For correct monitoring of central venous pressure (CVP) the tip of the
CVP catheter should be placed in the superior vena cava (SVC). Since
there is no useful guide for the optimal depth of insertion of CVP cat
heter in children undergoing cardiovascular surgery, we examined the r
elationship between the depth of the CVP catheter and easily measured
body-size variables, such as age, weight and height, and then created
a guide for the optimal placement of the paediatric population. The CV
P catheterization was performed through the right internal jugular vei
n by the high approach. The position of the catheter lip was determine
d by the wave form of the CVP tracing and the depth of insertion was a
ssessed by the external marking on the catheter at the cannulation sit
e. The position of the catheter lip, determined by postoperative AP ch
est x-ray, was identified by the level of thoracic vertebra (T) corres
ponding to the position of the catheter tip. We analyzed the relations
hip between the depth of the catheter and patient's age, weight and he
ight by linear regression analysis. The position of lip was normally d
istributed from T-1 to T-7 and the tips were centralized at levels of
T-3, T-4 and T-5 which anatomically correspond to SVC. We r values bet
ween the catheter depth and the three factors at each level were compa
rable, although the correlation between the depth of catheter and heig
ht was best. A simple guide for placement of the catheter tip at T-3,
T-4 and Tg levels as a function of patient's height was created. Since
height is a primary information variable which ir available even in e
mergency cases, we believe that the guide is acceptable and valuable t
o anaesthetists.