Jennifer Lyon, M.S., M.L.I.S. [email_address] CBC - Hematology Tests

Hematology Tests Complete Blood Count (CBC) Hematocrit WBC Count Hemoglobin Platelet Count Sed Rate (Erythrocyte Sedimentation Rate)

Complete Blood Count (CBC)

Hematocrit

WBC Count

Hemoglobin

Platelet Count

Sed Rate (Erythrocyte Sedimentation Rate)

Why is it important? Blood is a vital organ and its functions include maintaining body homeostasis (pH, temperature), fighting infection, supplying nutrients and oxygen, and removing waste materials. Alterations in blood cell levels can signal the presence of a serious infection, problems in oxygen supply, or potential tissue damage

Blood is a vital organ and its functions include maintaining body homeostasis (pH, temperature), fighting infection, supplying nutrients and oxygen, and removing waste materials.

Alterations in blood cell levels can signal the presence of a serious infection, problems in oxygen supply, or potential tissue damage

Sample Clinical Questions At what hematocrit level should blood transfusions be considered in the ICU? Do steroid drugs result in an increase in white blood cell levels? How do the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) diagnostic tests compare and is it necessary to do both tests in pediatric patients with suspected osteomyelitis and/or septic arthritis? What is the reliability/value of the hematocrit in a hemorrhaging patient? What are the infectious causes of thrombocytopenia?

At what hematocrit level should blood transfusions be considered in the ICU?

Do steroid drugs result in an increase in white blood cell levels?

How do the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) diagnostic tests compare and is it necessary to do both tests in pediatric patients with suspected osteomyelitis and/or septic arthritis?

What is the reliability/value of the hematocrit in a hemorrhaging patient?

What are the infectious causes of thrombocytopenia?

Complete Blood Count (CBC) The standard CBC usually includes: WBC count – The total number of white cells per mm 3 of blood. Hemoglobin - The amount of hemoglobin in the blood, expressed in grams per liter. Hematocrit (aka packed cell volume or PCV) – The fraction of whole blood volume that consists of red blood cells, usually given as a percentage. Platelet count – The total number of platelets per mm 3 of blood.

The standard CBC usually includes:

WBC count – The total number of white cells per mm 3 of blood.

Hemoglobin - The amount of hemoglobin in the blood, expressed in grams per liter.

Hematocrit (aka packed cell volume or PCV) – The fraction of whole blood volume that consists of red blood cells, usually given as a percentage.

Platelet count – The total number of platelets per mm 3 of blood.

Often shown in this form: WBC Count Hematocrit Platelet Count Hemoglobin

Hematocrit AKA Packed Cell Volume, Crit, HCT, PCV Represents the proportion of RBCs to plasma in the blood and is a quick way to get an idea of whether the number of RBCs is normal. Normal Values Varies some with altitude Adult Males: 40-50% Adult Females: 36-46% Pregnancy: decreases in last trimester Newborn: Up to 60% Children: varies with age

AKA Packed Cell Volume, Crit, HCT, PCV

Represents the proportion of RBCs to plasma in the blood and is a quick way to get an idea of whether the number of RBCs is normal.

Normal Values

Varies some with altitude

Adult Males: 40-50%

Adult Females: 36-46%

Pregnancy: decreases in last trimester

Newborn: Up to 60%

Children: varies with age

Abnormal Hematocrit Low hematocrit (lower RBC%): anemia (various types) blood loss (hemorrhage) bone marrow failure (radiation, toxin, fibrosis, tumor) destruction of red blood cells; leukemia; rheumatoid arthritis High hematocrit (higher RBC %): fluid volume deficit/dehydration burns; diarrhea excessive red blood cell production: erythrocytosis & polycythemia vera

Low hematocrit (lower RBC%):

anemia (various types)

blood loss (hemorrhage)

bone marrow failure (radiation, toxin, fibrosis, tumor)

destruction of red blood cells; leukemia; rheumatoid arthritis

High hematocrit (higher RBC %):

fluid volume deficit/dehydration

burns; diarrhea

excessive red blood cell production: erythrocytosis & polycythemia vera

RBC (Erythrocyte) Count Normal Values Men: 4.5-6.0 million/mm 3 Women: 4.1-5.4 million/mm 3 Children: 4.6-4.8 million/mm 3 , varies with age Newborn: 5.5-6 million/mm 3 with gradual decrease Note that values increase at high altitudes.

