Background: The current available literature is not unanimous in reporting the utility of short-axis and long-axis techniques for radial artery cannulation in both adults and children. This study was designed to compare short-axis out-of-plane (SA-OOP) and long-axis in-plane (LA-IP) techniques in ultrasound-guided radial artery cannulation in adults.
Methods: In this prospective randomized controlled trial, 150 adult patients of American Society of Anesthesiologists physical status I-III aged between 18 and 70 years were included. All patients were randomized into two groups (group SA-OOP) and (group LA-IP) of 75 each undergoing ultrasound-guided radial artery cannulation. The primary outcome was successful cannulation in the first attempt. Secondary outcomes included antero-posterior arterial diameter, skin-to-artery distance, ultrasonic localization time, cannulation time, no of attempts to cannulate artery, cannula insertion failure, and vascular complications.
Results: First-attempt arterial cannulation was successful in 80 % of patients in the SA-OOP group as opposed to 82.6 % patients in the LA-IP group (p = 0.67). The time to cannulate the artery was similar between the two groups, but the time to localize artery was significantly higher in the long-axis technique (p < 0.001).
Conclusions: The first-attempt cannulation success rate and cannulation time in adult patients are similar in ultrasound-guided radial artery cannulation with both short-axis as well as long-axis techniques. Trial registration Clinical Trial Registry of India (CTRI/2015/02/005552).
Keywords: Cannulation; Long-axis in-plane technique; Radial artery; Short-axis out-of-plane technique; Ultrasound.