Colonoscopy

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Tom in MO

Your arguement is the just a mirror of those who say I will take a tissue valve and have a redo in a few years because I don't like warfarin.

Why would you want 2 colonoscopies? Any procedure carries risks. The scope could perforate the colon and...

You go into a colonoscopy to explore, find, snip and probe. All at once. You want to have a whole nother low fiber for days, clear liquids for a day, purging concoctions all over again?

If you have been coagulated properly for a while, you can go off warfarin for 5 days and restart without major problems. Yes I chickened but I still held off lovenox for 24 hours with an INR of 1.5.

Clots on valves take a while to form. It is a reasonable risk to take once than to chance and compound risks.
 
Bridging is only needed if they take remove tissue (e.g. polyps, samples, etc.). Most colonoscopies do not include those activities. So you can have a colonoscopy on warfarin. If they find things they want to sample or things they want to surgically remove, you'll need a second colonoscopy w/o warfarin. So you bet right, one and done, no risk of stroke from being off warfarin. If you bet wrong, two colonoscopies within a couple of weeks. The second one being off warfarin.
Hi Tom. So if I understand you correctly you do the first on Warfarin and hope they find nothing?
 
I agree with everything you say, but just wanted to add something here:

Clots on valves take a while to form. It is a reasonable risk to take once than to chance and compound risks.
another issue which is covered by AC Therapy is the triggering of thrombosis caused by pressure jets on valve opening and valve closing. These triggered micro clots will then move along the direction of the pipe (the Aorta) and may lodge in places not desired >if not broken down before they get there<

One of the purposes of AC Therapy is to slow down the formation and give additional time for that normal body process (of breaking them down).

I believe that the number of Dynes needed will mean you're doing exersize (probably fitness training or event levels) to trigger this. I would guess that a sedentary period would not be high risk.


1617833332280.png


the interested may research: Fluid Mechanics of Heart Valves by Yognathan (et al)

the usual disclaimer applies
1617833506583.png
 
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My 2 cents worth. Bridge for the colonoscopy and get it done in one shot if needed.

As to clotting, I had knee replaced last November. Stopped warfarin on Sunday. Started lovenox shots Tuesday, but held Wed evening shot on advice from doc. Surgery Thursday morning and tested at an INR of 1.06. Much lower than I would have liked. Given usual does of warfarin that evening. Doc decided due to bleeding in knee they would hold the heparin for a few days.

Next day, Friday, I had a stroke in early afternoon. I do not remember anything and woke up Sat morning in ICU. Doc came in and said they felt a blood clot had formed on valve and let loose causing the stroke. They had given me the stroke buster shot, TBA and it worked. Saw doc notes and they did 3 CT scans day of stroke. Was in until following Thursday and they put me on heparin and wanted me over 2.0 INR before they released me. Cardiologist said I was extra sensitive and there will be more planning next time I bridge. No after affects from stroke as they caught it fast and shot worked. Interesting as hospital bill showed shot cost $29,000. I am sure insurance paid alot less.

In 2018 I bridged 3 times for 2 tests and 1 surgery with no issues. I think they started me one day too early for bridging this time and I would have liked to be closer to an INR of 1.5 day of surgery. Not sure what surgeon would have wanted this time, but past tests and surgery I was told 1.5 was ok
 
Thanks Pellicle,

They did testing before I was released and feel I have no lasting effects. I have noticed nothing different. I was lucky it happened in the hospital and nurse figured it out quickly and got a doctor in who called a stroke alert. A team including a neurologist showed up and took great care of me leading to shot being given within time it works best.
 
as a PS
I was lucky it happened in the hospital and nurse figured it out quickly and got a doctor in who called a stroke alert.
for what its worth my Uncle (a fit and strong grazier without any heart conditions) died days after a back fusion surgery from a stroke. He was released from hospital and died suddenly one evening (in front of his wife (my Aunt)).

I sometimes think that some of these bone surgeries are riskier than heart surgery.

