hb increase

[sona]

Hi all,

this is a rule of thumb that we have learnt till now that by transfusion of one unit of packed cells increases 1g/dl nomally here i have two questions

i) if the donors hb is less than 12 g/dl e.g 11g/dl or less ( miss interpreted at the time of donation ) what will be rate of hb increase if one unit of packed cells of such a unit is transfused????:cool:

ii) if the patient's hb increases more than 1 % what can be said ?

[Malcolm Needs ☆]

Hi all,

this is a rule of thumb that we have learnt till now that by transfusion of one unit of packed cells increases 1g/dl nomally here i have two questions

i) if the donors hb is less than 12 g/dl e.g 11g/dl or less ( miss interpreted at the time of donation ) what will be rate of hb increase if one unit of packed cells of such a unit is transfused????:cool:

ii) if the patient's hb increases more than 1 % what can be said ?

Hi sona,

Do you mean 1%, or 1 g/dL?

:confused::confused:

[David Saikin]

I have noticed that older patients usually get a better increment following tranfusion - - - don't ask me why, it is just an observation.

[heathervaught]

Sona -- it probably depends on the physiology of the patient. Blood volume and rate of RBC destruction will play a role in the post-transfusion hgb rise.

[Johnny]

What I understand is the the hgb will increase approx. 1 g\dL per unit (PRBC) in a 70 kg individual.

[Ellen Zeigler]

Hi all,

this is a rule of thumb that we have learnt till now that by transfusion of one unit of packed cells increases 1g/dl nomally here i have two questions

i) if the donors hb is less than 12 g/dl e.g 11g/dl or less ( miss interpreted at the time of donation ) what will be rate of hb increase if one unit of packed cells of such a unit is transfused????:cool:

ii) if the patient's hb increases more than 1 % what can be said ?

The probability of the collecting organization collecting a donor that is not eligible is slim. QC is performed with that procedures as with all others. More likely is the size of the patient, a patient who is on a diuretic, one who is actively bleeding and the hgb/hct is drawn prior to equilibration, or incorrect collection of the first specimen. /COLOR]

[sona]

Hi sona,

Do you mean 1%, or 1 g/dL?

:confused::confused:

hello malcom i know u know it its 1g\dl

[Malcolm Needs ☆]

hello malcom i know u know it its 1g\dl

Yes, I was just being devilish!!!!!!!

:):)

[GilTphoto]

I have been monitoring all patients where the Hgb increases more than 2 g/dL per unit. First I check the patient's weight to see if they are small. Next I check for Lasix being given post transfusion. Diuretics are often given to the elderly with CHF so they do not develop TACO. Finally, I check to see if the pretransfusion H+H specimen was drawn from a CVP line. It's possible the nurse did not discard enough blood, and the H+H was falsely low.

There seems to be a controversy over how much blood should be discarded from line draws. While the lab has always recommended 10mL discards, some places (like my hospital) has a corporate policy of only discarding 5 mLs. I don't agree, but have not been able to get them to change the policy, since it's corporate wide.

Another indication that the discard volume is not adequate, is many slightly elevated PT/PTT's in patient's not on anticoagualants, or with liver disease, or factor deficiencies. Of course they want FFP for all these patient's too!

WE get about 5-10 patients a month whose Hgb increased more than 2 grams per unit.

Just last month a patient had a pretransfusion Hgb of 6.3. Gave 2 units of RBC's. post Hgb result = 15........

[PammyDQ]

Food for thought: We weigh each individual unit of prbcs. Then we do a conversion to actual cell volume, which differs depending on the collection method (ie. apheresis double unit collection vs. whole blood single unit collection) due to different anticoagulant volume/types. We have done this to collect data for our medical director which may be used in the future for one of his research studies. In doing this, we get quite a range of volumes, from 135ml. to 270ml.! So some units are twice as large as others...

