Single-operator real-time ultrasound-guided spinal injection using SonixGPS™: a case series

Abstract

Purpose The SonixGPS TM is a novel needle tracking system that has recently been approved in Canada for ultrasound-guided needle interventions. It allows optimization of needle-beam alignment by providing a real-time display of current and predicted needle tip position. Currently, there is limited evidence on the effectiveness of this technique for performance of realtime spinal anesthesia. This case series reports performance of the SonixGPS system for real-time ultrasound-guided spinal anesthesia in elective patients scheduled for joint arthroplasty. Methods In this single-centre case series, 20 American Society of Anesthesiologists' class I-II patients scheduled for lower limb joint arthroplasty were recruited to undergo real-time ultrasound-guided spinal anesthesia with the SonixGPS after written informed consent. The primary outcome for this clinical cases series was the success rate of spinal anesthesia, and the main secondary outcome was time required to perform spinal anesthesia. Results Successful spinal anesthesia for joint arthroplasty was achieved in 18/20 patients, and 17 of these required only a single skin puncture. In 7/20 (35%) patients, dural puncture was achieved on the first needle pass, and in 11/20 (55%) patients, dural puncture was achieved with two or three needle redirections. Median (range) time taken to perform the block was 8 (5-14) min. The study procedure was aborted in two cases because our clinical protocol dictated using a standard approach if spinal anesthesia was unsuccessful after three ultrasound-guided insertion attempts. These two cases were classified as failures. No complications, including paresthesia, were observed during the procedure. All patients with successful spinal anesthesia found the technique acceptable and were willing to undergo a repeat procedure if deemed necessary. Conclusions This case series shows that real-time ultrasound-guided spinal anesthesia with the SonixGPS system is possible within an acceptable time frame. It proved effective with a low rate of failure and a low rate of complications. Our clinical experience suggests that a randomized trial is warranted to compare the SonixGPS with a standard block technique. Résumé Objectif Le SonixGPSTM est un système innovant de suivi de l'aiguille récemment approuvé au Canada pour les interventions échoguidées réalisées avec une aiguille. Cet appareil optimise l'alignement entre l'aiguille et le faisceau grâce à un affichage en temps réel du positionnement actuel et prévu de la pointe de l'aiguille. À l'heure actuelle, les données probantes concernant l'efficacité de cette technique pour réaliser une rachianesthésie en temps réel sont limitées. Cette série de cas porte sur la performance du système SonixGPS pour réaliser une rachianesthésie échoguidée en temps réel chez des patients devant subir une chirurgie non urgente d'arthroplastie.

Real‐time ultrasound‐guided spinal anesthesia using the SonixGPS ultrasound guidance system: a feasibility study

“…By consensus of all three investigators, we switched to the OOP technique in the remaining 16 patients, which has since been independently described and validated by Brinkmann et al 9 Dural puncture was successful in 12 of these 16 patients (75%), for an overall success rate of 14/20 (70%). In the four unsuccessful OOP cases, the procedure was abandoned because of repeated bony contact despite multiple needle passes (range 12-48).…”

“…This proved to be a technically easier approach, as suggested by the reduced number of needle passes and shorter block performance time. This approach has since been described and validated by Brinkmann et al 9 in a similar case series of 20 patients. They achieved successful dural puncture with a single skin puncture in 90% (18/20) of patients, and with a single needle pass in 39% (7/18) of these patients.…”

Ultrasound guidance for lumbar puncture

“…31 Real-time ultrasound-guided LP is most often performed using a longitudinal (in-plane), paramedian approach. [31][32][33][34][35][36][37] One prospective study using a conventional curvilinear transducer and a longitudinal paramedian approach demonstrated a 97% success rate with a median of 3 needle passes (interquartile range 1-6). 34 Although small studies describing real-time ultrasound guidance appear promising, lumbar spine mapping to mark the needle insertion site is currently the most common technique with the largest body of supporting evidence.…”

Localization of epidural space: A review of available technologies

“…Certain investigators have successfully used Sonix GPS (Ultrasonix, British Columbia, Canada) for peripheral nerve blocks and spinal anesthesia. [293031] Though promising, this technology requires a proprietary needle, which currently is not suitable for epidural insertion. There are also concerns about the accuracy of needle tip localization which further hinder its adoption into routine clinical practice.…”