Here are the results from our July Quick Question:
When do you perform partial thromboplastin time (PTT) mixing studies?
a. Any non-heparin PTT that is prolonged beyond the upper limit of normal: 43%
b. Any non-heparin PTT that is substantially prolonged beyond the upper limit of normal: 15%
c. We solicit clinical information before performing mixing studies: 28%
d. We don’t perform mixing studies: 9%
e. Please e-mail George if you have other comments: 5% (These appear as blog posts)
These results seem reasonable, but I would like to reiterate a comment I heard from Dr. Dorothy (Dot) Adcock-Funk at the Midwest Hemostasis conference in May, 2010 that there is little to be gained from performing mixing studies on a specimen that is prolonged just a second or two beyond the upper limit of the reference interval.
No comments here.