[Malcolm Needs ☆]

Food for thought: We weigh each individual unit of prbcs. Then we do a conversion to actual cell volume, which differs depending on the collection method (ie. apheresis double unit collection vs. whole blood single unit collection) due to different anticoagulant volume/types. We have done this to collect data for our medical director which may be used in the future for one of his research studies. In doing this, we get quite a range of volumes, from 135ml. to 270ml.! So some units are twice as large as others...

That is true, and seems a worthwhile way of doing it, but one must also remember that the donors will have a normal range of haematocrits, which will also complicate matters.

:redface:

[Deny Morlino]

This strikes me as a "rule of thumb" like many that have become entrenched in the medical field over the years due to one study or another, or perhaps some expert giving an opinion on the spot when asked for one that has subsequently become "the rule". With advances in the technology available to us today and in the future we will likely see many old standards challenged as new evidence comes to light. Keep an open mind and remember that the only constant in the medical field is constant change.

[Malcolm Needs ☆]

This strikes me as a "rule of thumb" like many that have become entrenched in the medical field over the years due to one study or another, or perhaps some expert giving an opinion on the spot when asked for one that has subsequently become "the rule". With advances in the technology available to us today and in the future we will likely see many old standards challenged as new evidence comes to light. Keep an open mind and remember that the only constant in the medical field is constant change.

Couldn't agree more Deny.

One only has to look at the "ideal" haemoglobin level for surgical patients pre and post procedure, and how this has changed over the years to see how true are your words of wisdom.

:D:D:D:D

[Deny Morlino]

Thanks, but I think wisdom is stretching it a good bit . The constant change we experience is a double-edged sword. It makes us a bit nutty because we have yet another change to contend with. It also keeps us excited and challenged because we do not wish to remain stagnant.

As has been suggested further back in this thread, there are many variables that must be considered when looking at the change in hemaglobin post transfusion. All must be taken into account and our "technical detective hats" placed upon our heads to determine if the outcome makes sense given the information provided. Sometimes you must look a bit further and ask for more pieces of information to arrive at a logical answer.

[Malcolm Needs ☆]

Again, I totally agree with what you say.

Actually, one of the parameters that is often missed in post-operative patients is that they still may be losing blood, albeit from a "silent" bleed.

[rravkin@aol.com]

Food for thought: We weigh each individual unit of prbcs. Then we do a conversion to actual cell volume, which differs depending on the collection method (ie. apheresis double unit collection vs. whole blood single unit collection) due to different anticoagulant volume/types. We have done this to collect data for our medical director which may be used in the future for one of his research studies. In doing this, we get quite a range of volumes, from 135ml. to 270ml.! So some units are twice as large as others...

PammyDQ,

After your process do you still enter the unit volume printed on the unit lable in your LIS or your calculation?:)

[rravkin@aol.com]

Sonya,

I wanted to thank you for submitting this thread and all the posts that follow. It is very interesting to consider the variables affecting post transfusion Hgb and outcomes in general. I particularly appreciate this thread because it points us to consider variables of the donor unit itself which can sometimes be overlooked especially when dealing with a problematic recipient.

[PammyDQ]

PammyDQ,

After your process do you still enter the unit volume printed on the unit lable in your LIS or your calculation?:)

There is no volume printed on the label of the rbcs we receive. The label states "from 500ml of CP2D whole blood" or other depending on the collection type. We use our calculated volume in our LIS and write it on our retype label. Ironically, our medical director also oversees another hospital which simply weighs their units and uses the mgs to = mls without any calculation.

Edited April 6, 2010 by PammyDQ
rephrased

[bbbirder]

There is no volume printed on the label of the rbcs we receive. The label states "from 500ml of CP2D whole blood" or other depending on the collection type. We use our calculated volume in our LIS and write it on our retype label. Ironically, our medical director also oversees another hospital which simply weighs their units and uses the mgs to = mls without any calculation.

And then there are hospitals like the one where I work, we don't weigh or calculate anything. We just use one default volume for RBCs. Much less work for us and we have never had any complaints from clinicians.

[clmergen]

We also use a default UNLESS it comes with a specific volume on it from the supplier.