A network member recently requested information about the practices of anesthesiologists when it comes to adding or mixing medications to blood products. To review a related discussion, please see: Which solutions other than isotonic saline are approved for addition to blood and components?

In response to the question about anesthesiologist practices regarding adding or mixing pain medications and antibiotics to blood or the IV through which blood is infusing, here are some interesting replies:

1. An anesthesiologist in Texas wrote that in general, anesthesiologists are given very little formal education about the addition of medications to blood products. Rather, the knowledge that anesthesiologists have about this practice is passed down 'from generation to generation', as residents watch their seniors put medications into the blood line.  This anesthesiologist pointed out that if you look on the blood warmer administration sets used in the OR, there is a place to add medications in front of the warmer as well as after the warmer. In 'big cases', anesthesiologists (at least the ones this physician knows about) put lots of three-way stopcocks on the blood warmer to administer medications. It was also pointed out that anesthesiologists give blood faster than almost anyone, since they often wait until blood becomes absolutely necessary.  As an example, the anesthesiologist reported that he often gives a unit over 10-15 minutes, but in a trauma, that can be shortened to 2-3 minutes.  So, how are anesthesiologists really practicing? To quote this contributor, "Nearly everything goes into the IV except calcium". Do all institutions always start a second IV in these cases?  "In practice, this would be a rare and an unusual event." Finally, the anesthesiologist mentioned that a few years ago, there was some discussion about using plasmalyte (instead of normal saline) for blood administration.  He says that most folks do this in order to prevent the hyperchloremic acidosis that comes with NaCl resuscitation.

2. A second anesthesiologist reported that while she did not represent anesthesiologists as a group, she was attuned in to their practice, being the chair of the American Society of Anesthesiologists Committee on Transfusion Medicine. She pointed out the ASA published a brochure entitled "Questions and Answers about Transfusion Practices", 3rd edition in 1997. One of the questions is "Which intravenous solutions are compatible with red blood cells?" This really deals more with diluting RBCs, but it's the only written document of the ASA that addresses the issue even peripherally. To quote this anesthesiologist: "Quite frankly, I don't think the basic issue you are concerned about is something the ASA would comment upon. They certainly would not publish anything that conflicted with Standards (at least not as long as I am Chairman of the committee!) On a practical note, what is really done? I understand the reluctance to start another IV. Sometimes there is no other site. I suspect the most common situation is patient-controlled analgesia (PCA). I really don't see a problem and am sure my colleagues "piggy back" the PCA line into an existing IV which may also be used for transfusion. I agree that a problem is especially unlikely to occur with a multi-lumen CVP. This is not an issue likely to be resolved. I'm sorry I can't be more helpful. I think it's one of those situations where the clinician does what's practical, regardless of policy. No one can put in writing that it's OK, but....."

3. The third reply came from a blood banker who said he would challenge the anesthesiologist to provide the data that their practice of adding medications to blood is safe, or to develop data. Blood bankers could help with the design and completion of such a study if there are no relevant data. Another option would be to ask some pharmacists as they mix iv solutions if they have information on what drugs are compatible or incompatible with blood.

4. Another blood banker pointed out that the Circular of Information states "No medications or solutions may be routinely added to or infused through the same tubing with blood or components except 0.9% Sodium Chloride, Injection (USP). Other solutions intended for intravenous use may be used in an administration set or added to blood or components under either of the following conditions: a) They have been approved for this use by the FDA or b) There is documentation available to show that addition to the component involved is safe and efficacious. ABO-compatible plasma, 5% Albumin, or Plasma Protein Fraction, or other suitable plasma expanders may be used with approval of the patient's physician." This blood banker went on to say that from what he has observed at his facility, official policy is not always followed.  He would suggest involving the hospital quality assurance committee with an investigation of practice patterns of anesthesiologists to determine whether or not hospital policy is being followed.

Editor's Note: It appears from the above discussion that we have conflict between practice and policy. It would certainly be reassuring to have data that it is safe to run medications through the same line as blood products.  Maybe such data will be forthcoming, now that this is out in the open?  If data were available, perhaps policies could be more in line with practice, and practice could be more in line with official policies.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator