MEAGHAN MOLLARD NUR 668 Hypothyroidism (Luzy, 2009)
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Transcript of MEAGHAN MOLLARD NUR 668 Hypothyroidism (Luzy, 2009)
MEAGHAN MOLLARDNUR 668
Hypothyroidism
(Luzy, 2009)
ICD9 Codes
244.1 Other post-ablative hypothyroidism244.8 Other specified acquired
hypothyroidism244.9 Unspecified acquired hypothyroidism
(Domino, 2014)
Definition of Hypothyroidism
UNDERACTIVE THYROIDAffects:
Metabolic and endocrine systemsClinical state resulting from decreased
circulating levels of free thyroid hormone produced by the thyroid gland OR resistance to the action of the thyroid hormone
(Domino, 2014 ;Hollier & Hensley, 2011 MayoClinic, 2012)
Anatomy
Small, butterfly shaped glandLocated at the base of the neck, below the
larynx and above the claviclesLocated below Adam’s apple in men
(MayoClinic, 2012 ; WebMD, 2014)
Pathophysiology
Thyroid gland produces hormones: Triiodothyronine (T3) Thyroxine (T4)
Both impact metabolism- maintaining the rate at which the body uses fats and carbs
Regulates how the body uses and stores energy Controls body temperature Influences heart rate Helps to regulate the production of proteins
(MayoClinic, 2012 ; Ross, 2014 ; Orlander, 2014)
Etiology
Hypothyroidism is broadly classified as a primary, secondary, or tertiary disease depending on the underlying cause Primary
there is impaired hormone release from the thyroid gland Causes: Hashimoto’s thyroiditis, iatrogenic, congenital, subacute
thyroiditis, sub-acute thyroiditis, iodine deficiency, medications, and postpartum thyroiditis
Secondary there is defective TSH signaling from the pituitary
Causes: Hypopituitarism, Sheehan Syndrome, Pituitary tumors Tertiary or Central
the hypothalamus fails to stimulate thyroid hormone release Cause: Hypothalamic dysfunction
(Domino, 2014)
Commonly Associated Conditions
HyponatremiaAnemiaIdiopathic
adrenocorticoid deficiency
Diabetes mellitusHypoparathyroidismMyasthenia gravisVitiligo
HypercholesterolemiaMitral valve prolapseDepressionRapid-cycling bipolar
disorderIschemic heart
diseaseMetabolic SyndromeDown syndromeCeliac Disease
(Domino, 2014)
Incidence
Predominant age: >40 yearsPredominant gender: Female>Male, 5-10:1More common in women with small body size
at birth and during childhood
(Domino, 2014 ; Ross, 2014)
Prevalence
3.7% of general population18 cases per 1,000 persons in the general
populationSubclinical hypothyroidism: 4-20%Common in elderly
(Domino, 2014 ; Orlander, 2014)
Screening Recommendations
Routine screening of all newborn babies in the United States
No universal screening recommendations for adults Two strategies for screening asymptomatic patients:
1. Screen all individuals over a certain age, when risk of hypothyroidism increases
2. Screen only those with clinical risk factors.
(Orlander, 2014 ; Ross, 2014)
Specific Screening Recommendations
The American Thyroid Association: All patients over the age of 35 and every 5 years
thereafterThe American College of Physicians:
All women older than 50 years who have 1 or more clinical features of the disease
The American Academy of Family Physicians: Asymptomatic patients older than 60 years
The American Association of Clinical Endocrinologists: TSH measurements in all women of childbearing age
before pregnancy or during the first trimester(Orlander, 2014)
Screening Indications
Women older than 60Family history of thyroid diseasePregnancyUse of medications that may impair thyroid
functionHistory of goiterAutoimmune disease or type 1 diabetesPrevious thyroid surgeryPrevious treatment with radioactive iodine therapy
or anti-thyroid medicationsRadiation therapy to head, neck or upper chest
(MayoClinic, 2012 ; Ross, 2014)
Risk Factors
Women >60 years Increasing age Family History Personal or family history of autoimmune diseases, including type 1
diabetes mellitus (DM), Addison disease Previous postpartum thyroiditis
OR pregnant or delivered baby within last 6 months Previous head or neck irradiation History of thyroid surgery Treatment hyperthyroidism Hypothalmic disease Pituitary disease History of Graves disease Treatment with lithium, immune modulators, or iodine containing
antiarrhythmic amiodarone
(Domino, 2014 ; Hollier & Hensley, 2011)
Subjective Clinical Findings
History: Onset insidious, subtle Weakness, fatigue, lethargy Cold intolerance Decreased memory and concentration Hearing impairment Constipation Muscle cramps Modest weight gain (10lbs) Swelling in hands and feet Decreased sweating Menorrhagia, decreased libdo, infertility Depression Hoarseness
(Domino, 2014 ; WebMD, 2014)
Objective Clinical Findings
Physical Exam: Dry coarse skin Dull facial expression Coarsening or huskiness of voice Periorbital puffiness Swelling of hands and feet (nonpitting) Bradycardia Hypothermia Reduced systolic BP Increased diastolic BP Reduced body and scalp hair Delayed relaxation of deep-tendon reflexes Macroglossia
(Domino, 2014 ; 24Remedy, 2015)
(Brownstein, 2015)
Hypothyroidism in Infants
Affects 1 in every 4000 newbornsCaused by:
Lack of thyroid gland Dysfunctional gland
Signs and Symptoms: Jaundice Choking Enlarged, protruding tongue Puffy face Constipation Poor muscle tone Excessive sleepiness
(MayoClinic, 2012 ; Orlander, 2014)
Hypothyroidism in Children and Teens
S/S similar to adults In addition..
