Month: October 2020

Description

Rheumatic fever is an inflammatory disease that can develop as a complication of inadequately treated strep throat or scarlet fever.

• Rheumatic fever (RF) is a systemic illness that may occur following group A beta-hemolytic streptococcal (GABHS) pharyngitis in children.
• Studies in the 1950s during an epidemic on a military base demonstrated 3% incidence of rheumatic fever in adults with streptococcal pharyngitis not treated with antibiotics.
• Strep throat and scarlet fever are caused by an infection with streptococcus bacteria.

Pathophysiology

Rheumatic fever develops in children and adolescents following pharyngitis with GABHS (ie, Streptococcus pyogenes).

• The organisms attach to the epithelial cells of the upper respiratory tract and produce a battery of enzymes, which allows them to damage and invade human tissues.
• After an incubation period of 2-4 days, the invading organisms elicit an acute inflammatory response, with 3-5 days of sore throat, fever, malaise, headache, and elevated leukocyte count.
• In a small percentage of patients, infection leads to rheumatic fever several weeks after a sore throat has resolved; only infections of the pharynxhave been shown to initiate or reactivate rheumatic fever.
• Direct contact with oral (PO) or respiratory secretions transmits the organism, and crowding enhances transmission; patients remain infected for weeks after symptomatic resolution of pharyngitis and may serve as a reservoir for infecting others.
• Severe scarring of the valves develops during a period of months to years after an episode of acute rheumatic fever, and recurrent episodes may cause progressive damage to the valves.
• The mitral valve is affected most commonly and severely (65-70% of patients); the aortic valve is affected second most commonly (25%).

Statistics and Incidences

Rheumatic fever is most common in 5- to 15-year-old children, though it can develop in younger children and adults.

• The prevalence of RHD in the United States was less than 0.05 per 1000 population, with only rare regional outbreaks reported in Tennessee in the 1960s and in Utah, Ohio, and Pennsylvania in the 1980’s.
• However, a recent assessment of temporal trends of patients diagnosed with acute rheumatic fever in the United States from 2001-2011 showed that since 2001, national acute rheumatic fever admissions has steadily increased, with a peak in 2005, and decreased thereafter.
• Worldwide, there are over 15 million cases of RHD, with 282,000 new cases and 33,000 deaths from this disease each year.
• RHD is the major cause of morbidity from rheumatic fever and is the major cause of mitral insufficiency and stenosis in the United States and the world.
• Native Hawaiians and Maori (both of Polynesian descent) have a higher incidence of rheumatic fever; incidence of rheumatic fever in these patients is 13.4 per 100,000 hospitalized children per year, even with antibiotic prophylaxis of streptococcal pharyngitis.
• Rheumatic fever occurs in equal numbers in males and females; females with rheumatic fever fare worse than males and have a slightly higher incidence of chorea.
• Rheumatic fever is principally a disease of childhood, with a median age of 10 years; however, GABHS pharyngitis is uncommon in children younger than 3 years, and acute rheumatic fever is extremely rare in these younger children in industrialized countries.

Causes

Rheumatic fever is believed to result from an autoimmune response; however, the exact pathogenesis remains unclear.

• GABHS infection. Rheumatic fever only develops in children and adolescents following group A beta-hemolytic streptococcal (GABHS) pharyngitis, and only infections of the pharynx initiate or reactivate rheumatic fever.
• Molecular mimicry. So-called molecular mimicry between streptococcal and human proteins is felt to involve both the B and T cells of peripheral blood, with infiltration of the heart by T cells; some believe that an increased production of inflammatory cytokines is the final mechanism of the autoimmune reaction that causes damage to cardiac tissue in RHD.
• Streptococcal antigens. Streptococcal antigens, which are structurally similar to those in the heart, include hyaluronate in the bacterial capsule, cell wall polysaccharides (similar to glycoproteins in heart valves), and membrane antigens that share epitopes with the sarcolemma and smooth muscle.
• Decrease in regulatory T-cells. Decreased levels of regulatory T-cells have also been associated with rheumatic heart disease and with increased severity.

Clinical Manifestations

Revised in 1992 and again in 2016, the modified Jones criteria provide guidelines for making the diagnosis of rheumatic fever; the modified Jones criteria for recurrent rheumatic fever require the presence of 2 major, or 1 major and 2 minor, or 3 minor criteria for the diagnosis of rheumatic fever.

Major Diagnostic Criteria

• Carditis. Carditis in the child may be clinical and/or subclinical (echo).
• Polyarthritis. Monoarthritis or polyarthralgia are adequate to achieve major diagnostic criteria in Moderate/High-risk populations; for polyarthralgia exclusion of other more likely causes is also required.
• Chorea. Jerky, uncontrollable body movements (Sydenham chorea, or St. Vitus’ dance) — most often in the hands, feet, and face.
• Subcutaneous nodules. Small, painless bumps (nodules) beneath the skin.
• Erythema marginatum. Flat or slightly raised, painless rash with a ragged edge.

Minor Diagnostic Criteria

• Fever. Fever of ≥38.5°C ( ≥38°C to achieve a minor diagnostic criteria in Moderate/High-risk populations.
• Polyarthralgia. Painful and tender joints — most often in the knees, ankles, elbows, and wrists.
• Prolonged PR interval. Prolonged PR interval for age on electrocardiography.
• Increased ESR. Elevated peak erythrocyte sedimentation rate during acute illness ≥60 mm/h and/or C-reactive protein ≥3.0 mg/dl.

Assessment and Diagnostic Findings

Although there’s no single test for rheumatic fever, diagnosis is based on medical history, physical exam and certain test results.

• Throat culture. Throat cultures for GABHS infections usually are negative by the time symptoms of rheumatic fever or rheumatic heart disease (RHD) appear; make attempts to isolate the organism prior to the initiation of antibiotic therapy to help confirm a diagnosis of streptococcal pharyngitis and to allow typing of the organism if it is isolated successfully.
• Rapid antigen detection test. This test allows rapid detection of group A streptococci (GAS) antigen, allowing the diagnosis of streptococcal pharyngitis to be made and antibiotic therapy to be initiated while the patient is still in the physician’s office.
• Antistreptococcal antibodies. Clinical features of rheumatic fever begin when antistreptococcal antibody levels are at their peak; thus, these tests are useful for confirming previous GAS infection; antistreptococcal antibodies are particularly useful in patients who present with chorea as the only diagnostic criterion.
• Acute-phase reactants. C-reactive protein and erythrocyte sedimentation rate are elevated in individuals with rheumatic fever due to the inflammatory nature of the disease; both tests have high sensitivity but low specificity for rheumatic fever.
• Heart reactive antibodies. Tropomyosin is elevated in persons with acute rheumatic fever.
• Rapid detection test for D8/17. This immunofluorescence technique for identifying the B-cell marker D8/17 is positive in 90% of patients with rheumatic fever and may be useful for identifying patients who are at risk of developing rheumatic fever.
• Chest radiography. Cardiomegaly, pulmonary congestion, and other findings consistent with heart failure may be observed on chest radiograph in individuals with rheumatic fever.
• Echocardiography. In individuals with acute RHD, echocardiography identified and quantitated valve insufficiency and ventricular dysfunction.

Medical Management

Therapy is directed towards eliminating the GABHS pharyngitis (if still present), suppressing inflammation from the autoimmune response, and providing supportive treatment of congestive heart failure (CHF).

• Anti-inflammatory. Treatment of the acute inflammatory manifestations of acute rheumatic fever consists of salicylates and steroids; aspirin in anti-inflammatory doses effectively reduces all manifestations of the disease except chorea, and the response typically is dramatic.
• Corticosteroids. If moderate to severe carditis is present as indicated by cardiomegaly, third-degree heart block, or CHF, add PO prednisone to salicylate therapy.
• Anticonvulsant medications. For severe involuntary movements caused by Sydenham chorea, your doctor might prescribe an anticonvulsant, such as valproic acid (Depakene) or carbamazepine (Carbatrol, Tegretol, others).
• Antibiotics. Your child’s doctor will prescribe penicillin or another antibiotic to eliminate remaining strep bacteria.
• Surgical care. When heart failure persists or worsens after aggressive medical therapy for acute RHD, surgery to decrease valve insufficiency may be lifesaving; approximately 40% of patients with acute rheumatic fever subsequently develop mitral stenosis as adults.
• Diet. Advise nutritious diet without restrictions except in patients with CHF, who should follow a fluid-restricted and sodium-restricted diet; potassiumsupplementation may be necessary because of the mineralocorticoid effect of corticosteroid and the diuretics if used.
• Activity. Initially, place patients on bed rest, followed by a period of indoor activity before they are permitted to return to school; do not allow full activity until the APRs have returned to normal; patients with chorea may require a wheelchair and should be on homebound instruction until the abnormal movements resolve.

