To the Editor.—The report "Cardiac Tamponade From Central Venous Catheters" by Drs Edwards and King (Archives 1982;117:965-967) describes a patient in whom cardiac tamponade developed after perforation of the right atrium with a central venous catheter. We agree with the recommendations made by the authors for insertion and caring for central venous catheters but would like to add another. In the case reported, the cardiac tamponade was caused by clear fluid, and not blood. Although we are not told whether the central venous catheter was used for fluid therapy, the fluid in the pericardium most likely resulted from either transfused solutions or from fluid used to keep the catheter patent.
Other investigators have reported that perforation of central veins or cardiac chambers by a catheter produces a seal around the catheter, so that no blood is extravasated.1,2 Even though the catheter's tip is outside the venous system, respiratory