Integrating ultrasound with the combined spinal-epidural kit as a rescue technique during difficult spinal anaesthesia

Abstract

Conducting spinal anaesthesia in patients with elevated body mass index is commonly difficult, yet there are no guidelines to direct best practice. Landmark techniques are sometimes insufficient, leading to increased failure rates and suboptimal patient outcomes. Although ultrasound-guided techniques are now considered standard care for central venous access and regional anaesthesia, there has been relatively sparse uptake of this widely available resource for central neuraxial block, despite evidence of its efficacy.This article outlines a successful case of ultrasound-assisted spinal anaesthesia, after landmark techniques failed, in conjunction with a combined spinal-epidural kit. This unique combination of techniques has not been published as an amalgamated rescue strategy for difficult spinal anaesthesia. This article adds to current evidence by highlighting the potential benefits of combining these techniques into a novel approach either when difficulties are expected or as a rescue technique after failed landmark-based attempts.

Keywords: anaesthesia; obesity (nutrition); orthopaedic and trauma surgery; sleep disorders (respiratory medicine); ultrasonography.

Figure 1

Day 1 postoperative image of the patient’s spine. Vertical lines indicate midline and were marked in transverse interlaminar view. Horizontal lines were marked in the parasagittal oblique view, indicating interlaminar levels. Informed consent was obtained from the patient for using clinical images.

Figure 2

Parasagittal oblique (interlaminar) view (PSO view). L3/4 space mid-screen. Suboptimal view, yet saw-tooth pattern of lamina and interspaces easily identified. Vertebral body cortex between lamina faintly seen at 10 cm depth. The ligamentum flavum was not visible in this patient. In the PSO view, with an interspace centred mid-screen, mark the skin at each level during the prescan. ESM, erector spinae muscle; ITS, intrathecal space; Lamina, L4 lamina; VB, vertebral body. Informed consent was obtained from the patient for using clinical images.

Figure 3

Transverse interlaminar/interspinous view (TI view). A key view for marking both the midline and each interlaminar/interspinous space. The ligamentum flavum and vertebral bodies were not visible in this view and are usually more hyperechoic in the parasagittal oblique view. Estimated depth can be approximated to transverse process depth when ligamentum flavum or vertebral bodies are not seen on either view. AP, articular process; ESM, erector spinae muscle; ISL, interspinous ligament; ITS, intrathecal space; TVP, transverse process. Informed consent was obtained from the patient for using clinical images.