Comparing the Utility of Landmark-Palpation Guided to Ultrasound-Guided Teaching Methodologies for Subclavian Central Venous Access Using a Formalin-Embalmed Cadaver Model

Abstract

Background: Low-risk and realistic simulation strategies are needed to train clinical learners to perform hands-on invasive procedures. This follow-up study compares the utility of landmark-guided palpation-based to ultrasound-guided teaching techniques for subclavian central venous access using formalin-embalmed cadavers. Methods: The subclavian veins of 3 cadavers were imaged with ultrasound to evaluate vein patency before palpation-based venous access was attempted. Twenty-three first-year medical students were trained to access the subclavian vein using palpation-based techniques. Training involved ten minutes of didactic orientation and ten minutes of hands-on practical instruction using cadavers. Participant confidence was measured using a 10-point Likert scale on pre-and post-training questionnaires. Objective skills testing for each participant included quantifying the number of skin punctures and recording the time elapsed from first skin puncture to fluid flashback into the syringe. Data was analyzed using a generalized linear model (GLM) approach. Results: Participant confidence significantly increased following training in both ultrasound and palpation training groups across all questionnaire items (P<0.001). The ultrasound group had fewer skin punctures (P<0.001) and fewer failures (1) than the palpation group (6). Participants in the ultrasound group were more confident than those in the palpation group in their ability to locate the vein and select the optimal site for needle access (P<0.05). Conclusion: Formalin-embalmed cadavers provide a safe, stress-free, and effective means by which to train students in subclavian vein access using both palpation and ultrasound-based techniques. Repeated practice accessing and aspirating fluid from a cadaveric subclavian vein significantly increases trainee confidence, an essential factor in physician performance that may lead to fewer complications. Introducing this type of low-risk and hands-on practice may be beneficial for trainees before they attempt subclavian vein access on live patients.