they both need updated.
heparin does not break down clots.
it is no more effective in "decloting" than saline is.
heparin is used in the case of a dvt or a pe to prevent the clot from growing, while the body's natural "clot buster" breaks down the clot. if desired, some man-made thrombolytic (alteplase, reteplase, streptokinase, urokinase) can be added to help the body break the clot down faster.
we use heplock in ivs/central lines to prevent clot formation, not to break down clots.
the correct drug for decloting is one of the thrombolyics. we used to use reteplase, but now strictly use alteplase ("cathflo activase").
now, on to the question of syringe size.
do not use a tb syringe.
how wrong she was for using a tb syringe depends on how she was using it.
if the line is only partially occluded (can flush but can't aspirate) then a 5 or 10 cc syringe (depends on hospital policy) filled with the thrombolytic can be used to simply instill the drug into the line, like giving an iv push med. if she used a tb syringe here, then more than likely no harm was done.
if the line is completely occluded, then a vaccuum must first be created in order to allow the agent to reach the clot. basically, you suck the air out, and then (without letting more air get in) replace that air with the thrombolytic. there are a couple of ways to do this. a tb syringe would most likely be unsuccessful in creating that vaccuum. again, probably no harm done, but very ineffective.
if, however, she had a completely occulded line, and instead of creating a vaccuum, was using the tb syirnge to "force" the drug into the line, this is a big, huge no-no. completely against standards of care, and could have caused the line to rupture.