Giving O Positive Units to an Rh Negative patient

[John C. Staley]

Add my 30+ years of experience in level II trauma centers to the O Pos / Rh Pos to male trauma patients and female trauma patients over 50 group. Sorry, but in times like that the possibility of your patient developing anti-D should be the very least of your worries. Get the ABO compatible and everything else will work out.

[TVC15]

Add my 30+ years of experience in level II trauma centers to the O Pos / Rh Pos to male trauma patients and female trauma patients over 50 group. Sorry, but in times like that the possibility of your patient developing anti-D should be the very least of your worries. Get the ABO compatible and everything else will work out.

Believe me I worked at a top notch Level I Trauma Center and it was the least of my worried since we gave O Negs to our patients. I know I am not the lone voice...all of the Level 1 Trauma Centers in the large Texas cites follow the same policy. O Negs are not super difficult to come by with all of the large blood centers in the US. I know Gulf Coast in Houston collects over 1000 units per day. Carter Blood Care in Dallas the same. Only once at the trauma center I worked at did we have a shortage of O Negs...so we had them imported from Wisconsin.

For all of you out there saying there is no risk...then why don't you include everyone vs. excluding women of child bearing age?

No one should be given the opportunity to make any of the Rh antibodies especially when there are O Negs on the shelf to be used in the trauma setting.

[Malcolm Needs ☆]

For all of you out there saying there is no risk...then why don't you include everyone vs. excluding women of child bearing age?

Well, that one is fairly easy.

Whereas anti-D can cause problems cross-matching in the future, or cause delayed or immediate transfusion reactions if further D Positive blood is transfused for a trauma, to a large extent, the latter can be seen when the first unit is transfused, and can be dealt with by various means (albeit, it is a real pain for the doctors should it happen during a trauma crisis).

Anti-D in pregnancy, however, causes major problems. It can result in the requirement for multiple intrauterine foetal transfusions and extrauterine exchange transfusions and, of course, if not recognised early enough in pregnancy, intrauterine death. Even in these days of fantastic Foetal Medicine Units, ultrasound/Doppler guided IUTs, there is a significant danger to the foetus.

Firstly, the foetus has to be immobilised with a fairly strong muscle relaxant, but, even then, there is a high risk of foeto-maternal haemorrage, the risk of foetal exsangunation and, although the risks are coming down, there is still approximately a 2% risk of foetal death each time an IUT is administered.

For this reason, we would also ensure that our O, D Negative blood for trauma, used for females of child-bearing potential are also K-. We do not want these individuals to make anti-K either, because it can cause such nasty HDFN.

One of your comments was though, that we do not want people given blood in the trauma situation to make Rh antibodies. If you are giving O, rr blood in all cases to try to stop this happening, how do you square the circle with your R1R1 patients making anti-c (another Rh antibody that can cause severe transfusion reactions and HDFN)?

The reason the Guidelines in the UK say what they do is because there has been a high level risk assessment performed, with Level 1 evidence taken into account, and the risk benefit analysis has shown that giving O D positive blood to males and women over 60 (soon to be over 50) is almost as safe as giving O D negative blood to alol patients in the trauma area.

Incidentally, although I now work as the manager in a Reference Laboratory, in another life I worked in Hospital Blood Transfusion Departments, and was the lead Biomedical Scientist when we dealt with three different IRA bombs in London (Chelsea Barracks, Hyde Park Corner and Harrods) and two major train crashes, so I have had experience of working during major incidents requiring mass transfusions for trauma.

[TVC15]

Well, that one is fairly easy.

Whereas anti-D can cause problems cross-matching in the future, or cause delayed or immediate transfusion reactions if further D Positive blood is transfused for a trauma, to a large extent, the latter can be seen when the first unit is transfused, and can be dealt with by various means (albeit, it is a real pain for the doctors should it happen during a trauma crisis).

