Ultrasound-Guided Peripheral IV for Difficult Access: DIVA Score and Technique

Difficult intravenous access (DIVA) affects approximately 10–24% of hospitalized patients who need peripheral IV placement. In these patients, standard landmark-and-palpation technique fails at high rates (>60% first-attempt failure for DIVA score ≥4), leading to multiple painful attempts, patient distress, vein damage, and unnecessary escalation to central access. Ultrasound-guided peripheral IV placement transforms this situation — achieving >80% first-attempt success rates in DIVA patients and reducing the progression to unnecessary PICC placements.

Parent guide: Ultrasound-Guided Vascular Access: Complete Reference

The DIVA Score: Predicting IV Access Difficulty

The DIVA (Difficult Intravenous Access) score, validated by Egan et al. (2012), identifies patients at high risk for failed standard PIV placement:

Criterion	Score
History of difficult IV access (patient reports or documented)	1
No visible veins in the antecubital fossa	1
No palpable veins in the antecubital fossa	1
Current or prior IV drug use	2

Score interpretation:

0–1: Standard PIV approach; low probability of failure
2–3: Consider ultrasound guidance for PIV or escalation to midline
≥4: High probability of failed standard PIV; escalate to US-guided PIV, midline, or PICC consultation

How to Apply DIVA Score in Practice

When a PIV order is received, perform a brief visual and palpation assessment before attempting placement
If antecubital veins are not visible and not palpable (DIVA ≥2), use ultrasound before attempting
Document DIVA score in the nursing note or IV assessment
DIVA ≥4 patients should go directly to US-guided approach — do not attempt standard PIV and document failures first (except in emergencies)

VEIN-Q score (an alternative validated tool) incorporates similar criteria and may be used at institutions that have standardized on that assessment.

Vein Selection for US-Guided PIV

Target Vessels (Preferred to Least Preferred)

Forearm veins (best for PIV):

Median antebrachial vein (central forearm)
Lateral forearm veins
Medial forearm basilic tributaries

Antecubital fossa veins (acceptable but position risk):

Median cubital vein
Median basilic vein
Note: AVs in the antecubital fossa are at high risk for positional occlusion with elbow flexion — use with awareness of this limitation

Upper arm veins (last-choice for PIV, but accessible with US):

Brachial vein (in proximity to brachial artery and median nerve — caution)
Basilic vein in the upper arm (suitable; larger but deeper)

Avoid:

Wrist and hand veins — higher phlebitis rate, patient discomfort, positional issues
Foot and leg veins (adults) — use only if all other options exhausted; high DVT risk
Antecubital when dexterity is required (elbow flexion occludes the IV)

Vein Criteria for US-Guided PIV

Minimum diameter: ≥3 mm (inner lumen diameter on US transverse view). Veins <3 mm in diameter are typically too small to reliably cannulate with a standard 20G PIV catheter using US guidance.

Depth: The target vein should be accessible to a standard-length PIV catheter:

For veins ≤0.6 cm deep: standard 3/4" to 1" PIV catheter is adequate
For veins 0.6–1.5 cm deep: use longer catheter (1.88" or 2.5" over-the-needle catheter, or long-line PIV)
For veins >1.5 cm deep: a standard PIV catheter will not remain in the vessel after the needle is removed (catheter length doesn’t reach the lumen); escalate to midline or PICC

Catheter-to-vein ratio consideration for US PIV: For longer-dwell access, ensure the vein is ≥2–3 mm larger than the catheter outer diameter to reduce phlebitis risk.

Catheter Length Requirements

This is the most commonly misunderstood aspect of US-guided PIV placement. When a vein is visualized with ultrasound, the depth determines which catheter length is appropriate:

The “one-third rule” (practical guideline): At least one-third of the catheter must remain within the vein after insertion for the catheter to remain intraluminal with normal patient movement. If a vein is 2 cm deep and you use a 1" (2.5 cm) catheter: 1 cm enters the vein, 1.5 cm is in tissue — inadequate retention. For 2 cm deep vein, use a 3-inch (7.5 cm) long-line catheter.

