title: The effects of the Trendelenburg position and the Valsalva manoeuvre on internal jugular vein diameter and placement in children.
abstract: BACKGROUND
  We compared the effects of various surgical positions, with and without the Valsalva manoeuvre, on the diameter of the right internal jugular vein (RIJV).
  
  
  METHODS
  We recruited 100 American Society of Anesthesiologists physical status class I patients aged 2-12 years. The patients' heart rate, blood pressure, peripheral oxygen saturation and end-tidal CO2 pressure were monitored. Induction of anaesthesia was done using 1% propofol 10 mg/mL and fentanyl 2 µg/kg, while maintenance was achieved with 2% sevoflurane in a mixture of 50/50 oxygen and air (administered via a laryngeal mask airway). The RIJV diameter was measured using ultrasonography when the patient was in the supine position. Thereafter, it was measured when the patient was in the supine position + Valsalva, followed by the Trendelenburg, Trendelenburg + Valsalva, reverse Trendelenburg, and reverse Trendelenburg + Valsalva positions. A 15° depression or elevation was applied for the Trendelenburg position, and an airway pressure of 20 cmH2O was applied in the Valsalva manoeuvre. During ultrasonography, the patient's head was tilted 20° to the left.
  
  
  RESULTS
  When compared to the mean RIJV diameter in the supine position, the mean RIJV diameter was significantly greater in all positions (p < 0.001) except for the reverse Trendelenburg position. The greatest increase in diameter was observed in the Trendelenburg position with the Valsalva manoeuvre (p < 0.001).
  
  
  CONCLUSIONS
  In paediatric patients, the application of the Trendelenburg position with the Valsalva manoeuvre gave the greatest increase in RIJV diameter. The reverse Trendelenburg position had no significant effect on RIJV diameter.
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Gamze Naime
authors.initials: GN
authors.lastname: Dincyurek
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Elif Basagan
authors.initials: EB
authors.lastname: Mogol
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Gurkan
authors.initials: G
authors.lastname: Turker
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Belgin
authors.initials: B
authors.lastname: Yavascaoglu
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Alp
authors.initials: A
authors.lastname: Gurbet
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Fatma Nur
authors.initials: FN
authors.lastname: Kaya
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Bachri Ramadan
authors.initials: BR
authors.lastname: Moustafa
authors.affiliation: Department of Anesthesiology, Uludag University Faculty of Medicine, Bursa, Turkey.
authors.forename: Tolga
authors.initials: T
authors.lastname: Yazici
mesh_terms: D000758:Anesthesia / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D018475:Head-Down Tilt; D006801:Humans; D007601:Jugular Veins / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D008738:Methyl Ethers / Q000627:therapeutic use; D015742:Propofol / Q000627:therapeutic use; D000077149:Sevoflurane; D016683:Supine Position; D014463:Ultrasonography; D014636:Valsalva Maneuver
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane; D015742:Propofol
keywords: Trendelenburg; Valsalva; catheterisation; reverse Trendelenburg; ultrasonography