Pharmacologic Management

Treatment and prevention of group A streptococci pharyngitis outlined here are based on the current recommendations of the American Heart Association Practice Guidelines on Prevention of Rheumatic Fever and Diagnosis and Treatment of Acute Streptococcal Pharyngitis.

• Antibiotics. The roles for antibiotics are to (1) initially treat GABHS pharyngitis, (2) prevent recurrent streptococcal pharyngitis, rheumatic fever (RF), and rheumatic heart disease (RHD), and (3) provide prophylaxis against bacterial endocarditis.
• Anti-inflammatory agents. Manifestations of acute rheumatic fever (including carditis) typically respond rapidly to therapy with anti-inflammatory agents; aspirin, in anti-inflammatory doses, is DOC; prednisone is added when evidence of worsening carditis and heart failure is noted.
• Therapy for congestive heart failure. Heart failure in RHD probably is related in part to the severe insufficiency of the mitral and aortic valves and in part to pancarditis; therapy traditionally has consisted of an inotropic agent (digitalis) in combination with diuretics (furosemide, spironolactone) and afterload reduction (captopril).

Nursing Management

Nursing care of a child with rheumatic fever include:

Nursing Assessment

Nursing assessment for a child with rheumatic fever are as follows:

• History. Obtain a complete up-to-date history from the child and the caregiver; ask about a recent sore throat or upper respiratory infection; find out when the symptoms began, the extent of the illness, and what if any treatment was obtained.
• Physical exam. Begin with a careful review of all systems, and note the child’s physical condition; observe for any signs that may be classified as major or minor manifestations; in the physical exam, observe for elevated temperature and pulse, and carefully examine for erythema marginatum, subcutaneous nodules, swollen or painful joints, or signs of chorea.

Nursing Diagnoses

Based on the assessment data, the major nursing diagnoses are:

• Acute pain related to joint pain when extremities are touched or moved.
• Deficient diversional activity related to prescribed bed rest.
• Activity intolerance related to carditis or arthralgia.
• Risk for injury related to chorea.
• Risk for noncompliance with prophylactic drug therapy related to financial or emotional burden of lifelong therapy.
• Deficient knowledge of caregiver related to the condition, need for long-term therapy, and risk factors.

Nursing Interventions

Nursing interventions for a child with rheumatic fever include:

• Provide comfort and reduce pain. Position the child to reduce joint pain; warm baths and gentle range-of-motion exercises help to alleviate some of the joint discomforts; use pain indicator scales with children so they are able to express the level of their pain.
• Provide diversional activities and sensory stimulation. For those who do not feel very ill, bed rest can cause distress or resentment; be creative in finding diversional activities that allow bed rest but prevent restlessness and boredom, such as a good book; quiet games can provide some entertainment, and plan all activities with the child’s developmental stage in mind.
• Promote energy conservation. Provide rest periods between activities to help pace the child’s energies and provide for maximum comfort; if the child has chorea, inform visitors that the child cannot control these movements, which are as upsetting to the child as they are to others.
• Prevent injury. Protect the child from injury by keeping the side rails up and padding them; do not leave a child with chorea unattended in a wheelchair, and use all appropriate safety measures.

Evaluation

Goals are met as evidenced by:

• Reducing pain.
• Providing diversional activities and sensory stimulation.
• Conserving energy.
• Preventing injury.

Documentation Guidelines

Documentation in a child with rheumatic fever includes:

• Baseline and subsequent assessment findings to include signs and symptoms.
• Individual cultural or religious restrictions and personal preferences.
• Plan of care and persons involved.
• Teaching plan.
• Client’s responses to teachings, interventions, and actions performed.
• Attainment or progress toward the desired outcome.
• Long-term needs, and who is responsible for actions to be taken.

Acute Rheumatic Fever Nursing Care Plans

Acute Pain

Acute Pain: Unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of such damage; sudden or slow onset of any intensity from mild to severe with anticipated or predictable end and a duration of <6 months.

May be related to

• Inflammation
• Arthralgia

Possibly evidenced by

• Verbal description of pain
• Guarding and protective behavior of painful joints
• Warmth at affected joints
• Edema
• Redness

Desired Outcomes

• Child will verbalize less pain by using a scale of 1 to 10.
• Child will appear relaxed without guarding.
• Child’s joints will not become inflamed, red, or warm.

Hyperthermia

Hyperthermia: Body temperature elevated above normal range.

May be related to

• Illness or inflammatory disease

Possibly evidenced by

• Increase body temperature above normal range
• Hot, flushed skin
• Chills
• Tachycardia, tachypnea

Desired Outcomes

• Child will demonstrate temperature within the normal range and be free of chills.

Activity Intolerance

Activity Intolerance: Insufficient physiologic or physiological energy to endure or complete required or desired activity.

May be related to

• Decrease cardiac output
• Muscle weakness

Possibly evidenced by

• Prolonged bed rest
• Imposed activity restriction
• Imbalanced oxygen supply and demand

Desired Outcomes

• Child can work within the limits of tolerance for that perfectly measured.

Risk for Infection

Risk for Infection: At increased risk for being invaded by pathogenic organisms.

May be related to

• Chronic recurrence of disease

Possibly evidenced by

• [not applicable]

Desired Outcomes

• Child will experience an absence of occurrence of reinfection.
• Child will be afebrile; no complaints of discomfort.
• Child will take medications as ordered.

Common Laboratory Test

Phases of Diagnostic Testing

Diagnostic testing involves three phases: pretest, intratest, and post-test. Nurses have responsibilities for each phase of diagnostic testing.

Pretest

In the pretest, the main focus is on preparing the client for the diagnostic procedure. Responsibilities during pretest include:

• Assessment of the patient to assist in determining precautions.
• Preparation of the equipment and supplies needed.
• Preparation of a consent form, if required.
• Providing information and answering client questions about the procedure.

Intratest

During intratest, the main focus is specimen collection and performing or assisting with certain diagnostic procedures. Additional responsibilities during intratest are:

• Use of standard precautions or sterile technique if necessary.
• Providing emotional support to the patient and monitoring the patient’s response during the procedure.
• Ensuring the correct labeling, storage, and transportation of the specimen.

Post-Test

During the last part of diagnostic testing, the nursing care revolves around observations and follow-up activities for the patient. For example, if a contrast media was injected during a CT scan, the nurse should encourage the patient to increase fluid intake to promote excretion of the dye. Additional responsibilities during post-test include:

• Compare the previous and current test results
• Reporting of the results to the appropriate members of the healthcare team.

Summary of Normal Laboratory Values

Summary of the different normal laboratory values. You can learn more about each diagnostic testing in the sections ahead.

Erythrocyte Studies

• Red Blood Cell Count (RBC): Male adult: 4.5 – 6.2 million/mm3 ; Female adult: 4.5 – 5.0 million/mm3
• Hemoglobin (Hgb): Male: 14-16.5 g/dL; Female: 12-15 g/dL
• Hematocrit (Hct): Male: 42 – 52%; Female: 35 – 47%
• Mean corpuscular volume (MCV): 78 – 100 μm3 (male) 78 – 102 μm3 (female)
• Mean corpuscular hemoglobin (MCH): 25 – 35pg
• Mean corpuscular hemoglobin concentration (MCHC): 31 – 37%
• Serum iron: Male: 65 – 175 mcg/dL; Female: 50 – 170 mcg/dL
• Erythrocyte sedimentation rate (ESR): 0 – 30 mm/hour (value may vary depending on age)

White Blood Cells and Differential

• White Blood Cell (WBC) Count: 4,500 to 11,000 cells/mm³
• Neutrophils: 55 – 70% or 1,800 to 7,800 cells/mm³
• Lymphocytes: 20 – 40% or 1,000 to 4,800 cells/mm³
• Monocytes: 2 – 8% or 0.0 to 800 cells/mm³
• Eosinophils: 1 – 4% or 0.0 to 450 cells/mm³
• Basophils: 0–2% or 0.0 to 200 cells/mm³
• Bands: 0–2 % or 0.0 to 700 cells/mm³

Coagulation Studies

• Platelet count (PLT): 150,000 to 400,000 cells/mm³
• Activated partial thromboplastin time (APTT): 20 to 60 seconds, depending on the type of activator used.
• Prothrombin time (PT): 11 – 13 seconds
• Partial Thromboplastin Time (PTT): 25 – 35 seconds
• International Normalized Ratio (INR): The INR standardizes the PT ratio and is calculated in the laboratory setting by raising the observed PT ratio to the power of the international sensitivity index specific to the thromboplastin reagent used.
• Fibrinogen: 203 – 377 mg/dL
• Bleeding time: 1 to 3 minutes (Duke method), 3 to 6 minutes (Ivy method)
• D-Dimer: < 500 ng/mL

