Complete Blood Count, WBC Count and Differential
Complete Blood Count, WBC Count and Differential
SpecimenWhole blood from one full lavender-top (EDTA) tube.
|Age||Conventional Units WBC ×103/microL||Neutrophils||Lymphocytes||Monocytes||Eosinophils||Basophils|
|(Absolute) and %||(Absolute) and %||(Absolute) and %||(Absolute) and %||(Absolute) and %|
|Birth||9.1–30.1||(5.5–18.3) 24–58%||(2.8–9.3) 26–56%||(0.5–1.7) 7–13%||(0.02–0.7) 0–8%||(0.1–0.2) 0–2.5%|
|1–23 mo||6.1–17.5||(1.9–5.4) 21–67%||(3.7–10.7) 20–64%||(0.3–0.8) 4–11%||(0.2–0.5) 0–3.3%||(0–0.1) 0–1%|
|2–10 yr||4.5–13.5||(2.4–7.3) 30–77%||(1.7–5.1) 14–50%||(0.2–0.6) 4–9%||(0.1–0.3) 0–5.8%||(0–0.1) 0–1%|
|11 yr–older adult||4.5–11.1||(2.7–6.5) 40–75%||(1.5–3.7) 12–44%||(0.2–0.4) 4–9%||(0.05–0.5) 0–5.5%||(0–0.1) 0–1%|
|Age||Immature Granulocytes (Absolute) (103/microL)||Immature Granulocyte Fraction (IGF) (%)|
|10 yr−older adult||0–0.09||0–0.9%|
The absolute neutrophil count (ANC) reflects the number of segmented and band type neutrophils in the total WBC count. It is used as an indicator of immune status because it reflects the type and number of WBC available to rapidly respond to an infection. Neutropenia is a decrease below normal in the number of neutrophils. ANC = Total WBC × ((Segs/100) + (Bands/100)) or total WBC × (% Segs + % Bands). The normal value varies with age but in general mild neutropenia is less than 1.5, moderate neutropenia is between 0.5 and 1, and severe neutropenia is less than 0.5. The ANC is helpful when managing patients receiving chemotherapy. It can drive decisions to place a hospitalized patient in isolation in order to protect them from exposure to infectious agents. When the patient is aware of their ANC they can also make informed decisions in taking actions to avoid exposure to crowds, avoid touching things in public places that may carry germs, or avoiding friends and family who may be sick.
Acute leukocytosis is initially accompanied by changes in the WBC count population, followed by changes within the individual WBCs. Leukocytosis usually occurs by way of increase in a single WBC family rather than a proportional increase in all cell types. Toxic granulation and vacuolation are commonly seen in leukocytosis accompanied by a shift to the left, or increase in the percentage of immature neutrophils to mature segmented neutrophils. An increased number or percentage of immature granulocytes, reflected by a shift to the left, represents production of WBCs and is useful as an indicator of infection. Immature neutrophils are called bands and can represent 3–5% of total circulating neutrophils in healthy individuals. Bandemia is defined by the presence of greater than 6–10% band neutrophils in the total neutrophil cell population. These changes in the white cell population are most commonly associated with an infectious process, usually bacterial, but they can occur in healthy individuals who are under stress (in response to epinephrine production), such as women in childbirth and very young infants. The WBC count and differential of a woman in labor or of an actively crying infant may show an overall increase in WBCs with a shift to the left. Before initiating any kind of intervention, it is important to determine whether an increased WBC count is the result of a normal condition involving physiological stress or a pathological process. The use of multiple specimen types may confuse the interpretation of results in infants. Multiple samples from the same collection site (i.e., capillary versus venous) may be necessary to obtain an accurate assessment of the WBC picture in these young patients.
Neutrophils are normally found as the predominant WBC type in the circulating blood. Also called polymorphonuclear cells, they are the body’s first line of defense through the process of phagocytosis. They also contain enzymes and pyogenes, which combat foreign invaders.
Lymphocytes are agranular, mononuclear blood cells that are smaller than granulocytes. They are found in the next highest percentage in normal circulation. Lymphocytes are classified as B cells and T cells. Both types are formed in the bone marrow, but B cells mature in the bone marrow and T cells mature in the thymus. Lymphocytes play a major role in the body’s natural defense system. B cells differentiate into immunoglobulin-synthesizing plasma cells. T cells function as cellular mediators of immunity and comprise helper/inducer (CD4) lymphocytes, delayed hypersensitivity lymphocytes, cytotoxic (CD8 or CD4) lymphocytes, and suppressor (CD8) lymphocytes.
