Question for Al

[ccrawford]

I followed the thread on subdurals with interest as I have been having a bunch of problems with my back. Some time ago, there was discussion of what the risk of stroke was for every day you were outside the low end of your range. Do you remember the answer ?

 

[RandyL]

I don't know what the risk is but I do know that I have to get an epidural. I have been to 2 different chiro's and can't seem to get better. I have to stop taking coumadin 5 days before the procedure. What seems to be the problem with your back?

 

[ccrawford]

Two different problems: the lumbar area probably has a compression problem with one of the vertebrae. The cervix area is likely a bone spur which causes my neck and shoulders to ache and my right index finger to be numb. The people who make Tylenol are doing well by me.

 

[Dennis S]

Good question

Good question

I followed the thread on subdurals with interest as I have been having a bunch of problems with my back. Some time ago, there was discussion of what the risk of stroke was for every day you were outside the low end of your range. Do you remember the answer ?

I have also wondered about this. I seem to recall that the odds for a clotting event for an un-medicated (no coumadin) mech. aorta valve are in the vicinity of 4% over a year. I am the furthest thing from a statistician (not even sure I can spell it). But it seems to me that if that 4% exposure is assumed to be distributed evenly throughout the year, it would be comparable to one of four aces hidden in a deck of 365 cards. So, for approximately every 90 cards picked (1 per day over a 90 day period) you might expect to pull that bad ace. (Since 4 bad events predicted to occur over 365 days seems approximately the same odds as 1 bad event predicted to occur over a 90 day period). So I have assumed my odds of a clotting event (ASSUMING I am right on the 4% per year) are about 1 out of 90 for any particular day I am out of range. Now, I hope somone who works with statistics will come and show the error of these calculations. My son, who is usually pretty good with these things says that the odds of a stroke on a given day out of range are considerably more favorable than what I have calculated. Unfortunately, I didn't follow his calculations, and we ran out of time to work on the problem. I would love to have someone show me that I have overstated the problem. Even if I am correct, odds of 1 out of 90 are pretty good, I guess.

 

[Blanche]

I am less concerned with odds than I am with risk-management. After 10 years of successful anticoagulation, my husband had a series of strokes that left him hospitalized for near three weeks. His INR was 1.6 when he had the first one. The doctors called it a "Coumadin failure." In other words, he has a series of strokes (TIA, CAV, TIA) because his INR was too low and clots formed on his valve. Changed his whole life....and that of our family.

Surely, one should be on some bridging therapy before the surgery.

Blanche

 

[Dustin]

I followed the thread on subdurals with interest as I have been having a bunch of problems with my back. Some time ago, there was discussion of what the risk of stroke was for every day you were outside the low end of your range. Do you remember the answer ?

Sometimes I wonder why you would want to drop below 2 for any kind of procedure knowing the increased risk of an embolism. Why do doctors prefer a stroke over a prolonged bleed?

 

[Ross]

Dustin, in this case, a bleed could mean paralysis. I wouldn't want to live my life as a paraplegic nor a stroke victim. There isn't much choice on this one.

 

[ccrawford]

I figured out where I had seen the risk numbers - it was in our very own Al Lodwick's book and/or web site. Here's what Al says: For the following scenario- a person has stopped warfarin 2 or 3 days previous to a procedure and takes 2 or 3 more days after the procedure to get in range, then the risks are:
For an Afib patient the risk is .012% to .3% (note the highest risk is a third of one percent)
For a mechanical valve patient, the risk is .02% to .06%
For a patient with DVT the risk is 1% per day the first month and .2% the second and third month. While most of the above risks appear pretty low, a bridging strategy would still be highly advised, and Al describes it in the web site. Hope this clarifies things a little

 

[ccrawford]

Dustin - To try to respond to your question. Most patients who are aware of the issue do not want to get out of range - ever. The problem is that their doctor calls the shots. Some docs are not aware of the risks and the existance of bridging therapies. Some may be biased based on how they perceive their malpractive insurance coverage. Lastly, there may be that old issue "this is how I've always done this".

 

[RandyL]

I figured out where I had seen the risk numbers - it was in our very own Al Lodwick's book and/or web site. Here's what Al says: For the following scenario- a person has stopped warfarin 2 or 3 days previous to a procedure and takes 2 or 3 more days after the procedure to get in range, then the risks are:
For an Afib patient the risk is .012% to .3% (note the highest risk is a third of one percent)
For a mechanical valve patient, the risk is .02% to .06%
For a patient with DVT the risk is 1% per day the first month and .2% the second and third month. While most of the above risks appear pretty low, a bridging strategy would still be highly advised, and Al describes it in the web site. Hope this clarifies things a little

so is that 2 hundreths of a percent? if so the chance of a stroke are almost nil.

 

[ccrawford]

between .02 and .06 % is how I read it, and yes this seems small. I welcome any corrections or opposing views. I still will try to opt for bridging therapy wherever I can.

 

[Guest]

I have been away and not able to post for awhile, but this seems to be the right numbers.

It is not an easy decision. Nobody can make it for you.