Optimal prediction of the central venous catheter insertion depth on a routine chest x-ray

Cardiac tamponade is a serious complication of central venous catheter (CVC) insertion. The position of the carina has been shown to be near the pericardial reflection and can easily be identified as a landmark on routine chest x-ray (CXR). The purpose of this study was to show a simple way to predict optimal CVC depth, thereby facilitating safe positioning of the CVC tip.

Subjects included 119 inpatients undergoing gastroenterologic surgery. Central venous catheterization was performed through the right internal jugular vein or the right subclavian vein. The insertion depth was measured. Postoperatively, the CVC tip position was confirmed by CXR and the distance between the CVC tip and the carina was measured. We compared the "original measurement" up to the carina from the insertion point with the "calculated measurement" derived by adding half the length of the right clavicle and the vertical length between the sternal head of the right clavicle and the carina on the CXR.

There was a significant correlation between the original measurement and the calculated measurement when performed through the internal jugular vein and the subclavian vein.

The appropriate length of CVC inserted through the right internal jugular vein or right subclavian vein could be estimated by the calculated measurement of adding half the length of the right clavicle and the vertical length between the sternal head of the right clavicle and the carina.