(PPS: turns out its yes , other)
 
Updates:
I had my colonoscopy with my INR at 1.7. I withheld Lovenox for 24 hours prior to the procedure on Tuesday morning. They removed two small polyps and used clips.

When I got home Tuesday evening, I restarted Warfarin and Lovenox, I continued Lovenox on Wednesday morning and I noticed significant bleeding. I was advised to stop Lovenox and my INR was 2.0

Thursday was better. I cant say less blood but it is there. INR 2.0 no Lovenox.

Friday looks more less like Thursday with only difference that I have been eating food for 3 days without getting too detailed the difference is in the consistency of what comes out not the color.

Since I am not having any other symptoms, I am monitoring with hope that if I don't get my INR too high we will have progress. I notice the blood with bowel movement.

I don't want ER visit on a weekend but if it becomes serious enough there is no choice and that is where we are at.

My surprise is that my INR did not drop fast, I thought I would be below 1.5 but I did not get there.
 
Tom in MO

Your arguement is the just a mirror of those who say I will take a tissue valve and have a redo in a few years because I don't like warfarin.

Why would you want 2 colonoscopies? Any procedure carries risks. The scope could perforate the colon and...

You go into a colonoscopy to explore, find, snip and probe. All at once. You want to have a whole nother low fiber for days, clear liquids for a day, purging concoctions all over again?

If you have been coagulated properly for a while, you can go off warfarin for 5 days and restart without major problems. Yes I chickened but I still held off lovenox for 24 hours with an INR of 1.5.

Clots on valves take a while to form. It is a reasonable risk to take once than to chance and compound risks.

It is not "my argument." It's a clinical choice for me, the patient, provided by the colonoscopy expert, my colorectal surgeon. Nobody wants even 1 colonoscopy, but nobody wants to throw a clot either. Due to bowel problems that led to a 6" colectomy I have had numerous colonoscopies and sigmoidoscopies and they have never "snipped" or "probed" or taken samples. They drove the snake through and watched. I would rather risk a second colonoscopy and have one on warfarin then risk throwing a clot to avoid a second colonoscopy. There is no risk with the just a colonoscopy to your valve. There is risk if they take samples, remove polyps or bridge.

By the way, you don't have to have low fiber for days or purging concoctions for a colonoscopy. All you need is to skip dinner the night before, don't eat, drink clear liquids, and have back to back enemas at home a few hours before the colonoscopy. However, most people think enemas are distasteful so it's not a choice given by many doctors who perform colonoscopies. I found out about the enema option by complaining abut the drug-induced purge.

Hi Tom. So if I understand you correctly you do the first on Warfarin and hope they find nothing?

Yes. The colonoscopy is just on Warfarin. Since I had prior bowel troubles and hemorrhoids, before my valve surgery, I had a consultation with my colorectal surgeon about warfarin and the impacts for someone with my pre-existing problems. I had a colonoscopy before surgery so I could check it out and push back the next one 10 years.
 
It is not "my argument." It's a clinical choice for me, the patient, provided by the colonoscopy expert, my colorectal surgeon. Nobody wants even 1 colonoscopy, but nobody wants to throw a clot either. Due to bowel problems that led to a 6" colectomy I have had numerous colonoscopies and sigmoidoscopies and they have never "snipped" or "probed" or taken samples. They drove the snake through and watched. I would rather risk a second colonoscopy and have one on warfarin then risk throwing a clot to avoid a second colonoscopy. There is no risk with the just a colonoscopy to your valve. There is risk if they take samples, remove polyps or bridge.

By the way, you don't have to have low fiber for days or purging concoctions for a colonoscopy. All you need is to skip dinner the night before, don't eat, drink clear liquids, and have back to back enemas at home a few hours before the colonoscopy. However, most people think enemas are distasteful so it's not a choice given by many doctors who perform colonoscopies. I found out about the enema option by complaining abut the drug-induced purge.



