Teaching spinal ultrasound to anesthesiologists: How much hands-on experience is necessary to achieve competency?
Abstract Number: 190
Abstract Type: Original Research
Introduction: Spinal ultrasound (US) to facilitate lumbar spinals and epidurals has recently received much attention from anesthesiologists (1-3). There are only a few studies analyzing the learning curve of US-facilitated regional techniques, none of them are on spinal US.The purpose of this study was to determine the amount of teaching needed to achieve competency in spinal US.
Method: After REB approval, 18 anesthesiologists were recruited for this prospective cohort study. The participants were given reading material and a video presentation on spinal US, and attended a 45-minute lecture, as well as a 30-minute hands-on workshop 1 week later. They were then assessed individually, 1-2 weeks after the teaching session. The assessment was done on a live model, using a low frequency curved US probe (2-5mHz). The participants were asked to determine, at random lumbar spinal levels, the optimal insertion point, and the depth to the epidural space (20 attempts, 2 minutes per attempt). For each incorrect attempt, feedback was provided by an expert. Learning curves were constructed for the interspace assessment using the cumulative sum (CUSUM) method. The concordance correlation coefficient (CCC) was calculated to find the agreement between the US depth determined by the participant in their correct attempts, and the expert benchmarking. Statistical analysis was carried out using STATA
Results: Even though the correct interspace was found with an overall success rate of 74% (p25-75: 53-85%), only 5/18 participants achieved competence based on CUSUM (Figure 1). The number of attempts required to demonstrate this statistically ranged from 8 to 18. In 8/18 participants, more than 20 attempts would have been required to determine competence. The CCC for the US depth estimate was ≥ 0.4 in 8/18 participants, and ≥ 0.8 in only 2/8 participants.
Conclusions: Under the study conditions, almost half of the participants would require more attempts to achieve competence. The inter-individual variability in learning curves suggests that more training is needed based on individual performances. This model should serve as a guideline for the design of workshops, and to plan the effective teaching of spinal ultrasound assessment.
References: 1. J Clin Anesth 2002; 14: 169-75; 2. Anesth Analg 2007; 104: 1188-92; 3. Anesthesiol Clin 2008; 26: 145-58.