Interdisciplinary development and evaluation of a novel needle guide for ultrasound-guided lumbar epidural placement

Abstract

PurposeA solution for real-time, ultrasound-guided, central neuraxial blockade placement remains elusive. A device that enables single-operator neuraxial placement while simultaneously visualising the spinal anatomy and needle trajectory may improve patient safety. We engineered a novel needle guide, the EpiGuide two dimensional (2D), and compared prepuncture insertion sites as located using the guide versus standard manual palpation.MethodsInterdisciplinary collaboration between engineers and obstetric anaesthesiologists and multiple iterative refinement led to the EpiGuide 2D, a prototype multichannel needle guide for ultrasound transducers. Following ethics committee approval, 22 healthy adult participants were recruited to undergo prepuncture lumbar epidural placement using the guide. The primary outcome was accuracy, defined as the percentage of successful placements of prepuncture needle insertion sites within the manually palpated intervertebral space. The secondary outcome was distance between the prepuncture insertion sites guided by the EpiGuide 2D versus by sites guided by manually palpation.ResultsMean (SD) body mass index of participants was 22.6 (2.1) kg/m2. The success rate of selecting a prepuncture site within the manually palpated intervertebral space using EpiGuide 2D was 95.5% (42 of 44 attempts). Of the failed sites, the mean (SD) distance to the intervertebral space was 1.3 (0.3) mm in the caudal direction. The mean (SD) distance between EpiGuide 2D sites and palpated sites was 3.6 (2.0) mm.ConclusionThe EpiGuide 2D, jointly developed between engineers and anaesthesiologists, was found to be as accurate as manual palpation in placing a prepuncture site within the intervertebral space.