To investigate the least practice number for novice anesthetists to learn the skill of ultrasound-guided indwelling of radial artery catheters, investigate the regular pattern of learning a new skill, so as to provide the reference basis for formulating the criterion of the qualifications to practice the ultrasound-guided indwelling of radial artery catheters and the skill training.

From May 2014 to November 2014, 9 post-graduate-1 year residents at Peking University Third Hospital completed a 6-month anesthesia rotation.Each resident select 25 patients in chronological order, 225 patients in total. To standardize the patient population, eligibility criteria of patients were those aged 18 to 80 years old and ASA class I or II, undergoing selective surgery. Time to perform the catheter indwelling and frequency of catheter indwelling were recorded. Cumulated the CUSUM (σ) for every attempt. Defined the respective and the overall learning curve, then use the functional equation to get the slope (K) for every attempt of indwelling. The slope is decreasing, when the slope changes into negative, the number corresponding to the changement is the minimum training experience necessary to succeed at this skill.

The 9 residents’overall catheter indwelling frequency was 14 when the slope (K)=0.

The learning curve indicated that the minimum number of training experience necessary to succeed in grasping this skill is approximately 14. It is a favorable and useful skill, what’s more, it can be learned quickly. So it is highly recommended in the clinical work.

Learning curve; Ultrasonography; Radial artery; Indwelling; Catheters; Anesthe siology; Resident