From Alan Neal, Pathlab, NZ. Just wanted a private conversation about the January 11, 2018 Fritsma Factor entry, "POC and Plasma-Based PT/INRs." I do not agree with the comments made within this article and challenge the logic used. Essentially, if monitoring an enzymatic pathway such as coagulation, with the 'detector' being used is fibrinogen to fibrin, then that rate of reaction will be dependent on the substrate concentration, i. e., fibrinogen, and the sensitivity of the analyser to detect the end point. So if no or reduced fibrinogen or dysfibrinogen, then reduced Vmax and hence PT/INR will be more prolonged than test system using a clot based end point detection.
Posts - Screening Assays
Jan 22, 2018 10:41am
Nov 8, 2017 6:36pm
Jan 5, 2017 9:24am
From Diane Treadway: Hi, we had a situation in our cath lab last week. The patient was on the table. They performed an ISTAT PT and obtained 13.0 seconds and 1.1 INR. The patient had had a PT drawn and run by the main lab earlier. Those results on a Stago instrument were 24.2 seconds and a 2.2 INR.