Normal Values

Men: 4.5-6.0 million/mm 3

Women: 4.1-5.4 million/mm 3

Children: 4.6-4.8 million/mm 3 , varies with age

Newborn: 5.5-6 million/mm 3 with gradual decrease

Note that values increase at high altitudes.

Increased RBC Count AKA Erythrocytosis or Polycythemia Physiological increases can be due to high altitude and increased physical training Secondary polycythemia is due to an oxygen need Polycythemia Vera – a chronic myeloproliferative disorder, blood cells increase in #, particularly, but not limited to RBCs

AKA Erythrocytosis or Polycythemia

Physiological increases can be due to high altitude and increased physical training

Secondary polycythemia is due to an oxygen need

Polycythemia Vera – a chronic myeloproliferative disorder, blood cells increase in #, particularly, but not limited to RBCs

Anemia * : Decreased RBC Count Anemia * can be caused by Loss of erythrocytes (usually bleeding) Destruction of erythrocytes Lack of something needed for erythrocyte development Bone marrow suppression Major concern is lack of oxygen to the body. *Note: Anemia may be defined as a decrease in the total # of RBCs, a decrease in the total amount of hemoglobin in RBCs, or both depending on the source.

Anemia * can be caused by

Loss of erythrocytes (usually bleeding)

Destruction of erythrocytes

Lack of something needed for erythrocyte development

Bone marrow suppression

Major concern is lack of oxygen to the body.

Hemoglobin (Hg) Level Hemoglobin consists of a pigment (heme) containing iron and a protein (globin). It carries oxygen in the RBC for delivery to the body. Normal values Adult males: 13-18 g/100ml Adult females: 12-16 g/100ml Pregnancy: 11-12 g/100ml Fetal: 17-19 g/100ml Newborn: drops from fetal level over time Children: 14-17 g/100ml, depending on age

Hemoglobin consists of a pigment (heme) containing iron and a protein (globin). It carries oxygen in the RBC for delivery to the body.

Normal values

Adult males: 13-18 g/100ml

Adult females: 12-16 g/100ml

Pregnancy: 11-12 g/100ml

Fetal: 17-19 g/100ml

Newborn: drops from fetal level over time

Children: 14-17 g/100ml, depending on age

Hemoglobin One subunit of oxygenated hemglobin (hemoglobin consists of four such units) One subunit of deoxygenated hemglobin.

Sickle Cell Hemoglobin Single amino acid change between normal and sickle cell hemoglobin: Glutamic acid (Glu) at position is altered to Valine (Val). This single change causes the red blood cells to deform. Sickled RBC

Abnormal Hemoglobin Level Lower-than-normal hemoglobin can be caused by the same things as low RBC count plus other causes: anemia (various types); erythropoietin deficiency (from kidney disease); bleeding; red blood cell destruction associated with transfusion reaction; lead poisoning; methemoglobinemia; malnutrition; nutritional deficiencies; overhydration Higher-than-normal hemoglobin may indicate: congenital heart disease; cor pulmonale; pulmonary fibrosis; polycythemia vera; increased RBC formation associated with excess erythropoietin Note: Any increase in Hemoglobin level must be evaluated relative to the number and size of the RBCs

Lower-than-normal hemoglobin can be caused by the same things as low RBC count plus other causes:

anemia (various types); erythropoietin deficiency (from kidney disease); bleeding; red blood cell destruction associated with transfusion reaction; lead poisoning; methemoglobinemia; malnutrition; nutritional deficiencies; overhydration

Higher-than-normal hemoglobin may indicate:

congenital heart disease; cor pulmonale; pulmonary fibrosis; polycythemia vera; increased RBC formation associated with excess erythropoietin

WBC (Leukocyte) Count Total number of white blood cells (leukocytes) per cubic millimeter of blood Normal Values Adults: 4,500 - 10,000/mm 3 Newborns: 18,000 – 40,000/mm 3 Children: may be normal up to 14,500/mm 3 Aged: may decrease with age The division of the total into percentages of different leukocyte types is called a differential; “Diff” for short

