Learning process and improvement of point-of-care ultrasound technique for subxiphoid visualization of the inferior vena cava

Background Medical residents' training in ultrasonography usually follows the recommendations of the American College of Emergency Physicians (ACEP), even though these do not provide specific technical guidelines. Adequate training is considered to require 25 practical iterations in the majority of ultrasound procedures. However, the effectiveness of this approach has not been verified experimentally. We set out to determine the number of repetitions required for an acceptable ultrasound procedure of the inferior vena cava (IVC), as an important and emerging ultrasound procedure in cardiology. Methods Using three human models, each of eight medical residents in the Emergency Medicine (EM) Program at the Universidad del Rosario performed 25 iterations of the recommended procedure, with image quality evaluation by an EM physician expert in the technique. Logistic regression analysis was used to determine the lowest number of repetitions required to achieve an adjusted probability of success of 80 and 90 %, respectively. Results We obtained 200 ultrasound images. The percentage success by each resident ranged from 52 to 96 %. There was no statistical significance in the relation between gender and success ( p = 0.83), but there was an association between year of residency and success ( p