Verification of the position of a central venous catheter by intra-atrial ECG. When does this method fail?

The purpose of this study was to determine why intra-atrial ECG tracing for checking the position of a central venous catheter fails in certain patients. Three hundred and fifty prospective and consecutive patients scheduled for central venous catheterization using various puncture sites and techniques were investigated. The catheters were 20 cm in length. After its introduction, the catheter was connected to an Alphacard (Sterimed, Saarbrücken) for the intra-atrial ECG tracing. The method failed in 29 patients, of whom nine had manifest myocardial pathology. In two patients the catheter looped, while in the remaining 18 the catheter proved to be too short. In these 18 patients, the cannulation was mainly performed via the external jugular vein and/or from the left side. Most of the patients were elderly males, and 11 of the 18 patients showed radiological signs of pulmonary emphysema. In such individuals it is advisable to use a catheter longer than 20 cm.