[Intra-arterial ECG leads of a positive P-wave potential during central venous catheterization]

The application of a central venous catheter (CVC) is a routine procedure in anaesthesia and intensive care medicine. Although the procedure is generally carried out without complications, nevertheless numerous and, in part acute life threatening and lethal complications have been described. The complication rate during placement of a CVC is up to 12%. To ensure the correct position of the catheter, different methods may be used: for example the intravascular feeder of a positive P-wave of the ECG. In the case of a position check via the ECG (α-Card), the catheter's point serves as a unipolar electrode. The intraatrial ECG lead is used as a raised and heightened P-wave potential for the correct catheter position. In this case, we present a 65 year-old critically ill patient with an occlusion of the right superficial femoral artery and acute respiratory distress syndrome (ARDS) in whom a puncture trial of the right internal jugular vein was carried out. This was followed by the placement of the CVC intended for the right internal jugular vein which, however, turned out to be a direct puncture of the right carotid artery. Despite the inaccurate intra-arterial position, forwarding of the catheter showed a typical raised and heightened P-wave potential. The artery puncture was checked via a blood gas analysis and the artery blood pressure diagram tracing. The removal and correct placement of the CVC were achieved without any problems. These findings emphasize the P-wave potential in the ECG feeder does not correlate with the transition from the superior vena cava to the right atrium. Consequently, this does not preclude an intra-arterial malposition.