title: The Optimal Angle of Head Rotation for Internal Jugular Cannulation as Determined by Ultrasound Evaluation.
abstract: OBJECTIVE
  The aim of this study was to determine the degree of head rotation that creates the maximal anatomic separation between the right internal jugular vein and the carotid artery.
  
  
  METHODS
  Single-center prospective, observational cohort study.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  Fifty patients aged>21 years and undergoing cardiac surgery.
  
  
  METHODS
  An ultrasound machine equipped with a digital caliper was used to determine the relational anatomy of the internal jugular vein and the carotid artery, with patients in the Trendelenburg position at head angles of -15°, 0°,+15°,+30°,+45°,+60°,+75°, and+90°.
  
  
  RESULTS
  When examining the percentage of the internal jugular vein vertical diameter that is not overlapped by the carotid artery (vertically unencumbered), there was a difference between the head angle groups (p<0.01). Unencumbered vertical distance was different between+75° versus 0°, and+75° versus+15°. At+75°, 60.3%±5.3% of the internal jugular vein was unencumbered vertically, whereas at 0°, it was 37.2%±3.9%, and at+15° it was 40.3%±3.8%. Only 72% of the patients were able to position their head at+75°, and 54% of the subjects were able to position their head at+90°.
  
  
  CONCLUSIONS
  The authors found the internal jugular vein becomes more vertically separated from the carotid artery at more extreme angles of contralateral head rotation.
authors.affiliation: Departments of Anesthesia.
authors.forename: Vincent
authors.initials: V
authors.lastname: DeAngelis
authors.affiliation: Departments of Anesthesia.
authors.forename: John
authors.initials: J
authors.lastname: Denny
authors.affiliation: Departments of Anesthesia.
authors.forename: Darrick
authors.initials: D
authors.lastname: Chyu
authors.affiliation: Departments of Anesthesia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Jan
authors.affiliation: Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ.
authors.forename: Anthony
authors.initials: A
authors.lastname: Lemaire
authors.affiliation: Departments of Anesthesia.
authors.forename: Antonio
authors.initials: A
authors.lastname: Chiricolo
authors.affiliation: Departments of Anesthesia. Electronic address: alsolina@mac.com.
authors.forename: Al
authors.initials: A
authors.lastname: Solina
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D002405:Catheterization, Central Venous / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006257:Head; D018475:Head-Down Tilt; D006801:Humans; D007601:Jugular Veins / Q000000981:diagnostic imaging*; D008297:Male; D056888:Patient Positioning / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014463:Ultrasonography; D057772:Vascular System Injuries / Q000517:prevention & control*
keywords: carotid artery injury; central line; central line complications; internal jugular cannulation; internal jugular vein; ultrasound