TG

Thyroglobulin

Synonym/acronym: Tg.

Common use

To evaluate thyroid gland function related to disorders such as tumor, inflammation, structural damage, and cancer.

Specimen

Serum (1 mL) collected in a gold-, red-, or red/gray-top tube.

Normal findings

(Method: Chemiluminescent enzyme immunoassay)

Age	Conventional Units	SI Units (Conventional Units × 1)
Premature infant
1 day	107–395 ng/mL	107–395 mcg/L
3 days	49–163 ng/mL	49–163 mcg/L
Cord blood	5–65 ng/mL	5–65 mcg/L
1 day	6–93 ng/mL	6–93 mcg/L
10 days	9–148 ng/mL	9–148 mcg/L
1 mo	17–63 ng/mL	17–63 mcg/L
7–12 yr	20–50 ng/mL	20–50 mcg/L
12–18 yr	9–27 ng/mL	9–27 mcg/L
Adult–older adult	0–50 ng/mL	0–50 mcg/L

Description

Thyroglobulin is an iodinated glycoprotein secreted by follicular epithelial cells of the thyroid gland. It is the storage form of the thyroid hormones thyroxine (T₄) and triiodothyronine (T₃). When thyroid hormones are released into the bloodstream, they split from thyroglobulin in response to thyroid-stimulating hormone. Values greater than 55 ng/mL are indicative of tumor recurrence in athyrotic patients.

This procedure is contraindicated for

N/A

Indications

Assist in the diagnosis of subacute thyroiditis
Assist in the diagnosis of suspected disorders of excess thyroid hormone
Manage differentiated or metastatic cancer of the thyroid
Monitor response to treatment of goiter
Monitor T₄ therapy in patients with solitary nodules

Potential diagnosis

Increased in

Thyroglobulin is secreted by normal, abnormal, and cancerous thyroid tissue cells.
Differentiated thyroid cancer
Graves’ disease (untreated) (autoimmune destruction of thyroid tissue cells)
Surgery or irradiation of the thyroid (elevated levels indicate residual or disseminated carcinoma)
T₄-binding globulin deficiency
Thyroiditis (related to leakage from inflamed, damaged thyroid tissue cells)
Thyrotoxicosis

Decreased in

(feedback loop suppresses production)

(related to insufficient synthesis)

Critical findings

N/A

Interfering factors

Drugs that may decrease thyroglobulin levels include neomycin and T₄.
Autoantibodies to thyroglobulin can cause decreased values.
Recent thyroid surgery or needle biopsy can interfere with test results.

Nursing Implications and Procedure

Pretest

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 the thyroid gland.
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 endocrine system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values).
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.

Intratest

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.
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.

Post-Test

Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
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.
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.

Related Monographs

Related tests include ACTH, albumin, ACE, antibodies thyroglobulin, biopsy thyroid, copper, follicle-stimulating hormone, growth hormone, luteinizing hormone, PTH, protein, RAIU, TBII, thyroid scan, TSH, TSI, T₄, free T₄, T₃, free T₃, and US thyroid.
Refer to the Endocrine System table at the end of the book for related tests by body system.

Triglycerides

Synonym/acronym: Trigs, TG.

Common use

To evaluate triglyceride levels to assess cardiovascular disease risk and evaluate the effectiveness of therapeutic interventions.

Specimen

Serum (1 mL) collected in a gold-, red-, or red/gray-top tube. Plasma (1 mL) collected in a green-top (heparin) tube is also acceptable.

Normal findings

(Method: Spectrophotometry)

ATP III Classification	Conventional Units	SI Units (Conventional Units × 0.0113)
Normal	Less than 150 mg/dL	Less than 1.7 mmol/L
Borderline high	150–199 mg/dL	1.7–2.2 mmol/L
High	200–499 mg/dL	2.2–5.6 mmol/L
Very high	Greater than 500 mg/dL	Greater than 5.6 mmol/L

Description

Fat or adipose is an important source of energy. Triglycerides (TGs) are a combination of three fatty acids and one glycerol molecule. Much of the fatty acids used in various metabolic processes come from dietary sources. However, the body also generates fatty acids, from available glucose and amino acids, that are converted into glycogen or stored energy by the liver. Beyond triglyceride, total cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol values, other important risk factors must be considered. In November 2013, new guidelines for the prevention of cardiovascular disease (CVD) were developed by the American College of Cardiology (ACA) and the American Heart Association (AHA) in conjunction with members of the National Heart, Lung, and Blood Institute’s (NHLBI) ATP IV Expert Panel. The updated, evidence-based guidelines redefine the condition of concern as atherosclerotic cardiovascular disease (ASCVD) and expand ASCVD to include CVD, stroke, and peripheral artery disease. Some of the important highlights include:

Movement away from the use of LDL cholesterol targets in determining treatment with statins. Recommendations that focus on selecting (a) the patients that fall into four groups most likely to benefit from statin therapy, and (b) the level of statin intensity most likely to affect or reduce development of ASCVD.
Development of a new 10-yr risk assessment tool based on findings from a large, diverse population. Evidence-based risk factors include age, sex, ethnicity, total cholesterol, high-density lipoprotein (HDL) cholesterol, blood pressure, blood-pressure treatment status, diabetes, and current use of tobacco products.
Recommendations for aspects of lifestyle that would encourage prevention of ASCVD to include adherence to a Mediterranean- or DASH (Dietary Approaches to Stop Hypertension)-style diet; dietary restriction of saturated fats, trans fats, sugar, and sodium; and regular participation in aerobic exercise. The guidelines contain reductions in BMI cutoffs for men and women designed to promote discussions between HCPs and their patients regarding the benefits of maintaining a healthy weight.
Recognition that additional biological markers, such as family history, high-sensitivity C-reactive protein, ankle-brachial index (ABI), and coronary artery calcium (CAC) score may be selectively used with the assessment tool to assist in predicting and evaluating risk.
Recognition that other biomarkers such as apolipoprotein B, eGFR, creatinine, lipoprotein (a) or Lp (a), and microalbumin warrant further study and may be considered for inclusion in future guidelines.

Triglyceride levels vary by age, gender, weight, and race:

Levels increase with age.
Levels are higher in men than in women (among women, those who take oral contraceptives have levels that are 20 to 40 mg/dL higher than those who do not).
Levels are higher in overweight and obese people than in those with normal weight.
Levels in African Americans are approximately 10 to 20 mg/dL lower than in whites.

This procedure is contraindicated for

N/A

Indications

Evaluate known or suspected disorders associated with altered triglyceride levels
Identify hyperlipoproteinemia (hyperlipidemia) in patients with a family history of the disorder
Monitor the response to drugs known to alter triglyceride levels
Screen adults who are either over 40 yr or obese to estimate the risk for atherosclerotic cardiovascular disease

Potential diagnosis

Increased in

Acute myocardial infarction (elevated TG is identified as an independent risk factor in the development of CAD)
Alcoholism (related to decreased breakdown of fats in the liver and increased blood levels)
Anorexia nervosa (compensatory increase secondary to starvation)
Chronic ischemic heart disease (elevated TG is identified as an independent risk factor in the development of CAD)
Cirrhosis (increased TG blood levels related to decreased breakdown of fats in the liver)
Glycogen storage disease (G6PD deficiency, e.g., von Gierke’s disease, results in hepatic overproduction of very-low-density lipoprotein [VLDL] cholesterol, the TG-rich lipoprotein)
Gout (TG is frequently elevated in patients with gout, possibly related to alterations in apolipoprotein E genotypes)
Hyperlipoproteinemia (related to increase in transport proteins)
Hypertension (associated with elevated TG, which is identified as an independent risk factor in the development of CAD)
Hypothyroidism (significant relationship between elevated TG and decreased metabolism)
Impaired glucose tolerance (increase in insulin stimulates production of TG by liver)
Metabolic syndrome (syndrome consisting of obesity, high blood pressure, and insulin resistance)
Nephrotic syndrome (related to absence or insufficient levels of lipoprotein lipase to remove circulating TG and to decreased catabolism of TG-rich VLDL lipoproteins)
Obesity (significant and complex relationship between obesity and elevated TG)
Pancreatitis (acute and chronic; related to effects on insulin production)
Pregnancy (increased demand for production of hormones related to pregnancy)
Renal failure (related to diabetes; elevated insulin levels stimulate production of TG by liver)
Respiratory distress syndrome (related to artificial lung surfactant used for therapy)
Stress (related to poor diet; effect of hormones secreted under stressful situations that affect glucose levels)
Syndrome X (metabolic syndrome consisting of obesity, high blood pressure, and insulin resistance)
Werner’s syndrome (clinical features resemble syndrome X)

Decreased in

(related to cessation of liver function that results in decreased production of TG and TG transport proteins)

(related to increased catabolism of VLDL transport proteins and general increase in metabolism)