Poor growth-> short stature Delayed puberty Poor mental development
(MayoClinic, 2012)
Differential Diagnosis
AnemiaDementiaChronic heart failureKidney failureAutoimmune Thyroid
DiseasePregnancyConstipationDepressionDysmenorrheaFibromyalgia
Euthyroid Sick SyndromeGoiterMyxedema Coma or CrisisRiedel ThyroiditisSub-acute ThyroiditisThyroid LymphomaIodine DeficiencyAddison DiseaseAnovulationApneaChronic Fatigue Syndrome
(Domino, 2014 ; Orlander, 2014)
Social and Environmental Considerations
No specific diets are required for hypothyroidism
Dose may need to be increased if thyroid disease worsens: During pregnancy Gastrointestinal conditions that impair T4 absorption Weight gain Aluminum containing antacids, high fiber diets, and
iron tablets can interfere with T4 absorption
(Ross, 2014)
Diagnosis
Based on: 1. Symptoms 2. Blood tests
TSH-thyroid stimulating hormone T4-thyroxine
Serum TSH normal – no further testing performed Serum TSH high -> Free T4 to determine degree of
disease
(MayoClinic, 2012)
Laboratory Tests
Initial lab tests: Subclinical hypothyroidism
TSH elevated (>4.5mlU/L) Serum free T4 normal
Primary hypothyroidism TSH elevated (>4-5mU/L) Serum free T4 decreased
Severe hypothyroidism Anemia Elevated Cholesterol Elevated creative phosphokinase, lactate dehydrogenase,
aspartate aminotransferase
(Domino, 2014)
Imaging
Initial approach: None necessary, unless signs or cardiac involvement Chest radiograph may show enlarged heart
(pericardial effusion)
(Domino, 2014 ; Gupta & Ammini, 2012)
Prevention
Monitoring for those being treated for hyperthyroidism
Newborn T4screening at 2-6 days of age.
Management/ Treatment
Goal of treatment include:
Return blood levels of TSH and T4 to the normal range
Alleviate symptoms
Decision to treat subclinical hypothyroidism is controversial Typically treated if TSH is >10mU/L to prevent symptom
development
(Ross, 2014)
Non-pharmacological
Adequate restEliminate emotional stressModerate exercise for stress controlEat a well balanced diet
High in fiber to prevent constipation Low fat for weight reduction
Annual lipid level assessment
(Cornille, 2004)
Pharmacologic
Standard treatment: Oral form of T4- synthetic thyroid hormone Administered to supplement or replace exogenous
production Given once daily on an empty stomach – at least one
hour before eating or two hours after eating Levothyroxine Levothroid Synthroid Levoxyl Unithyroid
PREFERABLE TO STAY ON SAME TYPE OF T4
(Ross, 2014)
Pharmacologic Management
Prescribe an initial dose of T4 Start hormone replacement for healthy adults at 1.6mcg per
kg/day ->with a typical maintenance dose between 50-200mcg/d depending on disease severity and underlying cause
->Retest TSH in 6 weeks ->T4 dose can be adjusted depending on results
-> This process may need to be repeated several times before hormone level returns to normal• -> Once optimal dose identified recommended monitoring
yearly
• NEVER OVER REPLACE T4-> Can cause mild hyperthyroidism which can increase the
risk for Afib and accelerate bone loss
(Kansagra, McCudden & Willis, 2010; Ross, 2014)
Prognosis
Return to normal stateRelapse will occur if treatment interruptedIf untreated, may progress to myxedema
coma
(Domino, 2014)
Complications
GoiterHeart problemsMental health issuesIncreased susceptibility to infectionMegacolonSexual dysfunctionOrganic psychosis with paranoiaAdrenal crisisInfertilityHypersensitivity to opiatesLong-term treatment leads to bone demineralizationMyxedema coma->MEDICAL EMERGENCY!