Serum Electrolytes

• Potassium (K+): 3.5 – 5.0 mEq/L
• Sodium (Na+): 135-145 mEq/L
• Chloride (Cl-): 95 – 105 mEq/L
• Calcium (Ca+):
  • Total calcium: 4.5 – 5.5 mEq/L (8.5 to 10.5 mg/dL)
  • Ionized calcium: 2.5 mEq/L (4.0 – 5.0 mg/dL) 56% of total calcium
• Phosphorus (P): 1.8 – 2.6 mEq/L (2.7 to 4.5 mg/dL)
• Magnesium (Mg): 1.6 to 2.6 mg/dL
• Serum Osmolality: 280 to 300 mOsm/kg
• Serum bicarbonate: 22 to 29 mEq/L

Renal Function Studies

• Creatinine (Cr): 0.6 to 1.3 mg/dL
• Blood urea nitrogen (BUN): 8 to 25 mg/dL

Glucose Studies

• Glucose:
  • Glucose, fasting: 70 – 110 mg/dL
  • Glucose, monitoring: 60 – 110 mg/dL
  • Glucose, 2-hr postprandial: < 140mg/dL
• Glucose Tolerance Test (GTT)
  • 70 – 110 mg/dL (baseline fasting)
  • 110 – 170 mg/dL (30 minute fasting)
  • 120 – 170 mg/dL (60 minute fasting)
  • 100 – 140 mg/dL (90 minute fasting)
  • 70 – 120 mg/dL (120 minute fasting)
• Glycosylated hemoglobin (HbA1c)
  • 7% or lower (good control of diabetes)
  • 7% to 8% (fair control of diabetes)
  • Higher than 8 % (poor control of diabetes)
• Diabetes Mellitus autoantibody panel: Less than 1:4 titer with no antibody detected

Arterial Blood Gases (ABGs)

• Arterial blood pH: 7.35 – 7.45
• Oxygen saturation (SaO2): >95%
• Partial pressure of carbon dioxide (PCO2): 35 – 45 mmHg
• Partial pressure of oxygen (PaO2): 80 – 100 mmHg
• Bicarbonate (HCO3): 22 – 26 mEq/L

Liver Function Tests

• Alanine Aminotransferase (ALT):
  • Male: 10 to 55 units/L
  • Female: 7 to 30 units/L
• Aspartate Aminotransferase (AST):
  • Male: 10 – 40 units/L
  • Female: 9 – 25 units/L
• Total bilirubin: 0.3 – 1.0 mg/dL
• Direct bilirubin (conjugated): 0.0 to 0.2 mg/dL
• Indirect bilirubin (unconjugated): 0.1 to 1 mg/dL; Critical level: > 12 mg/dL
• Albumin: 3.4 to 5 g/dL
• Ammonia: 35 – 65 mcg/dL (adult)
• Amylase: 25 to 151 units/L
• Lipase: 10 to 140 units/L
• Protein: 6 to 8 g/dL

Lipoprotein Profile

• Cholesterol: Less than 200 mg/dL
• High-density lipoprotein (HDL): 30 to 70 mg/dL
• Low density lipoprotein (LDL): Less than 130 mg/dL
• Triglycerides: Less than 150 mg/dL

Cardiac Markers and Serum Enzymes

• Creatine kinase (CK)
  • Male: 38 – 174 U/L
  • Female: 26 – 140 U/L
• Creatinine kinase isoenzymes
  • CK-MM: 95% – 100% of total
  • CK-MB: 0% – 5% of total
  • CK-BB: 0%
• Myoglobin: 5–70 ng/mL
• Troponin:
  • Troponin: Less than 0.04 ng/mL; above 0.40 ng/mL may indicate MI
  • Troponin T: Greater than 0.1 to 0.2 ng/mL may indicate MI
  • Troponin I: Less than 0.6 ng/mL; >1.5 ng/mL indicates myocardial infarction
• Atrial natriuretic peptide (ANP): 22 to 27 pg/mL
• Brain natriuretic peptide (BNP): less than 100 pg/mL
• C-type natriuretic peptide (CNP): reference range provided with results should be reviewed

HIV and AIDS Testing

• CD4+ T-cell count:
  • Normal: 500 to 1600 cells/L.
  • Severe: Less than 200 cells/L
  • CD4-to-CD8 ratio: 2:1

Thyroid function test

• Triiodothyronine (T₃): 80 to 230 ng/dL
• Thyroxine (T₄): 5 to 12 mcg/dL
• Thyroxine, free (FT₄): 0.8 to 2.4 ng/dL
• Thyroid-stimulating hormone (thyrotropin): 0.2 to 5.4 microunits/mL

Urinalysis

• Color: Pale yellow
• Odor: Aromatic odor
• Turbidity: Clear
• Specific gravity: 1.016 to 1.022
• pH: 4.5 to 7.8
• Protein: Negative
• Ketones: Negative
• Bilirubin: Negative
• Glucose: >0.5 g/day
• Red blood cells: < 3 cells/HPF
• White blood cells: < or = 4 cells/HPF
• Bacteria: None or >1000/ml
• Casts: None to few
• Crystals: None
• Uric acid: 250 to 750 mg/24 hours
• Sodium: 40 to 220 mEq/24 hours
• Potassium: 25 to 125 mEq/24 hours
• Magnesium: 7.3 – 12.2 mg/dL

Hepatitis Testing

• Hepatitis A: Presence of immunoglobulin M (IgM) antibody to Hepatitis A and presence of total antibody (IgG and IgM) may suggest recent or current Hep A infection.
• Hepatitis B: Detection of Hep B core Antigen (HBcAg), envelope antigen (HBeAg), and surface antigen (HBsAg), or their corresponding antibodies.
• Hepatitis C: Confirmed by the presence of antibodies to Hep C virus.
• Hepatitis D: Detection of Hep D antigen (HDAg) early in the course of infection and detection of Hep D virus antibody in later stages of the disease.
• Hepatitis E: Specific serological tests for hepatitis E virus include detection of IgM and IgG antibodies to hepatitis E.

Therapeutic Drug Levels

• Acetaminophen (Tylenol): 10 to 20 mcg/mL
• Carbamazepine (Tegretol): 5 to 12 mcg/mL
• Digoxin (Lanoxin): 0.5 to 2 ng/mL
• Gentamicin (Garamycin): 5 – 10 mcg/mL (peak); <2.0 mcg/mL (trough)
• Lithium (Lithobid): 0.5 to 1.2 mEq/L
• Magnesium sulfate: 4 to 7 mg/dL
• Phenobarbital (Luminal): 10 to 30 mcg/mL
• Phenytoin (Dilantin): 10 to 20 mcg/mL
• Salicylate: 100 to 250 mcg/mL
• Theophylline: 10 to 20 mcg/dL
• Tobramycin (Tobrex): 5 – 10 mcg/mL (peak); 0.5 – 2.0 mcg/mL (trough)
• Valproic acid (Depakene): 50 – 100 mcg/mL
• Vancomycin (Vancocin): 20 – 40 mcg/mL (peak); 5 – 15 mcg/mL (trough)

Erythrocyte Studies Normal Lab Values

Here are the normal lab values related to erythrocyte studies which include hemoglobin, hematocrit, red blood cell count, serum iron, and erythrocyte sedimentation rate. Venous blood is used as a specimen for completed blood count (CBC) which is a basic screening test that is frequently ordered to give an idea about the health of a patient.

Red Blood Cells (RBC)

Red blood cells or erythrocytes transport oxygen from the lungs to the bodily tissues. RBCs are produced in the red bone marrow, can survive in the peripheral blood for 120 days, and are removed from the blood through the bone marrow, liver, and spleen.

Normal values for red blood cell count:

• Male adult: 4.5 – 6.2 million/mm³
• Female adult: 4.5 – 5.0 million/mm³

Indications of RBC count:

• Helps in diagnosing anemia and blood dyscrasia.

Hemoglobin (Hgb)

Hemoglobin is the protein component of red blood cells that serves as a vehicle for oxygen and carbon dioxide transport. It is composed of a pigment (heme) which carries iron, and a protein (globin). The hemoglobin test is a measure of the total amount of hemoglobin in the blood.

Normal values chart for hemoglobin count:

• Male adult: 14 – 16.5 g/dL
• Female adult: 12 – 16 g/dL

Indications of Hemoglobin count: 

• Hemoglobin count is indicated to help measure the severity of anemia (low hemoglobin) or polycythemia (high hemoglobin).
• Monitor the effectiveness of a therapeutic regimen.

Hematocrit (Hct)

Hematocrit or packed cell volume (Hct, PCV, or crit) represents the percentage of the total blood volume that is made up of the red blood cell (RBC).

