8/4- Approach to Anemia Flashcards
What are reticulocytes?
Young RBCs just released from the bone marrow
- Typically 1% of RBCs
When will reticulocytes be high?
- Blood loss
- Premature destruction of RBC (hemolysis)
In hemolysis, the % of reticulocytes roughly tells you what?
In hemolysis the % of reticulocytes roughly correlates with red blood cell life span
- The higher the reticulocyte count (retic) the shorter the red cell life span.
How long does it take a reticulocyte to mature?
1 day
What is the lifespan of a RBC?
120 days
CBC normal values (will be provided on tests)?
Mean normal values for hemoglobin?
Note that adult men have a hB that is about 1.5 g/dL higher than women
What is anemia (basic def)?
Reduction in the RBC mass
Classification of anemia based on mechanism?
1. Physiologic- due to expanded plasma volume– anemia of pregnancy
2. Hypoproliferative- due to decreased bone marrow production– reticulocyte low count
3. Proliferative- due to blood loss or hemolysis– reticulocyte high count
What basic labs may help in approaching anemia?
- CBC, reticulocyte count, peripheral blood smear
- Comprehensive metabolic panel (CMP) for electrolytes (Na, K, Cl, CO2, Ca) and renal function (BUN, creatinine), and liver function (total protein, albumin, ALT, AST, alkaline phosphatase, total and direct bilirubin)
Symptoms and signs of anemia?
- Mild anemia: asymptomatic
- Breathlessness and fatigue
- Pallor: shunting away from the skin (nail beds, conjunctivae, and buccal mucosa)
- Tachycardia: severe anemia, pulse at rest is elevated, palpitations
- Systolic flow murmur
- Other findings depending on the cause
- Pounding headache with exertion
- Dizziness and syncope
- Insomnia, inability to concentrate and disorientation
- Angina, claudication, heart failure
What important family history should be explored when considering anemia?
- Anemia
- Cholecystectomy and splenectomy at a young age (hereditary hemolytic disease)
- Ethnicity
What is this showing?
Pallor
What is this showing?
Retinal hemorrhages in severe anemia
Other things to look at on physical exam for anemia?
- Scleral icterus and jaundice
- Lymph node enlargement
- Splenomegaly
- Hepatomegaly
- Petechiae, ecchymoses, hematomas
- FOB (fecal occult blood)
Blood tube: Purple or lavender
Purple or lavender: EDTA—strong calcium chelator—CBC, reticulocyte counts
Blood tube: Red
Red: no anticoagulant, the blood clots and there may be a separator—serum is then available for electrolytes, antibodies, etc
Blood tube: Blue
Blue: citrate a week calcium chelator—you can add back calcium so that you can do clotting assays for PT, aPTT etc
Blood tube: Green
Green: heparin –for flow cytometry
Equation for packed cell volume?
Packed cell volume = hematocrit = RBC x MCV
(MCV = mean cellular volume)