Using LOR Syringe Probes as a Method to Reduce Errors in Epidural Analgesia -- a Robotic Simulation Study

Epidural analgesia involves injection of anesthetics into the epidural space, using a Touhy needle to proceed through the layers in the epidural region and a "loss of resistance" (LOR) syringe to sense the environment stiffness. The anesthesiologist's case experience is one of the leading causes of accidental dural puncture and failed epidural - the two most common complications of epidural analgesia. Robotic simulation is an appealing solution to help train novices in this task. Another benefit of it is the ability to record the kinematic information throughout the procedure. In this work, we used a haptic bimanual simulator, that we designed and validated in previous work, to explore the effect LOR probing strategies had on procedure outcomes. Our results indicate that most participants probed more with the LOR syringe in successful trials, compared to unsuccessful trials. Furthermore, this result was more prominent in the three layers preceding the epidural space. Our findings can assist in creating better instructions for training novices in the task of epidural analgesia. We posit that instructing anesthesia residents to use the LOR syringe more extensively and educating them to do so more when they are in proximity to the epidural space can help improve skill acquisition in this task.

Design and Validation of a Bimanual Haptic Epidural Needle Insertion Simulator

The case experience of anesthesiologists is one of the leading causes of accidental dural puncture and failed epidural - the most common complications of epidural analgesia. We designed a bimanual haptic simulator to train anesthesiologists and optimize epidural analgesia skill acquisition, and present a validation study conducted with 15 anesthesiologists of different competency levels from several hospitals in Israel. Our simulator emulates the forces applied on the epidural (Touhy) needle, held by one hand, and those applied on the Loss of Resistance (LOR) syringe, held by the second hand. The resistance is calculated based on a model of the Epidural region layers that is parameterized by the weight of the patient. We measured the movements of both haptic devices, and quantified the rate of results (success, failed epidurals and dural punctures), insertion strategies, and answers of participants to questionnaires about their perception of the realism of the simulation. We demonstrated good construct validity by showing that the simulator can distinguish between real-life novices and experts. Good face and content validity were shown in experienced users' perception of the simulator as realistic and well-targeted. We found differences in strategies between different level anesthesiologists, and suggest trainee-based instruction in advanced training stages.