title: Use of vertebral body units to locate the cavoatrial junction for optimum central venous catheter tip positioning.
abstract: BACKGROUND
  Central venous catheter (CVC) placement plays an important role in clinical practice; however, optimal positioning of the CVC tip remains a controversial issue. The objective of this study was to evaluate the use of vertebral body unit (VBUs), to locate the cavoatrial junction (CAJ), for optimal CVC tip placement based on chest radiography (CXR) using the carina as a landmark.
  
  
  METHODS
  524 patients who underwent coronary computed tomographic angiography (CTA) and CXR were included. The position of the CAJ was identified using VBUs, and the efficacy of VBUs for locating the CAJ with the carina as a landmark was analysed using multiple regression analysis. A VBU was defined as the distance between two adjacent vertebral bodies, including the inter-vertebral disk space.
  
  
  RESULTS
  The mean (sd) distance from the carina to the superior CAJ was 54.3 (9.7) mm on CTA; the mean distance in VBUs at the level of the carina was 21.4 (1.7) mm on CTA and 22.6 (2.1) mm on CXR. The mean CAJ position was 2.5 VBUs below the carina on CTA and 2.4 VBUs below on CXR with 95% limits of agreement between -0.6 and +0.3.
  
  
  CONCLUSIONS
  The position of the CVC tip in relation to the carina can be described using the thoracic spine as an internal ruler, and the position of the CAJ in adults was reliably estimated to be 2.4 VBUs below the carina.
  
  
  BACKGROUND
  KCT0001319.
authors.affiliation: Department of Radiology, Samsung Changwon Hospital, Sungkyunkwan University, School of Medicine, Changwon, South Korea.
authors.forename: Y G
authors.initials: YG
authors.lastname: Song
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Samsung Changwon Hospital, Sungkyunkwan University, School of Medicine, Changwon, South Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Byun
authors.affiliation: Department of Emergency Medicine, Samsung Changwon Hospital, Sungkyunkwan University, School of Medicine, Changwon, South Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Hwang
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Changwon Hospital, Sungkyunkwan University, School of Medicine, Changwon, South Korea.
authors.forename: C W
authors.initials: CW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University, School of Medicine, Changwon, South Korea sgshim218@gmail.com.
authors.forename: S G
authors.initials: SG
authors.lastname: Shim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002405:Catheterization, Central Venous / Q000379:methods*; D062905:Central Venous Catheters; D017023:Coronary Angiography; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013902:Radiography, Thoracic; D013131:Spine / Q000033:anatomy & histology*; D014683:Vena Cava, Superior / Q000033:anatomy & histology*
keywords: central venous catheter; right atrium; superior vena cava; vertebra