Application of intravenous electrocardiography for insertion of central veins dialysis catheters.

One fifth of the inserted dialysis catheters in the internal jugular or subclavian veins may be misplaced. Appropriate positioning of the catheter tip is sometimes difficult. We attempted to use intravenous electrocardiography (ECG) to guide catheter tip positioning in 30 hemodialysis patients (17 (57%) were men, and the mean age was 43 +/- 12 years). who required vascular accesses for dialysis by insertion of double lumen temporary catheters via the jugular veins. Before cathe-terization, standard ECG on the long lead D II was performed and P-wave height was recorded. P-wave voltage was also measured via the blue (venous) and red (arterial) lumens, using the guide wire as an electrical conductor. After confirmation of the appropriate position of the catheter tip at the superior vena cava (SVC)-right atrial junction using chest radiography, the ECG lead corres-ponding to the right hand was connected to the guide wire lodged inside the lumen of the blue catheter. P-wave height in the long lead D II was recorded. The guide wire was withdrawn so as to bring its tip tangent to the tip of the red catheter. ECG was performed on the long lead D II in a similar manner, and the P-wave height was recorded. The mean P-wave voltage in normal ECG and intravenous ECG (red and blue catheter tips) measured 1.27 +/- 0.38 mm, 3.10 +/- 0.95 mm, and 5.42 +/- 1.76 mm, respectively. The difference between the mean P-wave voltages measured in standard and intravenous ECG (blue and red catheter tips) was statistically significant (P< 0.05). We conclude that the dialysis catheter tip can be positioned appropriately via the measurement of the P-wave height by intravenous ECG and using the sinoatrial node as an accurate landmark. This method can complement the chest radiography in the appropriate placement of the central vein catheters.