Background:

• Arterial line epidemiology: 10 million annually, forearm radial artery site most commonly used/least complications
• Cath lab literature in Europe
• Anatomy of forearm arteries and anatomical snuffbox
• Indications same as any arterial line

Why place a dRA line over fRA line?

• Benefits:
  • Antegrade hand perfusion
  • Lower rates of fRA occlusion: spares for future procedures
  • Comfort: Patient able to flex/extend wrist, or have wrist restraints
  • May not have fRA available: contractures of wrist/forearm, hematoma around it from previous attempts making it difficult
  • Leaves fRA for future attempts: “can always move more proximal” but now avoiding a brachial line which is higher risk for malperfusion

The literature for dRA:

• Some data suggest lower rates first pass success as compared to fRA (blind)
  • Other data (several ICU non-inferiority trials) suggest no difference; likely improve over time
• Significantly lower rates of fRA occlusion (traditionally ~30%)
• Lowower rates of hematoma, bleeding, and time-to-hemostasis: less area for hematoma to track
• Correlates well with fRA pressure and central pressures
• Less frequent loss of pressure waveform events

Placing the line:

• Similar to fRA line, except different site
• dRA is smaller than fRA, but not significantly; able to accept same size catheter as fRA (e.g., 5 Fr sheaths used for interventional procedures)
• Position arm in “holding a wine glass” position with towel roll
• Dynamic US guidance: practical tips on walking in needle tip

Complications:

• Similar to fRA line for the most part
  • Unique to dRA:
    • Avoid cephalic vein superficial to and radial veins/nerve beside
    • Avoid extensor pollicis longus and brevis tendons
    • Recommend going in anatomical snuffbox rather than dorsal hand encroaching upon princeps pollicis artery and through dorsal interosseous muscle

Summary:

• dRA lines are safe and feasible for arterial pressure monitoring in critically ill patients
• These may be more comfortable for patients, associated with less complications and less fRA occlusion, and spare fRA for future interventions
• An arterial line at this site allows continuous antegrade perfusion of hand
• Use anatomic snuffbox and US guidance

Please see Snuff said: anatomical snuffbox distal radial arterial lines for the win for more information on dRA.