Malposition of central venous catheter in a small tributary of left brachiocephalic vein.

Erroneous positioning of central venous catheters in small tributaries of large central veins is a rare occurrence. We describe two such unusual incidents involving cannulation of the small tributaries of left brachiocephalic vein. Malposition was suspected when the central venous waveform could not be obtained despite all attempts. Unusual central venous waveforms may indicate central venous catheter malposition, and these waveforms have not previously been described.