Why are CBC*s needed
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Transcript Why are CBC*s needed
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
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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
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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