(For those of you who don't want to read the whole thing, the evidence suggests that LR and PRBCs are compatible as long as the ratio of LR to PRBCs does not exceed 1:1. A safety margin of 1:2 is probably a good idea)
In 1975, Ryden and Oberman published the first data on the
Compatibility of Common Intravenous Solutions with CPD Blood. Working with CPD preserved
whole blood, they demonstrated grossly visible clot formation in vitro in samples of LR and whole blood at a citrate: calcium ratio of 4:1 or lower when incubated for 5 minutes. Largely based on these findings, AABB incorporated the prohibition against the combination of LR and blood components when they developed their guidelines.
Then, in 1991, Cull and Lally looked at the
Compatibility of (CPD preserved) packed erythrocytes and Ringer's lactate solution.. They examined a variety of ratios of CPD PRBCs: LR from 5:1 to 1:20. Clotting was observed in the 1:1 dilution, but not in the 2:1 or 5:1 dilutions at up to two hours. Units of PRBCs diluted with LR and passed through a 170 micron filter were compared to PRBCs similarly diluted with NS. No difference in flow rate was found.
In 1998, Lorenzo et al
advised that blood bank guidelines be revised to allow the use of LR in the rapid transfusion of PRBCs when they assessed infusion time, filter weight, and clot formation after admixing whole blood and PRBCs with NS, LR, and LR with increasing concentrations of added calcium chloride from 1g to 5g. They found no differences except for the presence of visible clot in the LR + 5g calcium chloride mixture.
In 2009, Albert et al found that
Ringer's lactate is compatible with the rapid infusion of AS-3 preserved packed red blood cells. when they used ELISA to compare prothrombin activation fragment 1 + 2 (the breakdown products of thrombin generation) levels in units of PRBCs similarly diluted in NS and LR then run through filters and fluid warmers (to simulate intraoperative transfusion practices) and found the levels of F1+2 to be sub-physiologic.
Then last year, Levac et al demonstrated that
Ringer's lactate is compatible with saline-adenine-glucose-mannitol preserved packed red blood cells for rapid transfusion.. "Samples from 12 units of SAGM-PRBC were diluted from 0-97.5% with RL and normal saline (NS), incubated for 30 min, and passed through 40 μm filters." F1+2 levels were measured via ELISA. 8 samples were diluted with LR and incubated for 30 to 240 min and analyzed in a similar manner. At 120 minutes and up, some clotting was observed, but there was no clotting at 60 minutes. They concluded that LR/ PRBC co-administration is safe as long as cells are administered over 60 minutes or less.
Though generally resulting in benign hemoglobinemia and hemoglobinuria, there are case reports of serious sequelae from acute non-immune hemolytic transfusion reaction (pseudo-hemolytic transfusion reaction) including renal failure and hypotension. However, lysis of cells was never the concern with LR. It is an accurate concern if red blood cells are diluted/ co-administered in hypotonic solutions like D5W which should never be done.
To my knowledge, there are no papers refuting the safety of PRBC/LR co-administration with modern anticoagulant techniques. If you know of any, please share.
I am not aware of any study of the effect of LR other factors, although platelet activation might occur. That would be an interesting thing to look at.
Personally, I still make a good-faith effort to dilute/ transfuse with NS because the guidelines exist and have not been update to reflect the data (the number one problem with guidelines IMHO). However, I don't go out of my way if there is LR hanging and I need to give products rapidly. I do always run platelets through their own line so the latter is essentially a null issue to me.
- pod