Normal values for hematocrit count:

• Male adult: 42 – 52%
• Female adult: 35 – 47%

Red Blood Cell Indices

Red blood cell indicates (RBC Indices) determine the characteristics of an RBC. It is useful in diagnosing pernicious and iron deficiency anemias and other liver diseases.

• Mean corpuscular volume (MCV): The average size of the individual RBC.
• Mean corpuscular hemoglobin (MCH): The amount of Hgb present in one cell.
• Mean corpuscular hemoglobin concentration (MCHC): The proportion of each cell occupied by the Hgb.

Normal Lab Values for RBC Indices are: 

• Mean corpuscular volume (MCV): Male: 78 – 100 μm³; Female: 78 – 102 μm³
• Mean corpuscular hemoglobin (MCH): 25 – 35pg
• Mean corpuscular hemoglobin concentration (MCHC): 31 – 37%

Serum Iron (Fe)

Iron is essential for the production of blood helps transport oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs.

Normal lab values for serum iron:

• Male adult: 65 – 175 mcg/dL
• Female adult: 50 – 170 mcg/dL

Indication of serum iron: 

• Helps in diagnosing anemia and hemolytic disorder.

Nursing considerations for serum iron: 

• Recent intake of a meal containing high iron content may affect the results.
• Drugs that may cause decreased iron levels include adrenocorticotropic hormone, cholestyramine, colchicine, deferoxamine, and testosterone.
• Drugs that may cause increased iron levels include dextrans, ethanol, estrogens, iron preparations, methyldopa, and oral contraceptives.

Erythrocyte Sedimentation Rate (ESR)

Erythrocyte sedimentation rate (ESR) is a measurement of the rate at which erythrocytes settle in a blood sample within one hour.

Normal lab values for erythrocyte sedimentation rate:

• 0 – 30 mm/hour (value may vary depending on age)

Indication for Erythrocyte Sedimentation Rate: 

• Assist in the diagnosis of conditions related to acute and chronic infection, inflammation, and tissue necrosis or infarction.

Nursing consideration

• Fasting is not required
• Fatty meal prior extraction may cause plasma alterations

White Blood Cells and Differential

The normal laboratory value for WBC count has two components: the total number of white blood cells and differential count.

White Blood Cells (WBC)

White blood cells act as the body’s first line of defense against foreign bodies, tissues, and other substances. WBC count assesses the total number of WBC in a cubic millimeter of blood. White blood cell differential provides specific information on white blood cell types:

• Neutrophils are the most common type of WBC and serve as the primary defense against infection.
• Lymphocytes play a big role in response to inflammation or infection.
• Monocytes are cells that respond to infection, inflammation, and foreign bodies by killing and digesting the foreign organism (phagocytosis).
• Eosinophils respond during an allergic reaction and parasitic infections.
• Basophils are involved during an allergic reaction, inflammation, and autoimmune diseases.
• Bands are immature WBCs that are first released from the bone marrow into the blood.

Normal lab values for white blood cell count and WBC differential: 

• WBC Count: 4,500 to 11,000 cells/mm³
• Neutrophils: 55 – 70% or 1,800 to 7,800 cells/mm³
• Lymphocytes: 20 – 40% or 1,000 to 4,800 cells/mm³
• Monocytes: 2 – 8% or 0.0 to 800 cells/mm³
• Eosinophils: 1 – 4% or 0.0 to 450 cells/mm³
• Basophils: 0–2% or 0.0 to 200 cells/mm³
• Bands: 0–2 % or 0.0 to 700 cells/mm³

Nursing consideration for WBC count: 

• A high total WBC count with a left shift means that the bone marrow will release an increased amount of neutrophils in response to inflammation or infection.
• A “shift to the right” which is usually seen in liver disease, megaloblastic and pernicious anemia, and Down syndrome, indicates that cells have more than the usual number of nuclear segments.
• A “shift to the left” indicates an increased number of immature neutrophils is found in the blood.
• A low total WBC count with a left shift means a recovery from bone marrow depression or an infection of such intensity that the demand for neutrophils in the tissue is greater than the capacity of the bone marrow to release them into the circulation.

Coagulation Studies Normal Lab Values

Physicians order coagulation studies such as platelet count, activated partial thromboplastin time, prothrombin time, international normalized ratio, bleeding time, and D-dimer to evaluate the clotting function of an individual. In this section, we’ll discuss the indications and nursing implications of each lab test.

Platelets (PLT)

Platelets are produced in the bone marrow and play a role in hemostasis. Platelets function in hemostatic plug formation, clot retraction, and coagulation factor activation.

Normal values for platelet count:

• 150,000 to 400,000 cells/mm³

Nursing considerations for Platelet counts: 

• High altitudes, persistent cold temperature, and strenuous exercise increase platelet counts.
• Assess the venipuncture site for bleeding in clients with known thrombocytopenia.
• Bleeding precautions should be instituted in clients with a low platelet count.

Activated Partial Thromboplastin Time (APTT)

Activated partial thromboplastin time (APTT) evaluates the function of the contact activation pathway and coagulation sequence by measuring the amount of time it requires for recalcified citrated plasma to clot after partial thromboplastin is added to it. The test screens for deficiencies and inhibitors of all factors, except factors VII and XIII.

Normal lab value for activated partial thromboplastin time:

• 20 to 60 seconds, depending on the type of activator used.

Indication for APTT: 

• Monitors the effectiveness of heparin therapy.
• Detect coagulation disorders in clotting factors such as hemophilia A (factor VIII) and hemophilia B (factor IX).
• Determine individuals who may be prone to bleeding during invasive procedures.

Nursing consideration for APTT: 

• Do not draw samples from an arm into which heparin is infusing.
• If the client is receiving intermittent heparin by intermittent injection, plan to draw the blood sample 1 hour before the next dose of heparin.
• Apply direct pressure to the venipuncture site.
• Blood specimen should be transported to the laboratory immediately.
• The aPTT should be between 1.5 and 2.5 times normal when the client is receiving heparin therapy.
• Monitor for signs of bleeding if the aPTT value is longer than 90 seconds in a patient receiving heparin therapy.

Prothrombin Time and International Normalized Ratio (PT/INR)

Prothrombin is a vitamin K-dependent glycoprotein produced by the liver that is essential for fibrin clot formation. Each laboratory establishes a normal or control value based on the method used to perform the PT test. The PT measures the amount of time it takes in seconds for clot formation, the international normalized ratio (INR) is calculated from a PT result to monitor the effectiveness of warfarin.

Indication for PT and INR

• Monitor response to warfarin sodium (Coumadin) therapy.
• Screen for dysfunction of the extrinsic clotting system resulting from vitamin K deficiency disseminated intravascular coagulation or liver disease.

Normal Lab Value for Prothrombin Time (PT)

• Normal: 11 – 13 seconds
• Critical value: >20 seconds for persons who do not use anticoagulants.
• The INR standardizes the PT ratio and is calculated in the laboratory setting by raising the observed PT ratio to the power of the international sensitivity index specific to the thromboplastin reagent used.

Nursing Care for Prothrombin Time

• If a PT is prescribed, the baseline specimen should be drawn before anticoagulation therapy is started; note the time of collection on the laboratory form.
• Provide direct pressure to the venipuncture site for 3 to 5 minutes.
• Concurrent warfarin therapy with heparin therapy can lengthen the PT for up to 5 hours after dosing.
• Diets high in green leafy vegetables can increase the absorption of vitamin K, which shortens the PT.
• Orally administered anticoagulation therapy usually maintains the PT at 1.5 to 2 times the laboratory control value.
• Initiate bleeding precautions, if the PT value is longer than 30 seconds in a client receiving warfarin therapy.

Bleeding Time

Bleeding time assess the overall hemostatic function (platelet response to injury and vasoconstrictive ability).

Indication for Bleeding Time

• Useful in detecting disorders of platelet function.

Nursing Considerations for Bleeding Time

• Assess and validate that the client has not been receiving anticoagulants, aspirin, or aspirin-containing products for 3 days prior to the test.
• Inform the client that punctures are made to measure the time it takes for bleeding to stop.
• Apply pressure dressing to clients with bleeding tendencies after the procedure.

Normal Values for Bleeding Time

• Duke method: 1 to 3 minutes
• Ivy method: 3 to 6 minutes

D-Dimer Test

D-Dimer is a blood test that measures clot formation and lysis that results from the degradation of fibrin.

Indication of D-Dimer Test

• Helps to diagnose the presence of thrombus in conditions such as deep vein thrombosis, pulmonary embolism, or stroke.
• Used to diagnose disseminated intravascular coagulation (DIC).
• Monitor the effectiveness of treatment.

