Real-time ultrasound-guided versus anatomic landmark-based thoracic epidural placement: a prospective, randomized, superiority trial

Figures

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  Fig. 1. Consort flow chart

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  Fig. 2. The technique of real-time ultrasound-guided thoracic epidural catheterization. A Patient positioned in the left-lateral decubitus position. Note the skin markings of the thoracic spinous processes (SP) and interspinous spaces (ISS) at the target thoracic level. B Paramedian sagittal oblique sonogram of the target intervertebral level showing the laminae and interlaminar spaces. C Paramedian, in-plane, real-time ultrasound-guided (USG) Tuohy needle insertion from the caudal end of the transducer and from the non-dependent side. D Paramedian sagittal oblique sonogram demonstrating the Tuohy needle (white arrowheads) insertion in-plane and with its tip located adjacent to the interlaminar space, (E) Eliciting loss-of-resistance (LOR) to injection of saline to locate the epidural space. Note how the hands of the operator support the Tuohy needle—LOR syringe assembly on the patients back, (F) Illustrating LOR to air to locate the epidural space. SP; indicates a spinous process, ISP; interspinous space, ESM; erector spinae muscle, LF; ligamentum flavum, * represents the interlaminar space

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  Fig. 3. Ultrasound sequence to identify the relevant sonoanatomy at the target intervertebral level for the real-time thoracic epidural catheterization. A Paramedian sagittal sonogram at the level of the 8th intercostal space after counting up from the 12.th rib. Note the rounded ribs and the hypoechoeic pleura. B Paramedian sagittal sonogram at the level of the transverse process (TP). Note the pleural is less clearly visualized at the level of the transverse processes. C Paramedian sagittal sonogram at the level of the articular processes. Note the sonographic appearance of the articular processes varies from that of the ribs and transverse processes. D Paramedian sagittal oblique sonogram at the level of the laminae of the thoracic vertebra, Note the flattened appearance of the lamina. R; represents the rib, TP; transverse process, ESM; erector spinae muscle, * represents the interlaminar space

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  Fig. 4. The first-pass success rate of thoracic epidural placement in the study groups. Data are presented as a proportion with its 95% CI (confidence interval). The Black dashed line represents the pre-specified superiority margin (δs = 0.05). Note the lower bound of the 95%CI for the first-pass success rate of Gp-Usg (real-time ultrasound-guided group) does not overlap the upper bound of the 95%CI of Gp-Conv (conventional anatomic landmark group) and it is beyond the pre-specified δs of 5% confirming clinical superiority of Gp-Usg. # represents inter-group difference p = 0.002, and TEP, thoracic epidural placement