Objective: To determine whether ultrasound guidance increases the success rates, decreases the complication rates, and shortens the time to successful radial artery catheterization in infants and small children.
Design: Randomized study.
Setting: Single university-affiliated hospital.
Patients: Infants and children weighing 3–20 kg, undergoing cardiac surgery for congenital heart disease.
Intervention: We randomly assigned the right and left radial arteries of patients undergoing arterial catheterization to ultrasound-guided technique versus the usual palpation technique.
Measurements: The primary study endpoints were the rates of successful cannulation at first and within three attempts. The secondary endpoints were time to radial artery identification, number of attempts for successful cannulation, and rate of complications.
Main Results: Compared with palpation, ultrasound-guided radial artery catheterization was successful in 76.3% versus 35.6% of first attempts and in 94.9% versus 50.8% of arteries after three attempts (both comparisons, p < 0.01). The median time [interquartile range] to identification of the arteries (18.5 seconds [11.25–27.25] vs 30 seconds [17.75–39.5]) was significantly shorter (p < 0.01), the number of attempts [interquartile range] at successful cannulation (1 [1–1] vs 2 [1–2]) was significantly fewer (p < 0.01), and the proportion of hematomas (5.1% vs 25.4%) was significantly lower (p < 0.01) in the ultrasound group than those in the palpation group.
Conclusions: In infants and small children, ultrasound-guided radial artery catheterization was more successful and expeditious than the usual palpation technique.