Preoperative Anemia: Relevance, Diagnostic, Therapy

Preoperative anemia with a preoperative hemoglobin level < 12 g/dl in female and <13 g/dl in male is an independent risk factor for morbidity and mortality. A metaanalysis of the German guideline on Preoperative Anemia identified a significant increased risk for mortality and for perioperative red blood cell transfusion in preoperative anemic patients undergoing elective cardiac- or non-cardiac surgery. If preoperative anemia is diagnosed, differential blood screening should be performed timely, usually 4-6 weeks before elective surgery. Most common cause of preoperative anemia are iron deficiency, renal failure as well as anemia of chronic diseases. Preoperative anemia should only be started after diagnosis. Oral iron therapy in preoperative anemia is recommend in case of existing iron deficiency while intravenous administration of iron is only recommended if the preoperative time interval for oral therapy is too short, or if there is an intolerance or resorption disorder for oral iron treatment. Erythropoietin might be indicated when renal anemia or anemia due to chronic diseases has been diagnosed. If concomitant iron deficiency is present, therapy with erythropoietin in combination with iron is recommended. Possible non-hematopoietic effects of erythropoietin, e.g. the potential impact on angiogenesis and tumor growth or rare severe cutaneous reactions requiring a differentiated and cautious use of erythropoietin. In the treatment with erythropoietin and/or iron it has to be considered not to exceed a preoperative hemoglobin value of 12 g/dl.