Longitudinal axis approach versus longitudinal oblique axis approach for ultrasound-guided radial artery cannulation in adult patients: A comparative study

Background and Aims: Ultrasonography (USG)-guided arterial cannulation is a frequently performed procedure in the operating room and intensive care unit. Conventionally, longitudinal/in-plane and transverse/out-of-plane approaches are used for cannulation. Recently, a longitudinal oblique approach has been described with the advantage of wide visualization area. Hence, the present study was designed to compare the success of USG-guided radial artery cannulation in longitudinal oblique axis (LOA) and longitudinal axis (LA).Material and Methods: Seventy patients requiring radial artery cannulation were randomly allocated into two groups: group L (USG-guided radial artery cannulation in LA) and group O (USG-guided radial artery cannulation in LOA). Primary outcome was to assess cannulation success in the first attempt, while the secondary outcomes were to assess the number of attempts, failure rate, total cannulation time, and associated complications.Results: First-attempt success was higher in group O (80%) compared to group L (54.3%), with a P value of 0.022. In group L, 31.4% required two attempts and 5.7% had three attempts, while in group O, 14.3% had two attempts and 2.9% required three attempts. Group L failure rate was 8.6%, while it was 2.9% in group O. The mean total cannulation time (sec) for group L was 146.83 +/- 89.37 and group O was 63.89 +/- 26.277. No complication was observed with group O, while in group L, 9% had hematoma formation.Conclusion: The LOA approach for USG-guided radial artery cannulation has higher first-pass success rate, total success rate, and requires less cannulation time compared to the LA approach.