So what’s the INR of FFP? Or stated another way, what’s the lowest you can correct a patient’s INR using infusions of fresh frozen plasma?
One of the mainstays of correcting coagulopathy, either from hemorrhage or due to medication like warfarin, is transfusion of FFP. Frequently, clinicians will write orders to administer FFP until a certain INR is achieved. What is a reaonable INR?
A “normal” INR is 1.0, plus or minus about 0.2, depending on your laboratory. However, two separate studies have shown that transfusion of FFP will not reliably decrease the INR below about 1.7.
Bottom line: The answer to the question is about 1.6. If any clinician orders FFP transfusions with a goal INR below this, it probably won’t happen. And since transfusions of any product have risks, my “juice to squeeze” ratio of risk vs benefit begins to fail at an INR of 1.6. Below that point, the patient needs a normal temperature and good perfusion to drop their INR further.
References:
- Toward rational fresh frozen plasma transfusion: the effect of plasma transfusion on coagulation test results. Am J Clin Pathol 126(1):133-139, 2006.
- Effect of fresh frozen plasma transfusion on prothrombin time and bleeding in patients with mild coagulation abnormalities. Transfusion 46(8):1279-1285, 2006.
