SRNA Blood transfusion question clarification

[Jacads]

---

Members do not see this ad.

I reasked my preceptor about the only board/clinical reason for a person to transfuse blood and was told quote "The ony true indication to give PRBC's is to increase patient's oxygen carrying capacity, based on ABGs, O2 sats." This is what I am tryng to find a reference for.

Thanks,

Jacads

 

[VolatileAgent]

are you sure you heard your preceptor right about O2 sats? there is no indication to ever make a call on transfusing someone based on 02 saturation. O2 saturation has nothing to do with transfusion threshold. if they are at the point that they are desaturating, you are in deep ****. (and, if he/she actually said that, then he/she needs some remediation before continuing to precept students.)

it's more appropriately based on allowable blood loss which should be calculated prior to the start of the case. you should always have a threshold at which you will say, "now i'm going to transfuse." and, you can't always rely on being able to do intraoperative tests to help you make that decision.

for example, what if you can't get an ABG (which, in your example, is really for a stat Hct) or send a CBC because the labs down (or any other myriad of reasons when something could go wrong)? don't think this happens? HA!

point is, you should already have an idea about when you would transfuse before you induce the patient (for an elective case). and, during an expected bloody case, this is why you have to be extra-vigilant in watching blood loss as well as watching other clinical signs (continued tachycardia, hypotension, patient pallor, etc.). i can tell horror stories about myomectomies on patients with a baseline crit of 6.0 who were being transfused as we rolled them into the OR suite to start the case...

so, there's really no magic formula about when to transfuse - and, hence, no one single reference that will give you the information you're looking for. it is very patient dependent. and, depending on which studies you read, it is occasionally better not to transfuse at all. (but that can be a controversial subject in and of itself.)

 

[Jacads]

He mentioned ABG's and briefly stated sats but stuck with the ABGs. The reason I am asking is because I might see this on my certification exam and am just trying to solidify the correct answer. I understand the formula's and about the ABL of 20% but just wanting clarification for exm questions.

are you sure you heard your preceptor right about O2 sats? there is no indication to ever make a call on transfusing someone based on 02 saturation. O2 saturation has nothing to do with transfusion threshold. if they are at the point that they are desaturating, you are in deep ****. (and, if he/she actually said that, then he/she needs some remediation before continuing to precept students.)

it's more appropriately based on allowable blood loss which should be calculated prior to the start of the case. you should always have a threshold at which you will say, "now i'm going to transfuse." and, you can't always rely on being able to do intraoperative tests to help you make that decision.

for example, what if you can't get an ABG (which, in your example, is really for a stat Hct) or send a CBC because the labs down (or any other myriad of reasons when something could go wrong)? don't think this happens? HA!

point is, you should already have an idea about when you would transfuse before you induce the patient (for an elective case). and, during an expected bloody case, this is why you have to be extra-vigilant in watching blood loss as well as watching other clinical signs (continued tachycardia, hypotension, patient pallor, etc.). i can tell horror stories about myomectomies on patients with a baseline crit of 6.0 who were being transfused as we rolled them into the OR suite to start the case...

so, there's really no magic formula about when to transfuse - and, hence, no one single reference that will give you the information you're looking for. it is very patient dependent. and, depending on which studies you read, it is occasionally better not to transfuse at all. (but that can be a controversial subject in and of itself.)

 

[stephend7799]

I reasked my preceptor about the only board/clinical reason for a person to transfuse blood and was told quote "The ony true indication to give PRBC's is to increase patient's oxygen carrying capacity, based on ABGs, O2 sats." This is what I am tryng to find a reference for.

Thanks,

Jacads

dude
why dont you go to allnursing.com.. the crnas in there know much more than any doctor in here.

 

[Jacads]

I'm sorry I thought this was an anesthesia forum not a urology forum specializing in dick heads.

dude
why dont you go to allnursing.com.. the crnas in there know much more than any doctor in here.

 

[VA Hopeful Dr]

dude
why dont you go to allnursing.com.. the crnas in there know much more than any doctor in here.

An SRNA comes here and asks a reasonable question that has nothing to do with The Debate that Must Not Be Named, and this is what they get? Its crap like what you post that makes the rest of us luck bad. Nicely done.

 

[VolatileAgent]

He mentioned ABG's and briefly stated sats but stuck with the ABGs. The reason I am asking is because I might see this on my certification exam and am just trying to solidify the correct answer. I understand the formula's and about the ABL of 20% but just wanting clarification for exm questions.

i've personally never heard of a hard and fast "20% rule". and, again, the abg really is only valuable in providing a Hct. what i personally do (and highly recommend to everyone else) is determine where the threshold is based upon the patient's baseline health. for example, let's say you have a patient who is 70kg, but with heart disease, and that you absolutely do not want their hct to fall below 27. at what point will you transfuse? and, let's say they are having a prostatectomy, a notoriously bloody elective procedure.

so, as an exercise for you, let's say that their starting Hb is 13 and their starting Hct is 38. what would be their allowable blood loss?