Normal Lab Value for D-Dimer

• < 500 ng/mL

Serum Electrolytes

Electrolytes are minerals that are involved in some of the important functions in our body. Serum electrolytes are routinely ordered for a patient admitted to a hospital as a screening test for electrolyte and acid-base imbalances. Here we discuss the normal lab values of the commonly ordered serum tests: potassium, serum sodium, serum chloride, and serum bicarbonate. Serum electrolytes may be ordered as a “Chem 7” or as a “basic metabolic panel (BMP)”.

Serum Potassium (K+)

Potassium is the most abundant intracellular cation that serves important functions such as regulate acid-base equilibrium, control cellular water balance, and transmit electrical impulses in skeletal and cardiac muscles.

Normal Values for Serum Potassium

• Potassium: 3.5 – 5.0 mEq/L

Indications for Serum Potassium

• Evaluates cardiac function, renal function, gastrointestinal function, and the need for IV replacement therapy.

Nursing Considerations for Serum Potassium

• Note on the laboratory form if the client is receiving potassium supplementation.
• Clients with elevated white blood cell counts and platelet counts may have falsely elevated potassium levels.

Serum Sodium (Na+)

Sodium is a major cation of extracellular fluid that maintains osmotic pressure and acid-base balance, and assists in the transmission of nerve impulses. Sodium is absorbed from the small intestine and excreted in the urine in amounts dependent on dietary intake.

Normal Lab Values for Serum Sodium

• 135-145 mEq/L

Indications for Serum Sodium

• Determine whole-body stores of sodium, because the ion is predominantly extracellular
• Monitor the effectiveness of drug, especially diuretics, on serum sodium levels.

Nursing consideration for Serum Sodium

• Drawing blood samples from an extremity in which an intravenous (IV) solution of sodium chloride is infusing increases the level, producing inaccurate results.

Serum Chloride (Cl-)

Chloride is a  hydrochloric acid salt that is the most abundant body anion in the extracellular fluid. Functions to counterbalance cations, such as sodium, and acts as a buffer during oxygen and carbon dioxide exchange in red blood cells (RBCs). Aids in digestion and maintaining osmotic pressure and water balance.

Normal Lab Value for Serum Chloride (Cl-)

• 95 – 105 mEq/L

Nursing Considerations for Serum Chloride

• Any condition accompanied by prolonged vomiting, diarrhea, or both will alter chloride levels.

Serum Bicarbonate

Part of the bicarbonate-carbonic acid buffering system and mainly responsible for regulating the pH of body fluids.

Normal Lab Value for Serum Bicarbonate

• 22 to 29 mEq/L

Nursing consideration for Serum Bicarbonate

• Ingestion of acidic or alkaline solutions may cause increased or decreased results, respectively.

Calcium (Ca+)

Calcium (Ca+) is a cation absorbed into the bloodstream from dietary sources and functions in bone formation, nerve impulse transmission, and contraction of myocardial and skeletal muscles. Calcium aids in blood clotting by converting prothrombin to thrombin.

Normal Lab Value for Calcium

• Total: 4.5 – 5.5 mEq/L (8.5 to 10.5 mg/dL)
• Ionized: 2.5 mEq/L (4.0 – 5.0 mg/dL) 56% of total calcium

Nursing Considerations

• Instruct the client to eat a diet with a normal calcium level (800 mg/day) for 3 days before the exam.
• Instruct the client that fasting may be required for 8 hours before the test.
• Note that calcium levels can be affected by decreased protein levels and the use of anticonvulsant medications

Phosphorus (P)

Phosphorus (Phosphate) is important in bone formation, energy storage and release, urinary acid-base buffering, and carbohydrate metabolism. Phosphorus is absorbed from food and is excreted by the kidneys. High concentrations of phosphorus are stored in bone and skeletal muscle.

Normal Lab Value for Phosphorus

• 1.8 – 2.6 mEq/L (2.7 to 4.5 mg/dL)

Nursing Consideration

• Instruct the client to fast before the test.

Magnesium (Mg)

Magnesium is used as an index to determine metabolic activity and renal function. Magnesium is needed in the blood-clotting mechanisms, regulates neuromuscular activity, acts as a cofactor that modifies the activity of many enzymes, and has an effect on the metabolism of calcium.

Normal Magnesium Lab Value

• 1.6 to 2.6 mg/dL

Nursing Considerations

• Prolonged use of magnesium products causes increased serum levels.
• Long-term parenteral nutrition therapy or excessive loss of body fluids may decrease serum levels.

Serum Osmolality

Serum osmolality is a measure of the solute concentration of the blood. Particles include sodium ions, glucose, and urea.  Serum osmolality is usually estimated by doubling the serum sodium because sodium is a major determinant of serum osmolality.

Normal Lab Value for Serum Osmolality

• 280 to 300 mOsm/kg

Renal Function Studies Normal Lab Values

In this section, we’ll be discussing the normal laboratory values of serum creatinine and blood urea nitrogen, including their indications and nursing considerations. These laboratory tests are helpful in determining the kidney function of an individual.

Serum Creatinine (Cr)

Creatinine is a specific indicator of renal function. Increased levels of creatinine indicate a slowing of the glomerular filtration rate.

Normal Lab Value for Serum Creatinine

• 0.6 to 1.3 mg/dL

Nursing Considerations

• Instruct the client to avoid excessive exercise for 8 hours and excessive red meat intake for 24 hours before the test.

Blood Urea Nitrogen (BUN)

Urea nitrogen is the nitrogen portion of urea, a substance formed in the liver through an enzymatic protein breakdown process. Urea is normally freely filtered through the renal glomeruli, with a small amount reabsorbed in the tubules and the remainder excreted in the urine. Elevated levels indicate a slowing of the glomerular filtration rate.

Normal Lab Value for Blood Urea Nitrogen

• 8 to 25 mg/dL

Nursing consideration

• BUN and creatinine ratios should be analyzed when renal function is evaluated.

Glucose Studies Normal Lab Values

Understanding the normal laboratory values of blood glucose is an essential key in managing diabetes mellitus. Included in this section are the lab values and nursing considerations for glycosylated hemoglobin, fasting blood sugar, glucose tolerance test, and diabetes mellitus antibody panel.

Fasting Blood Glucose

Fasting blood glucose or fasting blood sugar (FBS) levels are used to help diagnose diabetes mellitus and hypoglycemia. Glucose is a monosaccharide found in fruits and is formed from the digestion of carbohydrates and the conversion of glycogen by the liver. Glucose is the main source of cellular energy for the body and is essential for brain and erythrocyte function.

Normal Lab Value for Glucose

• Glucose, fasting: 70 – 110 mg/dL
• Glucose, monitoring: 60 – 110 mg/dL
• Glucose, 2-hr postprandial: < 140mg/dL

Nursing consideration:

• Instruct the client to fast for 8 to 12 hours before the test.
• Instruct a client with diabetes mellitus to withhold morning insulin or oral hypoglycemic medication until after the blood is drawn.

Glucose Tolerance Test (GTT)

The glucose tolerance test (GTT) aids in the diagnosis of diabetes mellitus. If the glucose levels peak at higher than normal at 1 and 2 hours after injection or ingestion of glucose and are slower than normal to return to fasting levels, then diabetes mellitus is confirmed.

Normal Lab Values for Glucose Tolerance Test (GTT)

• 70 – 110 mg/dL (baseline fasting)
• 110 – 170 mg/dL (30 minute fasting)
• 120 – 170 mg/dL (60 minute fasting)
• 100 – 140 mg/dL (90 minute fasting)
• 70 – 120 mg/dL (120 minute fasting)

Nursing Considerations

• Instruct the client to eat a high-carbohydrate (200 to 300 g) diet for 3 days before the test.
• Instruct the client to avoid alcohol, coffee, and smoking for 36 hours before the test.
• Instruct the client to avoid strenuous exercise for 8 hours before and after the test.
• Instruct the client to fast for 10 to 16 hours before the test.
• Instruct the client with diabetes mellitus to withhold morning insulin or oral hypoglycemic medication.
• Instruct the client that the test may take 3 to 5 hours, requires IV or oral administration of glucose, and the taking of multiple blood samples.

Glycosylated Hemoglobin (HbA1c)

Glycosylated hemoglobin is blood glucose bound to hemoglobin. Hemoglobin A₁C (glycosylated hemoglobin A; HbA1c) is a reflection of how well blood glucose levels have been controlled for the past 3 to 4 months. Hyperglycemia in clients with diabetes is usually a cause of an increase in the HbA1c.

Normal and Abnormal Lab Values for Glycosylated Hemoglobin

• 7% or lower (good control of diabetes)
• 7% to 8% (fair control of diabetes)
• Higher than 8 % (poor control of diabetes)

Nursing Consideration

• Fasting is not required before the test.

