The effect of reversed screen orientation versus standard orientation in bedside ultrasound on vascular access skill acquisition: a cadaver study

Ultrasound-guided vascular access (USGVA) is an essential clinical skill, but novice learners often face difficulties in interpreting ultrasound images and achieving spatial alignment during procedures. To address this challenge, we hypothesized that using a reversed screen orientation could facilitate the learning process. Reversed screen orientation refers to an ultrasound image flipped in the transverse plane, producing a top-to-bottom mirror image by activating the "reverse" function on the ultrasound (US) device. We assumed that this configuration might help align the visual trajectory of the needle with the user's hand movements, potentially easing spatial perception during the early stages of learning.

The study was conducted in the Anatomy Laboratory of Ordu University Medical Faculty with 60 final-year medical students with no prior US experience. Participants were randomly divided into two groups (A and B), who performed femoral vein needle punctures on cadavers under US guidance with standard (Group A) and reverse (Group B) screen. Each group used both screen orientations across two attempts. Before the procedure, students received theoretical training. Data collected included demographic information, needle visibility, procedure duration, success rates, and complications. Statistical analyses were performed using Statistical Package for the Social Sciences (SPSS), and significance was set at p < 0.05.

The results showed no significant differences in age or sex distribution between groups. In the first attempt, 83.3% of participants with posterior wall penetration were in Group A (standard screen orientation). Needle visualibity score was higher in Group B (reversed screen orientation). The perceived ease of the procedure showed a significant difference in favor of Group B in the second attempt. Overall, while the success rates and time taken were similar between groups, Group B exhibited improved needle visualization and fewer complications related to posterior wall penetration.

The findings indicate that reversed screen orientation may facilitate learning and enhance procedural outcomes in USGVA. This orientation aligns better with the spatial perception of needle movement, potentially improving hand-eye coordination. The study supports the integration of reversed screen techniques in US training to improve skill acquisition and reduce complication rates in vascular access procedures. However, limitations include the study being conducted at a single center and using only one cadaver, which may affect the generalizability of results. Future research should explore long-term effects and further validate these findings in diverse clinical settings.