Blunted erythropoietic response to anemia in multiply traumatized patients(Reprinted from Critical Care Medicine, vol 29, pg 743-747, 2001)

Objectives: To assess the relations between anemia, serum erythropoietin (E PO), iron status, and inflammatory mediators in multiply traumatized patien ts. Design: Prospective observational study. Setting: Intensive care unit. Patients: Twenty-three patients suffering from severe trauma (injury severi ty score greater than or equal to 30). Interventions: None. Measurements and Main Results: Blood samples were collected within 12 hrs a fter the accident (day 1) and in the morning on days 2, 4, 6, and 9 to dete rmine blood cell status, serum EPO, tumor necrosis factor-alpha (TNF-alpha) , soluble tumor necrosis factor-receptor I (sTNF-rl), interleukin-1 recepto r antagonist (IL1-ra), interleukin-6 (IL-6), neopterin, and iron status, re spectively. Hemoglobin concentration was low at admission (mean, 10.0 g/dL; range, 6.8-12.9 g/dL) and did not increase during the observation time. Se rum EPO concentration was 49.8 U/L (mean value) on day 1 and did not show s ignificant increases thereafter. No correlation was found between EPO and h emoglobin concentrations. TNF-alpha remained within the normal range. sTNF- rl was high at admission and increased further. IL1-ra was above the normal range. IL-6 was very high at admission and did not decrease thereafter. Th e initial neopterin concentration was normal, but increased until day 9. Se rum iron was significantly decreased on day 2 posttrauma and remained low d uring the study. Serum ferritin increased steadily from day 2, reaching its maximum on day 9. In contrast, concentrations of transferrin were low from admission onward. Conclusions: Multiply traumatized patients exhibit an inadequate EPO respon se to low hemoglobin concentrations. Thus, anemia in severe trauma is the r esult of a complex network of bleeding, blunted EPO response to low hemoglo bin concentrations, inflammatory mediators, and a hypoferremic state.