question...blood transfusion

[TJDoc7]

Came across a question, which pretty much described a person in the er, needed a plasma transfusion (type unknown)...which would be safe to give? I picked O- (to find out that is only for blood...plasma, AB+ would be safe to give/the right answer). I read the brief explanation, and saw that in plasma, the AB+ has NO antibodies to A, B or Rh factor, and is therefore safe...but my question is, then why in BLOOD is O- (with no A/B ag present) safe to give, and in plasma (specifically, WHY) is this safe to give in a person w/unknown blood type.

Not sure if this is just really basic and i'm overthinking it...to be honest, transfusion questions like this always gave me trouble for some reason. Any help to clear is up is much appreciated.

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[turkeyjerky]

because we don't give whole blood to people. it's either packed red blood cells, fresh frozen plasma, or platelets. each of the components do better when stored at different temps (4 degrees for rbcs, frozen for plasma and room temp for platelets).

if that's not enough, then here's the deal: if you give incompatible blood, the donor rbcs are hemolyzed by recipient antibodies. If you gave incompatible plasma, the donor antibodies are gonna hemolyze recipient red blood cells--because AB+ people have no antibodies (to A, B, or D antigens) the plasma is safe to give to anyone (conversely they can receive anyone's rbcs). (if you give incompatible platelets you either get a febrile reaction or just no increase in the patient's platelet count.)

btw, was this on wiki test prep? I did that question today too and got it wrong cause i immediately went for type O

 

[MilkmanAl]

I don't believe I've ever learned that, but it makes sense. Good stuff.

 

[TJDoc7]

hah yeah...I never heard of that either (kind of just attributed it to me being ****ty at transfusion questions, but it DID seem kind of weird.

Yes, it was on wikitestprep, was doing some questions on there earlier...also...question on that...I know a lot of the questions on there are extremely easy/not step level, but maybe it is completely me, but some of the newer (I guess some "unapproved ones" (like the transfusion question I just mentioned) seem to be a little more difficult, not just straight discrete knowlegde questions. It could just be me, but was just wondering if anyone else had noticed that. Regardless, it's free, so can't complain either way.

 

[TJDoc7]

because we don't give whole blood to people. it's either packed red blood cells, fresh frozen plasma, or platelets. each of the components do better when stored at different temps (4 degrees for rbcs, frozen for plasma and room temp for platelets).

if that's not enough, then here's the deal: if you give incompatible blood, the donor rbcs are hemolyzed by recipient antibodies. If you gave incompatible plasma, the donor antibodies are gonna hemolyze recipient red blood cells--because AB+ people have no antibodies (to A, B, or D antigens) the plasma is safe to give to anyone (conversely they can receive anyone's rbcs). (if you give incompatible platelets you either get a febrile reaction or just no increase in the patient's platelet count.)

btw, was this on wiki test prep? I did that question today too and got it wrong cause i immediately went for type O

turkeyjerky, sorry to bother but just to make sure I have this straight then...when we refer to O- being "universal donors" then, that ONLY applied to the packed rbc's (as you said, no whole blood transfusion?)...similarly, AB+ would be a "universal donor" ONLY for ffp (for the reasons you said above)...that's it then?

Thanks for time/help.

 

[hartbot]

So basically, the plasma is the portion of the blood that contains all the antibodies?

And these aren't removed when giving a plasma pack?

 

[AbbyNormal]

good reference ----> Red Cross Practice Guidelines for Blood Transfusion - PDF


If you belong to the blood group AB, you have both A and B antigens on the surface of your red blood cells and no A or B antibodies at all in your blood plasma.

If you belong to the blood group 0 (null), you have neither A or B antigens on the surface of your red blood cells but you have both A and B antibodies in your blood plasma.

The transfusion will work if a person who is going to receive blood has a blood group that doesn't have any antibodies against the donor blood's antigens. But if a person who is going to receive blood has antibodies matching the donor blood's antigens, the red blood cells in the donated blood will clump.


What is a plasma pack? I am not sure if you mean FFP (fresh frozen plasma) which is given for coagulation or PPF (plasma protein fraction) which is a colloid given for volume. PPF is useful because it is stored at room temperature and has a longer shelf life than other blood components thus ICUs can keep it in stock; also it does not require blood typing.

 

[turkeyjerky]

turkeyjerky, sorry to bother but just to make sure I have this straight then...when we refer to O- being "universal donors" then, that ONLY applied to the packed rbc's (as you said, no whole blood transfusion?)...similarly, AB+ would be a "universal donor" ONLY for ffp (for the reasons you said above)...that's it then?

Thanks for time/help.

Bingo.

 

[TJDoc7]

Thanks for that...also in addition, one of the earlier posts had mentioned "we don't give whole blood transfusions"...I don't know if that was meant in certain situations/context, but I thought there were situations where it IS warranted...I checked on it (and correct me if i'm worng), but this seems to be when they're all used:

-whole blood transfusion - hemorrhage, hypovolemic shock
-packed rbc's - when transfused whole blood results in overload
-fresh frozen plasma - clotting problems
-platelets...no platelets?...

