Ultrasound-Guided PICC Insertion: Complete Procedural Guide

Ultrasound guidance for PICC insertion is the standard of care per INS 2021 and virtually universal in professional PICC practice. It dramatically reduces complications: first-attempt insertion success rates increase from approximately 70% (landmark) to >95% (US-guided), inadvertent arterial puncture rates drop from ~5% to <1%, and catheter-to-vein ratio can be accurately assessed before catheter selection.

This guide focuses specifically on the ultrasound components of PICC insertion — vein survey, basilic vein cannulation technique (long-axis preferred), guidewire confirmation, and integration with ECG tip guidance.

Parent guide: Ultrasound-Guided Vascular Access: Complete Reference

Pre-Insertion Vein Survey

A systematic pre-insertion US survey of both upper extremities is the most valuable pre-PICC assessment tool. Performed before consent, before equipment setup, and before skin preparation.

Survey Protocol

Equipment: Linear US probe (10–15 MHz), non-sterile gel, tourniquet.

Patient position: Supine, arm abducted 45–90°. Apply tourniquet to mid-upper arm.

Scan each vein bilaterally (if no laterality contraindication):

Basilic vein at mid-upper arm: transverse view; measure inner lumen diameter; assess compressibility; check for thrombosis (incompressibility, intraluminal echogenicity)
Brachial veins: identify adjacent to brachial artery; measure
Cephalic vein: lateral upper arm; measure
Axillary vein: scan proximal to the basilic entry point; confirm patency

Document for each target vessel:

Vessel name
Diameter (mm)
Depth from skin surface (mm)
Presence of thrombus: yes/no
Compressibility: complete/partial/absent

What to Look for in the Survey

Adequate PICC target:

Diameter ≥3 mm (preferred ≥4 mm)
Compressible (no thrombosis)
No adjacent artery in immediate proximity to planned needle path
Accessible at a stable site (away from flexion points)

Disqualifying findings:

Non-compressible vessel (DVT) — do not place PICC in a vessel with DVT
Diameter <2.5 mm — catheter-to-vein ratio will be excessive for any standard PICC
Superficial thrombophlebitis or skin infection at planned insertion site

Side selection: Right arm preferred (direct path to SVC without navigating left brachiocephalic curve). If bilateral options are equivalent, choose right. If right side has smaller vessels, contraindication, or DVT, proceed with left.

Catheter-to-Vein Ratio Assessment

Once target vein is identified:

Measure the vein inner lumen diameter in transverse view at the planned insertion site
Identify the smallest-gauge PICC that meets clinical lumen count requirement
Check manufacturer’s outer diameter for that catheter
Calculate: (Catheter OD / Vein inner diameter) × 100 = catheter-to-vein ratio (%)
Target: ≤45%

Example: 4 Fr double-lumen PICC (outer diameter ~1.7 mm) in a basilic vein measuring 4.5 mm inner diameter: 1.7 / 4.5 × 100 = 38% ✓ (acceptable)

If ratio exceeds 45%, choose a smaller PICC or target a larger vein; reconsider whether single-lumen catheter is sufficient.

Long-Axis (In-Plane) Technique for Basilic Vein Cannulation

Why Long-Axis for PICC

For PICC insertion — unlike peripheral PIV where speed and a small footprint are priorities — the long-axis technique is preferred because:

The needle must advance a longer path to the basilic vein (often 1–3 cm deep)
Needle tip visualization along the full path reduces inadvertent vessel wall puncture
The brachial artery and median nerve are in close proximity; real-time tip confirmation is safer
After vein entry, the guidewire advancement can also be confirmed in the same long-axis view

Technique

Setup:

Sterile probe cover and sterile gel (PICC is a sterile procedure with maximal sterile barrier)
Linear probe; set depth to 3–4 cm for most upper arm veins
Identify basilic vein in transverse view first to confirm patency and depth
Rotate probe to long-axis (parallel to vessel): the vessel appears as an elongated channel

Needle approach:

Enter skin from the short end of the probe footprint
Approach angle: 20–30° (shallower than PIV because the needle must travel a long path through tissue to reach a deep vessel)
The needle should appear as a bright hyperechoic line running along the vessel in the long-axis view

Advancing to the vessel:

Walk the needle through the tissue layers visible on screen: skin, subcutaneous fat, fascia, then vessel wall
The needle tip touching the anterior wall of the vessel produces a characteristic “tenting” of the vessel wall before puncture
Upon puncture, the needle tip appears to “pop” through the anterior vessel wall into the dark vessel lumen

Guidewire advancement (confirm on US):

After blood return: advance guidewire 15–20 cm
If available, confirm guidewire in vessel with US: the guidewire is highly echogenic (bright white) — it should be visible as a bright line within the vessel lumen on long-axis view
Critical check: Confirm the guidewire is in the vein, not the adjacent brachial artery — artery and vein are close in this region; confirm with compressibility and color Doppler

Integrating ECG Tip Guidance

After the catheter is advanced to pre-measured length:

ECG guidance systems (Sherlock 3CG, PALMS):

The ECG intravascular electrode (in the saline-filled catheter or guidewire) displays P-wave amplitude
Maximum upright P-wave = CAJ position
As catheter is advanced past the CAJ: P-wave begins to invert

Procedure:

Advance catheter to 2–3 cm short of pre-measured length
Activate ECG guidance system; observe P-wave on monitor
Slowly advance catheter until P-wave reaches maximum amplitude (equal to or greater than surface lead amplitude)
Note catheter position at maximum P-wave; this is the CAJ — confirm external catheter length
If P-wave begins to invert: catheter is in the RA — withdraw 1–2 cm

Documentation: Record P-wave characteristics in insertion note (e.g., “P-wave maximum at 42 cm; no inversion; ECG confirmation of CAJ position”).

For AF patients: ECG guidance is unreliable — obtain post-procedure CXR.

Managing Common Ultrasound-Specific Challenges

Losing the Vessel During Insertion

Problem: The vessel goes out of view during needle advancement.

Solutions:

Slow down — rapid probe movements cause the vessel to “escape” from the image
Maintain gentle probe pressure (too much pressure collapses the vein)
Use the vessel’s position landmarks to re-identify (the artery should be adjacent)
Scan in short-axis to re-identify the vein, then return to long-axis

Guidewire Coils at the Shoulder

Problem: Guidewire will not advance past the subclavian/cephalic junction or meets resistance at the shoulder.

This is not an ultrasound issue but occurs frequently with upper arm PICC. The cephalic vein has a torturous junction with the axillary vein. Solutions:

Internal rotation of the arm (turn palm to face bed)
Abduction of the arm to 90° or beyond
Have patient turn head toward the insertion arm (blocks IJ entry)
If resistance persists: withdraw guidewire 5–10 cm; reposition arm; re-advance

US-Guided Verification of Deep Vessel

Problem: Very deep target vein (>2 cm) — needle visualization is poor.