Acute Normovolemic Hemodilution in Cardiac Surgery?

[vector2]

How many of you guys are routinely doing this? Do you have an institutional guideline in place? Do you feel it's reduced allogeneic transfusion requirements?

I feel like I don't take very much when I do it (500cc), and the pts that I do collect from (pre-op crits around 38-40+) rarely require a ton of products post-pump anyway.

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[abolt18]

Never done it. Always been intrigued.

 

[pgg]

Always do it.

We have a spiffy multicolored nomogram on the wall that suggests how much to take off based on starting Hb and body weight. I usually ignore it and aim for two 450 mL units (one if the pt is small or very anemic). I tend to be a little aggressive with the bleeding because I'm a believer in the magic of whole blood, and I can always give it back early if I over bleed.

Rarely have to support BP during the bleed. Sometimes give the leftover albumin the perfusionists didn't prime with. For our CABGs the bleed is usually about the time the legs are propped up to prep for vein harvest so they get some extra preload to compensate. Rarely have to support them in those cases.

Very very ocassionally they get a unit of bank RBCs while on pump because of a Hb <7, but I try hard not to give the ANH blood back before we're off pump, to preserve the platelets and clotting factors.

I don't feel like we transfuse that often but is that because of the ANH? Who knows. The people I don't do ANH for are already anemic so they often get transfused anyway. It's generally the lower transfusion risk people that get ANH anyway.

We send a ROTEM after the protamine is in and the ANH blood is given back. The surgeons will sometimes just say to give FFP or platelets regardless of the ROTEM or ACT. They are ANH believers.

We have scales with a rocker for taking precise volumes off. I think some of us don't use the rocker and let the ANH blood separate, so they can give the RBCs back on pump if needed and keep the supernatant for return post-CPB. I don't know how often they do that. I use the rocker.

 

[partydoc]

I do it I wouldn’t say routinely but not uncommonly. Most of our patients dont have the red cell mass to give. No institutional guidelines , never done any formal look to see if it reduces transfusion, but our surgeons say it definitely helps the patients dry up and if they see a difference and request less platelets or whatever that’s good enough for me.

I used to take very little off but I’ve been trying to be more aggressive.

 

[T-burglar]

Very few of my patients are candidates for that unfortunately

 

[dabears505]

You take a liter off and they don't get hypotensive?

 

[dchz]

Did it for virtually every case for fellowship. Been in my current job 2.5 years, still can't find a CBD bag... I would like it for myself if I'm planning a circ arrest case in advance.

I know it's a good benefit for circ arrest cases as we routinely give a lot of blood products for those cases.

But I'm not sure how much it really benefits other cases since our surgeons are superb - Most of the pump runs are less than 2 hours. Almost never need blood products for most cases. The other day we did 2 circ arrest cases and finished before 5 pm. And we gave 10 units of cryo for one case and none in the other case.

Very few of my patients are candidates for that unfortunately

You can take drain whole blood and give the RBC back once the plasma separates. And also volume resuscitate. in extreme cases when you KNOW you have to give products, one could argue taking out whole blood and giving back RBC will save a lot of yellow stuff later.

You take a liter off and they don't get hypotensive?

You are allowed to give back crystalloids to maintain preload, hence the normvolemic hemodilution part.

 

[pgg]

You take a liter off and they don't get hypotensive?

Generally not.

If they do, a liter or so of crystalloid, +/- some 25% albumin is usually enough.

Most of these old sick hearts get a couple mcg/min of norepi started at induction anyway. If they need a bit extra, no big deal.

 

[dchz]

Always do it.

We have a spiffy multicolored nomogram on the wall that suggests how much to take off based on starting Hb and body weight. I usually ignore it and aim for two 450 mL units (one if the pt is small or very anemic). I tend to be a little aggressive with the bleeding because I'm a believer in the magic of whole blood, and I can always give it back early if I over bleed.

Rarely have to support BP during the bleed. Sometimes give the leftover albumin the perfusionists didn't prime with. For our CABGs the bleed is usually about the time the legs are propped up to prep for vein harvest so they get some extra preload to compensate. Rarely have to support them in those cases.

Very very ocassionally they get a unit of bank RBCs while on pump because of a Hb <7, but I try hard not to give the ANH blood back before we're off pump, to preserve the platelets and clotting factors.

I don't feel like we transfuse that often but is that because of the ANH? Who knows. The people I don't do ANH for are already anemic so they often get transfused anyway. It's generally the lower transfusion risk people that get ANH anyway.