(Domino, 2014 ; MayoClinic, 2012)
Complications of Hypothyroidism during Pregnancy
PreeclampsiaAnemiaPostpartum hemorrhageCardiac ventricular dysfunctionIncreased risk of spontaneous abortionLow birth weightImpaired cognitive developmentFetal mortality
(Ross, 2014)
Follow-up
Monitoring depends on the underlying causesMonitor TSH:
Initially after 6 weeks of therapy -> Q6-12 weeks until stabilized-> annually
Follow cardiac status closely in older patientsCheck TSH more frequently in the setting of:
Pregnancy Initiation of estrogen supplementation After large changes in body weight
In central hypothyroidism, TSH unreliable Monitor free T4, T3
(Domino, 2014)
Counseling/Education
Stress the importance of compliance with thyroid replacement therapy
Explain need for lifelong treatmentInstruct to report any signs of infection or heart
problemsEducate of the signs of thyrotoxicityEducate high-bulk may help avoid constipationEducate about signs and symptoms of
overtreatment Tachycardia, palpitations, Afib, nervousness, tiredness,
headache, increased excitability, sleeplessness, tremors, possible angina
(Domino, 2014)
Patient Resources
“The Basics”“Beyond the Basics”
http://www.uptodate.com/contents/hypothyroidism-underactive-thyroid-beyond-the-basics?source=see_link
(Ross, 2014)
Consultation/Referral
Suspected myxedema coma is a medical emergency with a high risk of mortality!
Indications for referral to an endocrinologist: Nodular thyroid, suspicious thyroid nodules or
compressive symptoms (Ex: dysphagia) Pregnancy Underlying cardiac disorder or other endocrine disorders Age younger than 18 years Secondary or tertiary hypothyroidism Unusual constellation of thyroid function test results Inability to maintain TSH in target range Unresponsiveness to treatment
(Orlander, 2014)
Expected Course
Improvement expected 2-weeks after initiation of medication therapy
Signs and symptoms should resolve in 3 to 6 months
Lifelong therapy needed
(Hollier & Hensley, 2011)
Question 1
Hypothyroidism affects what body systems? 1. Respiratory and endocrine 2. Cardiac and metabolic 3. Metabolic and integumentary 4. Metabolic and endocrine
Answer with Rationale
4. Metabolic and endocrine systems
Question 2
Which individual is at the highest risk for hypothyroidism? 1. 67 y.o., white, female 2. 28 y.o., white, male 3. 50 y.o., black, female 4. 70 y.o., hispanic, male
Answer with Rationale
1. 67 y.o., white, female Increased risk with advanced age >60 y.o. More common in whites (5.1%), African Americans
tend to produce less TSH than white Hypothyroidism 5-10x more common in women than
men
Question 3
What is the starting replacement dose of T4 in a healthy adult? 1. 2.4 mcg/kg/day 2. 1.6 mcg/kg/day 3. 1.2 mcg/kg/day 4. 0.4 mcg/kg/day
Answer with Rationale
2. 1.6 mcg/kg/day 60kg patient
1.6mcg/kg/day 96mcg/day-> 100mcg tablet QD
(Kansagra, McCudden & Willis, 2010)
Question 4
Most effective treatment regime for managing hypothyroidism? 1. Balanced diet and adequate fluid intake 2. Synthetic hormone replacement therapy 3. Regular exercise and adequate rest
Answer with Rationale
2. Synthetic hormone replacement Best treatment, balanced diet, adequate rest, and
exercise regime are all non-pharmocological measures for managing hypothyroidism. There is no other method for complete management besides a synthetic hormone.
