Arterial Line Insertion (Micropuncture Kit) (Saumil Patel)

Last updated: February 9, 2026

A micropuncture kit contains a 10 cm catheter (with an internal dilator) and a 21-gauge, 7 cm needle.

A micropuncture kit with full sterile technique (including chlorhexidine gluconate [ChloraPrep], gloves, and towels) is often preferred when the artery is particularly calcified, as the needle provides better penetration than standard kits.

Procedure

The procedure follows standard Seldinger technique:

1. Identify the target artery using ultrasound.
2. Enter the artery with the needle.
3. Stabilize the needle at the skin and advance the wire.
4. Remove the needle while keeping the wire in place.
5. Advance the dilator over the wire (approximately 2 mm beyond the skin) to dilate the subcutaneous tissue without puncturing the artery further.
6. Remove the dilator and thread the catheter over the wire.