Ultrasound guidance improves overall success of radial arterial line cannulation: Study

More than 10 million arterial lines are placed annually worldwide, many of which happen in the emergency department. Before the introduction of point-of-care ultrasound, landmark-guided palpation (LMGP) was considered standard of care.

Hence, Ryan C Gibbons and colleagues from the Department of Emergency Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania conducted the present study with the objective to compare ultrasound-guided (USG) and LMGP of radial arterial line cannulation by novice emergency medicine interns.

The authors carried out a single-center, prospective, randomized controlled trial of a convenience sample of adult patients who presented to an urban, university hospital with 100,000 visits annually. Forty patients were enrolled with 20 patients randomized to each group.

There was no funding for this study. Patients who required an arterial line were blindly randomized into LMGP or USG groups. Only novice emergency medicine interns, defined as interns with <15 previous placements, who were not blinded, performed the cannulation. Statistical analyses included t and Fisher exact tests.

The key findings were-

a. USG had a first-pass success of 75% vs. 0% for LMGP (p < 0.00001) and an overall success of 100% vs. 15% for LMGP (p < 0.00001), a mean of 1.30 attempts vs. 2.95 attempts for LMGP (a difference of 1.65; p < 0.0001), and a mean time for placement of 264 s vs. 524 s for LMGP (a difference of 260; p = 0.0025).

b. Of the failed LMGP, USG crossover was 100% successful with a mean of 1.37 attempts (95% confidence interval 0.58-2.16) and 180 s for placement (95% confidence interval 97.92-262.08). c. Five percent of LMGP had a complication vs. 0% for USG (p = 1.0).

Therefore, the authors concluded that " USG improved first-pass and overall success of radial arterial line cannulation while reducing time to access and attempts when used by novice emergency medicine interns."