(remember: patient's bleed whole blood. that is, if you don't replace their fluid at the right rate, you're not going to necessarily see a drop in hb/hct to give you an accurate picture based on lab parameters. likewise, it takes time for them to equilibrate/shift spaces with whatever you are giving them. this is why it is more important to calculate allowable blood loss prior to induction.)

 

[VolatileAgent]

also, in my original reply, i meant to say a "bsl Hb of 6.0", not crit. (true story. the lady had tried everything else, lupron, etc. and just continued to bleed. if we'd waited, her h/h would never have been stable. so, we transfused her to tank her up and then rolled her in to do the hysterectomy. and, she fortunately did very well.)

 

[Jacads]

Thanks for the advice textbooks can only give a foundation and every patient/situation is different.

 

[Dr. J?]

I'm sorry I thought this was an anesthesia forum not a urology forum specializing in dick heads.

Well done, sir! Stephen 7799, take a hint. Don't try to hijack legitimate knowledge-seeking posts.

 

[VolatileAgent]

Thanks for the advice textbooks can only give a foundation and every patient/situation is different.

don't you want to work through my scenario? i'm offering you a more meaningful, legitimate, real-life based teaching/learning opportunity than your preceptor did.

give it a try. these are the types of problems that are essentially fourth-year medical student/basic, early-on-in-anesthesiology-residency things we are expected to tackle and know. simply saying "abg, sat O2, and oxygen-carrying capacity" are kinda meaningless explanations that don't really help you understand the why behind the what and how.

if you don't know where to start, i'll help. it's important that you understand this so you can deliver effective care. otherwise, you're just guessing when you should transfuse. i mean, if you want to participate in bloody cases - and perhaps ultimately without supervision - don't you think you should know this?

 

[sevoflurane]

Try using this:

EBV x (Hct intitial- Hct threshold)/ Hct initial = ABL

😉

EBV= estimated blood volume. You need weight, gender and age to figure this one out.

 

[militarymd]

Try using this:

EBV x (Hct intitial- Hct threshold)/ Hct initial = ABL

😉

EBV= estimated blood volume. You need weight, gender and age to figure this one out.

gobity gook...dribble....

 

[UTSouthwestern]

gobity gook...dribble....

It's GOBBLEDY-GOOK . . . DRIVEL . . .
Don't make me correct you again.

 

[militarymd]

It's GOBBLEDY-GOOK . . . DRIVEL . . .
Don't make me correct you again.

 

[UTSouthwestern]

Hey I've got to be able to get you on something, you know?

 

[militarymd]

Seriously....In actual practice, Those calculations just don't seem to help me.

I have in mind about hot much blood I'm willing to let the patient lose.

Once I get near that number:
1) I check labs if there is time
2) if there is no time, give blood or not based on your medical judgement.

 

[jetproppilot]

Seriously....In actual practice, Those calculations just don't seem to help me.

I have in mind about hot much blood I'm willing to let the patient lose.

Once I get near that number:
1) I check labs if there is time
2) if there is no time, give blood or not based on your medical judgement.

Ditto.

 

[Noyac]

Try using this:

EBV x (Hct intitial- Hct threshold)/ Hct initial = ABL

😉

EBV= estimated blood volume. You need weight, gender and age to figure this one out.

The reason this is Gobbledy-Gook is b/c you are often off on your estimated blood loss, and the IVF factor.

 

[sevoflurane]

OK.... WHAT THE HELL is "GOBBLEDY-GOOK . . . DRIVEL" ???? 😕

 

[SilverStreak]

Seriously....In actual practice, Those calculations just don't seem to help me.

I have in mind about hot much blood I'm willing to let the patient lose.

Once I get near that number:
1) I check labs if there is time
2) if there is no time, give blood or not based on your medical judgement.

But, before you were where you are today, put yourself in a student's place. How did you come to learn what line you set on how much blood is acceptable?

I'm guessing it all depends on a number of factors, of course patient history, preop labs, meds the patient took preop that may cause increased bleeding, particular surgery/and surgeon-some are notorious for having more bleeding/issues than others.

Also, I find my eyebrows raised sometimes on the stated EBL we see on the op note. I don't think they always give an accurate count, but no evidence just a hunch from knowing some of them.

That's all I know about trying to gauge when to transfuse in the OR. Not much yet, but there's my stab at what basic things you would make a decision from.