Question 5
3 common symptoms of hypothyroidism include: 1. Weight gain, cold intolerance, dry skin 2. Heat intolerance, excessive sweating, and
palpitations 3. Fatigue, difficulty concentrating, weight loss 4. Increased blood pressure, high pitched voice,
constipation
Answer with Rationale
1. Weight gain, cold intolerance, and dry skin
Question 6
What is the most common cause of primary hypothyroidism? 1. Subacutethyroiditis 2. postoperative thyroidectomy 3. post-ablative therapy 4. Hashimoto’s thyroiditis
Answer with Rationale
4. Hashimoto’s thyroiditis Most common cause of hypothyroidism in the U.S.,
with an incidence of 3.5 cases per 1,000 women per year and 0.8 cases per 1,000 men per year
Question 7
Most common synthetic hormone used to treat hypothyroidism? 1. Thyroid stimulating hormone 2. T3 3. T4
Answer with Rationale
3. T4Standard treatment:
Administered to supplement or replace endogenous production
Oral form of T4- synthetic thyroid hormone
Question 8
What gland produces TSH, which stimulates the production of T3 and T4? 1. Thyroid gland 2. Pituitary gland 3. Adrenal gland 4. Thymus gland
Answer with Rationale
3. Pituitary gland The thyroid is controlled by the pituitary gland,
producing TSH, stimulating the thyroid to produce T 3 and T4
Question 9
TSH and T4 levels in primary hypothyroidism 1. Elevated TSH and elevated free T4 2. Elevated TSH and decreased free T4 3. Decreased TSH and elevated free T4 4. Decreased TSH and decreased free T4
Answer with Rationale
2. Elevated TSH and decreased free T4 Primary hypothyroidism
TSH elevated (>4-5mU/L) Serum free T4 decreased
Question 10
When screening for hypothyroidism, what is the initial blood test? 1. Free T4 2. T3 3. TSH 4. All of the above
Answer with Rationale
3 Serum TSH normal – no further testing performed Serum TSH high -> Free T4 to determine degree of
disease
References
24Remedy. (2015). Identifying the symptoms of hypothyroidism & how to prevent them. Retrieved on January 10, 2015 from http://www.24remedy.com/health-care/symptoms-of-hypothyroidism/.
Brownstein, D. (2015). The thyroid gland. Retrieved on January 10, 2015 from http://www.celticseasaltblog.com/articles/health-and-fitness/the-thyroid-gland/.
Cornille, A. (2004). Thyroid hormones, symptoms, and treatments for hypothyroidism. Retrieved on January 20, 2015 from http://www.project-aware.org/Resource/articlearchives/thyroid.shtml.
Luzy, R. (2009). Difference between hypothyroidism and hyperthyroidism. Retrieved on January 10, 2015 from http://www.differencebetween.net/science/health/difference-between-hypothyroidism-and-hyperthyroidism/.
Domino, F.J. (2014). 5 Minute clinical consult 2014. Lippincott Williams & Wilkins. Gupta, Y., & Ammini, A.C. (2012). Vitiligo, hypothyroidism and cardiomyopathy. Indian Journal of Endocrinology and
Metabolism, 16(3): 463-465. Hollier, A. & Hensley, R. ( 2011). Clinical Guidelines in Primary Care: A Reference and Review Book. Lafayette, LA:
Advanced Practice Education Associates, Inc. Kangsagra, S.M., McCuden, C.R., & Willis, M.S. (2010). The challenges and complexities of thyroid hormone
replacement. LabMedicine: 41(6): 229-348. MayoClinic. (2012). Hypothyroidism (underactive thyroid). Retrieved on January 7, 2015 from
http://www.mayoclinic.org/diseases-conditions/hypothyroidism Orlander, P.R. (2014). Hypothyroidism. Retrieved on January 19, 2015 from
http://emedicine.medscape.com/article/122393-overview#a0156. Ross, D.S. (2014). Patient information: hypothyroidism (underactive thyroid) (beyond the basics). Retrieved on January
20, 2015 from http://www.uptodate.com/contents/hypothyroidism-underactive-thyroid-beyond-the-basics. Ross, D.S. (2014). Diagnosis of and screening for hypothyroidism in nonpregnant adults. Retrieved on January 20, 2014
from http://www.uptodate.com/contents/diagnosis-of-and-screnning-for-hypothyroidisn-in-nonpregnantaduts WebMD. (2014). Women’s health. Retrieved on January 10, 2015 from http://www.webmd.com/women/picture-of-the-
thyroid. WebMD. (2013). Hypothyroidism (underactive thyroid). Retrieved on January 7, 2015 from
http://www.webmd.com/women/hypothyroidism-underactive-thyroid-symptoms-causes-treatments.