Yes. The colonoscopy is just on Warfarin. Since I had prior bowel troubles and hemorrhoids, before my valve surgery, I had a consultation with my colorectal surgeon about warfarin and the impacts for someone with my pre-existing problems. I had a colonoscopy before surgery so I could check it out and push back the next one 10 years.
I have done colonoscopy off warfarin and on warfarin. They have never found a polyp so my last two have been on warfarin. My doctor said he plans on only doing one more because I am now over 70 and never had a polyp. Surprised me because my brother and cousin had colon cancer.
 
If they remove polyps they will want you back for a real colonoscopy. I need to go back this year due to the size they found, I will always be on the real procedure plan.

Understood - you have Risk factors, I do not. The "real" protocol now includes the position that stool samples are adequate unless there are known Risk factors or the stool shows a risk factor. Cologuard includes a DNA screening that is more effective than the older cheap stool lab.
 
well then, perhaps print and take this along
http://cjeastwd.blogspot.com/2017/12/perioperative-management-of-inr.html


I had some removed in that ...



to bridge or not to bridge is dependent on your clotting risk factors. I personally would not (with your mentioned history) be quick to resume Anti Coagulation Therapy (and that's what bridging is, replacing one ACT with another

View attachment 887676
Heparin is quick to act and quick to vanish, Warfarin is by nature more the furnace that needs to be stoked to keep ACT at the level needed; it gets cold more quickly than it reheats however.

Reach out if you wish to discuss more, but read that blog post (and linked journal article) carefully. By carefully I mean as if you were taking a test on this and don't want to fail.

Best Wishes

pellice - thanks for all this very usefull information. I am now also facing my first colonoscopy after AVR in 2016 and are advised by my doctors to bridge with Heparin. Reading your posting it sounds that your are not in favor to bridge with Heparin (my textbook regime: stop Warfarin 5 days prior procedure, start Heparin injections 3 days prior procedure, stop 24h before, resume Warfarin within 24h post procedure with Heparin etc.).

Of course - messing with two very different AC agents can be tricky - but going with a low INR over multiple days can be risky as well and my target INR is 2.5-3.0 because of a very bad experience with the On-X valve that I had in 2017.

Obviously I am not looking forward to this colonoscopy that I need every 5 years.
 
Hi
Of course - messing with two very different AC agents can be tricky - but going with a low INR over multiple days can be risky as well and my target INR is 2.5-3.0 because of a very bad experience with the On-X valve that I had in 2017.

that's no good ... I recall vaguely you had some issue with being lower than 2.5

If I was you I wouldn't be too worried about being INR > 3, but I'd keep it under 4 (which is pretty standard old school Mitral valve stuff) remember that graph I often post:

14626794599_c646b1872d_b.jpg


risks are low right up till INR < 4.5

also, in case you're not clear on bridging and heparin it goes like this:
Heparin works on a different part of the coagulation "cascade" to warfarin, this makes it conveniently possible to measure INR (attributable to warfarin) with our Coaguchek's (and other lab gear) and know when its safe to come off Heparin. Its often the case that they like to cease warfarin and substiture with Heparin (the bridge) and then because heparin "switches off fast" you can be un-anti-coagulagted (or normal) for a short time for the event.


bridging Therapy.png


of course how quickly you resume depends on your personal clotting risk VS the risk of disturbing "healing" (which relies on clotting) just in the short term post "procedure".

Also worth mentioning is that once you've come off Warfarin it takes longer to resurme your INR, not least because of the time taken to resume the "levels" of warfarin in your blood ...

warfarin accumulation.png

you recall that warfarin is "cleared" by the body (Cytochrome P450) but that has a half life of about 2 days. So the "balance" of your "theraputic level" is obtained some days after recommencing (as shown above in this crude model). In that case it took 6 days to reach the Goldilocks zone (not too hot, not too cold) of warfarin (mine).

Best Wishes for your colonoscopy ... my "proctologist" is now seeking my arse again too.
 
pellice - thanks for all this very usefull information. I am now also facing my first colonoscopy after AVR in 2016 and are advised by my doctors to bridge with Heparin. Reading your posting it sounds that your are not in favor to bridge with Heparin (my textbook regime: stop Warfarin 5 days prior procedure, start Heparin injections 3 days prior procedure, stop 24h before, resume Warfarin within 24h post procedure with Heparin etc.).