Monocytes are mononuclear cells similar to lymphocytes, but they are related more closely to granulocytes in terms of their function. They are formed in the bone marrow from the same cells as those that produce neutrophils. The major function of monocytes is phagocytosis. Monocytes stay in the peripheral blood for about 70 hr, after which they migrate into the tissues and become macrophages.
The function of eosinophils is phagocytosis of antigen-antibody complexes. They become active in the later stages of inflammation. Eosinophils respond to allergic and parasitic diseases: They have granules that contain histamine used to kill foreign cells in the body and proteolytic enzymes that damage parasitic worms (see monograph titled “Eosinophil Count”).
Basophils are found in small numbers in the circulating blood. They have a phagocytic function and, similar to eosinophils, contain numerous specific granules. Basophilic granules contain heparin, histamines, and serotonin. Basophils may also be found in tissue and as such are classified as mast cells. Basophilia is noted in conditions such as leukemia, Hodgkin’s disease, polycythemia vera, ulcerative colitis, nephrosis, and chronic hypersensitivity states.
This procedure is contraindicated for
- Assist in confirming suspected bone marrow depression
- Assist in determining the cause of an elevated WBC count (e.g., infection, inflammatory process)
- Detect hematological disorder, neoplasm, or immunological abnormality
- Determine the presence of a hereditary hematological abnormality
- Monitor the effects of physical or emotional stress
- Monitor the progression of nonhematological disorders, such as chronic obstructive pulmonary disease, malabsorption syndromes, cancer, and renal disease
- Monitor the response to drugs or chemotherapy and evaluate undesired reactions to drugs that may cause blood dyscrasias
- Provide screening as part of a CBC in a general physical examination, especially on admission to a health-care facility or before surgery
- Normal physiological and environmental conditions:
- Early infancy (increases are believed to be related to the physiological stress of birth and metabolic demands of rapid development)
- Emotional stress (related to secretion of epinephrine)
- Exposure to extreme heat or cold (related to physiological stress)
- Pregnancy and labor (WBC counts may be modestly elevated due to increased neutrophils into the third trimester and during labor, returning to normal within a week postpartum)
- Strenuous exercise (related to epinephrine secretion; increases are short in duration, minutes to hours)
- Ultraviolet light (related to physiological stress and possible inflammatory response)
- Pathological conditions:
- Acute hemolysis, especially due to splenectomy or transfusion reactions (related to leukocyte response to remove lysed RBC fragments)
- All types of infections (related to an inflammatory or infectious response)
- Anemias (bone marrow disorders affecting RBC production may result in elevated WBC count)
- Collagen disorders (related to an inflammatory or infectious response)
- Cushing’s disease (related to overproduction of cortisol, a corticosteroid, which stimulates WBC production)
- Inflammatory disorders (related to an inflammatory or infectious response)
- Leukemias and other malignancies (related to bone marrow disorders that result in abnormal WBC production)
- Parasitic infestations (related to an inflammatory or infectious response)
- Polycythemia vera (myeloproliferative bone marrow disorder causing an increase in all cell lines)
- Diurnal rhythms (lowest in the morning)
- Alcoholism (related to WBC changes associated with nutritional deficiencies of vitamin B12 or folate)
- Anemias (related to WBC changes associated with nutritional deficiencies of vitamin B12 or folate, especially in megaloblastic anemias)
- Bone marrow depression (related to decreased production)
- Malaria (related to hypersplenism)
- Malnutrition (related to WBC changes associated with nutritional deficiencies of vitamin B12 or folate)
- Radiation (related to physical cell destruction due to toxic effects of radiation)
- Rheumatoid arthritis (related to side effect of medications used to treat the condition)
- Systemic lupus erythematosus (SLE) and other autoimmune disorders (related to side effect of medications used to treat the condition)
- Toxic and antineoplastic drugs (related to bone marrow suppression)
- Very low birth weight neonates (related to bone marrow activity being diverted to develop RBCs in response to hypoxia)
- Viral infections (leukopenia, lymphocytopenia, and abnormal lymphocytes may be present in the early stages of viral infections)
LeukopeniaNormal physiological conditions