Anti-D in pregnancy, however, causes major problems. It can result in the requirement for multiple intrauterine foetal transfusions and extrauterine exchange transfusions and, of course, if not recognised early enough in pregnancy, intrauterine death. Even in these days of fantastic Foetal Medicine Units, ultrasound/Doppler guided IUTs, there is a significant danger to the foetus.

Firstly, the foetus has to be immobilised with a fairly strong muscle relaxant, but, even then, there is a high risk of foeto-maternal haemorrage, the risk of foetal exsangunation and, although the risks are coming down, there is still approximately a 2% risk of foetal death each time an IUT is administered.

For this reason, we would also ensure that our O, D Negative blood for trauma, used for females of child-bearing potential are also K-. We do not want these individuals to make anti-K either, because it can cause such nasty HDFN.

One of your comments was though, that we do not want people given blood in the trauma situation to make Rh antibodies. If you are giving O, rr blood in all cases to try to stop this happening, how do you square the circle with your R1R1 patients making anti-c (another Rh antibody that can cause severe transfusion reactions and HDFN)?

The reason the Guidelines in the UK say what they do is because there has been a high level risk assessment performed, with Level 1 evidence taken into account, and the risk benefit analysis has shown that giving O D positive blood to males and women over 60 (soon to be over 50) is almost as safe as giving O D negative blood to alol patients in the trauma area.

Incidentally, although I now work as the manager in a Reference Laboratory, in another life I worked in Hospital Blood Transfusion Departments, and was the lead Biomedical Scientist when we dealt with three different IRA bombs in London (Chelsea Barracks, Hyde Park Corner and Harrods) and two major train crashes, so I have had experience of working during major incidents requiring mass transfusions for trauma.

Hi Malcolm...I appreciate your knowledge but I really don't need the anti-D lecture for women of child bearing age...I was being sarcastic with my question:tongue:

I will just be thankful that I am not the lone voice nor was I ever causing potential harm to the trauma patients that I gave O Neg units to. I actually feel very proud to have helped save as many lives as I did.

[Malcolm Needs ☆]

Okay, I can accept that you were being sarcastic, although I think you should remember that sarcasm is more easily discerned when heard than read, unless it is made absolutely plain, but you have, nevertheless, not answered my question about anti-c being produced in an R1R1 trauma patient, when rr blood is given.

I am very interested in your answer, as I am R1R1 myself, as is my sister of child-bearing potential.

[TVC15]

Okay, I can accept that you were being sarcastic, although I think you should remember that sarcasm is more easily discerned when heard than read, unless it is made absolutely plain, but you have, nevertheless, not answered my question about anti-c being produced in an R1R1 trauma patient, when rr blood is given.

I am very interested in your answer, as I am R1R1 myself, as is my sister of child-bearing potential.

I round my circle by way of the fact that anti-D is the most immunogenic of them all and if you made anti-D you have an increased probability to make any of the other Rh antibodies who's antigen you don't possess. If you are one of the few who do not become sensitized via an O Pos transfusion then your probability to make any of the other Rh antibodies also decreases.

And by the fact that anti-D is the most immunogenic of them all.

[Malcolm Needs ☆]

I agree that, without doubt, the D antigen (not anti-D) is the most immunogenic of the common antigens, but others, including the c antigen are not too far behind.

The argument about making other antibody specificities within the Rh Blood Group System I can accept. This is why we see so many examples of anti-E in patients with anti-c.

So, it still doesn't answer my question about R1R1 patients receiving a double dose of the c antigen and so risking immunisation to the c antigen.

[Eoin]

Ah A lively debate - that's what we like.

