Real-time ultrasound-guided mid-thoracic epidural access using a novel paramedian cross (PX) view and drip infusion technique: a brief technical report

Background Real-time ultrasound guidance (USG) has been applied for lower thoracic epidural access, but the more challenging mid-thoracic epidural (MTE) access remains underexplored. This report presents a technique of real-time US guidance with a novel paramedian cross view, termed "the PX view," for securing MTE catheters, along with an outcome analysis from a retrospective case series.Methods Medical records of patients who underwent USG-MTE catheter placement with the PX view and drip infusion technique from January to December 2022 were reviewed. All catheters were placed with patients in the prone position under mild to moderate procedural sedation. The process of acquiring the PX view, in-plane needling technique, and the use of drip infusion to identify loss of resistance were detailed. The incidence of successful PX view attainment, the number of attempts, redirections, failures, and any technique-related complications were recorded.Results Fifty-one patients underwent USG-MTE catheter attempts, (42 with median sternotomy, 3 fractured ribs, 3 upper abdominal laparotomies, 2 modified radical mastectomies, and 1 thoracotomy). A satisfactory PX view was obtained in all patients, and the epidural space was identified during the first needle entry in 49 cases, resulting in a 96% first-attempt success rate. Seven patients required needle redirections, while two patients needed a second needle entry. No technique-related complications were documented.Conclusion The combination of the PX view and the drip infusion method proved effective for real-time ultrasound-guided MTE catheter placement.