Catheter-Induced Cardiac Tamponade

To the Editor The recent editorial by Shamir and Bruce1 comments on ways to prevent cardiac tamponade associated with insertion of a central venous catheter (CVC). The optimal position of the CVC tip remains the subject of debate because no position is absolutely safe.2 The United States Food and Drug Administration strongly advises that the CVC tip should not be placed in the heart. However, pericardial tamponade may also occur with perforation of the superior vena cava below the pericardial reflection, which is not visible on chest radiographs. Schuster et al.3 suggested placement of the tip of the CVC above the carina as a reliable landmark for the pericardial reflection. However, the cephalic limit of the pericardial reflection is highly variable, and accordingly, it is difficult to ensure placement outside the pericardium.4 In patients with sinus rhythm, electrocardiogram (ECG) guidance is a reliable bedside method to site the CVC tip in a proper position (during the insertion procedure!), which should at least have been mentioned by Shamir and Bruce.5,6 With an intraluminal wire or saline as electroconductive medium, the tip of the CVC serves as an electrode (Einthoven lead II) to obtain the intravascular ECG. An adapter allows the operator to switch from a surface (Einthoven lead II) to an intravascular ECG. The first increase in P-wave amplitude relates to the pericardial reflection.7 The P-wave amplitude increases to its maximum once the catheter tip levels with the superior vena cava/right atrial junction.8 Further advancement of the catheter tip results in a decrease in P-wave amplitude or biphasic P wave.6,8 We suggest placing the CVC tip at the maximal P-wave amplitude.6,8 Wolfram Schummer, MD, DEAA, EDIC Jena and SRH Zentralklinikum Suhl Department of Anesthesiology and Intensive Care Medicine Friedrich Schiller University Jena, Germany [email protected]