Neutrophils Increased (neutrophilia)Acute hemolysis Acute hemorrhage Extremes in temperature Infectious diseases Inflammatory conditions (rheumatic fever, gout, rheumatoid arthritis, vasculitis, myositis) Malignancies Metabolic disorders (uremia, eclampsia, diabetic ketoacidosis, thyroid storm, Cushing’s syndrome) Myelocytic leukemia Physiological stress (e.g., allergies, asthma, exercise, childbirth, surgery) Tissue necrosis (burns, crushing injuries, abscesses, myocardial infarction) Tissue poisoning with toxins and venoms
Neutrophils Decreased (neutropenia)Acromegaly Addison’s disease Anaphylaxis Anorexia nervosa, starvation, malnutrition Bone marrow depression (viruses, toxic chemicals, overwhelming infection, radiation, Gaucher’s disease) Disseminated SLE Thyrotoxicosis Viral infection (mononucleosis, hepatitis, influenza) Vitamin B12 or folate deficiency
Lymphocytes Increased (lymphocytosis)Addison’s disease Felty’s syndrome Infections Lymphocytic leukemia Lymphomas Lymphosarcoma Myeloma Rickets Thyrotoxicosis Ulcerative colitis Waldenström’s macroglobulinemia
Lymphocytes Decreased (lymphopenia)Antineoplastic drugs Aplastic anemia Bone marrow failure Burns Gaucher’s disease Hemolytic disease of the newborn High doses of adrenocorticosteroids Hodgkin’s disease Hypersplenism Immunodeficiency diseases Malnutrition Pernicious anemia Pneumonia Radiation Rheumatic fever Septicemia Thrombocytopenic purpura Toxic chemical exposure Transfusion reaction
Monocytes Increased (monocytosis)Carcinomas Cirrhosis Collagen diseases Gaucher’s disease Hemolytic anemias Hodgkin’s disease Infections Lymphomas Monocytic leukemia Polycythemia vera Radiation Sarcoidosis SLE Thrombocytopenic purpura Ulcerative colitis
- Total WBC count of less than 2 × 103/microL (SI: Less than 2 × 109/L)
- Absolute neutrophil count of less than 0.5 × 103/microL (SI: Less than 0.5 × 109/L)
- Total WBC count of greater than 30 × 103/microL (SI: Greater than 30 × 109/L)
Note and immediately report to the requesting health-care provider (HCP) any critically increased or decreased values and related symptoms.
It is essential that a critical finding be communicated immediately to the requesting health-care provider (HCP). A listing of these findings varies among facilities.
Timely notification of a critical finding for lab or diagnostic studies is a role expectation of the professional nurse. Notification processes will vary among facilities. Upon receipt of the critical value the information should be read back to the caller to verify accuracy. Most policies require immediate notification of the primary HCP, Hospitalist, or on-call HCP. Reported information includes the patient’s name, unique identifiers, critical value, name of the person giving the report, and name of the person receiving the report. Documentation of notification should be made in the medical record with the name of the HCP notified, time and date of notification, and any orders received. Any delay in a timely report of a critical finding may require completion of a notification form with review by Risk Management.
The presence of abnormal cells, other morphological characteristics, or cellular inclusions may signify a potentially life-threatening or serious health condition and should be investigated. Examples are hypersegmented neutrophils, agranular neutrophils, blasts or other immature cells, Auer rods, Döhle bodies, marked toxic granulation, or plasma cells.
- Drugs that may decrease the overall WBC count include acetyldigitoxin, acetylsalicylic acid, aminoglutethimide, aminopyrine, aminosalicylic acid, ampicillin, amsacrine, antazoline, anticonvulsants, antineoplastic agents (therapeutic intent), antipyrine, barbiturates, busulfan, carbutamide, carmustine, chlorambucil, chloramphenicol, chlordane, chlorophenothane, chlortetracycline, chlorthalidone, cisplatin, colchicine, colistimethate, cycloheximide, cyclophosphamide, cytarabine, dacarbazine, dactinomycin, diaprim, diazepam, diethylpropion, digitalis, dipyridamole, dipyrone, fumagillin, glaucarubin, glucosulfone, hexachlorobenzene, hydroflumethiazide, hydroxychloroquine, iothiouracil, iproniazid, lincomycin, local anesthetics, mefenamic acid, mepazine, meprobamate, mercaptopurine, methotrexate, methylpromazine, mitomycin, paramethadione, parathion, penicillin, phenacemide, phenindione, phenothiazine, pipamazine, prednisone (by Coulter S method), primaquine, procainamide, procarbazine, prochlorperazine, promazine, promethazine, pyrazolones, quinacrine, quinines, radioactive compounds, razoxane, ristocetin, sulfa drugs, tamoxifen, tetracycline, thenalidine, thioridazine, tolazamide, tolazoline, tolbutamide, trimethadione, and urethane.
- A significant decrease in basophil count occurs rapidly after intravenous injection of propanidid and thiopental.
