CBC Flashcards
CBC Components
Red Blood Cell Count, Red Blood Cell Indices (MCV - Mean Corpuscular Volume, MHC - Mean Corpuscular Hemoglobin, MCHC - Mean Corpuscular Hemoglobin Concentration, RDW - Red Cell Distribution Width). Peripheral Smear, Platelet Count, Hematocrit, Hemoglobin, White Blood Cell Count, White Blood Cell Differential.
CBC Used to
Make Diagnosis, Narrow Differential, Guide for further diagnostic testing
Complaints Supporting CBC
Fever, Fatigue, Dyspnea, Bleeding, Bruising, Heme Positive, Weightloss, Lymphadenopathy, Dizziness (not vertigo), Palpitations, Angina, Jaundice)
RBC
Life span 120 days, Biconcave, no nucleus, B12, Fe, Folate for production, flexible, contains Hemoglobin, formation stimulated by erythropoietin, removed by spleen.
Red Blood Cell Count
Male: 4.7 - 6.1 Females: 4.2 - 5.4 Anemia = >10% below normal Erythocytosis = excess RBC’s
RBC Indices
Helpful in categorizing anemias, classifies RBC into size, hgb concentration
Hematocrit (Hct) - Measures packed RBC volume (PCV)
Male: 42 - 52 % Female: 37 - 47 Critical 60%
Hemoglobin (Hgb) - in peripheral venous system
Male: 14 - 18 g/dL Female: 12 - 16 g/dL Pregnant > 11g/dL
Rule of Threes/Normal Values
Hct = 3 x Hgb Hgb = 3 x RBC Count
RBC, Hgb, Hct Causes of Decrese
Hemorrhage, hemolysis, dietary deficiency (B12, folate), genetic defect, drugs, marrow failure, chronic illness, marrow/organ failure, hemo-dilution (too much fluid to fast)
RBC, Hgb, Hct Causes of Increase
Hemoconcentration, Chronic hypoxia - COPD, Smoking. Polycythemia vera, high altitude living, drugs.
Mean Corpuscular Volume (MCV)
Reflects average size of RBC. MCV = (Hct x 10) / RBC Normal: 80-95 fL = normocytic 95 fL = macrcytic cells
Mean Corpuscular Hemoglobin (MCH)
Average amount (weight) of Hgb in each RBC MCH = Hgb / RBC Normal: 27 - 31 pg
Mean Corpuscular Hemogobin Concentration (MCHC)
Average concentration of Hgb in a RBC MCHC = Hgb / Hct Normal: 32 - 36 % <32 % hypochromic (pale RBC) 32 - 36% normochromic
Red Cell Distribution Width
Cell size variability Reference Range: 11 - 14.5 % If elevated, considerable size variation (anisocytosis)
Peripheral Smear
Looks at abnormal shapes (pikilocytosis), staining patterns.
Target Cells
Hemoglobinopathies, Thalassemia