Comparison of Success Rates of Different Methods of Ultrasound-Guided Radial Artery Cannulation (Short-Axis and Long-Axis Methods) Against the Traditional Palpatory Method: A Prospective Randomized Study

OBJECTIVE: Recent meta-analysis comparing the success rates of various methods of arterial cannulation in adult patients found heterogeneity in the available data. Hence, we did this study to evaluate and compare the success rate of palpatory method with that of ultrasound guided methods of radial artery cannulation. The aim is to compare the first-attempt success rate of the palpatory method with that of ultrasound-guided radial artery cannulation techniques, namely, the short-axis out-of-plane and the long-axis in-plane methods. METHODS: This is a prospective, randomized, parallel-arm study. Ninety patients aged from 18 to 50 years (presenting for various surgeries requiring radial artery cannulation for invasive blood pressure monitoring or frequent arterial blood gas analysis) were divided into 3 groups. Each group had one of the 3 techniques of radial arterial cannulation, namely palpatory, short-axis ultrasound method, and long-axis ultrasound method. The parameters analyzed were first-attempt success rate, number of attempts needed, cannulation time, need for crossover of technique, and incidence of complications. Multivariate analysis was done with one-way ANOVA, with Tukey's post hoc test. For categorical data, the chi-square test was used. The probability value of .05 was considered as a significant level. RESULTS: The first-attempt success rate was 76.7% in the long-axis method, 86.7% in the short-axis method, and 56.7% in the palpatory method. The short-axis method has been shown to have a shorter cannulation time, fewer attempts needed for successful cannulation, and lower need for crossover of techniques when the first 2 attempts fail. CONCLUSIONS: : We conclude that the ultrasound-guided short-axis method of radial artery cannulation is associated with higher first-attempt success rate compared to the traditional palpatory method.