Transthoracic echocardiographic guidance for obtaining an optimal insertion length of internal jugular venous catheters in infants.

BACKGROUND: There are multiple methods of determining the optimal position of central venous catheter (CVC) tips. The purpose of this study was to assess the feasibility of transthoracic echocardiography (TTE), and compare TTE and height-based method for correct positioning of CVCs in infants undergoing cardiac surgery.

METHODS: Ultrasonography-guided central venous catheterization was performed via the right internal jugular vein. Longitudinal images of the right atrium and superior vena cava were obtained using TTE. The catheter tip was located 10 mm above the crista terminalis. If the catheter tip was not clearly visualized, the probe was rotated to obtain transverse images and the CVC tip was positioned at the level of the pulmonary artery bifurcation. The mean distance from the catheter tip to the level of the carina was compared with that calculated using a height-based formula.

RESULTS: Among 106 cases, positioning of the CVC tip under TTE guidance failed in four patients; thus, the success rate was 96.2%. The mean distance from the CVC tip to the level of the carina was different for positioning using the TTE method (-3.8 ± 8.2 mm; 95% confidence interval, -5.5 to -2.2 mm) and that using the height-based formula (6.1 ± 9.6 mm; 95% CI, 4.2 to 8.0 mm; P = 0.001). The distance was consistent regardless of the height when the insertion length was determined using TTE (r = -0.048, P > 0.05).

CONCLUSIONS: Transthoracic echocardiography is a practical method for the correct placement of the CVC tip with less variability compared to the height-based method.