ACUTE MI -PT/INR results! I need explanation! - page 2

PT/INR 0.6 seconds/1.8 I understand anything over 1 is high for INR and the patient is at risk for bleeding but I cannot find and explanation for reduced PT other than I think the clot forms too rapidly. Am I on the right... Read More

  1. 1
    It would be great if you had the clinical experience to SEE what happens sometimes with blood. When you draw blood the specimen is a very viscous fliud. I have seen blood clot immediately in the tubes. When you draw a Pt/PTT/INR its in a blue tube is has a chemical additive in it. the reason you must fill the tube to a certain level is to get the correct ratio of 3.2% sodium citrate to blood specimen. This directly effects clotting time. If a specimen clots relatively quickly, then this can be indicative of a person having an MI cause by a blood clot. This is the exact reason we pump people full of anticoagulants in the cath lab.
    onthemark likes this.

    Get the hottest topics every week!

    Subscribe to our free Nursing Insights newsletter.

  2. 1
    The INR is actually the patient's clotting time in seconds/the accepted reference of 12 seconds.

    A bad draw resulting in hemolysis can throw this off - anything that stimulates platelet aggregation can throw it off. (Like leaving a tourniquet on for over 60 seconds.) A "short draw" will disrupt the delicate blood-to-Sodium Citrate anticoagulant ratio in the blue top tube used for these draws, which is why the lab often cannot accept a short tube for anticoag tests.

    High hematocrits will also disrupt the result, by disrupting the 9:1 blood to anticoagulant ratio. The lab has to adjust the amount of sodium citrate in the tube for this: Sodium Citrate needed for accurate test = 1.85 x 10^3 x [100- (patient hematocrit percentage x 100)] x volume of patient's blood. So be nice when they ask for an additional draw!
    nursej22 likes this.
  3. 1
    In the last thirteen years, I have seen one case of pts INR getting too low 1.7 and he threw a clot to a diagonal branch (had anterior MI). The usual route to an MI: the vulnerable plaque inside a coronary artery ruptures setting off the clotting cascade, and formation of a clot. Once its 90-100% blocked , the pt has an MI. In the cath labs that I have worked, the pts with INRs of 1.8 or less the cardiologists will cath them. Otherwise, they will postpone until their INR is in a safer range.
    CCL RN likes this.
  4. 1
    Quote from chademack
    It would be great if you had the clinical experience to SEE what happens sometimes with blood. When you draw blood the specimen is a very viscous fliud. I have seen blood clot immediately in the tubes. When you draw a Pt/PTT/INR its in a blue tube is has a chemical additive in it. the reason you must fill the tube to a certain level is to get the correct ratio of 3.2% sodium citrate to blood specimen. This directly effects clotting time. If a specimen clots relatively quickly, then this can be indicative of a person having an MI cause by a blood clot. This is the exact reason we pump people full of anticoagulants in the cath lab.
    Nope. We anticoagulate pts in the CCL because we are placing wires, balloons, and stents in their coronary arteries. For a STEMI, they get an ASA and hep bolus, to keep the blood thin and easy to flow around the newly formed clot, and to prevent the body from making the clot bigger. The clot, like skip said, is usually caused by ruptured plaque and the resulting clotting cascade. Not from a blood clot from a coagulopathy.

    Now, I've seen STEMIs caused by such things like that, showering of clots, or septic emboli, rare but true. But if the blood clots in the blood tube, like you used in your example, it's not indicative of an acute mi, probably more indicative of hemolysis.
    MMARN likes this.


Nursing Jobs in every specialty and state. Visit today and Create Job Alerts, Manage Your Resume, and Apply for Jobs.

A Big Thank You To Our Sponsors
Top