Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ How do I work up my patient with anemia? ++ Table Graphic Jump Location|Download (.pdf)|Print Key concept Anemia is defined in clinical practice as a hemoglobin level <13.5 g/dL in men and <12 g/dL in women. Symptoms of anemia correlate with the degree and rate of development. An underlying abnormality should always be explored in an anemic patient. Clinical scenario A 69-year-old man with a history of an Escherichia coli urinary tract infection treated 8 days ago with ceftriaxone presents to the emergency room with symptoms of fatigue and jaundice. Physical examination reveals pallor and icteric sclerae. Laboratory evaluation reveals a hemoglobin level of 7.9 g/dL, elevated lactate dehydrogenase (LDH), low haptoglobin, indirect hyperbilirubinemia, and reticulocytosis. Review of the peripheral smear shows increased reticulocytes, anisocytosis, and spherocytic red blood cells (RBCs). A direct antiglobulin test (DAT) is positive for IgG. The patient is managed with supportive measures and recovers spontaneously after 7 days. Action items Production of RBCs requires the interaction of several elements and catalysts, including functional bone marrow, erythropoietin, iron, vitamins, and cytokines; deficiency in any of these can lead to anemia. A systematic approach in narrowing down the cause of anemia should be taken to ensure an accurate diagnosis and avoid unnecessary testing. Discussion In approaching a patient with anemia, the initial work-up should delineate whether the cause is a result of marrow underproduction or peripheral destruction or sequestration. This should be followed by a focused work-up of the suspected cause. Apparent or occult blood loss should be excluded, after which the pathogenesis can be categorized as follows. Underproduction anemias Anemia plus corrected reticulocyte count <2% Corrected reticulocyte count = reticulocyte % × patient’s hematocrit/normal hematocrit1 Select examples1: Microcytic RBCs: disorders in heme or globin synthesis (eg, iron deficiency, congenital sideroblastic anemia, thalassemia) Normocytic RBCs: anemia of chronic disease (can be microcytic), chronic kidney disease, or compound deficiencies (eg, iron and folate deficiency) Macrocytic RBCs: deficiency of vitamin B12 or folate, or liver disease Anemia secondary to increased RBC destruction (hemolytic anemia) Intravascular hemolysis: hemoglobinemia, hemoglobinuria, hemosiderinuria, decreased haptoglobin, or elevated LDH2 Extravascular hemolysis (spleen, liver): no release of hemoglobin in the blood; no hemoglobinemia, no hemoglobinuria, no or minimal consumption of haptoglobin, and LDH can be normal Recycled hemoglobin in the spleen or liver can result in indirect hyperbilirubinemia and bilirubinate gallstones2 Select examples1,2 See Table below ++Table Graphic Jump LocationView Table||Download (.pdf) HEMOLYSIS IMMUNE-MEDIATED NON–IMMUNE-MEDIATED Intravascular Complement-mediated destruction: Paroxysmal nocturnal hemoglobinuria Acute hemolytic transfusion reaction (ABO incompatibility) Paroxysmal cold hemoglobinuria Examples: Thrombotic microangiopathy (eg, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, disseminated intravascular coagulopathy) Direct trauma (eg, mechanical valve or foot-strike hemolysis) Extravascular Removed by macrophages in the reticuloendothelial system: Drug-immune hemolytic anemia Autoimmune hemolytic anemia RBC defects (eg, membrane defects, hemoglobin defects, or metabolic defects) Hypersplenism or liver disease Infections: babesiosis or malaria ++ Table Graphic Jump Location|... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth