Changes in Gaze Behavior during the Learning of the Epidural Technique with a Simulator in Anesthesia Novices

Background: Current literature demonstrates the ability of eye tracking to provide reliable quantitative data as an objective assessment tool, with potential applications to medical and surgical training to improve performance. Objective: The aim of this study was to evaluate the changes in gaze behavior in anesthesia novice trainees when performing a simulated epidural technique before and after a hands-on training on the epidural simulator. Methods: We enrolled 48 novice trainees who had never previously performed an epidural block. After a standardized learning module, each trainee practiced the epidural procedure on the epidural simulator while wearing a pair of eye tracking glasses (Tobii Pro Glasses 50 Hz wearable wireless eye tracker). After this baseline recording, each trainee spent two hours practicing with the epidural simulator and afterwards once again performed the eye tracking epidural procedure. Eye tracking metrics and epidural learning (duration of the procedure and number of attempts) before and after the simulated practice were recorded. Results: The duration of the epidural procedure and of the epidural needle advancement phase (P < 0.05) and the number of epidural attempts (P < 0.001) were reduced after the tutorial. When considering the eye tracking metrics, after the tutorial, the number of visit counts decreased and their duration increased (P < 0.05). The number of epidural needle insertions (additional attempts) showed a significant positive correlation with the visits number (aOR = 2.02 (95% CI = 1.26 - 3.55;P = 0.008)) and a significant negative correlation with the visit duration (aOR = 0.65 (95% CI = 0.39 - 0.99;P = 0.05)). Conclusion: We observed significant changes in gaze behavior associated with increased performance during the epidural technique learning with a simulator in anesthesia trainees who had never previously performed an epidural block. These results may create a prototype for future studies on eye tracking technique as a teaching and evaluating tool in simulation.

Accuracy of the SpineNav3DTM Ultrasound Technology in Estimating the Epidural Space Depth for Epidural and Spinal Insertion in Pregnant Obese Patients

Introduction: Ultrasound facilitates neuraxial puncture in obese parturients. Unfortunately, the widespread adoption of neuraxial ultrasound may be limited by the lack of technical expertise or the limited availability of the equipment. A wireless portable ultrasound device (Accuro, Rivanna Medical, Charlottesville, VA) with automated pattern recognition software (SpineNav3DTM technology) has been introduced to obtain the automated real-time identification of interspaces and epidural depth. The primary objective of this study was to assess the accuracy of the SpineNav3DTM ultrasound technology (Accuro) in estimating the epidural space depth compared to the standard ultrasound examination in pregnant obese patients. The secondary aim was to compare the ultrasound measurements with the measured needle depth during epidural and spinal insertion. Methods: The study was conducted at S Gerardo Hospital, Monza, Italy from March 2021 to April 2021. Obese laboring women requesting epidural analgesia or undergoing elective cesarean delivery under spinal anesthesia were recruited. All the subjects had their lumbar area scanned for the measurements of the depth of the epidural space by the SpineNav3DTM ultrasound technology and by the standard US and then both compared with the needle insertion depth in a double-blind fashion. Results: Forty-eight women were enrolled in the study. There was agreement (±0.25 cm) between the epidural depth (in cm) measured with the Accuro, versus the standard ultrasound. There was a significant difference between the mean depth of epidural space s measured by Accuro or Standard US and needle insertion depth (P < 0.001). Conclusions: The handheld ultrasound system with 3D spine navigation technology can automatically identify and measure the epidural depth with the same accuracy as the standard ultrasounds in obese pregnant women.