Application Of Ultrasound In Cervical Plexus Block

Objective:The aim of the study was to establish the method of ultrasonic localization of cervical vertebral transverse process and then confirm its validity. Basing on these, we compare the anesthetic effect between C4 single-injection technique and C2, C3, C4 three-injection technique cervical plexus block under ultrasound which were both classic technique.Methods:Three parts were included in the study. We examined the feasibility of ultrasonic localization of cervical vertebral transverse process.15 healthy volunteers were given to match two methods to locate right cervical transverse process. Then we compared the correctness of ultrasound guidence and traditional technique to position cervical transverse process which was confirmed by C-arm machine.In the second part 60 healthy volunteers were involved. We used M-mode ultrasound to observe diaphragm movements as the foundation to observe diaphragm movement decrease after the cervical plexus block. We examined the movements of two sides and compare the diaphragm movements of male and female.In the third part, we compared the anesthesia effects of C4 single-injection technique and C2, C3, C4 three-injection technique cervical plexus block. C4 single-injection technique cervical plexus block:The probe was placed below mastoid process to perform vertebral artery and then touched the vertebral artery loop between the C1 and C2 vertebral transverse process. Moving the probe along the posterior border line of the sternocleidomastoid caudally, we found the position of C2, C3 and C4 transverse processes. Displaying the high-level echo line of the cortex, we injected 9 ml 0.375% ropivacaine on the tip of C4 vertebral transverse process by in-plane-technique. C2, C3, C4 three-injection technique cervical plexus block:Displaying the high-level echo line of the cortex of C2,C3,C4 vertebral transverse processes, we injected 3 ml 0.375% ropivacaine on tip of each transverse process. Same bilateral superficial cervical plexus block technique was used in two groups:the probe was placed on the midpoint of posterior border of the sternocleidomastoid. The needle went to the sternocleidomastoid-scalene intermuscular plane and injected 0.2% ropivacaine 5 ml cranially and 5 ml caudally. We observe the time of pain sensory block, the excellence rate, the physical sign on 5 min,10 min,15 min,20 min,30 min and diaphragm movement decrease after block.Result:Positioning C2,C3 transverse process by ultrasound has higher accuracy rate than traditional technique (P<0.05).There is no difference to position C4 transverse process by two method. C2, C3, C4 three-injection technique cervical plexus block has more perfect anesthetic effect than C4 single-injection technique and fewer incidence of phrenic nerve block and other complications but there is no difference in the success rate of two methods. (P<0.05)Conclusion:Ultrasound can be an instrument to position C2, C3, C4 transverse process and guide the cervical plexus block. C2, C3, C4 three-point-technique has higher success rate but fewer complications than C4 one-point-technique by the precise ultrasound guidance. C2, C3, C4 three-injection technique with precise position deserves promotion in the clinic work.