Evaluation of the learning curve for ultrasound-guided distal radial artery cannulation in novices using a cumulative sum analysis: A prospective observational study

Distal radial artery (dRA) cannulation for invasive blood pressure monitoring under ultrasound (US) guidance is technically challenging. In addition, the learning curve for this technique has not yet been clarified. This study aimed to assess the learning curve for US-guided dRA cannulation among novice anesthesiologists. The first 180 patients who underwent US-guided dRA cannulation performed by 3 third-year anesthesiology residents between December 2022 and June 2023 were prospectively included in this study. The turning point (TP) was determined using the cumulative sum analysis curves. Novice anesthesiologists performed 20 procedures to master the learning curve, thereby reducing the overall procedure, identification, and cannulation times. Subgroup analysis revealed that the TP for the overall procedural time was 21, 17, and 22 procedures for the 3 operators. The TP for the identification time was 21, 17, and 23 for the 3 operators, and the TP for the cannulation time was 18, 11, and 22, respectively. The overall procedural time, identification time, and cannulation time were shorter in the post-TP group than in the pre-TP group. The first-attempt success rate and the number of needle attempts were higher in the post-TP group than in the pre-TP group. However, the incidence of puncture-related complications was not significantly different between the 2 groups. For novice anesthesiologists with limited experience, 20 procedures are required to overcome the learning curve of US-guided dRA cannulation. The present data may provide a theoretical basis for training for this technique in various institutions. This study was registered in the Chinese Clinical Trials Registry (registration number: ChiCTR2100043714, registration date: 27/02/2021).