CBC
Complete Blood Count
What is CBC?
 Commonly ordered blood test
 Calculation of the formed elements of blood
o RBC Count
o RBC Indices
o Hemoglobin
o Hematocrit
o WBC Count
o WBC Differential
o Platelet Count
CBC Collection Tube
 Purple top tube
 Anti-coagulant additive
 Mix 5-10 times
Why are CBCs needed?
 Screening during a general physical examination
 Especially on admission to a health care facility or
before surgery
Red Blood Cells (RBC)
 Normal Values
 Males: 4.7-6.1 million/mm3
 Females: 4.0-5.0 million/mm3
RBC
 Determines RBC/mm3
 Contains hemoglobin which is responsible for the
transport of oxygen and carbon dioxide
 Increased RBC occurs in polychythmia vera
 Decreased RBC occurs in anemia
 Congenital heart disease and events that induce
chronic hypoxia
 Moving to a high altitude or lung disease
Red Blood Cell Indices
 Red blood cell indices provide information about
the mean corpuscular volume (MCV), mean
corpuscular hemoglobin (MCH), mean
corpuscular hemoglobin concentration (MCHC),
and Red blood cell distribution width (RDW)
 Normal Values:
 MCV: 85-95fL
 MCH:28-32pg/cell
 MCHC:33-35g/dL
 RDW:11.6-14.8
Results
Increased in…
 MCV: Alcoholism, Antimetabolite therapy,
liver disease, pernicious anemia, Vit. B12
anemia
 MCH: Macrocytic anemias
 MCHC: Thalassemia, Spherocytosis
 RDW: Anemias with heterogeneous cell
size
Results
Decreased in…
 MCV: Iron-deficiency anemia, Thalassemias
 MCH: Hypochromic anemias, Microcytic anemias
 MCHC: Iron deficiency anemia
 RDW: N/A
Nursing Interventions
 Assist in the diagnosis of anemia
 Detect a hematologic disorder, neoplasm, or
immunologic abnormality
 Determine the presence of a hereditary hematologic
abnormality
 Monitor the progression of nonhematologic
disorders such as COPD, cancer, and renal disease
 Monitor the response to drugs or chemotherapy,
and evaluate undesired reactions to drugs that may
cause blood dyscrasias
Hemoglobin
 Carries O2 and removes CO2
 Buffer for acid-base balance in extracellular fluid
 Levels used with Hematocrit to evaluate anemia
 Normal ranges
 Males: 13.2-17.3 g/dL
 Females: 11.7-15.5 g/dL
Critical Values
 Less than 6.0 g/dL
 More than 18.0 g/dL
 High Hgb
 Polychythmia
 Low Hgb
 Anemia
Results
Increased in…
Decreased in…
 Burns
 Anemia
 CHF
 Carcinoma
 COPD
 Fluid retention
 Dehydration
 Incompatible blood
 Erythrocytosis
transfusion
 Hodgkin’s disease
 Pregnancy
Nursing Interventions
 Monitor fluid imbalances
 Monitor response to drugs or chemotherapy and
evaluate undesired reactions to drugs
 Screening as part of CBC
Hematocrit
 Measures the amount of red blood
cells (RBC) in the blood
 Expressed as a fraction or
percentage
 Increases when RBC number
increases or plasma level drops
 Decreases due to RBC production
decrease, blood loss or RBC
destruction
Normal Values
Age
Hematocrit (%)
Cord Blood
47-57
1 Day Old
51-65
2 Weeks Old
47-57
1 Month Old
38-52
6 Months Old
35-41
1 Year Old
37-41
10 Years Old
36-42
Adult Male
43-49
Adult Female
38-44
Abnormal Values
Increase
• Burns
•
•
•
•
•
•
•
•
CHF
COPD
Dehydration
Erythrocytosis
Hemoconcentration
High Altitudes
Polycythemia
Shock
Decrease
• Anemia
• Blood Loss
• Bone Marrow
Hyperplasia
• Chronic Disease
• Hemolytic Disorders
• Hemorrhage
• Fluid Retention
• Nutritional Deficit
• Pregnancy
White Blood Cells (WBC)
 Normal Ranges: (adults)
5000-10,000/mm3
 Critical Values
 >30,000/mm 3
 <2500mm3
 WBCs constitute the
body’s primary defense
system against foreign
organisms, and tissues
 Life span = 13 to 20 days
 Old WBCs are destroyed
by the lymphatic system
and excreted in feces
Nursing Interventions
 Assist in determining the cause of an elevated
WBC (e.g. infection, inflammatory process)
 Monitor the progression of nonhematologic
disorders (e.g. chronic obstructive pulmonary disease,
malaborption syndrome, cancer, renal disease)
 Monitor the response to medication (e.g.