(related to decrease in transport proteins)

(inadequate supply from dietary sources)

Critical findings

N/A

Interfering factors

Drugs that may increase triglyceride levels include acetylsalicylic acid, aldatense, atenolol, bisoprolol, β blockers, bendroflumethiazide, cholestyramine, conjugated estrogens, cyclosporine, estrogen/progestin therapy, estropipate, ethynodiol, etretinate, furosemide, glucocorticoids, hydrochlorothiazide, isotretinoin, labetalol, levonorgestrel, medroxyprogesterone, mepindolol, methyclothiazide, metoprolol, miconazole, mirtazapine, nadolol, nafarelin, oral contraceptives, oxprenolol, pindolol, prazosin, propranolol, tamoxifen, thiazides, ticlopidine, timolol, and tretinoin.
Drugs and substances that may decrease triglyceride levels include anabolic steroids, ascorbic acid, beclobrate, bezafibrate, captopril, carvedilol, celiprolol, celiprolol, chenodiol, cholestyramine, cilazapril, ciprofibrate, clofibrate, colestipol, danazol, dextrothyroxine, doxazosin, enalapril, eptastatin (type IIb only), fenofibrate, flaxseed oil, fluvastatin, gemfibrozil, halofenate, insulin, levonorgestrel, levothyroxine, lifibrol, lovastatin, medroxyprogesterone, metformin, nafenopin, niacin, niceritrol, Norplant, pentoxifylline, pinacidil, pindolol, pravastatin, prazosin, probucol, simvastatin, and verapamil.
Failure to follow dietary restrictions before the procedure may cause the procedure to be canceled or repeated.

Nursing Implications and Procedure

Potential nursing problems

Problem	Signs & Symptoms	Interventions
Nutrition (Related to excess caloric intake with large amounts of dietary sodium and fat; cultural lifestyle; overeating associated with anxiety, depression, compulsive disorder; genetics; inadequate or unhealthy food resources)	Observable obesity; high fat or sodium food selections; high BMI; high consumption of ethnic foods; sedentary lifestyle; dietary religious beliefs and food selections; binge eating; diet high in refined sugar; repetitive dieting and failure	Discuss ideal body weight and the purpose and relationship between ideal weight and caloric intake to support cardiac health; review ways to decrease intake of saturated fats and increase intake of polyunsaturated fats; discuss limiting cholesterol intake to less than 300 mg per day; discuss limiting the intake of refined processed sugar; teach limiting sodium intake to the HCP’s recommended restriction; encourage intake of fresh fruits and vegetables, unprocessed carbohydrates, poultry, and grains
Health management (Related to failure to regulate diet; lack of exercise; alcohol use; smoking)	Inability or failure to recognize or process information toward improving health and preventing illness with associated mental and physical effects	Encourage 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; collaborate with physician for bone density evaluation
Tissue perfusion (Related to hypovolemia; decreased hemoglobin; interrupted arterial flow; interrupted venous flow)	Hypotension; dizziness; cool extremities; pallor; capillary refill greater than 3 sec in fingers and toes; weak pedal pulses; altered level of consciousness; altered sensation	Monitor blood pressure; assess for dizziness; assess extremities for skin temperature, color, warmth; assess capillary refill; assess pedal pulses; monitor for numbness, tingling, hyperesthesia, hypoesthesia; monitor for DVT; instruct in careful use of heat and cold on affected areas; use foot cradle to keep pressure off of affected body parts
Fear (Related to loss of control; ineffective coping; change in life expectancy; unfamiliar surroundings; illness; disease; unknown)	Expression of fear; preoccupation with fear; increased tension; increased blood pressure; increased heart rate; vomiting; diarrhea; nausea; fatigue; weakness; insomnia; shortness of breath; increased respiratory rate; withdrawal; panic attacks	Access social services; provide specific and culturally appropriate education; assist the patient and family to recognize effective coping strategies; assist the patient to acknowledge his or her fear; provide a safe environment to decrease fear; explore cultural influences that may enhance fear; utilize therapeutic touch as appropriate to decrease fear; collaborate with social services, respiratory services, physical therapy, and occupational therapy to address specific medical problems associated with fear

Pretest

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 monitoring and evaluating lipid levels.
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 cardiovascular system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
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.
Instruct the patient to fast for 12 hr before specimen collection; fasting is required prior to measurement of triglyceride levels. Ideally, the patient should be on a stable diet for 3 wk and avoid alcohol consumption for 3 days before specimen collection; alcohol increases triglyceride levels. Protocols may vary among facilities.
Note that there are no medication restrictions unless by medical direction.

