An " after versus before" observational study on external military operations in patients presenting with a haemorrhage of traumatic origin, reported a significant improvement in level of Prothrombin during the "after" period (which corresponded with FLYP administration - The before period corresponded with Saline infusion without any FLYP). In total, 124 patients were required to observe a statistically significant difference (p <0.001). In the absence of another publication on the subject we propose to include 70 patients per group, which should allow the significant results of the observational study cited above to be replicated.