Fig. 1

The ultrasound-guided thoracic paravertebral nerve block and erector spinae plane block. a, b An ultrasound high-frequency line array probe was used to scan at approximately 2–2.5 cm next to T4–5 spinous process in the median sagittal position. The transverse process (TP), pleura, and thoracic paravertebral space could be clearly visualized under the ultrasound, and 30 ml of 0.5% ropivacaine hydrochloride was injected into T4–5 paravertebral spaces using an out-of-plane approach technique. a Ultrasound-guided thoracic paravertebral nerve block before injection. b After ultrasound-guided thoracic paravertebral nerve block by local anesthetic injection, the pleura would be pushed downward. c, d An ultrasound high-frequency line array probe was used to scan at approximately 2–2.5 cm next to T4–5 spinous process in the median sagittal position. With an out-of-plane approach technique, trapezius muscle (TM), rhomboid muscle (RM) and erector spinae muscle (ESM) were sequentially breached, and 30 ml of 0.5% ropivacaine hydrochloride was injected into the deep surface between erector spinae muscle and T4 and T5 transverse processes (TP). c Ultrasound-guided erector spinae plane block before injection. d Ultrasound-guided erector spinae plane block after injection