24-gauge × 0.75-inch, or 24-gauge × 0.56-inch tapered

or nontapered cannula with stylet for larger to smaller

neonates, respectively

8. Antiseptic ointment (optional)

9. Arterial pressure transducer and extension tubing (see

Chapter 9)

10. 5-0 nylon suture with curved needle (optional)

11. Needle holder (optional)

12. Suture scissors (optional)

13. T connector primed with heparinized flush solution

14. Transparent, semipermeable dressing

Nonsterile

1. Equipment for transillumination (see Chapter 13) or

Doppler ultrasound

Use of Doppler ultrasound for localization of the

artery (9,10) and assessment of the adequacy of the palmar circulation has been described (11,12)

2. 0.5-inch, water-resistant adhesive tape

3. Materials for forearm restraint (see Chapter 4) for radial

or ulnar cannulation

4. A constant-infusion pump capable of delivering flush

solution at rate of 0.5 to 1 mL/h against back pressure

Chapter 31 ■ Peripheral Arterial Cannulation 183

Additional Equipment Required for

Cutdown Procedure

All equipment except mask must be sterile.

1. Gown and mask

2. 0.5% lidocaine hydrochloride in labeled 3-mL syringe

3. No. 11 scalpel and holder

4. Two curved mosquito hemostats

5. Nerve hook

6. 5-0 nylon suture

D. Precautions

1. When performing radial artery cannulation, always

check ulnar collateral circulation using the Allen test

(13–15) prior to undertaking the procedure. This test is

recognized to have limitations regarding accuracy and

interrater reliability (16), so careful observation for

signs of impaired distal perfusion is still required during

and after the procedure. Doppler ultrasound (11,12)

may also be useful in assessing collateral circulation.

2. When performing dorsalis pedis or posterior tibial cannulation, a modified Allen test can be performed by

raising the foot, occluding the dorsalis pedis and posterior tibial arteries, releasing pressure over one, and

monitoring for tissue perfusion within 10 seconds,

although this technique is less reliable than testing in

the hand (17).