1. Introduction
SECONDARY
Advantages of Combined spinal-epidural anesthesia (CSEA) are fast onset, precise block, and time controllable, and is widely used in the majority of secondary hospitals.Traditional landmark-guided method is often faced with inaccurate positioning.Recently, popularization of ultrasonography has brought about the innovation of anesthesia technology and has emerged as a way to facilitate CSEA perform. Currently, ultrasound has also been likened to clinician second stethoscope, namely operations can be performed under visualization. Studies have shown that pre-puncture or real-time ultrasound scanning, visual identification and marking of the puncture position, can improve the success rate of puncture, shorten the puncture time, reduce the number of needle insertions in predictable anatomical difficulties.