BACKGROUND AND OBJECTIVES: Objective performance measurements are necessary during the learning process of anesthetic techniques. This study aimed at describing the cusum (cumulative sum) analysis to build subarachnoid puncture learning curves. METHODS: The successful subarachnoid space identification during the first attempt, in the first interspace approached, and the success of 275 spinal blocks performed by 5 residents during the initial six-month training period were used to build learning curves through the cusum analysis. Acceptable failure rates were taken from a sample of 264 spinal blocks performed by experienced anesthesiologists. The number of blocks needed for proficiency was calculated for each resident, for each attribute. RESULTS: A wide variability in the number of blocks needed for attaining proficiency was observed, depending on the resident or on the attribute. However, most residents attained proficiency after 50 blocks. All residents achieved a 90% success rate after 30 blocks. CONCLUSIONS: Cusum analysis may be used for objectively measuring performance during the learning phase of spinal anesthesia. A minimum of 50 blocks is required in order to attain proficiency in identifying subarachnoid space.
ANESTHESIOLOGY: teaching; ANESTHETIC TECHNIQUES, Regional: spinal block