Diabetes Mellitus Autoantibody Panel

Used to evaluate insulin resistance and to identify type 1 diabetes and clients with a suspected allergy to insulin.

Normal Lab Value for DM Autoantibody Panel: 

• Less than 1:4 titer with no antibody detected

Arterial Blood Gas (ABG) Normal Lab Values

Arterial Blood Gases (ABGs) are measured in a laboratory test to determine the extent of compensation by the buffer system. It measures the acidity (pH) and the levels of oxygen and carbon dioxide in arterial blood. Blood for an ABG test is taken from an artery whereas most other blood tests are done on a sample of blood taken from a vein. To help you interpret ABG results, check out our 8-Step Guide to ABG Analysis Tic-Tac-Toe Method.

Normal Lab Values for Arterial Blood Gases

• pH: 7.35 – 7.45
• HCO3: 22 – 26 mEq/L
• PCO2: 35 – 45 mmHg
• PaO2: 80 – 100 mmHg
• SaO2: >95

Liver Function Tests Normal Lab Values

Conditions affecting the gastrointestinal tract can be easily evaluated by studying the normal laboratory values of alanine aminotransferase, aspartate aminotransferase, bilirubin, albumin, ammonia, amylase, lipase, protein, and lipids.

Alanine Aminotransferase (ALT)

Alanine Aminotransferase (ALT) test is used to identify hepatocellular injury and inflammation of the liver and to monitor improvement or worsening of the disease. ALT was formerly known as serum pyretic transaminase (SGPT).

Normal Lab Value for Alanine Aminotransferase (ALT) 

• Male: 10 to 55 units/L
• Female: 7 to 30 units/L

Nursing Considerations

• No fasting is required.
• Previous intramuscular injections may cause elevated levels.

Aspartate Aminotransferase (AST)

Aspartate Aminotransferase (AST) test is used to evaluate a client with a suspected hepatocellular disease, injury, or inflammation (may also be used along with cardiac markers to evaluate coronary artery occlusive disease). AST was formerly known as serum glutamic-oxaloacetic transaminase (SGOT).

Normal Lab Value for Aspartate Aminotransferase (AST)

• Male: 10 – 40 units/L
• Female: 9 – 25 units/L

Nursing Considerations

• No fasting is required.
• Previous intramuscular injections may cause elevated levels.

Bilirubin

Bilirubin is produced by the liver, spleen, and bone marrow and is also a by-product of hemoglobin breakdown. Total bilirubin levels can be broken into direct bilirubin, which is excreted primarily via the intestinal tract, and indirect bilirubin, which circulates primarily in the bloodstream. Total bilirubin levels increase with any type of jaundice; direct and indirect bilirubin levels help differentiate the cause of jaundice.

Normal Lab Values for Bilirubin

• Total bilirubin: 0.3 – 1.0 mg/dL
• Direct bilirubin (conjugated): 0.0 to 0.2 mg/dL
• Indirect bilirubin (unconjugated): 0.1 to 1 mg/dL
• Critical level: > 12 mg/dL

Nursing Considerations

• Instruct the client to eat a diet low in yellow foods, avoiding foods such as carrots, yams, yellow beans, and pumpkin, for 3 to 4 days before the blood is drawn.
• Instruct the client to fast for 4 hours before the blood is drawn.
• Note that results will be elevated with the ingestion of alcohol or the administration of morphine sulfate, theophylline, ascorbic acid (vitamin C), or acetylsalicylic acid (Aspirin).
• Note that results are invalidated if the client has received a radioactive scan within 24 hours before the test.

Albumin

Albumin is the main plasma protein of blood that maintains oncotic pressure and transports bilirubin, fatty acids, medications, hormones, and other substances that are insoluble in water. Albumin is increased in conditions such as dehydration, diarrhea, and metastatic carcinoma; decreased in conditions such as acute infection, ascites, and alcoholism. Presence of detectable albumin, or protein, in the urine is indicative of abnormal renal function.

Normal Lab Value for Albumin

• 3.4 to 5 g/dL

Nursing Considerations

• Fasting is not required.

Ammonia

Ammonia is a by-product of protein catabolism; most of it is created by bacteria acting on proteins present in the gut. Ammonia is metabolized by the liver and excreted by the kidneys as urea. Elevated levels resulting from hepatic dysfunction may lead to encephalopathy. Venous ammonia levels are not a reliable indicator of hepatic coma.

Normal Lab Value for Ammonia

• Adults: 35 – 65 mcg/dL

Nursing Considerations

• Instruct the client to fast, except for water, and to refrain from smoking for 8 to 10 hours before the test; smoking increases ammonia levels.
• Place the specimen on ice and transport to the laboratory immediately.

Amylase

Amylase is an enzyme, produced by the pancreas and salivary glands, aids in the digestion of complex carbohydrates and is excreted by the kidneys. In acute pancreatitis, the amylase level may exceed five times the normal value; the level starts rising 6 hours after the onset of pain, peaks at about 24 hours, and returns to normal in 2 to 3 days after the onset of pain. In chronic pancreatitis, the rise in serum amylase usually does not normally exceed three times the normal value.

Normal Lab Values for Amylase

• 25 to 151 units/L

Nursing Considerations

• On the laboratory form, list the medications that the client has taken during the previous 24 hours before the test.
• Note that many medications may cause false-positive or false-negative results.
• Results are invalidated if the specimen was obtained less than 72 hours after cholecystography with radiopaque dyes.

Lipase

Lipase is a pancreatic enzyme converts fats and triglycerides into fatty acids and glycerol. Elevated lipase levels occur in pancreatic disorders; elevations may not occur until 24 to 36 hours after the onset of illness and may remain elevated for up to 14 days.

Normal Lab Values for Lipase

• 10 to 140 units/L

Nursing Consideration

• Endoscopic retrograde cholangiopancreatography (ERCP) may increase lipase activity.

Serum Protein

Serum protein reflects the total amount of albumin and globulins in the plasma. Protein regulates osmotic pressure and is necessary for the formation of many hormones, enzymes, and antibodies; it is a major source of building material for blood, skin, hair, nails, and internal organs. Increased in conditions such as Addison’s disease, autoimmune collagen disorders, chronic infection, and Crohn’s disease. Decreased in conditions such as burns, cirrhosis, edema, and severe hepatic disease.

Normal Lab Value for Serum Protein: 

• 6 to 8 g/dL

Lipoprotein Profile

Lipid assessment or lipid profile includes total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides.

• Cholesterol is present in all body tissues and is a major component of LDL, brain, and nerve cells, cell membranes, and some gallbladder stones.
• Triglycerides constitute a major part of very-low-density lipoproteins and a small part of LDLs. Increased cholesterol levels, LDL levels, and triglyceride levels place the client at risk for coronary artery disease. HDL helps protect against the risk of coronary artery disease.

Normal Lab Values for Lipid Profile

• Cholesterol: Less than 200 mg/dL
• Triglycerides: Less than 150 mg/dL
• HDLs: 30 to 70 mg/dL
• LDLs: Less than 130 mg/dL

Nursing Considerations

• Oral contraceptives may increase the lipid level.
• Instruct the client to abstain from foods and fluid, except for water, for 12 to 14 hours and from alcohol for 24 hours before the test.
• Instruct the client to avoid consuming high-cholesterol foods with the evening meal before the test.

Cardiac Markers and Serum Enzymes

Serum enzymes and cardiac markers are released into the circulation normally following a myocardial injury as seen in acute myocardial infarction (MI) or other conditions such as heart failure.

Creatine Kinase (CK)

Creatine kinase (CK) is an enzyme found in muscle and brain tissue that reflects tissue catabolism resulting from cell trauma. The CK level begins to rise within 6 hours of muscle damage, peaks at 18 hours, and returns to normal in 2 to 3 days. The test for CK is performed to detect myocardial or skeletal muscle damage or central nervous systemdamage. Isoenzymes include CK-MB (cardiac), CK-BB (brain), and CK-MM (muscles):

• CK-MM is found mainly in skeletal muscle.
• CK-MB is found mainly in cardiac muscle
• CK-BB is found mainly in brain tissue

Normal Lab Values for Creatinine Kinase and Isoenzymes

• Creatine kinase (CK)
  • Male: 38 – 174 U/L
  • Women: 26 – 140 U/L
• Creatinine kinase isoenzymes
  • CK-MM: 95% – 100% of total
  • CK-MB: 0% – 5% of total
  • CK-BB: 0%

Nursing Considerations

• If the test is to evaluate skeletal muscle, instruct the client to avoid strenuous physical activity for 24 hours before the test.
• Instruct the client to avoid ingestion of alcohol for 24 hours before the test.
• Invasive procedures and intramuscular injections may falsely elevate CK levels.

