Anemia I Flashcards
What is anemia?
A decrease in the circulating RBC mass
What are the major RBC measurements that when reduced indicate anemia?
RBC count (number of RBCs in a specified vol of whole blood)
Hemoglobin (conc of Hb in whole blood)
Hematocrit (vol of packed RBCs)
What Hb and Hct level indicates anemia?
<14 g/dL for men and <12 g/dL for women
<40% for men and <35% for women
What do RBCs originate from?
Myeloid stem cell
What are reticulocytes and what is their life span?
Immature RBCs
3 days in bone marrow and 1 day in circulation
What is the life span of RBCs?
120 days (then removed by spleen primarily)
What does retic count indicate?
Bone marrow production of RBCs to see if it is working well
Normal: .5-2%
What do reticulocytes look like on a peripheral smear?
“Lots of blue means lots of new”- bigger than normal RBCs and have a hint of blue because lack central pallor that indicated mature RBC
3 causes of anemia
Decreased RBC production (nutritional deficiencies, chronic disease, ineffective erythropoesis) Increased RBC desctruction (hemolysis) Blood loss (menstrual, GI, trauma)
What are the RBC indices?
MCV, MCH and MCHC
How do you classify RBCs by size?
Normocytic, microcytic or macrocytic
Mean corpuscular volume (MCV)
Calculated value to determine avg vol (size) or RBCs
Normocytic is 80-100
Mean corpuscular hemoglobin (MCH)
Average Hb content in a RBC
Mean corpuscular hemoglobin concentration (MCHC)
Average Hb concentration per RBC
How do you talk about MCH and MCHC?
Usually follow MCV so “microcytic hypochromic”
Red cell distribution width (RDW)
Measure of variation in RBC size
Normal: 11-15%
What is anisocytosis?
Variation in size of RBCs
Signs and symptoms of anemia
Fatigue/weakness, HA, dizzy, dyspnea, palpitations
Pallor, heme + stool, orthostatic chances, tachycardia
3 categories of anemia and their probable causes
Microcytic hypochromic (iron deficiency, thalassemia, sideroblastic anemia) Normocytic normochromic (hypothyroidism, liver disease, chronic disease) Macrocytic/megaloblastic (folate or B12 deficiency)
What are the major causes of iron deficiency anemia?
Blood loss (most common), decreased dietary intake, decreased iron absorption (Celiac, bariatric surgery, H pylori)
Diagnostic studies for iron deficiency anemia
Decreased RBC, H/H
MCV can be normal early on but will be microcytic later
Iron: decreased ferritin and serum Fe, increased TIBC
Increased RDW
Retic count probably low (but may be inappropriately normal)
What do you see on a peripheral smear of iron deficiency anemia?
RBCs that are microcytic and hypochromic, anisocytosis and poikilocytosis (varies in shape)
Other manifestations of iron deficiency anemia
Glossitis, angular cheilitis, koilonychia (spoon nails)
Pica (crave ice)
Dysphagia (esophageal webs- Plummer Vinson syndrome)
Restless legs syndrome
What is the most important part of treating iron deficiency anemia?
Determine the underlying cause!
Treatments for iron deficiency anemia
Replace iron stores:
Orally ferrous sulfate 325 mg BID-TID and should see return of HCT 1/2 way to normal in 3 weeks and full return to baseline at 2 months (continue for 3-6 mos to replenish stores)
Parenteral iron used in some people
Blood transfusions in ppl not recommended for iron replacement
What are the thalassemias?
Inherited hemoglobinopathy with reduction in the synthesis of globin chains
Leads to ineffective erythropoiesis and hemolysis
What is the result of the thalassemias?
Varying anemia and extramedullary hematopoiesis (produce RBCs outside of bone marrow)
Bone changes, impaired growth and iron overload
What is alpha-thalassemia?
Deletion of one or more of the four alpha-globin chains
4 types of alpha-thalassemia
1 deletion: silent carrier
2 deletions: alpha-thal minor or mild microcytic anemia
3 deletions: Hb H disease or mod microcytic anemia-chronic hemolytic anemia
4 deletions: hydrops fetalis (fatal in utero)
What is beta-thalassemia?
Reduced or absent beta-globin chain synthesis (usually due to pt mutation)
3 types of beta-thalassemia
Thalassemia minor (trait)- 1 chain, asymptomatic and mild microcytic anemia Thalassemia intermedia- less sever than major, non-transfusion dependent, chronic hemolytic anemia Thalassemia major- both chains, transfusion-dependent, sever hemolytic anemia
Labs seen in the thalassemias
Normal to increased RBC MCV super low (<75) RDW is normal Retic count: variably increased Normal to increased ferritin and iron Normal to decreased TIBC
What is hemoglobin electrophoresis?
Used in the diagnosis of the thalassemias to detect the type of Hb present
Treatments for thalassemia
Tailored to severity obvi
Folic acid supplementation (for chronic hemolysis)
AVOID IRON SUPPLEMENTS
Severe: regular transfusion schedule, hematopoietic cell transplant or genetic counseling
What is the process of sideroblastic anemia?
Hereditary or acquired RBC disorder
Abnormal RBC iron metabolism- diminished heme synthesis- iron accumulates in cells
What do you use to seesideroblastic anemia?
Bone marrow aspirate: ring sideroblasts (blue-stained iron) *hallmark
Peripheral smear: siderocytes with pappenheimer bodies
Causes of sideroblastic anemia
Acquired is most common in adults
Often a variant of myelodysplastic syndrome
Chronic alcoholism, meds, copper deficiency
What is the highest prevalence of thalassemias?
Africa, Asia and the Mediterranean region
Diagnostics of sideroblastic anemia
Elevated RDW
Normal to low retic count
Normal or elevated ferritin (leads to systemic volume overload- may look just like hereditary hemochromatosis)
Treatments for sideroblastic anemia
Treat the underlying cause duh
Discontinue offending drugs/toxic agents
Pyridoxine (vitamin B6) to help with Hb synthesis
Transfusion/manage iron overload
What is the second most common cause of anemia worldwide?
Anemia of chronic disease
What causes anemia of chronic disease?
Hepcidin-induced alterations in iron metabolism
Inability to increase erythropoiesis
Impaired to erythropoietin production
What is hepcidin?
Key regulator of the entry of iron into circulation
High levels are seen in inflammation (because of iron trapping in macrophages and decreased gut iron absorption)
Labs seen in anemia of chronic disease
Mild anemia: Hb or 10-11 g/dL
Normocytic, normochromic
Retic count may be low
Normal or increased serum ferritin (acute phase reactant)
Serum Fe and TIBC low (inflammation setting)
Treatment for anemia of chronic disease
Obvi treat the underlying cause
Erythropoietin may help
