Ultrasound-Guided Out-of-Plane Versus In-Plane Radial Artery Cannulation in Adult Cardiac Surgical Patients.

OBJECTIVES: The primary objective was to compare the rate of first-pass radial arterial cannulation using out-of-plane ultrasound guidance with in-plane imaging. The secondary endpoints were a comparison of the number of times the cannula was redirected, the number of attempts, the number of skin punctures, the incidence of hematoma, the time to completion of the cannulation procedure, and the number of failed attempts between the 2 ultrasound imaging techniques. DESIGN: A prospective, randomized, observational study. SETTING: A tertiary cardiac care center. PARTICIPANTS: Adult patients undergoing elective cardiac surgery. INTERVENTIONS: Radial artery cannulation with ultrasound guidance. MEASUREMENTS AND MAIN RESULTS: Eighty-four adult patients scheduled for elective cardiac surgery were randomly assigned to the out-of-plane ultrasound group (group I, n = 42) or the in-plane ultrasound group (group II, n = 42) for left radial artery cannulation. A linear ultrasound probe was used to identify the radial artery. In each approach, the number of times first-pass success was achieved, the number of times the cannula was redirected, the number of skin punctures, the incidence of hematomas, and the number of failed attempts were recorded. The first-pass success rate was greater in the in-plane ultrasound group and was statistically significant (p = 0.007). In the out-of-plane ultrasound group, a larger number of patients needed redirection of the cannula (p = 0.002). The number of patients in whom the skin needed to be punctured more than once was greater in the out-of-plane ultrasound group compared with the in-plane ultrasound group (p = 0.002). The incidence of hematoma formation and time to completion of the technique were similar in both groups (p = 0.241 and p = 0.792, respectively). CONCLUSIONS: In-plane ultrasound guidance appeared to be superior for achieving a higher first-pass success rate more often with minimal redirections and skin punctures compared with out-of-plane ultrasound guidance.