chemotherapy)
An increase in WBCs = Leukocytosis
Pathologic Conditions:
• Transfusion reactions
• All types of infections
Physiological and
environmental
conditions:
• Anemia
• Appendicitis
• Cushing’s disease
• Emotional stress
• Inflammatory
• Exposure to cold
disorders
• Leukemia
• Menstruation
• Pregnancy and labor
• Strenuous exercise
A decrease in WBCs = Leukopenia
Physiological
conditions:
• Diurnal rhythms
Pathologic Conditions:
• Alcoholism
• Anemia
• Bone marrow
depression
• Malnutrition
• Radiation
• Viral infections
White Blood Cell Count and Cell
Differential
 WBC’s constitute the bodies primary defence
system
 Normal life span is 13 to 20 days; old cells are
destroyed by lymphatic system and excreted
 Produced in the bone marrow
Differential WBC Count
 The WBC’s in the count and differential are
reported as an absolute value, as a percent or as
SI Units
 using a base cell count of 100 cells, the relative
percentages are counted
 Absolute value is obtained by multiplying the
percentage by the total count
Contains K3 or K2 EDTA
(Ethylenediaminetetracetic Acid),
the chemical of choice to prevent
sample clotting; binds to Ca and
prevents the activation of clotting
Neutrophils
 Defend against bacteria and fungal infection; first response
 Activity and large numbers formulate pus
 Normal Values: 50-70% or 1.8-7.7
 ↑Neutrophilia—acute hemolysis, hemorrhage, extremes in
temperature, infection, inflammatory conditions
 ↓ Neutropenia—acromegaly, Addison’s disease,
anaphylaxis, starvation, bone marrow depression,
Lymphocytes
 A cell of the lymphatic system that participates in the immune response
 3 Types
 B Cells: make antibodies that bind to pathogens; retain memory
 T Cells: immune response coordination
 Natural Killer Cells: kill the cells of the body which display signal
 Normal Values: 20-30% or 1.0-4.8
 ↑ Lymphocytosis—Addison’s disease, Infections, Lymphocytotic
Leukemia, Lymphomas, Myeloma, Rickets, Ulcerative Colitis
 ↓ Lymphopenia—AIDS, Burns, Newborn Hemolytic Disease,
Immunodeficiency, Malnutrition, Pneumonia, Radiation, Septicemia,
Transfusion Reaction
Monocytes
 Present pieces of pathogens to T-Cells so that pathogens
can be recognized to mount antibody response; long living
 Leave the blood stream to become tissue macrophages to
remove dead cell debris and attack microorganisms
 Normal Values: 2-8% or 0-0.8
 ↑ Monocytosis—Carcinomas, Hemolytic Anemia, Hodgkin’s
Disease, Infections, Lymphomas, Monocytotic Leukemia
 ↓ Monocytopneia—Aplastic Anemia, Corticosteroid Therapy
(Prednisone)
Eosiniphils
 Primary deal with parasitic infections
 Inflammatory cells in allergic reactions
 Normal Values: 2-4% or 0-0.45
 ↑ Eosinophilia—Allergies, Parasitic Infection,
Autoimmune Disorders, Asthma
 ↓ Eosinopenia—Steroid Therapy
Basophils
 Responsible for allergic and antigen response by
releasing histamine causing inflammation
 Inflammatory cells in allergic reactions
 Normal Values: 0.5%-1% or 0-0.2
 ↑ Basophilia—Inflammatory processes during healing
 ↓ Basopenia—Hypersensitivity reactions and
corticosteroid therapy
Platelets
 Small disk-like shaped fragments of
cells
 Formed in the red bone marrow and
circulate freely in blood in an inactive
state
 When injury occurs, platelets collect at
a site and are activated
 Substances released from the platelet
granules activate coagulation factors in
the blood plasma and initiate the
formation of a stable clot composed of
fibrin
Platelets
 Platelet counts are done to establish the patients
coagulation abilities
 Normal Values
 Adults: 150 000 - 400 000/ mm3 of blood
 Abnormal Values
Increased Values
Results in increased
coagulation of blood
Decreased Values
Results in decreased
coagulation of blood
Nursing Interventions
Coagulation System Tests
 Evaluate Bleeding Time
 Amount of time for bleeding to stop after a
small incision is made in the skin
 Normal bleeding time: 3-7 minutes
 Prolongation occurs in patients with decreased
platelet count, anti-coagulation therapy, ASA
ingestion, leukemia, or clotting factor
deficiencies
Nursing Interventions
Coagulation System Tests
 Evaluate Factors Assay
 Measures the hemostatic activity
 Decreased activity of the coagulation factors
will result in defective clot formation
Nursing Interventions
Patients With Increased Platelet Count
 Monitor patients for risk of vascular thrombosis
or pulmonary emboli
 Administer anti-coagulation therapy
 Encourage healthy diet and exercise
Nursing Interventions
Patients With Decreased Platelet Count
•
•
Monitor patients for risk of spontaneous bleeding
Patient teaching
Interfering Factors
 Failure to fill tube
 Hemolyzed or clotted specimens
 Recent transfusion history
Nursing Implications for CBC
 If lab is performing, make sure they
are aware of any latex allergies
 Keep patient calm
 Ensure they breathe normally
 Avoid any movement
 Ensure prompt transportation of
specimen to the lab
Case Study 1
Your patient is post-op day 1. She had a total knee
replacement. You notice that the site is bleeding,
inflamed and reddened upon your morning
assessment. You call the doctor and he says to obtain
a complete blood count and that he will be in
tomorrow. You get it back later that day.
What would you expect the results to be and why?
Answers
 RBC will  due to loss of blood
 3.8 x 106 cells/mm3
 Hematocrit and hemoglobin levels  due to loss
of blood
 Hemoglobin: 7g/dL
 Hematocrit: 20%
 WBC will be  due to risk for infection
 11 000 mm3
 Platelets will  due to inc bleeding and inability to
clot
 140 000/mm3