Ultrasound-guided regional anesthesia: how much practice do novices require before achieving competency in ultrasound needle visualization using a cadaver model.

BACKGROUND AND OBJECTIVES: Ultrasound needle visualization is a fundamental skill required for competency in ultrasound-guided regional anesthesia. The primary objective of this study using a cadaver model was to quantify the number of procedures that novices need to perform before competency, using a predefined dynamic scoring system was achieved in ultrasound needle visualization skills.

METHODS: Fifteen trainees, novices to ultrasound-guided regional anesthesia, performed 30 simulated sciatic nerve blocks in cadavers. After each procedure, a supervisor provided feedback regarding quality-compromising behaviors. Learning curves were constructed for each individual trainee by calculating cusum statistics. Trainees were categorized into those who were proficient, not proficient, and undetermined. A mathematical model predicted the number of procedures required before an acceptable success rate would be attained. Logistic regression was used to identify factors associated with success.

RESULTS: There was wide variability in individual cusum curves. The mean number of trials required to achieve competency in this cohort was 28. Trainees were categorized as proficient (n = 6), not proficient (n = 5), and undetermined (n = 4). With each subsequent procedure, there was a significant increase in the likelihood of success for trainees categorized as not proficient (P = 0.023) or undetermined (P = 0.024) but not for trainees categorized as proficient (P = 0.076). Participants recruited later in the study had an increased likelihood of success (P < 0.001).

CONCLUSIONS: Trainees became competent in ultrasound needle visualization at a variable rate. This study estimates that novices would require approximately 28 supervised trials with feedback before competency in ultrasound needle visualization is achieved.