I've frequently heard that clamping is not only unnecessary, but should not be done when using a positive displacement cap.  To me, this is a safetly issue in preventing air embolism should the cap become inadvertantlly disconnected, and that if the cateter manufacturer provides a clamp, than that clamp should always be used.  I'd be interested in some feedback to support my position or rationale for not clamping.  Thanks

I would always insist upon

I would always insist upon all catheters being clamped after use. The point at which you clamp is totally dependent upon the function of the needleless connector in use. Negative displacement = flush, clamp, then disconnect. Positive displaement= flush, disconnect, then clamp. Neutral displacement can be clamped at either point. Given the fact that there is no longer reimbursement for air emboli, I would insist on all catheters being clamped. I do think that they can come loose and allow air to enter even with a luer connection. Lynn

Lynn Hadaway, M.Ed., RN, BC, CRNI

Lynn Hadaway Associates, Inc.

126 Main Street, PO Box 10

Milner, GA 30257

Website http://www.hadawayassociates.com

Office Phone 770-358-7861

Confusion is the reason

Often, nurses are taught in school or by other nurses to clamp the catheter with the syringe still on after flushing the catheter.  This works well with a neutral or negative displacement cap.  If you are using a postive displacement cap, you can certainly clamp the catheter if you want to, but it needs to be done after the syringe is disconnected and the cap has had a chance to activate an give the positive push.  Many nurses get confused, and do not know what type of cap they are using on a particular catheter, especially when a facilty has more than one cap in its stock or accepts patients from multiple areas or other facilities and keeps the caps on that the patient arrived with.  If the nurse flushing the line does not know what type of cap it is, they cannot know the correct clamp sequence after a flush.  With more than 25 types of caps available on the market, it is hard to keep up.  Inservicing from the providing manufacturer is often done once, and does not always get every nurse. 

Many times nurses are told not to clamp a positive pressure device since if they don't clamp it at all they can't clamp at the wrong time, some may feel that is easier than trying to change their practice of clamping before taking off the syringe.

All caps today are luer locking, so the risk of one coming off is actually quite low. 

The safest practice is to clamp the catheter in the right sequence and is necessary when changing the caps. 

It is a matter of education.  If a hosptial can simplify and only use one type of cap, then staff can be taught the correct clamping sequence easily.  In addition, if a patient comes in from another location, the nurse should change the cap to the one the  hospital provides, thus the clamping sequence will remain correct.  Unfortunately this does not always happen.

Chris Cavanaugh, RN, BSN, CRNI, VA-BC

PICC and CVC clamping

I have always been taught to clamp ALL PICC lines.  I'm sure the manufacturer would agree.  When clamping a PICC line that has a positive cap, you are to clamp after the fact, that's all.  Flush your line, take off the sryinge, then clamp, that won't hurt the positive action of the system.