Ringer's lactate is compatible with saline-adenine-glucose-mannitol preserved packed red blood cells for rapid transfusion.

Purpose: Guidelines state that Ringer's lactate (RL) should not be co-administered with packed red blood cells (PRBC) due to a potential risk of clotting. The purpose of this study was to determine whether RL causes clotting in PRBC with the currently used preservative, saline-adenine-glucose-mannitol (SAGM).

Methods: Phase 1: 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. Additional samples were frozen and batch analyzed using an enzyme-linked immunosorbent assay (ELISA) to measure prothrombin activation fragment 1 + 2 (F1 + 2), indicative of thrombin generation. Packed red blood cells were also diluted, flushed with crystalloid using a rapid transfusion model, and filtered. Phase 2: Eight further units were serially diluted with RL and incubated for 30, 60, 120, 180, and 240 min. Fresh samples were analyzed by filtration and ELISA.

Results: Phase 1: No clotting was seen during filtration or using the transfusion model with NS or RL. The F1 + 2 ranged from 2.28 to 154.37 pmol·L⁻¹ in NS dilutions and from 2.80 to 1675.93 pmol·L⁻¹ in RL dilutions, indicating coagulation in some samples. Phase 2: No clotting was observed within 60 min by filtration or ELISA. However, 4 of the 8 units showed clots in the filters of some dilutions between 120 and 240 min.

Conclusions: No clotting was detected at any dilution of RL with SAGM- preserved PRBC within 60 min, but clotting was detected with extended incubation. The results indicate RL can be safely co-administered with PRBC during rapid transfusion (< 60 min).