INR/PT Lab Values

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I'm looking or assistance with understanding the INR and PT lab values for a care plan I'm doing. From what I'm reading the INR and PT should both go up and down in correlation with the other. Is this not true?

The lab values I had for this patient, INR was 1.02, normal is 0.8-1.1, and the PT was 5.8, normal range is 9.5-12.5. And their aPTT was 23.6, normal 26.0-36.0.

The INR is normal, while the PT was pretty low. I'm thinking I may have written the PT values down wrong since it's so low, or could these values be accurate? Everything I'm reading says they should both reflect either low, high or normal.

And isn't that PT really low? I would be worried about clotting, but these labs weren't even mentioned in report, and never repeated.

Specializes in Adult Gerontology Acute Care.

You have the right idea, however, you must realize that the human body is not a machine, and therefore, we cannot expect precisely for it to behave so. Ideally, the INR and PT values do, in fact, reflect and have a positive correlation, but this is for the HEALTHY individual. You add liver disease, medications, infections, etc., things change quite quickly. For the basics, the PT can be "low" and the INR be "normal" or vise-versa. These are all normal fluctuations within the body during normal physiological changes.

I hope I answered the question for you!


2 Posts

Thank you! It did help a lot. Now in regards to the PT levels. Wouldn't they be worried about that being too low? Or is that not low enough for anyone to be concerned?

FYI this patient is not on any anticoagulant therapy.

Specializes in Adult Gerontology Acute Care.

Not in the least bit. The PT/INR work through various clotting cascades, and is not the end, all, be all, lab values to be concerned about when they are low. The only concern would be if the patient was on Coumadin/warafin therapy and those values were low. Other than that. No worries.