In my facility, we flush peripherally inserted central catheters (PICCs) and implantable vascular access ports with saline. I believe we have more problems with clotted lines than we did in the past, when we flushed with heparin. Nurses in some other facilities in my city still routinely flush with 5 mL heparin, using the SASH protocol (saline, administer drug, saline, heparin). Which technique is considered best practice these days? -V.M., ILL.

Our consultant says, "When a nurse tells me an I.V. line is clotted, I have to ask where the clot is-inside the lumen or inside the vein?" Injecting t-PA into the line won't be effective if the clot is in the vein; in that case, a low-dose t-PA infusion is needed. But without a contrast study, a nurse at the bedside can't determine the clot location-all she knows is that the line isn't working.

Any facility that has a persistent problem with clotted lines, with or without heparin, must look at what's causing it, our consultant says. This requires a systems approach-not changing one component, such as the flush solution. See the resources below for more detailed information on getting to the root of the problem.

Resources: Hadaway L, Heparin locking for central venous catheters, Journal of the Association for Vascular Access, Winter 2007; Hadaway L, Technology of flushing vascular access devices, Journal of Infusion Nursing, May/June 2006.