The wire is really easy to see (WIRES): Sonographic visualization of the guidewire by novices

Abstract

Objective: To determine whether novices can distinguish between properly and improperly placed guidewires in a vascular access model after only minimal training. Methods: This was a prospective study involving trainees with no previous training in sonographic guidewire visualization. A vascular access model was created with guidewires positioned inside or adjacent to simulated veins. Subjects were taught to scan each wire to determine its location. Afterward, participants scanned a test model of five vein-wire pairs and recorded their answers as "inside," "outside," or "unsure." The test characteristics of sonographic guidewire localization were determined using actual wire location as the criterion standard. Results: Forty trainees (21 emergency medicine residents, 19 medical students) participated, and each examined five simulated veins. There were 156 true positives (intravascular wire correctly identified), 38 true negatives (extravascular wire correctly identified), 2 false negatives, 2 false positives, and 2 cases in which the participant marked "not sure," which were reclassified as false negatives. Test characteristics were sensitivity 97.5% (95% CI 93.3-99.2) and specificity 95.0% (95% CI 81.8-99.1). The overall accuracy was 97.0%. Conclusions: Sonographic guidewire visualization, a step recommended for ensuring proper vessel cannulation during central venous access, can be accomplished by novices with a high degree of accuracy. © Canadian Association of Emergency Physicians.