Myoglobin

Myoglobin, an oxygen-binding protein that is found in striated (cardiac and skeletal) muscle, releases oxygen at very low tensions. Any injury to skeletal muscle will cause a release of myoglobin into the blood. Myoglobin rise in 2-4 hours after an MI making it an early marker for determining cardiac damage.

Normal Lab Values for Myoglobin

• Myoglobin: 5–70 ng/mL

Nursing Considerations

• The level can rise as early as 2 hours after a myocardial infarction, with a rapid decline in the level after 7 hours.
• Because the myoglobin level is not cardiac specific and rises and falls so rapidly, its use in diagnosing myocardial infarction may be limited.

Troponin I and Troponin T

Troponin is a regulatory protein found in striated muscle (myocardial and skeletal). Increased amounts of troponin are released into the bloodstream when an infarction causes damage to the myocardium. Troponin levels are elevated as early as 3 hours after MI. Troponin I levels may remain elevated for 7 to 10 days and Troponin T levels may remain elevated for as long as 10 to 14 days. Serial measurements are important to compare with a baseline test; elevations are clinically significant in the diagnosis of cardiac pathology.

Normal Lab Value for Troponin

• Troponin: Less than 0.04 ng/mL; above 0.40 ng/mL may indicate MI
• Troponin T: Greater than 0.1 to 0.2 ng/mL may indicate MI
• Troponin I: Less than 0.6 ng/mL; >1.5 ng/mL indicates myocardial infarction

Nursing Considerations

• Rotate venipuncture sites.
• Testing is repeated in 12 hours or as prescribed, followed by daily testing for 3 to 5 days.

Natriuretic Peptides

Natriuretic peptides are neuroendocrine peptides that are used to identify clients with heart failure. There are three major peptides:

• atrial natriuretic peptides (ANP) synthesized in cardiac ventricle muscle,
• brain natriuretic peptides (BNP)  synthesized in the cardiac ventricle muscle
• C-type natriuretic peptides (CNP) synthesized by endothelial cells.

BNP is the primary marker for identifying heart failure as the cause of dyspnea. The higher the BNP level, the more severe the heart failure. If the BNP level is elevated, dyspnea is due to heart failure; if it is normal, the dyspnea is due to a pulmonary problem.

Normal Lab Values for Natriuretic Peptics

• Atrial natriuretic peptide (ANP): 22 to 27 pg/mL
• Brain natriuretic peptide (BNP): less than 100 pg/mL
• C-type natriuretic peptide (CNP): reference range provided with results should be reviewed

Nursing Considerations

• Fasting is not required.

HIV and AIDS Testing

The following laboratory tests are used to diagnose human immunodeficiency virus (HIV), which is the cause of acquired immunodeficiency syndrome (AIDS). Common tests used to determine the presence of antibodies to HIV include ELISA, Western blot, and Immunofluorescence assay (IFA).

• A single reactive ELISA test by itself cannot be used to diagnose HIV and should be repeated in duplicate with the same blood sample; if the result is repeatedly reactive, follow-up tests using Western blot or IFA should be performed.
• A positive Western blot or IFA results is considered confirmatory for HIV.
• A positive ELISA result that fails to be confirmed by Western blot or IFA should not be considered negative, and repeat testing should take place in 3 to 6 months.

CD4+ T-cell counts

CD4+ T-cell counts help Monitors the progression of HIV. As the condition progresses, usually the number of CD4+ T-cells decreases, with a resultant decrease in immunity. In general, the immune system remains healthy with CD4+ T-cell counts higher than 500 cells/L. Immune system problems occur when the CD4+ T-cell count is between 200 and 499 cells/L. Severe immune system problems occur when the CD4+ T-cell count is lower than 200 cells/L.

Normal Lab Value for  CD4+ T-cell:

• Normal: 500 to 1600 cells/L.
• Severe: Less than 200 cells/L
• CD4-to-CD8 ratio: 2:1

Thyroid Studies Normal Lab Values

Thyroid studies are performed if a thyroid disorder is suspected. Common laboratory blood tests such as thyroxine, TSH, T4, and T3 are done to evaluate thyroid function. Thyroid studies help differentiate primary thyroid disease from secondary causes and from abnormalities in thyroxine-binding globulin levels. Thyroid peroxidase antibodies test may be done to identify the presence of autoimmune conditions involving the thyroid gland.

Laboratory Values for Thyroid Function Test

• Triiodothyronine (T₃): 80 to 230 ng/dL
• Thyroxine (T₄): 5 to 12 mcg/dL
• Thyroxine, free (FT₄): 0.8 to 2.4 ng/dL
• Thyroid-stimulating hormone (thyrotropin): 0.2 to 5.4 microunits/mL

Nursing Considerations

• Results of the test may be invalid if the client has undergone a radionuclide scan within 7 days before the test.

Hepatitis Testing

Serological tests for specific hepatitis virus markers assist in determining the specific type of hepatitis. Tests for hepatitis include radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), and microparticle enzyme immunoassay.

Nursing Considerations

• If the radioimmunoassay technique is being used, the injection of radionuclides within 1 week before the blood test is performed may cause falsely elevated results.

• Hepatitis A: Presence of immunoglobulin M (IgM) antibody to Hepatitis A and presence of total antibody (IgG and IgM) may suggest recent or current Hep A infection.
• Hepatitis B: Detection of Hep B core Antigen (HBcAg), envelope antigen (HBeAg), and surface antigen (HBsAg), or their corresponding antibodies.
• Hepatitis C: Confirmed by the presence of antibodies to Hep C virus.
• Hepatitis D: Detection of Hep D antigen (HDAg) early in the course of infection and detection of Hep D virus antibody in later stages of the disease.
• Hepatitis E: Specific serological tests for hepatitis E virus include detection of IgM and IgG antibodies to hepatitis E.

Therapeutic Drug Levels Normal Lab Values

Monitoring the therapeutic levels of certain medications is often conducted when the patient is taking medications with a narrow therapeutic range where a slight imbalance could be critical. Drug monitoring includes drawing blood samples for peak and trough levels to determine if blood serum levels of a specific drug are at a therapeutic level and not a subtherapeutic or toxic level. The peak level indicates the highest concentration of the drug in the blood serum while the trough level represents the lowest concentration. The following are the normal therapeutic serum medication levels:

• Acetaminophen (Tylenol): 10 to 20 mcg/mL
• Carbamazepine (Tegretol): 5 to 12 mcg/mL
• Digoxin (Lanoxin): 0.5 to 2 ng/mL
• Gentamicin (Garamycin): 5 – 10 mcg/mL (peak); <2.0 mcg/mL (trough)
• Lithium (Lithobid) 0.5 to 1.2 mEq/L
• Magnesium sulfate: 4 to 7 mg/dL
• Phenobarbital (Luminal): 10 to 30 mcg/mL
• Phenytoin (Dilantin): 10 to 20 mcg/mL
• Salicylate: 100 to 250 mcg/mL
• Theophylline: 10 to 20 mcg/dL
• Tobramycin (Tobrex): 5 – 10 mcg/mL (peak); 0.5 – 2.0 mcg/mL (trough)
• Valproic acid (Depakene): 50 – 100 mcg/mL
• Vancomycin (Vancocin): 20 – 40 mcg/mL (peak); 5 – 15 mcg/mL (trough)

How to Obtain a Blood Sample

A phlebotomist or a nurse with training and certification in collecting a blood sample are allowed to perform venipuncture for the purpose of blood specimen collection. These are the steps to follow in obtaining a blood sample:

1. Identify the client. Accurately identify the client by asking his or her name and birthdate; Explain the reason for the test and procedure to the client.
2. Proper position. Blood samples should be drawn in a sitting position and the client should remain in that position for at least 5 minutes before the blood collection.
3. Confirm the request. Check the laboratory form for the ordered test, client information, and additional requirements (fasting, dietary restrictions, medications).
4. Provide comfort. Make sure the client remove any tight clothing that might constrict the upper arm. The arm is placed in a downward position supported on the armrest.
5. Ensure proper hand hygiene. Perform hand washing before putting on non-latex gloves.
6. Identify the vein. Examine the client’s arm to select the most easily accessible vein for venipuncture then place the tourniquet 3 to 4 inches above the chosen site. Do not place the tourniquet tightly or leave on more than 2 minutes.
7. Prepare the site. When a vein is chosen, cleanse the area using alcohol in a circular motion beginning at the site and working toward.
8. Draw the sample. Ask the client to make a fist. Grasp the client’s arm firmly using your thumb to draw the skin taut and anchor the vein from rolling. Gently insert the needle at a 15 to 30º angle through the skin and into the lumen of the vein.
9. Fill the tube. Obtain the needed amount of blood sample, then release and remove the tourniquet.
10. Remove the needle.  In a swift backward motion, remove the needle from the client’s arm. and apply a folded gauze over the venipuncture site for 1 to 2 minutes.
11. Label the tube. Label the tube with the client’s name, date of birth, hospital number, date and time of the collection.
12. Transport specimen. Deliver the specimen to the laboratory for immediate processing and analysis.