As far as needing volume, at what point do you decide to give blood over a crystalloid or a colliod for volume replacement? If my hct is hanging low but acceptable, I would venture a guess that crystalloids or colloids would be a safer way for the patient, with less exposure to potential infectants in the blood.

 

[VentdependenT]

On another note, when do you all check coags and plates on a patient intraop.

I read somewhere in my MGH manual that after 2 L it should be checked.

On another note I read to check it or rather just begin replacing it after a massive transfusion (the entire blood volume lost).

I'm not talking about the massivley oozing pt in a liver transplant where DIC or bypass coagulopathy can be a culprit in addition to massive transfusion. In that situations its self explanitory.

 

[Tenesma]

Jacads... how many times are you going to post this question?????...

how many times do you have to hear that blood transfusion has NOTHING TO DO WITH SATURATION!!!! they are two entirely different issues...

THEREFORE YOU WILL NOT FIND ANY TEXTBOOKS TO EVER SUPPORT THAT NOTION... sorry dude

while the only way to calculate oxygen carrying capacity is a formula that requires knowledge of O2 Sat and PAO2, that doesn't imply anything regarding transfusion requirement.

geezzz already...


THE ONLY GOLDEN CRITERIA FOR BLOOD TRANSFUSION ARE AS FOLLOWS
1) hemodynamically unstable patient in whom the culprit for the instability is suspected to be blood loss (IE: trauma patient)

2) symptoms of end-organ dysfunction or pt w/ potential end-organ dysfunction based on a measured hemoglobin level (IE: pt w/ angina w/ CAD w/ HGB=8)

OTHER CRITERIA include:
1) hematologic considerations (IE: exchange transfusing blood for a pt w/ Sickle cell crisis)

 

[jwk]

Also, I find my eyebrows raised sometimes on the stated EBL we see on the op note. I don't think they always give an accurate count, but no evidence just a hunch from knowing some of them.

Important blood loss concept for newbies:

1) The E in EBL means ESTIMATED - and it is a number that is RARELY in agreement with what the surgeons write in their op note, unless of course they use the number that YOU gave them.

2) Surgeons DO NOT want to admit they lost ANY blood, and certainly not enough to warrant transfusion. "Sorry Dr. Smith, I think your patient lost 3 liters of blood on that revision total hip, not just 250. They got 3 units back from the cellsaver and a couple banked blood, and I just now have gotten the pressure above 100 and the heart rate under 120."

3) For god's sake don't take your cellsaver tech's carefully charted estimate of EBL as legitimate just because of they effort they went into to come up with that number.

4) A dripping wet 4x4 sponge can hold 50cc of blood - a really soaking lap sponge can hold 200cc. But regardless, it's an ESTIMATE.

5) YOUR estimate is almost certainly better than anyone else's estimate since YOU have been monitoring ALL the blood loss and how it relates to the patient's condition throughout the case. And if they don't agree with your estimate, fine. That's THEIR problem. Write down what YOU think is appropriate, and remember, say it with me, it's an ESTIMATE.

 

[Noyac]

It is my understanding that the cell saver blood collected is about 1/3 of the actual EBL.

 

[Tenesma]

cell saver blood EBL has NO correlation with true EBL unless the surgeons only use the cell saver suction device and do not use any sponges/lap pads...

in large volume blood loss cases the closest approximation of true EBL is the number of PRBC transfused x 3

 

[jwk]

It is my understanding that the cell saver blood collected is about 1/3 of the actual EBL.

There's no way to tell.

If pooled blood is sucked up (such as large amounts of blood inside the abdomen) there's not near as much hemolysis caused by the suction, and more of the RBC's make it through processing. You might get better than 50-60% salvage rate with that.

Blood that is oozing and suctioned up (spine cases or total hips for example) gets hemolyzed much more as it gets beaten up going through the tubing with all that airflow, so many of the RBC's are destroyed. You're lucky if you get 1/3 of the RBC's actually salvaged.

If you ever watch the earlier part of the cellsaver wash cycle or look at the waste bag, you can often see the difference in the amount of hemolysis - more hemolysis and the effluent is more red - less hemolysis and the effluent is more clear.

 

[Noyac]

There's no way to tell.

If pooled blood is sucked up (such as large amounts of blood inside the abdomen) there's not near as much hemolysis caused by the suction, and more of the RBC's make it through processing. You might get better than 50-60% salvage rate with that.

Blood that is oozing and suctioned up (spine cases or total hips for example) gets hemolyzed much more as it gets beaten up going through the tubing with all that airflow, so many of the RBC's are destroyed. You're lucky if you get 1/3 of the RBC's actually salvaged.