Intratest

Potential complications: N/A
Ensure that the patient has complied with dietary restrictions and other pretesting preparations; assure that food has been restricted for at least 12 hr prior to the procedure.
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.
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.

Post-Test

Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
Instruct the patient to resume usual diet, as directed by the HCP.
Nutritional Considerations: Increased triglyceride levels may be associated with atherosclerosis and CAD. Nutritional therapy is recommended for the patient identified to be at risk for developing CAD or for individuals who have specific risk factors and/or existing medical conditions (e.g., elevated LDL cholesterol levels, other lipid disorders, insulin-dependent diabetes, insulin resistance, or metabolic syndrome). Other changeable risk factors warranting patient education include strategies to encourage patients, especially those who are overweight and with high blood pressure, to safely decrease sodium intake, achieve a normal weight, ensure regular participation in moderate aerobic physical activity three to four times per week, eliminate tobacco use, and adhere to a heart-healthy diet. If triglycerides also are elevated, the patient should be advised to eliminate or reduce alcohol. The 2013 Guideline on Lifestyle Manage-ment to Reduce Cardiovascular Risk published by the American College of Cardiology (ACC) and the American Heart Association (AHA) in conjunction with the National Heart, Lung, and Blood Institute (NHLBI) recommends a “Mediterranean”-style diet rather than a low-fat diet. The new guideline emphasizes inclusion of vegetables, whole grains, fruits, low-fat dairy, nuts, legumes, and nontropical vegetable oils (e.g., olive, canola, peanut, sunflower, flaxseed) along with fish and lean poultry. A similar dietary pattern known as the Dietary Approaches to Stop Hypertension (DASH) diet makes additional recommendations for the reduction of dietary sodium. Both dietary styles emphasize a reduction in consumption of red meats, which are high in saturated fats and cholesterol, and other foods containing sugar, saturated fats, trans fats, and sodium.
Sensitivity to social and cultural issues: Numerous studies point to the increased prevalence of excess body weight in American children and adolescents. Experts estimate that obesity is present in 25% of the population ages 6 to 11 yr. The medical, social, and emotional consequences of excess body weight are significant. Special attention should be given to instructing the pediatric patient and caregiver regarding health risks and weight control.
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.
Patient Education
- 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 AHA (www.americanheart.org) or the NHLBI (www.nhlbi.nih.gov).
- 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.
- Teach the patient the negative effects that elevated triglycerides can have on cardiac health.
- Teach the patient to follow a diet of protein and complex carbohydrates.
Expected Patient Outcomes
- Knowledge
- States understanding that increased triglycerides can increase the risk of heart attack
- Compares traditionally ethnic foods to heart-healthy selections toward making dietary changes
- Skills
- Exhibits proficiency in making dietary selections that are heart healthy
- Identifies strategies for effective coping that do not involve overeating
- Attitude
- Discusses the correlation between selected diet and increased triglyceride levels
- Complies with HCP’s recommended lifestyle changes to improve triglyceride levels

Related Monographs

Related tests include antiarrhythmic drugs, apolipoprotein A and B, AST, atrial natriuretic peptide, blood gases, BNP, calcium (total and ionized), cholesterol (total, HDL, and LDL), CT cardiac scoring, C-reactive protein, CK and isoenzymes, echocardiography, glucose, glycated hemoglobin, Holter monitor, homocysteine, ketones, LDH and isoenzymes, lipoprotein electrophoresis, magnesium, MRI chest, myocardial infarct scan, myocardial perfusion heart scan, myoglobin, PET heart, potassium, and troponin.
Refer to the Cardiovascular System table at the end of the book for related tests by body system.

TG

TG

tg

tg

TG

TG

tg

tg

TG

Thyroglobulin

Common use

Specimen

Normal findings

Description

This procedure is contraindicated for

Indications

Potential diagnosis

Increased in

Decreased in

Critical findings

Interfering factors

Nursing Implications and Procedure

Pretest

Intratest

Post-Test

Related Monographs

Triglycerides

Common use

Specimen

Normal findings

Description

This procedure is contraindicated for

Indications

Potential diagnosis

Increased in

Decreased in

Critical findings

Interfering factors

Nursing Implications and Procedure

Potential nursing problems

Pretest

Intratest

Post-Test

Patient Education

Expected Patient Outcomes

Related Monographs

TG

TG

TG

TG