title: Defining normal jugular venous pressure with ultrasonography.
abstract: OBJECTIVE
  Determination of jugular venous pressure (JVP) by physical examination (E-JVP) is unreliable. Measurement of JVP with ultrasonography (U-JVP) is easy to perform, but the normal range is unknown. The objective of this study was to determine the normal range for U-JVP.
  
  
  METHODS
  We conducted a prospective anatomic study on a convenience sample of emergency department (ED) patients over 35 years of age. We excluded patients who had findings on history or physical examination suggesting an alteration of JVP. With the head of the bed at 45 degrees, we determined the point at which the diameter of the internal jugular vein (IJV) began to decrease on ultrasonography ("the taper"). Research assistants used 2 techniques to measure U-JVP in all participants: by measuring the vertical height (in centimetres) of the taper above the sternal angle, and adding 5 cm; and by recording the quadrant in the IJV's path from the clavicle to the angle of the jaw in which the taper was located. To determine interrater reliability, separate examiners measured the U-JVP of 15 participants.
  
  
  RESULTS
  We successfully determined the U-JVP of all 77 participants (38 male and 39 female). The mean U-JVP was 6.35 (95% confidence interval 6.11-6.59) cm. In 76 participants (98.7%), the taper was located in the first quadrant. Determination of interrater reliability found kappa values of 1.00 and 0.87 for techniques 1 and 2, respectively.
  
  
  CONCLUSIONS
  The normal U-JVP is 6.35 cm, a value that is slightly lower than the published normal E-JVP. Interrater reliability for U-JVP is excellent. The top of the IJV column is located less than 25% of the distance from the clavicle to the angle of the jaw in the majority of healthy adults. Our findings suggest that U-JVP provides the potential to reincorporate reliable JVP measurement into clinical assessment in the ED. However, further research in this area is warranted.
authors.affiliation: Emergency Department, Hôpital regional de Sudbury Regional Hospital, Northern Ontario Medical School of Medicine, 700 Paris St., Sudbury, Ontario, Canada. ssocransky@hrsrh.on.ca
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Socransky
authors.forename: Ray
authors.initials: R
authors.lastname: Wiss
authors.forename: Ron
authors.initials: R
authors.lastname: Robins
authors.forename: Alexandre
authors.initials: A
authors.lastname: Anawati
authors.forename: Marc-Andre
authors.initials: MA
authors.lastname: Roy
authors.forename: I Ching
authors.initials: IC
authors.lastname: Yeung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002496:Central Venous Pressure / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007601:Jugular Veins / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D014463:Ultrasonography