Of course - messing with two very different AC agents can be tricky - but going with a low INR over multiple days can be risky as well and my target INR is 2.5-3.0 because of a very bad experience with the On-X valve that I had in 2017.

Obviously I am not looking forward to this colonoscopy that I need every 5 years.

I am due for my 2nd colonoscopy since I had my AVR 2 years ago and I bridged then and will again. I stopped 5 days prop then check my INR day 3, once I get down to 2.0 I start my injections. My issues it takes over a week for me to get back above 2.0 to stop the injections. I had a GI bleed after last one and had to go back in hospital 2 days after the colonoscopy for a follow up. The would not put me on heparin while I was bleeding so for 2 days I was not on anything. I was told a day or 2 without anything is unlikely to cause issues and that years ago you would stop wars fringe then day after procedure you would take double doses of warfarin for at least 2 days to ramp up quickly. My understanding is that was fairly common in the past.
 
My issues it takes over a week for me to get back above 2.0 to stop the injections.

that's pretty consistent with my experience, as I took 6 days. Next time I intend to increase my doses, but to be honest I wasn't too worried because I'm in a low risk group.

I had a GI bleed after last one and had to go back in hospital 2 days after the colonoscopy for a follow up...
thats a sorry tale ... I'm glad you eventually came good
 
that's pretty consistent with my experience, as I took 6 days. Next time I intend to increase my doses, but to be honest I wasn't too worried because I'm in a low risk group.


thats a sorry tale ... I'm glad you eventually came good
Thanks for all the great information - pellice - yes I am not worried about the higher INR that I need to be in. The 6 or so days to get back into range are a concern. You mentioned that you consider to increase the initial dosage - I had the same thought - maybe a 10% increase for day 1 or 2 and then back to my normal regime. Hope I do not encounter GI bleed.
 
maybe a 10% increase for day 1 or 2 and then back to my normal regime. Hope I do not encounter GI bleed.
Not nearly enough. Check my graph (from the blog post) again carefully. Remember graphs are not just pictures they are the numbers ... (sorry if you were already thinking that way, but many seem to forget it after primary school)

1623099710195.png

So, my graph is a little complex, as you can see it has two Y-axes (one for INR, the other for dose in mg because its presenting two entirely different things together in a relationship). I explain that in the post. Quoting from that blog post:

My process was this:
  • measure INR daily (in the AM, usually about 8am)
  • my usual dose time is 7pm
  • I charted INR and dose
  • the graph below has INR on the LHS Y axis and dose in mg on the right axis
  • the bars represent actual data and the lines part of my model
  • my colonoscopy was Wednesday
So reading across (left to right) you can see that I had my last dose on Saturday (don't ask me why I did the half dose rather than just go off.

As I expected (from recording previous situations) it took until Wednesday (the exact day of the colonoscopy) to reach the agreed INR.

I then took 9mg (which7mg +30% extra) and observed that it was not coming up at a good rate (not unexpected, but one has to do the experiment right?) and so on Friday I took 12mg (or nearly 80% more). I then took 8mg until the following Wed when (being concerned about a possible overshoot {see the magenta ellipse}) I reduced back to my normal dose and then managed "normally".

So, as @Keithl has suggested double doses in the first two or maybe 3 days would get you there faster. Plinking around with an increase of 10% is like putting a cup of water into the bath to raise the level.

This graph shows an estimation of the "load" of warfarin that accumulates in your body as a result of resuming taking dose of 5mg

1623103031581.png

it takes about 6 days to get to steady state (its theory right, practice will be slightly different), and so the INR will lag behind that by one or two days.

Now if you take double the dose in the first two days you will see this

1623103210788.png


where the accumulation load will get there faster and then roll off to the "steady state (follow along the blue line for dose right :).

To me its uncertain what sort of INR effect this will have, so myself I'd be inclined to do with a staged double, then decreasing

1623103301984.png


anyone have any thoughts on the above?
 
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