To assess the relationship between hemoglobin and erythropoietin in MICU patients.
We prospectively analyzed 55 admissions who were predicted to stay in the MICU for at least 72 hours between March 2001 and September 2002. We did not enter subjects with chronic renal failure on dialysis. We recorded hemoglobin (Hb) levels and collected serum at baseline (during the first 3 days) and at 30 days from MICU admission. Serum was frozen and we later measured erythropoietin (EPO) using an ELISA method.
There was no relationship between EPO values and Hb levels for the 55 enrolled subjects, even though 25 of them were anemic (Hb<13g/dL). There also was no relationship for the 42 surviving subjects at baseline (r = 0.22, p = 0.17) and at 30 days (r = 0.10, p = 0.57.) EPO levels were not appropriately elevated in anemic subjects at baseline (mean 38 U/L, ± 56 SD) and were even less elevated at 30 days (mean 21 U/L ± 16), see figure.CONCLUSIONS: EPO is not appropriately elevated in critical illness, and remains low after recovery from acute illness in anemic patients.
Patients with critical illness appear to have a suppression of EPO production. This would indicate that there is an anemia of critical illness. Although transfusions remain accepted therapy for blood loss, the lack of appropriately increased levels of EPO in anemic patients for at least 30 days may suggest the use of recombinant human EPO to stimulate red blood cell production.
S.C. Campbell, OrthoBiotech, Industry.