Respiratory jugular venodilation: its anatomic rationale as a landmark for right internal jugular vein puncture as determined by ultrasonography.

OBJECTIVE To reveal anatomic factors that determine the visibility of respiratory jugular venodilation, a landmark for right internal jugular vein puncture, in ventilated patients. DESIGN Prospective observational study. SETTING Single community hospital. PARTICIPANTS Adult patients undergoing general endotracheal anesthesia. INTERVENTIONS Anatomy of the right neck, including the carotid artery and internal jugular vein, was evaluated in a blind manner using 7.5-MHz ultrasonography in patients simulating the position for internal jugular vein puncture. Anatomic variables correlated with the visibility of respiratory jugular venodilation were analyzed. MEASUREMENTS AND MAIN RESULTS Of 124 patients, respiratory jugular venodilation was observed in 94 patients (75.8%). Satisfactory quality of ultrasound image was obtained for all patients. The visibility of venodilation correlated with the extent of change of the vein size during a respiratory cycle but not with the end-expiratory or end-inspiratory vein diameter. These results indicated that there was no correlation between the vessel size and the visibility of venodilation, suggesting that it is rational to attribute the increased success rate of the respiratory jugular venodilation-guided puncture to accurate vein localization rather than to a larger target size. Among the demographic variables examined, body weight and obesity correlated with the visibility of venodilation, but age, gender, and height did not correlate. In obese patients, the respiratory change of the vein diameter was smaller, and the vein was deeper. CONCLUSIONS The visibility of respiratory jugular venodilation does not correlate with the vein size but with the extent of its dynamic change during a respiratory cycle.