Depth of a central venous catheter tip: length of insertion guideline for pediatric patients

In pediatric patients, several studies have been undertaken to establish central venous catheter (CVC) tip optimal depth. Assessments of catheter tip position using chest radiographs may be misleading, whereas transesophageal echocardiography (TEE) has been shown to accurately monitor catheter tip placement at the superior vena cava-right atrial (SVC-RA) junction. The aim of this study was to issue a guideline for ideal catheter insertion depth, from the right internal jugular vein (IJV) using TEE to confirm the position of the catheter tip at the SVC-RA junction.

Over a 6-month period, we studied 60 right internal jugular vein catheterizations in infants and children undergoing surgery for congenital heart disease. Positions of CVC tips were confirmed to be at the SVC-RA junction by TEE. Distance from the skin puncture site to the SVC-RA junction, height, weight, and age were recorded.

Distances measured were found to be highly correlated with patient height. The following guideline allows the CVC tip to be positioned above the RA in 97.5% of patients with an accuracy of 95%: optimal depth of insertion (cm) = 1.7 + (0.07 x height) in patients whose height is between 40 and 140 cm.

The model proposed for the insertion of the CVC tip in pediatric patients could be used to prevent inadvertent catheter tip placement into the atrium.