I would suggest that you must cut the pattern to suit the cloth. If you have a great supply and want to give them go for it (with the rider re the R1R1s below). I would have been jealous years ago of your O Neg supplies. Where I work now there is not as much a problem with O Negs, but years ago in the country areas in Australia, I would have been keeping the O Negs for obstetric patients, due to chronic shortages. We follow the British Guidelines as well (outlined by Malcolm). Here the O Negs we keep for emergency blood (uncrossed) is also CMV tested and Kell typed, so an extra cost there. I agree with Malcolm re O Negs to R1R1 patients (of whom I am also one). There are 17% odd of the Rh Pos (Caucasians), so that merits consideration as well.

Maybe a good study for someone to follow up patients who were bleeding out (the survivors) - just to see how many develop antibodies and include how many have needed transfusions again over say 10 - 20 years post the trauma / massive haemorrhage.

Cheers

Eoin

[SMILLER]

We are fortunate here to have a blood center only 15 minutes away. We use O negs for almost all traumas. If the area supply is low for some reason, we will switch to Rh pos RBCs for males and over 50 females. But this rarely is necessary. If we know that a patient is going to bleed massively, we will switch them early.

My main problem with transfusing Rh pos units to a patient (known or unknown depending on how quickly the ABO/Rh is done) is that they will seroconvert to produce anti-D. As has been pointed out, the next BB that sees this patient is going to have a delay in providing blood.

Our biggest nightmare is a trauma that turns out to have allo-antibodies. And if we routinely use Rh pos for all traumas, there are going to be alot more of those. Now for someone with only anti-D, I get it that all one has to do is select Rh neg units, but in the meantime, a bleeding arrival may have already recieved several Rh pos units (if that is the policy.) I say if that is not necessary don't do it. Likewise, if we have a patient with only anti-E and is c antigen negative, we will screen units for both.

But I do appreciate the issue with some big medical centers that do not want to risk exhausting O negs.

[AMcCord]

I would comment that the supply of O neg red cells in the US is NOT limitless and can be problematic. My hospital is in a region that is fortunate to be a net blood exporter, which is great for our local blood supply most of the time. However, there are always a few times a year when I am unable to receive or maintain a full stock of O neg because of high demand in my region and across the country. In some areas of the US it's a much more common problem. If the supply isn't there, we can be (and have been) forced to give Rh pos blood to some Rh neg patients who are not traumas, but who do need transfused urgently (GI bleeders, extreme anemia, etc.) in order to reserve the Rh negs for females of child bearing age and children. Maybe your trauma case won't make an anti-D, but my patient on Plavix with the GI bleed will and he/she may very well need blood again.

I think that it's important for us all to remember that trauma cases (and surgical cases gone haywire) utilizing large volumes of Rh negative blood have the potential to have an adverse impact on the care of patients outside the ER and outside the walls of our facility. So when you say that it's easy emough to get blood from Wisconsin, remember that patients in Wisconsin (or whichever region responds) may be the one feeling the bite. (And no, I'm not in Wisconsin.) That is why the issues of blood management and blood utilization are so critical now. There are studies out there on all kinds of related issues and more being done every day, making what we did 10 years ago, or even 2 years ago, questionable. What may be best for one single patient on one single occasion, when multiplied to thousands of patients, may not be good for universal patient care. We have to start thinking big picture. That is our challenge.

Edited April 26, 2012 by AMcCord

[MAGNUM]

Hi Malcolm,

Thanks for the response but my question is why risk it?

We too give O positive units in trauma/mass casuality situations. We can worry about the antibody when the patient is under control. Our main reasoning is to get some oxygen carrying capacity to the patient thereby getting them over the hump until we can better manage them. Incidently, we give Rh positive blood to males and females past child bearing age which is normally thought to be 50.

[John C. Staley]

For all of you out there saying there is no risk...then why don't you include everyone vs. excluding women of child bearing age?

I'm reasonably certain that no one here is "saying there is no risk". What most of us are saying is that, often the risk to the individual trauma patient is much more academic than real. The real risk for most of us is not having the Rh negative blood for a patient that really NEEDS it because it all went to a patient who would have done just fine, ie survived, with Rh positive blood.

