Influence of infusion flow rates on central venous pressure measurements through multi-lumen central venous catheters in intensive care.

Abstract

To study the influence on central venous pressure (CVP), measured at the distal port, of crystalloid infusions administered through the proximal port(s) of a central venous multi-lumen catheter. Thirty-one intensive care patients. CVP was measured at the distal port of a multi-lumen catheter inserted in the subclavian or internal jugular vein. Using the proximal port(s), saline (0.9%) was infused at rates varying from 2 ml/h to 14,340 ml/h. CVP measured before the infusion and during infusion (after 30 s to 1 min) were not significantly different. Positive pressure ventilation with PEEP (5.6 +/- 2.5 cmH(2)O) and/or norepinephrine infusion (0.25 +/- 0.21 microg kg(-1) min(-1)) did not produce any significant change in CVP during infusion. The administration of crystalloids at different flow rates through the proximal port(s) of a multi-lumen catheter placed in the superior vena cava does not affect CVP measurement at the distal port, even in mechanically ventilated patients or patients receiving vasopressors.