ECG-guided central venous catheter positioning: does it detect the pericardial reflection rather than the right atrium?

Central venous catheter tip migration due to tracheal extubation: a prospective randomized study

Considerable numbers of patients undergo central venous catheterization (CVC) under mechanical ventilation. We hypothesized that the return of spontaneous breathing and tracheal extubation could be associated with distal CVC tip migration towards intracardiac positions due to decreasing intrathoracic pressures and subsequent readjustment of mediastinal organs. Patients scheduled for cardiac surgery were randomized for right or left internal jugular vein (IJV) CVC placement under general anesthesia and mechanical ventilation. CVC tips were positioned at the cavoatrial junction and measured at the time of placement, postoperatively under mechanical ventilation, and after tracheal extubation until 48 h after surgery. Measurement methods included intravascular electrocardiography (ECG) P-wave amplitude, transesophageal echocardiography, and chest radiography (CXR). Out of 70 patients, 60 were eligible for final statistical analysis (31 right and 29 left IJV CVC). According to ECG interpretation, CVC tip positions remained below the pericardiac reflection point in the distal superior vena cava over the course of the three measurement intervals. The ECG revealed significant proximal migration of CVC tips from the time of placement to the time of tracheal extubation (1.19 ± 0.55 vs. 0.62 ± 0.31 mV; P < 0.001). A CXR using CVC tip to carina distances revealed no significant tip migrations in the time between postoperative assessment and following tracheal extubation (5.1 ± 1.7 vs. 5.3 ± 1.5 cm; P = 0.196). In patients with CVCs positioned at the cavoatrial junction, tracheal extubation was not associated with significant postoperative CVC tip malposition, but tended to undergo proximal migration. This trend should be considered particularly in left-sided thoracocervical puncture approaches to avoid unfavorable CVC tip positions.