colloids. 1:1 or 2:1?

Why is it that EVERY text I read says that blood is to be replaced with crystalloid at 3:1 and colloid at 1:1, but yet 90% of all anesthetists and MDA's I ask say that blood is replaced at 2:1 by colloids? Blood replacement aside.....(hypothetically, so don't say "I wouldn't replace it with colloid!)if you calculate that you are 1000cc's behind and you only had colloid to give, would you feel satisfied that you were back even if you gave 300ish of colloid or 500cc colloid? For those that say it is indeed 2:1, please provide me with a reference because I can't find it. Thanks!

I wondered the same things. Miller, morgan and Mak all say colloids 1:1 but I freq see 2:1 given. One attending told me he based it more on the pt than the ebl. We all no EBL many times can be pretty unaccuate and sometimes derived from a negotiation b/t surgery and anesthesia. He said he judges it on vitals, filling pressures, changes in response to drugs that may not have occured earlier in the case ect then assesses ebl. Theoretically we are taught 1:1. Also take into account the degree of possible cap leak which if severe colloids may diffuse interstitially and draw more fluid out of the vasculature and cause more edema and interstitial fluid shifts as well as possible coagulopathy with some colloid products when given a bunch.

Come on guys. I KNOW the MAJORITY of you believes that colloids are to replace blood at 2:1. I'm trying to find the source of this because EVERY text that I read says 1:1. Where does this 2:1 come from? (Maybe it's in an older version of Barash, Miller, etc?) It's frustrating to be in clinical and get reprimanded/corrected on something that you can quote right out of 5 textbooks but you're still wrong anyway........ It's almost like "that's the way it always has been and that's the way it will stay regardless of what the current versions of the top 5 most respected anesthesia texts say."

Thanks in advance.

Come on guys. I KNOW the MAJORITY of you believes that colloids are to replace blood at 2:1. I'm trying to find the source of this because EVERY text that I read says 1:1. Where does this 2:1 come from? (Maybe it's in an older version of Barash, Miller, etc?) It's frustrating to be in clinical and get reprimanded/corrected on something that you can quote right out of 5 textbooks but you're still wrong anyway........ It's almost like "that's the way it always has been and that's the way it will stay regardless of what the current versions of the top 5 most respected anesthesia texts say."

Thanks in advance.

Well folks. If I start with a normovolemic patient, I´ll use colloid 1:1, and crystalloid 3:1. At least in theory.

Because at the op floor, I´ll tend to go more after clinical signs. When my medulla oblongata tells me that the patient reacts like he/shes hypovolemic, I´ll act on that gut feeling. I dont use equations :chuckle

Most patients get hypovolemic right from the start from regional blocks and the vasodilatation from anesthetics. Hypertonic patients have cronically constricted peripheral blood vessels, and compensates this with a relatively smaller blood volume. Add some anesthesia to that - and you get an even more pronounced hypovolemia.

Maybe thats the cause of the 2:1 colloid volume replacement? The first litre of colloid is for preop hypovolemia, the other litre for intraop blood loss?

I know my english sucks, but I hope you follow me?

/Anders Kohkoinen, Nurse Anesthesist, Sweden

Why is it that EVERY text I read says that blood is to be replaced with crystalloid at 3:1 and colloid at 1:1, but yet 90% of all anesthetists and MDA's I ask say that blood is replaced at 2:1 by colloids? Blood replacement aside.....(hypothetically, so don't say "I wouldn't replace it with colloid!)if you calculate that you are 1000cc's behind and you only had colloid to give, would you feel satisfied that you were back even if you gave 300ish of colloid or 500cc colloid? For those that say it is indeed 2:1, please provide me with a reference because I can't find it. Thanks!

Nope. I always learn 1:1 also. Haven't yet met anyone who said 2:1 for colloid. I don't doubt you, but haven't encountered it yet.

Z