i know the formulas for figuring out the hgb drop to transfuse for a predetermined hgb, and texts also utilize the 20% loss from the ebv. i was talking to my crna preceptor the other day and he stated he had a post c-section that lost around 2000cc's of blood and he went ahead and transfused, or wanted to transfuse can't remember which. he stated he was talking to the anesthesiologist and he stated that only time a transfusion is warranted (from a board testing standpoint) is when a patient cannot maintain there o2 saturation with their current hemoglobin level (i am referring to a low hemoglobin level causing the sat drops and not another reason). i cannot find this in any text and all texts will give you different "parameters" and i don't know of any particular hospital policies at any clinical site i have been at. can someone clarify this for me i know it depends on the patient and what is going on but is a dropping sat really the only true reason to give blood? if so can you give me a reference?
also is there any way we can have a srna section like the pre-crna so those of us in school can ask questions in an appropriate area so you don't have to weed out through the other non srna questions?
What do mean by "the expected distortion of the Svo2"? It is either distorted (dropped) or it is not. You don't give blood b/c you are expecting the sat to drop from low hgb. You'll give blood 1st to keep the pt/VS stable. The BP is where you'll see the effects of low hgb 1st, then later you may see a drop in sats (due to low hgb or low o2 carrying capacity: same difference), then even later you'll definitely see a drop in sats. This point is really late in the game to be thinking about transfusing.
He is saying that a person with low Hgb doesn't necessarily present with desaturation. This is b/c the person can compensate by increasing HR or CO = Increase tissue perfusion = Sats are maintained. At the point that you see the sats dropping (due to blood loss i.e. low hgb), this is really late in the game and you need to give blood ASAP now. One may say that this is not the point to give blood, but what they mean to say is that you should've been giving blood already to avoid getting to this point.
He is also saying you don't give blood for low Hbg but you give blood for loss of o2 carrying capacity 2nd to loss of bld (or low hgb). This is being a bit technical. Technically correct, but loss of o2 carrying capacity is due to loss of hgb. Initially a little loss of Hgb is compensated for by Inc HR/CO. Later, more loss of hgb leads to loss of O2 carrying capacity b/c the tissues extract more O2 than what is delivered ( = lowered sats).
So in the spirit of keeping it simple. loss of blood => loss hgb (don't necessary see drop in sats yet). More loss of hgb => loss of O2 carrying capicity => lowered sats.
Get it?
I think I do. Somebody who has lost a ton of blood during surgery needs his blood replaced first for BP stabilization, if it is low.; then for oxygen carrying. But I shouldn't look for a decreased SVO2 as my first indication to give blood because that is a late sign, the better sign is my Hgb value.
As CRNA's, do you order the blood and decide how much, or does the surgeon decide.
I think I do. Somebody who has lost a ton of blood during surgery needs his blood replaced first for BP stabilization, if it is low.; then for oxygen carrying. But I shouldn't look for a decreased SVO2 as my first indication to give blood because that is a late sign, the better sign is my Hgb value.
As CRNA's, do you order the blood and decide how much, or does the surgeon decide.
Many things can cause a drop in svo2 so dont think it only deals with Hgb. Like I said their is no cook book here. You have to assess the pt and all the data you have including H&H, BP, Sats, SVO2, HR, color, EBL. You assess everything all at once. Yes when you give blood it will help with pressure issues if hypovolemic but no you dont give blood soley for pressure issues. If your Hgb(O2 carrying capacity is good) and your BP sucks you may need volume but not blood. Some one can come in dehydrated as hell with super hemoconcrated blood be hypovolemic with BP in the toilet. Here you just need crystalloids.
In the OR you make can make the call for the need of a transfusion but the surgeon can as well. Got to collaborate.
I see what's going on here. this is all very funny to me. 1st BeatOU and the other students, I commend you for asking the questions. It makes us practitioners think and learn. So keep it up.
So you are on the right track, but if you are still confused, don't worry about it too much. When you are in the OR and facing these situations, what you learn will make more sense and you will have no trouble remembering it.
I say this situation is funny, because many of us in the OR do not (as Nitecap stated) follow a cook book of when to give blood, how much, etc. You use many indications (VS, skin color, hgb value, sat value, patients overall health, type & length of case, surgeons hx of bld loss, etc.) including your gut feeling. Just as Nitecap stated, you assess all of these things at once, and then you get resounding audible voice in your head that says "GIVE THE BLOOD or DON"T THE BLOOD yet" Many of us at times also wrestle with the decision of is it appropriate to give blood yet? It's not always clear cut to us either and we are suppose to be the experts. This is funny to me..b/c with all our learning we can go right back to step one, a beginner.
The simply answer is when a patient loses blood to the point that his VS are adversely affected AND you can no longer compesate for him by use of IV fluids (crystalloid & colloid) and meds (VPs, catecholamines, etc), you give blood to replace the blood loss and to maintain O2 carrying capacity (keep VSS).
No one simply just gives blood b/c of a sat value, or a hgb value, or even a BP, or even if your math calculations says give blood when you've loss 700cc of blood. I mean you can, but it's not the best way to practice anesthesia. Again, asses the whole patient and the whole situation.
Anesthesia can be very complicated and simply at the same time. What is very simple to us practioners (like when to give blood) can be very complicated and convuluted to the outsider. Anesthesia is both an art and a science, with lots of grey areas. This is what makes it special and fun. So if this is still confusing, don't sweat it. When you get in the OR, they'll be another 100 different & confusing issues waiting for ya to wrestle with.
You dont give blood soley for volume or coagulapathies ect though if the hgb is low and you transfuse it does help with your volume issue.
:yelclap: Thankyou!! Why do a lot of practitioners believe blood is the first line of defense for hypovolemia? They tend to forget about the hepatitis/hiv risk, the immunosuppressive reaction, increased risk of infections, and even an increase in tumor recurrence and mortality rate following cancer resections! If you give blood unneccesarily, you are putting your patient at risk. Blood is not always a good thing.
If only we could use a cellsaver in every case, it would be great!
BeatOU
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