Based on several studies, central line malposition occurs between 3.3-6.7% of the time.1 The historical recommendation is that malpositioned central lines should not be used for long periods of time, if at all. The basis for these recommendations is based primarily on theoretical grounds but has not been prospectively studied. The primary reason for this is that many of these malpositioned lines are removed fairly quickly after the malpositioned line is recognized. Therefore, there is not a lot of long-term data to determine the safety of using malpositioned central lines.
For the purpose of this blog, a malpositioned central line refers to a central venous catheter positioned so that its tip is directed away from the heart. An example of a malpositioned line could include a central line inserted into an internal jugular vein (IJ) that ends in a subclavian vein (SCV) or in the contralateral IJ. A different example is a SCV line that ends with its tip in the contralateral SCV or in an IJ vein. The theoretical risk with these examples of a malpositioned line is that fluid infused through said catheter will flow against the natural flow of blood. Infusion of fluids at a very rapid rate can theoretically increase the risk of vessel injury or thrombosis. In addition, if the catheter is directed cephalad in the IJ vein, fluids are directed towards the brain against the natural venous efflux from the brain which can theoretically increase intracranial pressure.
Another complication that has been reported with malpositioned central lines is the rare occurrence of vein perforation. One study reported that the incidence of vein perforation was 0.28 per 1,000 catheter days and was three-times more common in left-sided central lines.2 This complication is supposed to be much less common in this era of less rigid central venous catheters.
The short-term use of central lines that are malpositioned in the SCV is probably safe provided that the line is not being used for aggressive fluid resuscitation, chemotherapy, TPN or hyperosmolar fluids. Obviously, you would like to remove this central line once it is no longer necessary and ideally within 24 hours. Use of a central line that is malpositioned in the IJ vein is not recommended since fluid is directed towards the brain that can cause adverse consequences.
We certainly need more prospective data about the safety of using malpositioned central venous catheters. Ultimately, the question becomes whether it is riskier to use a malpositioned central line or to remove it and place a whole new central line with the inherent risk and inconvenience of any central line placement.
Sources:
- Schummer W. et al. Mechanical Complications and Malpositions of central venous cannulations by experienced operators: a prospective study of 1794 catheterizations in critically ill patients. Intensive Care Medicine. 2007; 33: 1055.
- Walshe, C. et al. Vascular erosion by central venous catheters used for total parenteral nutrition. Intensive Care Med (2007) 33:534–537