References and Sources

Suggested reading and additional resources for this Normal Laboratory Values guide:

• Corbett, J. V., & Banks, A. (2018). Laboratory Tests and Diagnostic Procedures with Nursing Diagnoses with Nursing Diagnoses. Pearson Education.
• Kratz, A., & Lewandrowski, K. B. (1998). Normal reference laboratory values. New England Journal of Medicine, 339(15), 1063-1072.
• Kratz, A., Ferraro, M., Sluss, P. M., & Lewandrowski, K. B. (2004). Laboratory reference values. New England Journal of Medicine, 351, 1548-1564.

Definition

• Asthma is a chronic inflammatory disease of the airways characterized by hyper-responsiveness, mucosal edema, and mucus production.
• This inflammation ultimately leads to recurrent episodes of asthma symptoms: cough, chest tightness, wheezing, and dyspnea.
• Patients with asthma may experience symptom-free periods alternating with acute exacerbations that last from minutes to hours or days.
• Asthma, the most common chronic disease of childhood, can begin at any age.

Causes

The main triggers for asthma are allergies, viral infections, autonomic nervous system imbalances that can cause an increase in parasympathetic stimulation, medications, psychological factors, and exercise. Of asthmatic conditions in patients under 30 years old, 70% are caused by allergies. Three major indoor allergens are dust mites, cockroaches, and cats. In older patients,the cause is almost always nonallergic types of irritants such as smog. Heredity plays a part in about one-third of the cases.

Pathophysiology

1. An asthma attack may occur spontaneously or in response to a trigger. Either way, the attack progresses in the following manner:

• There is an initial release of inflammatory mediators from bronchial mast cells, epithelial cells, and macrophages, followed by activation of other inflammatory cells
• Alteration of autonomic neural control of airway tone and epithelial integrity occur and the increased responsiveness in airways smooth muscle results in clinical manifestations (e.g. wheezing and dyspnea)

2. Three events contribute to clinical manifestations

• Bronchial spasm
• Inflammation and edema of the mucosa
• Production of thick mucus, which results in increased airway resistance, premature closure of airways, hyperinflation, increased work of breathing, and impaired gas exchange

3. If not treated promptly, status asthmaticus – an acute, severe, prolonged asthma attack that is unresponsive to the usual treatment – may occur, requiring hospitalization.

Classification

1. Extrinsic Asthma – called Atopic/allergic asthma. An “allergen” or an “antigen” is a foreign particle which enters the body. Our immune system over-reacts to these often harmless items, forming “antibodies” which are normally used to attack viruses or bacteria. Mast cells release these antibodies as well as other chemicals to defend the body.

Common irritants:

• Cockroach particles
• Cat hair and saliva
• Dog hair and saliva
• House dust mites
• Mold or yeast spores
• Metabisulfite, used as a preservative in many beverages and some foods
• Pollen

2. Intrinsic asthma – called non-allergic asthma, is not allergy-related, in fact it is caused by anything except an allergy. It may be caused by inhalation of chemicals such as cigarette smoke or cleaning agents, taking aspirin, a chest infection, stress, laughter, exercise, cold air, food preservatives or a myriad of other factors.

• Smoke
• Exercise
• Gas, wood, coal, and kerosene heating units
• Natural gas, propane, or kerosene used as cooking fuel
• Fumes
• Smog
• Viral respiratory infections
• Wood smoke
• Weather changes

 Clinical Manifestations

• Most common symptoms of asthma are cough (with or without mucus production), dyspnea, and wheezing (first on expiration, then possibly during inspiration as well).
• Asthma attacks frequently occur at night or in the early morning.
• An asthma exacerbation is frequently preceded by increasing symptoms over days, but it may begin abruptly.
• Chest tightness and dyspnea occur.
• Expiration requires effort and becomes prolonged.
• As exacerbation progresses, central cyanosis secondary to severe hypoxia may occur.
• Additional symptoms, such as diaphoresis, tachycardia, and a widened pulse pressure, may occur.
• Exercise-induced asthma: maximal symptoms during exercise, absence of nocturnal symptoms, and sometimes only a description of a “choking” sensation during exercise.
• A severe, continuous reaction, status asthmaticus, may occur. It is life-threatening.
• Eczema, rashes, and temporary edema are allergic reactions that may be noted with asthma.

Primary Nursing Diagnosis

Ineffective airway clearance related to obstruction from narrowed lumen and thick mucus

OUTCOMES. Respiratory status: Gas exchange; Respiratory status: Ventilation; Symptom control behavior; Treatment behavior: Illness or injury; Comfort level
INTERVENTIONS. Airway management; Anxiety reduction; Oxygen therapy; Airway suctioning;Airway insertion and stabilization; Cough enhancement; Mechanical ventilation; Positioning;Respiratory monitoring

Assessment and Diagnostic Methods

• Family, environment, and occupational history is essential.
• During acute episodes, sputum and blood test, pulse oximetry, ABGs, hypocapnia and respiratory alkalosis, and pulmonary function (forced expiratory volume [FEV] and forced vital capacity [FVC] decreased) tests are performed.
• Spirometry will detect:
  1. Decreased for expiratory volume (FEV)
  2. Decreased peak expiratory flow rate (PEFR)
  3. Diminished forced vital capacity (FVC)
  4. Diminished inspiratory capacity (IC)

Steps of Clinical and Diagnostic as per National Asthma Education and Prevention Program

Mild Intermittent Asthma

• Symptoms ? 2 times per week
• Brief exacerbations
• Nighttime symptoms ? 2 times a month
• Asymptomatic and normal PEF (peak expiratory flow) between exacerbations
• PEF or FEV, (forced expiratory volume in 1 second) ? 80% of predicted value
• PEF variability < 20%

Mild Persistent Asthma

• Symptoms > 2 times/week, but less than once a day
• Exacerbations may affect activity
• Nighttimes symptoms > 2 times a month
• PEF/FEV ? 80% of predicted value
• PEF variability 20%-30%

Moderate Persistent Asthma

• Daily Symptoms
• Daily use of inhaled short-acting ?₂ – agonists
• Exacerbations affect activity
• Exacerbations ? 2 times a week
• Exacerbations may last  days
• Nighttime symptoms > once a week
• PEF/FEV > 60%-<80% of predicted value
• PEF variability > 30%

Severe Persistent Asthma

• Continual symptoms
• Frequent exacerbations
• Frequent nighttime symptoms
• Limited physical activity
• PEF or FEV ? 60% of predicted value
• PEF variability > 30 %

Medical Management

Pharmacologic Therapy

There are two classes of medications—long-acting control and quick-relief medications—as well as combination products.

• Short-acting beta2-adrenergic agonists
• Anticholinergics
• Corticosteroids: metered-dose inhaler (MDI)
• Leukotriene modifiers inhibitors/antileukotrienes
• Methylxanthines

Nursing Management

The immediate nursing care of patients with asthma depends on the severity of symptoms. The patient and family are often frightened and anxious because of the patient’s dyspnea. Therefore, a calm approach is an important aspect of care.

• Assess the patient’s respiratory status by monitoring the severity of symptoms, breath sounds, peak flow, pulse oximetry, and vital signs.
• Obtain a history of allergic reactions to medications before administering medications.
• Identify medications the patient is currently taking.
• Administer medications as prescribed and monitor the patient’s responses to those medications; medications may include an antibiotic if the patient has an underlying respiratory infection.
• Administer fluids if the patient is dehydrated.
• Assist with intubation procedure, if required.

Teaching Points

• Teach patient and family about asthma (chronic inflammatory), purpose and action of medications, triggers to avoid and how to do so, and proper inhalation technique.
• Instruct patient and family about peak-flow monitoring.
• Teach patient how to implement an action plan and how and when to seek assistance.
• Obtain current educational materials for the patient based on the patient’s diagnosis, causative factors, educational level, and cultural background.

Continuing Care

• Emphasize adherence to prescribed therapy, preventive measures, and need for followup appointments.
• Refer for home health nurse as indicated.
• Home visit to assess for allergens may be indicated (with recurrent exacerbations).
• Refer patient to community support groups.
• Remind patients and families about the importance of health promotion strategies and recommended health screening.

Documentation Guidelines

• Respiratory status: Patency of airway, auscultation of the lungs, presence or absence of adventitious breath sounds, respiratory rate and depth
• Response to medications, oxygen therapy, hydration, bedrest
• Presence of complications: Respiratory failure, ruptured bleb that may result in a pneumothorax