title: Estimation of catheter insertion depth during ultrasound-guided subclavian venous catheterization.
abstract: BACKGROUND
  Several methods have been used to predict the optimal depth of central venous catheter (CVC) tip position when using the anatomical landmark technique. In the present study, we devised a simple formula to predict CVC depth using ultrasound images and chest X-ray (CXR) in patients undergoing ultrasound-guided subclavian venous catheterization.
  
  
  METHODS
  Central venous catheterization via the subclavian vein was performed under ultrasound guidance. We measured five parameters to determine the distance between the needle insertion point and the CVC tip: insertion point to vein puncture point (A), insertion point to a skin point indicating a vertical position above the vein puncture point (B), insertion point to the clavicular notch (C), clavicular notch to the carina (D), and catheter tip to carina (E). Catheter insertion depth was then determined as follows: calculated catheter insertion depth = A - B + C + D; actual catheter insertion depth = (A - B + C + D) + E.
  
  
  RESULTS
  The calculated CVC insertion depth (mean ± SD) was 15.4 ± 1.5 cm from the needle insertion point to the carina [95 % confidence interval (CI) 15.0-15.9 cm]. Actual depth was 15.4 ± 1.5 cm (95 % CI 15.0-15.9 cm). No significant difference was observed between the calculated CVC insertion depth and the actual distance from the needle insertion point to the carina (p = 0.940).
  
  
  CONCLUSIONS
  The appropriate length of a CVC inserted through the subclavian vein can be estimated by a formula using ultrasound images and CXR.
authors: Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-Si, Gyeonngi-do, 463-707, South Korea.
authors: Hyun-Jung
authors: HJ
authors: Shin
authors: Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-Si, Gyeonngi-do, 463-707, South Korea.
authors: Byung Gun
authors: BG
authors: Kim
authors: Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-Si, Gyeonngi-do, 463-707, South Korea.
authors: Hyo-Seok
authors: HS
authors: Na
authors: Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-Si, Gyeonngi-do, 463-707, South Korea.
authors: Ah-Young
authors: AY
authors: Oh
authors: Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea.
authors: Hee-Pyoung
authors: HP
authors: Park
authors: Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-Si, Gyeonngi-do, 463-707, South Korea. ytjeon@snubh.org.
authors: Young-Tae
authors: YT
authors: Jeon
mesh_terms: D000328:Adult; D002405:Catheterization, Central Venous / Q000379:methods*; D062905:Central Venous Catheters; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009339:Needles; D011446:Prospective Studies; D013902:Radiography, Thoracic; D014132:Trachea / Q000000981:diagnostic imaging
keywords: Central venous catheterization; Subclavian vein; Ultrasonography