Comparison of two ultrasound-guided techniques for radial arterial cannulation in adults – Observational cross-sectional study

BACKGROUND AND AIMS: Short axis, out of plane (SAOOP) and long axis, in-plane (LAIP) are two approaches employed under ultrasound-guided radial arterial cannulation. Dynamic needle tip positioning (DNTP) is a recently introduced approach which integrates the features of both. METHODS: A total of 114 adult patients from American Society of Anaesthesiologists (ASA) I-IV were studied in this hospital-based cross-sectional study after getting Institutional Ethical approval, CTRI registration and prior written informed consent. The primary objective was to compare the success rates among LAIP and DNTP techniques. The radial arterial diameter and its depth were correlated to the success rates in both. Statistical analysis was done using SPSS version 23.0. RESULTS: Success rates were similar in both (P value-0.094). Ultrasonographic location time (in seconds) was shorter in DNTP (4.351 ± 0.9727) compared to LAIP (7.140 ± 1.0763) (P value-0.0001). The mean overall diameter and depth of radial artery (in mm) were found to be 2.36 ± 0.02 and 2.51 ± 0.12, respectively. Pearson’s correlation coefficient between cannulation time and diameter was found to be -0.602 (P value-0.0001) and with depth of the radial artery was 0.034 (P value 0.723). CONCLUSION: The success rates were similar in both techniques. Ultrasonographic location time of the radial artery was more in LAIP although cannulation time was similar in both. Cannulation time decreased with an increase in the diameter of radial artery but was unaffected by the depth of the radial artery.