 

[turkeyjerky]

yeah, I suppose whole blood would be nice for hemorrhage, and I recently attended a talk about battlefield trauma in iraq by a surgeon where he mentioned its merits. Practically though, I just don't think it's used or readily available at most institutions. Typically you use packed rbc's and crystalloid (eg normal saline).

Rbcs are used to increase oxygen delivery, they're indicated if someone is symptomatic due to anemia (usually present if Hgb is below 8).
FFP indicated for a deficiency of multiple clotting factors, eg cirrhosis or warfarin overdose (in the setting of active bleeding, if it's just a supra-therapeutic INR give vitamin K).
Hypofibriniginemia (like in DIC) can be treated with cryoprecipitate, which has a greater concentration with less of a volume load than FFP.
Platelets are used for thrombocytopenia or platelet dysfunction. Keep the platelet level above 10k for prophylaxis, above 50K if active bleeding or surgery and above 100k in the setting of dysfunction.

 

[NRAI2001]

turkeyjerky, sorry to bother but just to make sure I have this straight then...when we refer to O- being "universal donors" then, that ONLY applied to the packed rbc's (as you said, no whole blood transfusion?)...similarly, AB+ would be a "universal donor" ONLY for ffp (for the reasons you said above)...that's it then?

Thanks for time/help.

Wow thats pretty cool... I never heard of this before and I ve never had a professor that made a distinction between the two. I always assumed plasma and blood went hand in hand. Makes total sense though when you think of it..basically:

O- = universal blood donor
AB+ = universal plasma donor

Does the USMLE test on this knowledge?? Bc I ve never read of this in any board book ive come across yet..

But someone mentioned something about "Hypofibriniginemia (like in DIC) can be treated with cryoprecipitate.." what is cryopercipitate exactly? Is it specific factors stored separate than general plasma? Is it synthetic?

 

[AbbyNormal]

But someone mentioned something about "Hypofibriniginemia (like in DIC) can be treated with cryoprecipitate.." what is cryopercipitate exactly? Is it specific factors stored separate than general plasma? Is it synthetic?

Cryoprecipitate contains concentrated levels of fibrinogen, Factor VIII:C, Factor VIII:vWF (von Willebrand factor), Factor XIII, and fibronectin.


Read the Red Cross PDF I linked for more information.

 

[lord_jeebus]

Does the USMLE test on this knowledge??

I'm pretty sure I've seen it on one of the Steps

 

[NRAI2001]

Cryoprecipitate contains concentrated levels of fibrinogen, Factor VIII:C, Factor VIII:vWF (von Willebrand factor), Factor XIII, and fibronectin.


Read the Red Cross PDF I linked for more information.

I read a part of the cryoprecipitate chapter. There was one part I was confused about:

"Patients with hemophilia A or von Willebrand's
disease (vWD) should only be treated with
cryoprecipitate when appropriate Factor VIII
concentrates or Factor VIII concentrates containing FVIII:
vWF are not available..."

So basically cryoprecipitate is not preferrential for factor 8 deficiencies and only used when alternatives are not available. What is given to patients with factor 8 deficiencies..? Is factor 8 a component of FFP (plasma)? According to UWorld Factor 8 is stored in endothelial cells complexed with vWF (and factor 8:vWF is released only with proper signals i.e. desmopression; which is also a therapy to hemophilia A).. when obtaining a plasma donation is factor 8 also taken??

 

[NRAI2001]

I'm pretty sure I've seen it on one of the Steps

The distinction between plasma donation vs. blood donation and finding matches?? I ve seen lots of discussion on blood typing; but never on "plasma-typing" and setting up plasma matches... but it is very intereting. Just wondering if I skipped over it or something??

 

[lord_jeebus]

The distinction between plasma donation vs. blood donation and finding matches?? I ve seen lots of discussion on blood typing; but never on "plasma-typing" and setting up plasma matches... but it is very intereting. Just wondering if I skipped over it or something??

Yeah, on transfusion of FFP.

I don't know if it was in the review books but it definitely came up during my preclinical hematology course.

 

[turkeyjerky]

I read a part of the cryoprecipitate chapter. There was one part I was confused about:

"Patients with hemophilia A or von Willebrand’s
disease (vWD) should only be treated with
cryoprecipitate when appropriate Factor VIII
concentrates or Factor VIII concentrates containing FVIII:
vWF are not available..."

So basically cryoprecipitate is not preferrential for factor 8 deficiencies and only used when alternatives are not available. What is given to patients with factor 8 deficiencies..? Is factor 8 a component of FFP (plasma)? According to UWorld Factor 8 is stored in endothelial cells complexed with vWF (and factor 8:vWF is released only with proper signals i.e. desmopression; which is also a therapy to hemophilia A).. when obtaining a plasma donation is factor 8 also taken??

They use recombinant factor VIII concentrate for hemophilia A. Cryoprecipitate is a blood product and hence should be used as sparingly as possible. It's prepared from FFP and contains virtually all of the aforementioned factors from the plasma it's prepared from.