenous catheter into a laboratory rat requires preparation, anesthesia, aseptic technique, and careful catheter placement.
Begin with equipment assembly: a 24‑ to 26‑gauge catheter (or a polyethylene tubing with a 0.2 mm inner diameter), a 1 ml syringe, heparinized saline (10 U/ml), sterile gauze, surgical scissors, forceps, adhesive tape, and a heating pad. Prepare a sterile field and arrange all items within easy reach.
Induce anesthesia using an inhalant agent (isoflurane 2–3 % in oxygen) or an injectable cocktail (ketamine 80 mg/kg and xylazine 10 mg/kg, intraperitoneally). Verify the absence of pedal reflex before proceeding. Maintain body temperature at 37 °C with the heating pad throughout the procedure.
Expose the lateral tail vein. Apply a warm water bath (37–40 °C) to the tail for 2–3 minutes to dilate the vessels. Clean the skin with 70 % ethanol, then with sterile saline. Using fine forceps, gently separate the skin from the underlying vein without damaging the vessel wall.
Insert the catheter as follows:
- Load the catheter into the syringe, remove air bubbles, and attach the syringe to the catheter hub.
- Align the catheter tip with the vein’s longitudinal axis, bevel up.
- Advance the catheter bevel into the lumen of the vein at a shallow angle (≈15°).
- Once blood flashback appears, advance the catheter an additional 2–3 mm to ensure secure entry.
- Secure the catheter with a small strip of adhesive tape, leaving the hub accessible.
Flush the catheter gently with 0.1 ml heparinized saline to confirm patency and prevent clot formation. Observe for resistance or leakage; if present, reposition or replace the catheter.
Post‑procedure care includes monitoring the animal until full recovery from anesthesia, checking the catheter site for signs of bleeding or infection, and maintaining a sterile environment for any subsequent infusions.
Proper documentation of catheter size, insertion site, and any complications is essential for reproducibility and animal welfare compliance.