Randomized Controlled Trial of Ultrasound versus Palpation Method for Arterial Cannulation in Infants Less Than 24 Months of Age

Introduction: Ultrasound guided peripheral arterial cannulation may increase success as the small diameter vessel can be visualized.Fewer attempts at arterial cannulation may reduce local vessel damage.However even the current small ultrasound probes provide additional bulk in a small area and palpation method may be preferred.Aim: To determine if ultrasound guided peripheral arterial catheter insertion results in fewer attempts, shorter time to cannulation and cost savings compared to palpation method in children <2 years of age.Methods: Patients ≤ 24 months scheduled for elective surgical procedures where arterial cannulation was planned were eligible for recruitment.Forty patients were randomized to receive either Ultrasound Assisted (US) or palpation method.The primary endpoint was time to successful cannulation between two groups using intention to treat analysis.After 3 failed attempts, providers could switch to alternative method.Secondary endpoints were number of attempted sites, number of attempts and cost of equipment.Results: Average weight of patients was 6.14 kg (95% CI 4.9-7.4kg) for the US group and 5.5 kg (95% CI 4.1-6.9)for the palpation group.There was no age difference between groups.The initial randomized method was successful in 33/ 40 patients (17/ 20 Ultrasound and 16/ 20 Palpation method).Crossover to the other method resulted in an additional 4 ultrasound successes and 3 palpation successes.There was no difference in technique for rates of initial randomized method of success or time to successful insertion.Cost savings in disposable equipment were demonstrated.Conclusions: For infants and small children, ultrasound and palpation methods for arterial cannulation are similar with respect to time to secure arterial access.