Use of a modified Doppler flow detector for percutaneous cannulation of the internal jugular vein

To lessen the risks associated with cannulation of the internal jugular vein, a method to identify the contours of the carotid artery and internal jugular vein at the site of cannulation is proposed. This method uses a doppler flow detector equipped with an adjustable electronic filter which selectively enhances the sound component due either to the arterial or venous flow. This method has been applied clinically and was found to be useful in the identification of the vessels. Since doppler flow detectors are readily available in many hospitals and the required modification is simple, we hope that other institutions will find this technique useful in their clinical practice.