Total number of white blood cells (leukocytes) per cubic millimeter of blood

Normal Values

Adults: 4,500 - 10,000/mm 3

Newborns: 18,000 – 40,000/mm 3

Children: may be normal up to 14,500/mm 3

Aged: may decrease with age

The division of the total into percentages of different leukocyte types is called a differential; “Diff” for short

Abnormal Total WBC Count Low numbers of WBCs (leukopenia) may indicate: bone marrow failure collagen-vascular diseases (such as lupus) disease of the liver or spleen radiation High numbers of WBCs (leukocytosis) may indicate: infectious diseases inflammatory diseases leukemia Stress or tissue damage

Low numbers of WBCs (leukopenia) may indicate:

bone marrow failure

collagen-vascular diseases (such as lupus)

disease of the liver or spleen

radiation

High numbers of WBCs (leukocytosis) may indicate:

infectious diseases

inflammatory diseases

leukemia

Stress or tissue damage

Platelet Count A normal platelet count is somewhere between 150,000 to 400,000/mm 3 of blood. Platelets (thrombocytes) are involved in blood coagulation and the stimulation of immune responses and healing at injury sites. Low platelet count (thrombocytopenia) may cause excessive bleeding. High platelet count may cause blood clots (emboli or thromboses) to form.

A normal platelet count is somewhere between 150,000 to 400,000/mm 3 of blood.

Platelets (thrombocytes) are involved in blood coagulation and the stimulation of immune responses and healing at injury sites.

Low platelet count (thrombocytopenia) may cause excessive bleeding.

High platelet count may cause blood clots (emboli or thromboses) to form.

Erythrocyte Sedimentation Rate AKA “ESR”, “Sed Rate” Measures the speed at which RBCs settle in a tube of anti-coagulated blood; expressed as mm/hr Normal Values Male: 15 mm/hr (>15 is elevated) Female: 20 mm/hr (>20 is elevated) Child: 10 mm/hr (>10 is elevated) Aged: 30 mm/hr (>30mm/hr is elevated)

AKA “ESR”, “Sed Rate”

Measures the speed at which RBCs settle in a tube of anti-coagulated blood; expressed as mm/hr

Normal Values

Male: 15 mm/hr (>15 is elevated)

Female: 20 mm/hr (>20 is elevated)

Child: 10 mm/hr (>10 is elevated)

Aged: 30 mm/hr (>30mm/hr is elevated)

Abnormal Sed Rate Increased Sed Rate: Normal in pregnancy Pathological in inflammation, infection and tissue injury Can be used to monitor the course of disease (rheumatoid arthritis, pelvic inflammatory disease, AIDS infections) Decreased Sed Rate: Sickle cell anemia, polycythemia vera, hypoalbuminemai, and Factor V deficiency

Increased Sed Rate:

Normal in pregnancy

Pathological in inflammation, infection and tissue injury

Can be used to monitor the course of disease (rheumatoid arthritis, pelvic inflammatory disease, AIDS infections)

Decreased Sed Rate:

Sickle cell anemia, polycythemia vera, hypoalbuminemai, and Factor V deficiency

Conclusion The use of these tests in diagnosing the specific type of anemia can be complex. A basic understanding of the four major tests in the CBC (WBCs, Hgb, Hct, platelets) is a good starting place. ~35-50 % (higher in men) Hct ~12-18 g/100ml Hgb ~4.5-10 thousand/mm 3 WBC count 150,000 to 400,000/mm3 Plateletcount

The use of these tests in diagnosing the specific type of anemia can be complex.

A basic understanding of the four major tests in the CBC (WBCs, Hgb, Hct, platelets) is a good starting place.

Resources Corbett JV. Laboratory Tests and Diagnostic Procedures with Nursing Diagnoses. 5 th ed. New Jersey: Prentice Hall Health, 2000. MedlinePlus: http://www.nlm.nih.gov/MedlinePlus http://www.emedicine.com http://www.labtestsonline.org http:// web.indstate.edu/thcme/PSP/blood/phleb.html

Corbett JV. Laboratory Tests and Diagnostic Procedures with Nursing Diagnoses. 5 th ed. New Jersey: Prentice Hall Health, 2000.

MedlinePlus: http://www.nlm.nih.gov/MedlinePlus

http://www.emedicine.com

http://www.labtestsonline.org

http:// web.indstate.edu/thcme/PSP/blood/phleb.html