Key Components of a Comprehensive Review of Systems and History for Anemia Evaluation
When evaluating a patient with anemia, a thorough review of systems and history should focus on identifying the underlying cause through specific clinical assessment components and targeted laboratory testing.
Initial History Assessment
- Duration and onset of symptoms, including syncope, exercise dyspnea, headache, vertigo, chest pain, fatigue (disruptive to daily activities), and abnormal menstruation in females 1
- Detailed medication history with emphasis on drug exposure that may cause anemia (chemotherapeutic agents, anticoagulants, NSAIDs) 1
- Comorbidities that may contribute to anemia (renal insufficiency, chronic inflammation, malignancy) 1
- Family history of inherited anemias (thalassemia, sickle cell disease) 1
- Dietary history to assess for nutritional deficiencies 1
- History of blood loss (melena, hematochezia, hematemesis, menorrhagia) 1
- Exposure to chemotherapy or radiation therapy 1
Physical Examination Elements
- Assessment for pallor, jaundice, petechiae, and heart murmurs 1
- Evaluation for splenomegaly or hepatomegaly 1
- Neurological examination for symptoms related to B12 deficiency 1
- Examination for signs of blood loss including stool guaiac testing 1
Laboratory Evaluation
- Complete blood count (CBC) with indices to characterize anemia and identify other cytopenias 1
- Peripheral blood smear review to assess red blood cell morphology 1
- Reticulocyte count to distinguish between production and destruction/loss problems 1
- Morphologic classification based on mean corpuscular volume (MCV) 1:
- Microcytic (<80 fL): iron deficiency, thalassemia, anemia of chronic disease
- Normocytic (80-100 fL): hemorrhage, hemolysis, bone marrow failure, chronic inflammation
- Macrocytic (>100 fL): B12/folate deficiency, alcoholism, MDS, medication effect
Specific Testing Based on Initial Findings
- Iron studies: serum iron, total iron binding capacity (TIBC), transferrin saturation, and ferritin 1
- Vitamin B12 and folate levels for macrocytic anemia 1
- Hemolysis evaluation: Coombs test, haptoglobin, LDH, bilirubin 1
- Renal function tests: glomerular filtration rate, erythropoietin level 1
- Bone marrow examination when indicated (suspected primary bone marrow disorder) 1
- Endogenous erythropoietin levels may predict response in patients with myelodysplasia 1
Special Considerations for Cancer-Related Anemia
- Assessment of chemotherapy regimen and cycle number, as anemia rates increase with additional cycles (from 19.5% in cycle 1 to 46.7% by cycle 5) 1
- Evaluation of nadir hemoglobin level and time to nadir (approximately 2 weeks) 1
- Consideration of anemia of chronic disease/inflammation related to cancer 1
- Evaluation for bone marrow infiltration by cancer 1
Kinetic Approach to Anemia Evaluation
- Reticulocyte index (RI) assessment 1:
- Low RI: decreased RBC production (iron/B12/folate deficiency, aplastic anemia, bone marrow dysfunction)
- High RI: normal/increased RBC production (blood loss or hemolysis)
Common Pitfalls to Avoid
- Failing to consider multiple causes of anemia in cancer patients 1
- Overlooking functional iron deficiency in the setting of inflammation 1
- Misinterpreting ferritin levels, which can be elevated in cancer patients despite iron deficiency due to inflammation 1
- Neglecting to perform Coombs testing in patients with chronic lymphocytic leukemia, non-Hodgkin's lymphoma, or history of autoimmune disease 1
- Initiating treatment without identifying and addressing the underlying cause 1
By systematically addressing these components in the review of systems and history, clinicians can effectively evaluate patients with anemia and develop appropriate management strategies based on the underlying etiology.