If you have the luxury of not having to worry about inventory levels of O Neg RBCs then more power to you. Most of us have not, do not and never will live in such an enviroment. We owe it to all of our patients to be the best stewards of the resource we can possibly be. We live in an imperfect world.

:juggle:

[Malcolm Needs ☆]

I'm reasonably certain that no one here is "saying there is no risk". What most of us are saying is that, often the risk to the individual trauma patient is much more academic than real. The real risk for most of us is not having the Rh negative blood for a patient that really NEEDS it because it all went to a patient who would have done just fine, ie survived, with Rh positive blood.

If you have the luxury of not having to worry about inventory levels of O Neg RBCs then more power to you. Most of us have not, do not and never will live in such an enviroment. We owe it to all of our patients to be the best stewards of the resource we can possibly be. We live in an imperfect world.

:juggle:

Careful John TVC15 was only being sarcastic (see above)!

[Eagle Eye]

I know we have shortage of O Negs!!!!

Hi Malcolm...I appreciate your knowledge but I really don't need the anti-D lecture for women of child bearing age...I was being sarcastic with my question:tongue:

I will just be thankful that I am not the lone voice nor was I ever causing potential harm to the trauma patients that I gave O Neg units to. I actually feel very proud to have helped save as many lives as I did.

[Eagle Eye]

I think that it's important for us all to remember that trauma cases (and surgical cases gone haywire) utilizing large volumes of Rh negative blood have the potential to have an adverse impact on the care of patients outside the ER and outside the walls of our facility. So when you say that it's easy emough to get blood from Wisconsin, remember that patients in Wisconsin (or whichever region responds) may be the one feeling the bite. (And no, I'm not in Wisconsin.) That is why the issues of blood management and blood utilization are so critical now. There are studies out there on all kinds of related issues and more being done every day, making what we did 10 years ago, or even 2 years ago, questionable. What may be best for one single patient on one single occasion, when multiplied to thousands of patients, may not be good for universal patient care. We have to start thinking big picture. That is our challenge.

EXCELLENT!!!!!!!!!!

This is exactly we keep our O Negs for our child bearing age female patients. Sometime we do not have enough supply of Rh Neg and we end up switching non trauma patients. Yes we sould be looking at big picture instead of thinking about only your hospital.

Edited April 26, 2012 by aakupaku

[Brenda K Hutson]

With 29 years in Blood Banking (most in CA); several large Trauma Centers.....

Last place I recall, had 2 separate trays with 6 units each; 6 O NEG in one; 6 O POS in the other. When the trauma alarm went off, we would call ER to see if male or female. If male, gave O POS; if female, gave O NEG.

And as others have said, if patient is bleeding out, they don't tend to make an Anti-D. In fact, I have only seen that occur once in my career, and that was not a trauma situation. That was an Rh Negative male in the OR who was bleeding and we were running out of inventory. So we switched him to O POS. The caviat with that is that you need to switch them back, "as soon as the bleeding slows down." But sometimes, you just don't know when that will be. In this guy's case, they did not request anymore units after the last O POS we gave him....uh oh. But it is a delicate balancing act.

And as far as possibly giving an Rh POS unit to a trauma patient who already has Anti-D.....when you think about it, that is the risk that every patient takes when then get uncrossmatched blood. And not just with the D antigen; but with all of them. But trauma centers have to play the balancing act to keep an adequate blood supply for patients who are known to be Rh NEG; or who are known to have Anti-D; or for women of child-bearing age.

Brenda Hutson, CLS(ASCP)SBB

[tbostock]

We give the first two units O Neg to see how badly they are going to bleed. If it looks bad, we only try to keep women in child-bearing years in O Negs until we can get a quick type. Everyone else goes immediately to O Pos. As stated above:

1. 85% of trauma patients are going to be Rh Pos anyway.

2. Out of the rest, 80% are males.

3. Out of the rest, only about 10% will make the Anti-D (conversion rate is MUCH lower in trauma).

4. A certain amount of trauma patients will succumb to their injuries.

So if you do the math, I believe it's somewhere around 0.5% of all trauma patients really need Rh Neg.

[AMcCord]

We give the first two units O Neg to see how badly they are going to bleed. If it looks bad, we only try to keep women in child-bearing years in O Negs until we can get a quick type. Everyone else goes immediately to O Pos. As stated above:

1. 85% of trauma patients are going to be Rh Pos anyway.

2. Out of the rest, 80% are males.

3. Out of the rest, only about 10% will make the Anti-D (conversion rate is MUCH lower in trauma).

4. A certain amount of trauma patients will succumb to their injuries.

So if you do the math, I believe it's somewhere around 0.5% of all trauma patients really need Rh Neg.

Nice SIMPLE plan.

[David Saikin]

Are you a Level I trauma center? Level I trauma centers usually have access to a good supply of O Negs. I am specifically speaking about trauma centers. O Negs should be used on trauma patients in the emergency release situtaion for all of the reasons I have mentioned.

I have to agree with Cliff - it must be nice to have access to unlimited amounts of O= and squander them on males and older females because that is what you are doing. My experience with changing Rh types is that if you give 1 0r 2 Rh+ units, the pt will become sensitized. If you switch early and keep giving + units the immune system is suppressed and anti-D sensitization does not take place. Most pts are Rh+, read the trauma literature on use of blood in trauma situations - most places save the Rh=s for females of child-bearing age ONLY; everyone else gets O+. Sensitization rates are low.

[kirkaw]

Brenda,

I would like some more information on the idea of switching an O negative male to O positive during surgery. We had a situation this past weekend where we had an emergency heart surgery on an O negative male who ended up using several units. The OR took 4 and requested 4 more. Our normal O neg inventory is 12 units (if we can get that many!) At what point would advocate switching this patient to O positive? Should it require medical director approval? If we do switch to O pos, when do you offer RhIg and how much do you give?

Thanks, Amelia

[Mabel Adams]

It's pretty tough to give enough RhIG to counteract transfused RBC units. Most of would not have that as a protocol unless we were forced to give D+ blood to a young D- female. Then I think I would try to arrange for her to have an exchange transfusion with Rh neg blood, then estimate residual Rh pos cells and give RhIG to handle that amount. That said, I don't know that we really have the capability to exchange an adult and I know we don't have a good way to estimate the residual Rh pos cells in the patient. Fetal Screen would be pretty inaccurate. Kleihauer won't work since it detects fetal Hgb. I guess we could ship her to someplace they can do flow cytometry for Rh pos cells. Mostly we will save our Rh neg cells for her so we don't ever have to do that.

[SMILLER]

My experience with changing Rh types is that if you give 1 0r 2 Rh+ units, the pt will become sensitized. If you switch early and keep giving + units the immune system is suppressed and anti-D sensitization does not take place. .

Anyone know the serological reason for this "suppression" when giving large amounts of Rh pos units to a Rh neg patient -- as opposed to only a few?

Thnaks, Scott

[Malcolm Needs ☆]

I think that it is just to do with the fact that, when a patient is exsanguinating, their immune system is suppressed, and, of course, under these circumstances they need a lot of blood quickly (hence a lot of D Positive units going in quickly to a D Negative patient meet a suppressed immune system - and lots of the red cells will also be on the floor), whereas, when only one or two units are given, it is usually when the patient's immune system is in prime working order - but I could be wrong.

[David Saikin]

Anyone know the serological reason for this "suppression" when giving large amounts of Rh pos units to a Rh neg patient -- as opposed to only a few?

Thnaks, Scott

The way I understand it is that you overwhelm the immune system . . . that was from a graduate Immunology course circa 1982.

[Malcolm Needs ☆]

That's sort of what I meant - but I think you put it better!