Correct positioning of the venous port-a-cath catheter: comparison of intravascular electrocardiography signal from guidewire and sodium bicarbonate flushed catheter.
A prospective study comparing the efficacy of wire-conducted intravascular ECG (IVECG) signal and signal from the port with a sodium bicarbonate (NaHCO3) flushed catheter to correctly place a catheter tip was carried out in 100 patients. The correct position of the catheter tip was confirmed as follows: with technique G, the IVECG signal was conducted from a guide wire to identify the tip position. With technique P, the IVECG signal was conducted from the port with a NaHCO3 (0.8 mmol/ml) flushed catheter to ascertain the tip position. Each patient received both technique G and technique P in a randomized sequence. The quality of IV-ECG signals, which included baseline drift, P wave pattern and QRS wave pattern, were assessed for ten seconds. Satisfactory quality of these IVECG signals was observed in all of the patients with technique P and 90 of the 100 patients with technique G, and this difference was significant (P=0.001). There was no obvious difference between the techniques in catheter tip placement time or the measured optimal catheter length. The incidence of atrial premature contractions was higher with technique G than with technique P (13% vs 2%; P=0.003). Therefore, technique P is a practical alternative for correctly placing the catheter tip of a Port-A-Cath.