devices for home self-testing PT or INR

Pam RN · Feb 16, 2007

I have the Coaguchek machine by Roche. I had a Mitral Valve Replacement 18 years ago this May and have been using the machine for about 8 years. After 10 years of needle sticks my veins were getting pretty scarred and as someone mentioned getting to a lab is not always convenient, especially when out of town. My cardiologist is in another city 90 miles from where I live so when I had my blood drawn at the hospital I worked at or at a hospital near my house it's a hassle because my doc is not on staff.

The company recently recalled the strips a few months ago and the FDA won't be approving new ones until April so back I went to the lab and I hate it. The machine could be improved due to size and the amount of strips used to run the controls but it really is so much better than going to the lab.

There are guidelines such as if my INR is greater than 5 or 6 I do have to have a venous draw to double check the value. Also, being a nurse, the Coumadin Clinic gave me some additional instructions to follow that they wouldn't give the average patient such as holding my dose if my INR is higher than 4.7. I check my level on the day they tell me to and then call in my result and then they call me with my instructions. It's that simple. They also told me that the patients who are able to understand how to use the machine and perform a fingerstick on themselves and get the drop of blood on the strip correctly. If the nurses at the office feel the patient can't perform this then they would not approve home use for them.

The home machine is not appropriate for every patient but I am so glad it's available as an option.

dria · Feb 16, 2007

My father has his own machine-checks his PT/INR and calls it in to the doc. Insurance picked up the tab for the machine itself, but we are currently having trouble getting them to cough up the $$$ for the lancet/test strip. They are surprisingly expensive...much more so than the glucometer strips.

dria · Feb 16, 2007

One more thing...as far as pricing or obtaining the item, we did not find any DME supplier that carried the it and ended up having to order directly from the manufacturer. The company was fantastic...a rep contacted the doctor's office to discuss the accuracy of home monitoring (and convinced him to write the order) and sent a rep way out where he lives (just east of where Jesus left his sandals) to instruct him on how to use the machine.

gauge14iv, MSN, APRN, NP · Feb 16, 2007

yeah the stips are about 250.00 for 48 strips for the coaguchek! But then it takes almost a year to use them all.

Also worth noting is that a machine the manufacturer sells to a docs office is different than a home use machine - that machine would have a CLIA waiver, the home use machine would not.

GingerSue · Feb 16, 2007

thanks for this information

At what INR level should the warfarin be held -- I see above that 4.7 was indicated, but I know that in a particular case - it is held because it was 3.7

(my textbook says that normal INR is between 2 to 3)

That's interesting about FDA approval for the strips - what was wrong with them that they were recalled?

kimmie518 · Feb 16, 2007

I can understand it's use if a patient can't make it into a laboratory, but anyone else using the machine is useless, and frankly, just lazy.

Once your therapeutic dose has been established, you don't need to adjust your dose so frequently.

GingerSue- Each hospital should have it's own policy pertaining to anticoag. holding. For classroom purposes, I would say anything about a 3 you would hold (if your coursework says 2-3 is normal).

PHLEBOTOMIST_TO_RN · Feb 16, 2007

Prothrombin time (PT) Normal:

10-13 seconds

International normalized ratio (INR):

1.0-1.4

GingerSue · Feb 16, 2007

Prothrombin time (PT) Normal:
10–13 seconds
International normalized ratio (INR):
1.0–1.4

okay - this pharmacology book says that INR is based on prothrombin time

a normal baseline or control PT is approximately 12 sec;

a therapeutic value (PT) is approximately 1.5 times the control (18 seconds)

and therapeutic INR values are 2.0 to 3.0 in most conditions

PHLEBOTOMIST_TO_RN · Feb 16, 2007

:roll :roll Never question the lab.......JK

kimmie518 · Feb 16, 2007

Prothrombin time (PT) Normal:
10-13 seconds
International normalized ratio (INR):
1.0-1.4

No, INR is 2-3.

An INR of 1.0-1.4 doesn't make any sense for a patient on anticoags. Since an INR is a ratio, you cant have a ratio of 1.0- that says a person on anticoags, has the same bleeding time compared to a "healthy" person, which is not the intended effect.

1.0-1.4 makes more sense for a healthy patient.

Where is your source from?

gauge14iv, MSN, APRN, NP · Feb 16, 2007

I can understand it's use if a patient can't make it into a laboratory, but anyone else using the machine is useless, and frankly, just lazy.
Once your therapeutic dose has been established, you don't need to adjust your dose so frequently.

In a ideal world - perhaps.

However - all kinds of things can affect the effectiveness of coumadin - diet, illness, other medications - you name it.

It also depends on what you are trying to achieve.

Frankly it isn't lazy - would YOU as a 30 year old person with a fulltime job and 3 kids, who is on coumadin for a DVT/clotting disorder want to have to make a trip to a lab once a week that takes you an hour and costs you 3 bucks for parking everytime? I'd say that would get old pretty fast and lazy would have nothing to do with it! And even though this patient is stable for say 3 weeks - would you want to let someone on >10mgs of coumadin go a month or two without monitoring? I'm thinking not. Give her the monitor!

gauge14iv, MSN, APRN, NP · Feb 16, 2007

1.0 to 1.4 is NORMAL INR for most people. It is not a therapeutic INR for people on anti-coagulants.