Probe Selection
Use a high-frequency linear probe (10-14 MHz). For PICC placement in the upper arm, the basilic or brachial vein is typically the target. Confirm the target is a vein (compressible, non-pulsatile) and measure its diameter. A vein-to-catheter ratio of 3:1 is ideal.
Short-Axis vs. Long-Axis Approach
Short-axis (transverse): Vein appears as a circle. Needle appears as a bright dot when it enters the lumen. Easier to learn. Use for initial cannulation.
Long-axis (longitudinal): Vein appears as a tube. Needle visible along its full length. Superior tip control. Use for position confirmation.
Access Guidance Settings by Machine
- All machines: 12-14 MHz, depth 1.5-3cm, gain moderate.
- MX7: Supports needle-guided brackets (Setup > Maintenance > Biopsy Guide).
- M8 Elite: Same bracket compatibility. iClear for vessel wall differentiation.
- Resona i9T: High frame rate for real-time needle tracking without lag.
- Consona N9: Standard B-mode guidance.
Confirming Arterial vs. Venous
Veins compress with light probe pressure and have non-pulsatile, respiratory-varying flow. Arteries resist compression and show pulsatile flow on color Doppler.
Frequently Asked Questions
What vein-to-catheter ratio?
3:1 or greater to reduce catheter-related thrombosis risk.
How to confirm artery vs. vein?
Veins compress with light pressure and have non-pulsatile flow. Arteries resist compression and show pulsatile flow.
Do I need a needle guide bracket?
Helpful for training. Experienced practitioners use freehand. MX7 and M8 Elite support multiple bracket models.