Catheter lengths available:

Standard PIV: 3/4" (2 cm), 1" (2.5 cm), 1.25" (3 cm), 1.5" (3.8 cm)
Extended-length peripheral catheters: 1.88" (4.8 cm), 2.5" (6.4 cm)
Long-line peripheral catheters: 3" (7.5 cm), 4.5" (11 cm)

Practical implication: For deep veins accessible only with ultrasound (typically 1.5–3 cm deep), you need extended-length catheters. Standard 1-inch PIV catheters are inadequate. Ensure your team has appropriate longer catheters in stock before implementing US PIV programs.

US-Guided PIV Technique (Short-Axis, Dynamic)

Equipment Setup

Linear US probe (7.5–15 MHz)
Non-sterile gel (for PIV — not a sterile procedure)
Target catheter with appropriate length for vessel depth
Tourniquet, alcohol wipe, tape/dressing, flush

Procedure

1. Apply tourniquet and scan:

Place tourniquet on upper arm for forearm/antecubital access
Apply gel to probe; scan in transverse (short-axis) view
Identify target vein: confirm compressibility, measure diameter and depth
Confirm no artery immediately adjacent to the planned needle path

2. Mark the target (optional):

Mark the skin overlying the center of the target vein with a skin marker
Note the depth to inform catheter length selection

3. Position probe and needle:

Hold probe with non-dominant hand
Advance needle from one side of the probe at 30–45° angle toward the vessel
The needle indicator on the probe side closest to the needle entry will help maintain orientation

4. Advance under real-time guidance:

Watch the US screen while advancing the needle
The needle appears as a bright dot on the transverse image
“Chase” the needle tip with the probe — keep the bright dot centered on the target vessel
When the bright dot is centered on the vessel and then “disappears” into the dark vessel lumen, the tip has entered the vessel

5. Confirm access:

Look for blood flashback in the catheter hub
Advance the guidewire or advance-on-needle catheter design into the vessel

6. Thread catheter:

While maintaining needle in vessel, lower the needle angle to 10–15° to thread catheter along the vessel
Advance catheter to appropriate depth (at minimum 2/3 of catheter length in vessel)
Remove needle; confirm no resistance to flush

7. Confirm position:

Apply saline flush: catheter should flush without resistance; no swelling at site
If available, confirm with long-axis US view showing catheter in vessel lumen

Common Pitfalls

Tracking shaft instead of tip: The most common error. Solution: jiggle the needle; trace the echogenic structure from probe entry to confirm it is needle.

Losing vessel from view: The vessel “jumps” off-screen when probe is tilted. Solution: practice probe stabilization; use smaller probe movements.

Insufficient catheter length: Standard 1-inch catheter used for deep vessel. Solution: always measure vessel depth before selecting catheter.

Arterial puncture: Usually from inadequate compressibility testing before needle insertion. Solution: always perform compressibility test; confirm non-pulsatile on color Doppler.

When to Escalate Beyond US-Guided PIV

US-guided PIV is not always the answer. Escalate to midline or PICC consultation when:

Vein diameter <3 mm or depth >2 cm with no appropriate extended catheter available
Three failed US-guided PIV attempts by experienced clinician
Therapy duration expected >5–7 days (PICC/midline more appropriate than repeated PIV access)
Therapy osmolarity or pH requires central access (no amount of peripheral access skill makes a PIV appropriate for TPN)
DIVA score ≥4 AND therapy duration >1 week AND no adequate veins on US survey → go directly to midline/PICC consultation without attempting PIV

See PICC vs Midline vs CVC Decision Guide and Evidence-Based Device Selection.

Related guides:

Related policies:

Vascular Visualization Technology

References

Egan G, et al. (2012). Prospective postmarket study to evaluate the DIVA score. J Vasc Access, 13(2):163–167.
Costantino TG, et al. (2005). Prospective experiment of US-assisted peripheral IV cannulation versus the standard technique. J Emerg Med, 29(3):299–302.
Stein J, et al. (2009). The ultrasound-guided insertion of midline catheters vs PICCs in the ED. J Emerg Med, 37(3):349–357.
Gorski LA, et al. (2021). INS Infusion Therapy Standards of Practice. J Infus Nurs, 44(Suppl 1).