Panic Value: INR or PT?

Hi, We run coagulation tests at my work place on an ACL 9000 from Instrumentation Laboratory and I would like to know what should be considered as a panic value, a high prothrombin time (PT) value or the international normalized ratio (INR) value? If it is the PT value, what value should be considered as a panic? Miguel A. Vélez MT (ASCP), Immuno Reference Laboratory

Hello, Mr. Vélez and thank you for your question. I recommend you use the INR value as your panic value, as the PT in seconds may vary slightly in sensitivity from lot to lot. It appears from our May, 2012 Quick Question survey that most of our participants choose the INR of 4.0 as their call-back value. Geo.