Small volume albumin administration protects against hemorrhagic shock-induced bone marrow dysfunction.

Background: Unexpected immuno-modulatory effects of colloids and crystalloids prompted an investigation of albumin's ability to prevent bone marrow (BM) suppression following trauma/hemorrhagic shock (T/HS: laparotomy + MAP 30 for 90 mins). Methods: In vitro: Normal rat BM was plated for granulocyte-macrophage (CFU-GM) and erythrocyte colony forming units (BFU-E) with 2% v/v plasma from sham (T/SS) or T/HS rats and albumin (2-8 mg/mL). In vivo: Male rats (n = 4/group) were subjected to T/SS or T/HS and resuscitated with shed blood and twice the volume as Lactated Ringer's (LR) or blood and 1, 2, or 3 mL of albumin (50 mg/mL). Bone marrow harvested 3 hours post-resuscitation was plated for CFU-GM and BFU-E. Results: In vitro: T/HS plasma decreased both CFU-GM and BFU-E growth as compared with T/SS, whereas increasing doses of albumin showed dose-dependent improvement in progenitor growth (p < 0.05). In vivo: The suppression of BM red and white cell progenitor growth seen in T/HS+LR rats as compared with T/SS was fully prevented by as little as 1 mL of albumin (p < 0.05). Conclusions: Small doses of albumin fully restore CFU-GM and BFU-E to sham values. We postulate that the binding of circulating toxic factors by albumin may play a role in this prevention of T/HS-induced BM suppression.