[Method for determining the amount of blood loss using the storage iron decrease rate as obtained from serum ferritin after intravenous iron therapy].

This is to introduce a new method for determining the amount of blood loss by measuring the storage iron decrease rate (SID), as obtained by following serum ferritin after intravenous iron therapy in a patient with iron deficiency anemia due to intestinal blood loss. The patient was followed from the day S, when iron therapy started, to the day E, when serum ferritin decreased to 12 microg/l, indicating the exhaustion of the iron stores. The SID was calculated from the formula: SID=(T-R)/D, where, T mg = total amount of injected iron, R mg = the difference in the iron in the hemoglobin (deltaHb) between day S and E, and D = days from S to E. The SID was thought to be iron loss only, as the contribution of iron absorption and iron loss to the SID, with the exception of bleeding, was believed to be negligible and as the serum ferritin decrease curve was exponentially linear. Using the formula, V = iron loss/iron in mean Hb, the amount of blood loss: V=29 ml/day was obtained. This method can also be used for the quantitation of blood loss in other patients with chronic blood loss, because the SID could also be determined in 12 cases of post-treatment iron deficiency anemia with chronic blood loss.