Effect of Shoulder Traction on Size and Relative Position of Internal Jugular Vein to Carotid Artery

• Carotid artery (CA) overlap (%) [ Time Frame: 10 seconds after head positioning ] [ Designated as safety issue: No ]
  CA overlap = (overlap distance between CA and internal jugular vein)/CA diameter) × 100 measured by ultrasound image
  
  

• IJV (internal jugular vein) safety portion (%) [ Time Frame: 10 seconds after head positioning ] [ Designated as safety issue: No ]
  IJV safety portion = (1-ovelap distance/IJV diameter) × 100 measured by ultrasound image
  
  
• overlap distance (mm) [ Time Frame: 10 seconds after head position ] [ Designated as safety issue: No ]
  overlap distance (mm) of carotid artery and internal jugular vein measured by ultrasound image
  
  
• jugular to carotid distance (mm) [ Time Frame: 10 seconds after head position ] [ Designated as safety issue: No ]
  the distance (mm) between lateral border of carotid artery and center of internal jugula vein measured by ultrasound image
  
  
• CA diameter (mm) [ Time Frame: 10 seconds after head positioning ] [ Designated as safety issue: No ]
  carotid artery diameter (mm) measured by ultrasound image
  
  
• IJV diameter (mm) [ Time Frame: 10 seconds after head positioning ] [ Designated as safety issue: No ]
  internal jugualr vein diameter (mm) measured by ultrasound image
  
  

Central venous catheterization is frequently performed in pediatric patients undergoing major surgery for fluid management and vasoactive drug therapy. Compared to subclavian vein, internal jugular vein (IJV) is generally preferred for catheterization because of the low incidence of serious complications, such as pneumothorax and hemothorax. However, especially in infants, IJV catheterization is still technically difficult because of the small size of the vein and anatomical variation.

In previous studies, ultrasound guidance and keeping in neutral head position have been recommended to increase the success rate and to decrease the overlap between carotid artery (CA) and IJV, respectively. However, devices for ultrasonography are not always available. Moreover, IJV catheterization without head rotation could be extremely difficult in infants because of relative the larger skull and the smaller neck than those of adults. Therefore, a simple method to relieve the overlap between CA and IJV would be needed.

During head rotation to the contralateral side, the cephalic part of IJV is moved to the same direction. Accordingly, the investigators thought that the counter traction of the caudal part of IJV using the caudo-lateral traction of the ipsilateral arm might relieve the overlap caused from head rotation. Therefore, the investigators evaluated the effect of the caudo-lateral traction of the ipsilateral arm on the overlap between common CA and IJV in infants.