Advice
The technology
The technology
Accuro (Rivanna Medical) is a handheld, battery-operated, ultrasound device used to guide location, angle, and depth of needle insertion when administering epidural or spinal anaesthesia. The device is a single unit consisting of an ultrasound system, ultrasound probe and rotatable touch screen display.
The ultrasound imaging uses an ultrasound transducer, which transmits and receives high frequency mechanical waves. These reflect off structures in the body. The reflected ultrasound energy is converted into an image in real time on the display screen or saved in the device memory.
The SpineNav3D technology helps to guide epidural location and depth. It works by interpreting 2D lumbar spine scans, automating spinal bone landmark detection and depth measurements, and providing a real-time assessment of scan plane orientation in 3D. To find the correct needle insertion site, the user aligns the device to the spine midline and locates the interlaminar space and depth of the epidural space using the ultrasound image and 3D spine model on the device screen. The user then releases a locator needle guide from the device, which marks the site of needle insertion. The needle is then inserted at the angle that the device was held at while scanning.
The device contains a non-replaceable rechargeable lithium ion battery. The device is placed in a disposable sterile cover for each use.
Innovations
The company claims the device is easier to use than a conventional ultrasound machine and can be used by people who are not trained sonographers. The BoneEnhance technology is claimed to have greater bone to tissue contrast than conventional ultrasound, and the SpineNav3D technology automatically interprets the ultrasound image. Because the device's display screen and ultrasound probe are integrated into the same unit, the entire device can be contained in a sterile cover.
Current care pathway
The point of injection is determined by feeling for specific bony landmarks on the spine and pelvis. A small volume of local anaesthetic is injected into the skin and interspinous ligament. For epidural anaesthesia, a needle is advanced slowly through the interspinous ligament until resistance is no longer felt to the attempted injection of air or saline, indicating that the tip of the needle is in the epidural space (the loss-of-resistance technique). A catheter is then passed through the needle, the needle is removed, and the catheter is secured and used to administer anaesthetic. For spinal anaesthesia, the needle is inserted into the spinal canal.
This procedure may be guided using ultrasound. It can be used in real time to image the needle passing towards and into the epidural space or spinal canal. Or an ultrasound scan is done of the patient's lumbar spine to locate the midline and the middle of an interspinous space, and their positions are marked on the skin (prepuncture ultrasound). The depth of the epidural space or spinal canal is also determined from the ultrasound scan.
The following publications have been identified as relevant to this care pathway:
Population, setting and intended user
Accuro is intended to help people who need epidural or spinal anaesthesia. This could be in an obstetric setting or in surgeries where local anaesthetic is used. The company says this could particularly benefit people for whom it is more difficult to locate the interspinal space, such as people with scoliosis or overweight or obesity.
Accuro is intended to be used by people administering anaesthesia in a secondary or tertiary care setting. The company says that minimal training is needed. It provides training resources including training videos and free online tutorials.
Costs
Technology costs
Accuro costs £4,995, excluding VAT. Sterile disposable consumables cost £10 (excluding VAT) per use and include 1 Accuro locator needle guide, 1 clear custom-fit cover, 1 ultrasound gel pack and 2 elastic bands to secure the cover. The company does not recommend using the device without the sterile consumables. The company estimates the anticipated in-service lifetime for the device would be around 5 years.
Resource consequences
The device is currently being used in 5 NHS trusts. The company says that at these trusts it is primarily used in people with obesity or who have difficult spinal anatomies. However, it says that some users employ the device for every spinal or epidural anaesthesia placement.
If this technology were adopted more widely, there would be limited resource consequences because the technology would be used alongside current palpation techniques for identifying the intervertebral space. When ultrasound is needed to administer spinal or epidural anaesthesia, the device could reduce the need for people trained in conventional ultrasound-guided needle placement. This is because the Accuro device could be used by the anaesthetist giving the anaesthetic.