If you ever watch the earlier part of the cellsaver wash cycle or look at the waste bag, you can often see the difference in the amount of hemolysis - more hemolysis and the effluent is more red - less hemolysis and the effluent is more clear.

Your right JWK, but I was talking about the amount in the canister mostly. Not the amount returned. I don't recall the study that looked at it but from what I remember it was about 30% of the actual EBL in the majority of cases. Majority can be 51% however, and then we are no better off in our estimate, if that makes sense.
By the way, isn't the bleeding usually oozing rather than pooled? It is in my experience. 👍

 

[SigmaSRNA]

i've personally never heard of a hard and fast "20% rule". and, again, the abg really is only valuable in providing a Hct. what i personally do (and highly recommend to everyone else) is determine where the threshold is based upon the patient's baseline health. for example, let's say you have a patient who is 70kg, but with heart disease, and that you absolutely do not want their hct to fall below 27. at what point will you transfuse? and, let's say they are having a prostatectomy, a notoriously bloody elective procedure.

so, as an exercise for you, let's say that their starting Hb is 13 and their starting Hct is 38. what would be their allowable blood loss?

(remember: patient's bleed whole blood. that is, if you don't replace their fluid at the right rate, you're not going to necessarily see a drop in hb/hct to give you an accurate picture based on lab parameters. likewise, it takes time for them to equilibrate/shift spaces with whatever you are giving them. this is why it is more important to calculate allowable blood loss prior to induction.)

Is the patient a man or woman?
Open question to everybody: In your individual practices, how low do you allow the crit to get? I know it depends on the medical hx of the patient, but in general, how low?

 

[jwk]

Your right JWK, but I was talking about the amount in the canister mostly. Not the amount returned. I don't recall the study that looked at it but from what I remember it was about 30% of the actual EBL in the majority of cases. Majority can be 51% however, and then we are no better off in our estimate, if that makes sense.
By the way, isn't the bleeding usually oozing rather than pooled? It is in my experience. 👍

Depends on the case - open up a ruptured AAA and you have lots of pooled blood.

Also - the amount of blood in the canister is meaningless because of irrigation fluids, lap wash, etc. The tech's try and keep up with it, and that's where they try and make these nice records to include everything and come up with an EBL, but it's really hard to keep track of accurately.

 

[Noyac]

Depends on the case - open up a ruptured AAA and you have lots of pooled blood.

Also - the amount of blood in the canister is meaningless because of irrigation fluids, lap wash, etc. The tech's try and keep up with it, and that's where they try and make these nice records to include everything and come up with an EBL, but it's really hard to keep track of accurately.

I don't know about your surgeons but we have 2 suctions on the field for cell saver cases and whenever we irrigate or suck old clotted blood we use the wall suction and we use the cell saver for active bleeding.
I will agree that it is really hard to to estimate EBL but I triple the cell-saver vol in the canister and estimate the wall suction and laps. This has worked for me.

 

[VolatileAgent]

Is the patient a man or woman?
Open question to everybody: In your individual practices, how low do you allow the crit to get? I know it depends on the medical hx of the patient, but in general, how low?

the calculating of the allowable blood loss (for those who scoff at this notion) is critical in doing peds cases. it's not just academic masturbation. it is a valuable way of managing a case. i'm appalled that many of the supposed senior members of this forum slammed sevo's explanation calling it "goobleydeegook" and whatnot. i seriously hope you guys don't routinely eyeball this or rely excessively on the luxury of labs. or, that you've gotten so cavalier about giving gas that you forget the nuts and bolts of good EBM and patient management - the whole picture. otherwise, the "CRNA movement" may have a point about our patient management skills and knowledge base being equal.

 

[cloud9]

the calculating of the allowable blood loss (for those who scoff at this notion) is critical in doing peds cases. it's not just academic masturbation. it is a valuable way of managing a case. i'm appalled that many of the supposed senior members of this forum slammed sevo's explanation calling it "goobleydeegook" and whatnot. i seriously hope you guys don't routinely eyeball this or rely excessively on the luxury of labs. or, that you've gotten so cavalier about giving gas that you forget the nuts and bolts of good EBM and patient management - the whole picture. otherwise, the "CRNA movement" may have a point about our patient management skills and knowledge base being equal.

So, in other words, the folks doing this for years don't have the knowledge base and expertise of the residents? Interesting.

 

[Mapleson D]

To the original poster, this is an important concept: an O2 sat measures just that - the saturation of the hemoglobin you've got. If you have 1 gram/dL hemoglobin and it's fully saturated with oxygen, you'll have a sat of 100%. But do you have adequate O2 carrying capacity? Absolutely not.

So as previous posters have said, O2 sat has absolutely no bearing whatsoever on whether to transfuse a patient.