NoBlood

We have a patient in a hospital who has blood clots located at the bilateral groin regions. They were pretty large and are now starting to break up and circulate. The docs have started the patient on heparin and Coumadin. H and H is stable. The doctors, however, say that many blood draws (adult tubes) are necessary over the next four to six hours or so. When pediatric tubes are mentioned, they are resistant to that. Is there anyone out there who has managed this successfully? Any and all suggestions are greatly appreciated. Thank you in advance.