Analysis of the radial and ulnar arteries using ultrasound and a vascular visualization device in children.

Background: Radial artery is the preferred site for cannulation. Recently, the ulnar artery was chosen as an alternative in adults.

Aims: We aimed to measure the diameter and depth of the ulnar and radial arteries using ultrasound, and our secondary purpose was to evaluate their anatomical position using a near-infrared transcutaneous illumination device.

Methods: Forty-eight children (age range: 0-144 months) were assigned to the following groups: group Infant (aged <12 months), group Preschool (aged ≤12 to <72 months), and group School (aged ≥72 months). The diameter, depth, and position of the ulnar and radial arteries were compared between groups.

Results: There was no significant difference between the diameters of the ulnar and radial arteries. In group Infant, group Preschool, and group School, mean diameters of the ulnar artery were 1.27 ± 0.15 mm, 1.62 ± 0.27 mm, and 2.03 ± 0.28 mm, respectively, and the radial artery were 1.29 ± 0.15 mm, 1.69 ± 0.27 mm, and 2.06 ± 0.29 mm, respectively. The corresponding differences between the diameters of ulnar and radial arteries were -0.02 mm, -0.07 mm, and -0.02 mm [95% CI -0.16 mm to 0.12 mm, -0.25 mm to 0.11 mm, and -0.25 mm to 0.21 mm; p = .776, p = .411, and p = .852]. In groups Preschool and School, the ulnar artery was at the recommended depth of 2-4 mm for arterial cannulation compared with the radial artery. In the Infant, Preschool, and School age groups, the ulnar and radial arteries were at the recommended depth of 2-4 mm for arterial cannulation in 70.0%, 100.0%, 93.8%, and 80.0%, 65.0%, and 50.0% of the cases, respectively. (difference: -10.0%, 35.0%, and 43.8%, 95%; CI -43.4% to 23.4%, 14.1% to 55.9%, and 19.4% to 68.1%, respectively).

Conclusions: The ulnar artery can be considered a promising alternative to the radial artery for facilitating arterial cannulation in children.