Here’s a summary of our June, 2012 Quick Question:
To perform the chromogenic anti-Xa heparin assay, how many separate reference curves do you maintain for unfractionated (UFH), low molecular weight (LMWH) heparin and fondaparinux?
a. One hybrid curve for UFH and LMWH, same curve (computed) for fonda: 7 (16%)
b. One hybrid curve for UFH and LMWH, a separate curve for fonda: 11 (25%)
c. One reference curve for each heparin: UFH, LMWH, and fonda: 22 (50%)
d. We don’t perform the chromogenic anti-Xa heparin assay: 4 (9%)
Most of us have chosen to stay with three curves rather than take advantage of the various manufacturers’ combined (hybrid) curve that may be used to measure either UFH or LMWH. I’m curious whether those who do not use the hybrid curve find it necessary to confirm the type of heparin being used before running the assay.