title: Estimation of Stellate Ganglion Block Injection Point Using the Cricoid Cartilage as Landmark Through X-ray Review.
abstract: BACKGROUND
  Stellate ganglion block is usually performed at the transverse process of C6, because the vertebral artery is located anterior to the transverse process of C7. The purpose of this study is to estimate the location of the transverse process of C6 using the cricoid cartilage in the performance of stellate ganglion block.
  
  
  METHODS
  We reviewed cervical lateral neutral-flexion-extension views of 48 patients who visited our pain clinic between January and June of 2010. We drew a horizontal line at the surface of the cricoid cartilage in the neutral and extension views of cervical lateral x-rays. We then measured the change in the shortest distance from this horizontal line to the lowest point of the transverse process of C6 between the neutral and extension views.
  
  
  RESULTS
  There was a statistically significant difference in the shortest distance from the horizontal line at the surface of the cricoid cartilage to the lowest point of transverse process of C6 between neutral position and neck extension position in both males and females, and between males and females in both neutral position and neck extension position. The cricoid cartilage level was 4.8 mm lower in males and 14.4 mm higher in females than the lowest point of transverse process of C6 in neck extension position.
  
  
  CONCLUSIONS
  Practitioners should recognize that the cricoid cartilage has cephalad movement in neck extension. In this way, the cricoid cartilage can be still useful as a landmark for stellate ganglion block.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jeong Soo
authors.initials: JS
authors.lastname: Park
authors.forename: Ki Jun
authors.initials: KJ
authors.lastname: Kim
authors.forename: Youn Woo
authors.initials: YW
authors.lastname: Lee
authors.forename: Duck Mi
authors.initials: DM
authors.lastname: Yoon
authors.forename: Kyung Bong
authors.initials: KB
authors.lastname: Yoon
authors.forename: Min Young
authors.initials: MY
authors.lastname: Han
authors.forename: Jong Bum
authors.initials: JB
authors.lastname: Choi