Effect of fibrinogen on reversal of dilutional coagulopathy: a porcine model.

BACKGROUND: This study was conducted to determine whether replacement of fibrinogen is useful in reversing dilutional coagulopathy following severe haemorrhage and administration of colloids.
METHODS: In 14 anaesthetized pigs, approximately 65% of the estimated blood volume was withdrawn and replaced with the same amount of gelatin solution to achieve dilutional coagulopathy. Animals were randomized to receive either 250 mg kg(-1) fibrinogen (n=7) or normal saline (n=7). A standardized liver injury was then inflicted to induce uncontrolled haemorrhage. Modified thrombelastography and standard coagulation tests were performed at baseline, after blood withdrawal, after dilution, after injection of the study drugs, and on conclusion of the protocol. Further, electron microscopy imaging of the blood clots was performed and blood loss after liver injury was determined.
RESULTS: Severely impaired haemostasis was observed after haemodilution with gelatin substitution. With administration of fibrinogen, clot firmness and dynamics of clot formation reached baseline values. Median blood loss following liver injury was significantly less (P=0.018) in the fibrinogen-treated animals (1100 ml; 800-1400 ml) than in the placebo group (2010 ml; 1800-2200 ml).
CONCLUSIONS: Replacing 65% of the estimated blood volume with gelatin in swine resulted in dilutional coagulopathy; subsequent fibrinogen administration improved clot formation and reduced blood loss significantly.