We send a ROTEM after the protamine is in and the ANH blood is given back. The surgeons will sometimes just say to give FFP or platelets regardless of the ROTEM or ACT. They are ANH believers.

We have scales with a rocker for taking precise volumes off. I think some of us don't use the rocker and let the ANH blood separate, so they can give the RBCs back on pump if needed and keep the supernatant for return post-CPB. I don't know how often they do that. I use the rocker.

I stopped using the rocker half way through fellowship once I realized the power of the CBD bag. I'm a big fan of keeping the supernatant and giving the RBC back.

I pretty much agree with your thoughts/methods except for the rotem timing. I would argue rotem/teg is more helpful if you get it while rewarming. If we only have 20mins of cpb left then I might even give supernatant back before they run the TEG/ROTEM.

 

[pgg]

I stopped using the rocker half way through fellowship once I realized the power of the CBD bag. I'm a big fan of keeping the supernatant and giving the RBC back.

We had a rash of those bags partially clotting off recently. Not sure if we got a a bad batch, or what. It made me a little more paranoid about rocking them. So I always use the scale that shuts off the bleed at the right volume, and make it rock.

I pretty much agree with your thoughts/methods except for the rotem timing. I would argue rotem/teg is more helpful if you get it while rewarming. If we only have 20mins of cpb left then I might even give supernatant back before they run the TEG/ROTEM.

When I was a fellow we sent labs when rewarming.

I don't like to give stuff on pump because I figure a lot of those factors will just languish in the leftover pump blood or wind up getting washed out in the final cell saver batch. And if they bleed on pump generally the pump suckers give them their cells back right away anyway.

I'm not sure what I'd do with the ROTEM results on the screen if I had given a couple units of whole blood since that blood sample was drawn.

And if I get the ROTEM results back before I return the ANH - am I really going to give products before giving the whole blood back?

 

[dchz]

And if I get the ROTEM results back before I return the ANH - am I really going to give products before giving the whole blood back?

Sorry I should have been more specific. You should definitely run TEG/ROTEM after the bagged whole blood /supernatant is in if you bagged the blood. That would give you the most accurate picture.

I think you're overestimating the harm of giving stuff on pump. There is some reaction. But it's not like the second you give it back, the bagged blood factors just stop working. after all, the pts plasma does just fine after 2 hours of pump run.

wind up getting washed out in the final cell saver batch.

Tell the perfusionist to bag it instead of putting it in the cell saver.

 

[sevoflurane]

How many of you guys are routinely doing this? Do you have an institutional guideline in place? Do you feel it's reduced allogeneic transfusion requirements?

I feel like I don't take very much when I do it (500cc), and the pts that I do collect from (pre-op crits around 38-40+) rarely require a ton of products post-pump anyway.

I rarely if ever use it.
Our blood product utilization is really good I think. Hardly ever give any products for most cases except for dhca/type A’s.

 

[Remxed]

In my fellowship, we have historically screened patients for ANH if they meet SCA guidelines:

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients - PubMed

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery...

pubmed.ncbi.nlm.nih.gov

"It seems that to achieve maximal benefit of ANH, ≥800 mL of blood needs to be removed before surgery."

However, it is resource intensive and not done frequently. Most often, we do ANH for JW patients (all connected through a continuous tubing to the patient of course) if they meet criteria.

 

[TexBlazer2106]

In my fellowship, we have historically screened patients for ANH if they meet SCA guidelines:

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients - PubMed

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery...

pubmed.ncbi.nlm.nih.gov

"It seems that to achieve maximal benefit of ANH, ≥800 mL of blood needs to be removed before surgery."

However, it is resource intensive and not done frequently. Most often, we do ANH for JW patients (all connected through a continuous tubing to the patient of course) if they meet criteria.

This is what I learned in fellowship, the 800cc floor. We would routinely take off 2 full bags. I always used the rocker in fellowship and would occasionally have some clots in the bags. In practice I haven’t had any rockers and have been nervous about it, but haven’t had any issues with clotting.

 

[dchz]

Those that use this method in their practice. Which bag do you use?

Brand/size of the bag? Pics if you have it plz.

 

[Drwine]

I used to do it a lot in the 1990's but abandoned it in the early 2000s.

 

[Iso4ane]

I used to do it a lot in the 1990's but abandoned it in the early 2000s.

Can’t leave us hanging. Why did you change your practice?

 

[zizzer]

Seemed to work well when I had it in residency for bigger cardiac cases. We would usually take about a liter of blood.