title: Using Ultrasonography to Determine Optimal Head-down Tilt Position Angle in Patients before Catheterization of the Internal Jugular Vein.
abstract: BACKGROUND
  It is believed that 15°-25° head-down tilt position increases the internal jugular vein cross-sectional area (IJV CSA). The increase in IJV CSA before puncture reduces the risk of its perforation. This pattern was not observed in all patients. We assumed that the absence of respiratory-based IJV excursion is one of the criteria of head-down tilt position effectiveness.
  
  
  OBJECTIVE
  The aim of this study is to determine the head-down tilt angle, which ensures the absence of the respiratory-based IJV excursion.
  
  
  METHODS
  Prospective study included twenty adult patients. The IJVs scanning was carried out in 1 min after placing the patients in a horizontal position on their back and in 1 min after placing them in the head-down tilt position at 5°, 10°, 15°, and 20° tilt angles.
  
  
  RESULTS
  We found that collapsibility index of <9% indicating the absence of respiratory-based IJV excursion was recorded in 25% of patients in the horizontal supine position. In this case, placing the patients in the Trendelenburg position for IJV catheterization may not be indicated. In 65% of the patients, the respiratory-based excursion was not observed at 10° head-down tilt position. Only 35% of the patients required 15° head-down tilt position.
  
  
  CONCLUSIONS
  In clinical settings, the disappearance of respiratory-based vein excursion on the ultrasound scanner screen can be considered as criteria of the head-down tilt position effectiveness.
authors.affiliation: Department of General and Clinical Pharmacology, Izhevsk State Medical Academy, Izhevsk, Russia; Department of Anesthesiology and Intensive Care, Clinical Hospital, Izhevsk, Russia.
authors.forename: Anton A
authors.initials: AA
authors.lastname: Kasatkin
authors.affiliation: Department of General and Clinical Pharmacology, Izhevsk State Medical Academy, Izhevsk, Russia.
authors.forename: Aleksandr L
authors.initials: AL
authors.lastname: Urakov
authors.affiliation: Department of Anesthesiology and Intensive Care, Clinical Hospital, Izhevsk, Russia.
authors.forename: Anna R
authors.initials: AR
authors.lastname: Nigmatullina
keywords: Internal jugular vein; respiratory-based internal jugular vein excursion; ultrasound scanning