- A significant decrease in lymphocyte count occurs rapidly after administration of corticotropin, mechlorethamine, methysergide, and x-ray therapy; and after megadoses of niacin, pyridoxine, and thiamine.
- Drugs that may increase the overall WBC count include amphetamine, amphotericin B, chloramphenicol, chloroform (normal response to anesthesia), colchicine (leukocytosis follows leukopenia), corticotropin, erythromycin, ether (normal response to anesthesia), fluroxene (normal response to anesthesia), isoflurane (normal response to anesthesia), niacinamide, phenylbutazone, prednisone, and quinine.
- Drug allergies may have a significant effect on eosinophil count and may affect the overall WBC count. Refer to the monograph titled “Eosinophil Count” for a detailed listing of interfering drugs.
- The WBC count may vary depending on the patient’s position, decreasing when the patient is recumbent owing to hemodilution and increasing when the patient rises owing to hemoconcentration.
- Venous stasis can falsely elevate results; the tourniquet should not be left on the arm for longer than 60 sec.
- Failure to fill the tube sufficiently (i.e., tube less than three-quarters full) may yield inadequate sample volume for automated analyzers and may be reason for specimen rejection.
- Hemolyzed or clotted specimens should be rejected for analysis.
- The presence of nucleated red blood cells or giant or clumped platelets affects the automated WBC, requiring a manual correction of the WBC count.
- Care should be taken in evaluating the CBC during the first few hours after transfusion.
- Patients with cold agglutinins or monoclonal gammopathies may have a falsely decreased WBC count as a result of cell clumping.
Nursing Implications and Procedure
Potential nursing problems
|Problem||Signs & Symptoms||Interventions|
|Infection (Related to metabolic or endocrine dysfunction; chronic debilitating illness; cirrhosis; trauma; vectors; decreased tissue perfusion; presence of gram—positive or gram-negative organisms)||Temperature; increased heart rate; increased blood pressure; shaking; chills; mottled skin; lethargy; fatigue; swelling; edema; pain; localized pressure; diaphoresis; night sweats; confusion; vomiting; nausea; headache||Promote good hygiene; assist with hygiene as needed; administer prescribed antibiotics, antipyretics; provide cooling measures; administer prescribed IV fluids; monitor vital signs and trend temperatures; encourage oral fluids; adhere to standard or universal precautions; isolate as appropriate; obtain cultures as ordered; encourage use of lightweight clothing and bedding; monitor and trend indicators of infection (WBC, C-reactive protein [CRP])|
|Fluid volume (Related to metabolic imbalances associated with disease process; insensible fluid loss; excessive diaphoresis)||Deficient: decreased urinary output, fatigue, sunken eyes, dark urine, decreased blood pressure, increased heart rate, and altered mental status||Record daily weight and monitor trends; record accurate intake and output; collaborate with physician with administration of IV fluids to support hydration; monitor laboratory values that reflect alterations in fluid status (potassium, blood urea nitrogen, creatinine, calcium, hemoglobin, and hematocrit); manage underlying cause of fluid alteration; monitor urine characteristics and respiratory status; establish baseline assessment data; collaborate with physician to adjust oral and intravenous fluids to provide optimal hydration status; administer replacement electrolytes as ordered|
|Fever (Related to increased basal metabolic rate; infection)||Elevated temperature; flushed, warm skin; diaphoresis; skin warm to touch; tachycardia; tachypnea; seizures; convulsions||Assess the patient’s temperature frequently; monitor for emotional labile events that could precipitate a thyroid storm or crisis and precipitate an elevation in temperature; ensure the patient’s immediate environment remains cool; encourage the use of light bedding and lightweight clothing to prevent overheating; increase fluid intake to offset insensible fluid loss; encourage bathing with tepid water for comfort and promotion of cooling; administer prescribed antithyroid therapy|
|Health management (Related to failure to regulate diet; lack of exercise; alcohol use; smoking; complexity of health-care system; complexity of therapeutic management; altered metabolic process; knowledge deficit; conflicted decision making; cultural family health patterns; barriers to healthy decisions; mistrust of health-care provider [HCP])||Inability or failure to recognize or process information toward improving health and preventing illness with associated mental and physical effects; ineffective health choices; increasing symptoms of illness; verbalizes that therapeutic regime is too difficult; patient and family do not support HCP’s suggestions for health improvement; refusal to follow recommended therapeutic regime||Ensure regular participation in weight-bearing exercise; assess diet, smoking, and alcohol use; teach the importance of adequate calcium intake with diet and supplements; refer to smoking cessation and alcohol treatment programs; teach the signs and symptoms of infection; assess family or cultural factors that impact the success of the therapeutic regime; assess the patient’s self-assessment of his or her health status; include the patient and family in designing the plan of care; tailor the plan of care to the patient’s lifestyle; collaborate with the patient and family to develop a system of managing own health; focus on behaviors that will make the biggest positive impact on improved health|
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this test can assist in assessing for infection or monitoring leukemia.
- Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
- Obtain a history of the patient’s hematopoietic, immune, and respiratory systems; symptoms; and results of previously performed laboratory tests and diagnostic and surgical procedures.
- Note any recent procedures that can interfere with test results.
- Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
- Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
- Potential complications: N/A
- Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
- Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture. The specimen should be mixed gently by inverting the tube 10 times. The specimen should be analyzed within 24 hr when stored at room temperature or within 48 hr if stored at refrigerated temperature. If it is anticipated the specimen will not be analyzed within 24 hr, two blood smears should be made immediately after the venipuncture and submitted with the blood sample. Smears made from specimens older than 24 hr may contain an unacceptable number of misleading artifactual abnormalities of the RBCs, such as echinocytes and spherocytes, as well as necrobiotic white blood cells.
- Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
- Promptly transport the specimen to the laboratory for processing and analysis.
- Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
- Nutritional Considerations: Infection, fever, sepsis, and trauma can result in an impaired nutritional status. Malnutrition can occur for many reasons, including fatigue, lack of appetite, and gastrointestinal distress.
- Nutritional Considerations: Adequate intake of vitamins A and C, and zinc are also important for regenerating body stores depleted by the effort exerted in fighting infections. Educate the patient or caregiver regarding the importance of following the prescribed diet.
- Nutritional Considerations: Educate the patient with vitamin A deficiency, as appropriate, that the main dietary source of vitamin A comes from carotene, a yellow pigment noticeable in most fruits and vegetables, especially carrots, sweet potatoes, squash, apricots, and cantaloupe. It is also present in spinach, collards, broccoli, and cabbage. This vitamin is fairly stable at most cooking temperatures, but it is destroyed easily by light and oxidation.
- Nutritional Considerations: Educate the patient with vitamin C deficiency, as appropriate, that citrus fruits are excellent dietary sources of vitamin C. Other good sources are green and red peppers, tomatoes, white potatoes, cabbage, broccoli, chard, kale, turnip greens, asparagus, berries, melons, pineapple, and guava. Vitamin C is destroyed by exposure to air, light, heat, or alkalis. Boiling water before cooking eliminates dissolved oxygen that destroys vitamin C in the process of boiling. Vegetables should be crisp and cooked as quickly as possible.
- Nutritional Considerations: Topical or oral supplementation may be ordered for patients with zinc deficiency. Dietary sources high in zinc include shellfish, red meat, wheat germ, nuts, and processed foods such as canned pork and beans and canned chili. Patients should be informed that phytates (from whole grains, coffee, cocoa, or tea) bind zinc and prevent it from being absorbed. Decreases in zinc also can be induced by increased intake of iron, copper, or manganese. Vitamin and mineral supplements with a greater than 3:1 iron/zinc ratio inhibit zinc absorption.
- Recognize anxiety related to test results, and be supportive of fear of shortened life expectancy.
- Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Discuss the implications of abnormal test results on the patient’s lifestyle.
- Provide teaching and information regarding the clinical implications of the test results, as appropriate.
- Educate the patient regarding access to counseling services.
- Provide contact information, if desired, for the National Cancer Institute (www.nci.nih.org) and for the Institute of Medicine of the National Academies (www.iom.edu).
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP.
- Answer any questions or address any concerns voiced by the patient or family.
Expected Patient Outcomes
- States understanding of the signs and symptoms of infection
- States understanding of the importance of compliance with follow-up laboratory tests to manage disease process
- Demonstrates proficiency in taking prescribed antibiotics
- Demonstrates proficiency in taking and recording temperature
- Complies with the request to make lifestyle alterations that will decrease infection risk
- Complies with the request to increase fluid intake to offset fluid loss and prevent dehydration
- Related tests include albumin, antibody, anti–neutrophilic cytoplasmic biopsy bone marrow, biopsy lymph node, CBC, CBC RBC count, CBC RBC indices, CBC RBC morphology, culture bacterial (see individually listed culture monographs), culture fungal, culture viral, eosinophil count, ESR, fecal analysis, Gram stain, infectious mononucleosis, LAP, procalcitonin, UA, US abdomen, and WBC scan.
- Refer to the Hematopoietic, Immune, and Respiratory systems tables at the end of the book for related tests by body system.