hypothyroidism
ETIOLOGY
REMEMBER HASHIMOTO THYROIDITIS IS HYPOTHYROID
USUALLY >40 YEARS
WOMEN> MEN
COMMON IN ADULTS >65 YEARS
HYPOTHYROID
CAUSES
MOST ARE AUTOIMMUNE
HASHIMOTOS THYROIDITIS OR CHRONIC LYMPHOCYTIC THYROIDITIS IS AUTOIMMUNE AND THYROID GLAND IS GRADUALLY DESTROYED.
THYROIDITIS.
CONGENITAL HYPOTHYROIDISM.
THYROIDECTOMY.
RADIATION OF THYROID.
LITHIUM
AMIODARONE
PITUITARY OR HYPOTHALAMIC DX
IODINE DEFICIENCY OR EXCESS
HASHIMOTOS MAIN CAUSE OF<THYROID
TWO MAIN TYPES
GOITROUS AUTOIMMUNE THYROIDITIS
ATROPHIC AUTOIMMUNE THYROIDITIS
CAUSES <THY, BUT INITIALLY HYPERTHYROIDISM CAN OCCU-CALLED HASHITOXICOSIS
DX:
>TSH
<T4
> ANTI TPO (ANTITHYROID PEROXIDASE) ANTIBODIES-NOT ROUTINELY DONE-USU BY SPECIALIST FOR SUBCLINICAL
CLINICAL PRESENTATION
WEIGHT GAIN
HAIR LOSS-THINNING HAIR
COLD INTOLERANCE
FATIGUE
JOINT AND MUSCLE PAIN ARTHRALGIA MYALGIA
BRITTLE NAILS
DRY SKIN
BRADYCARDIA
DEPRESSION
IRRITABILITY AND MOOD CHANGES
DOE
HOARSENESS
PERIORBITAL EDEMA
LOSS OF EYEBROWS
DIASTOLIC HYPERTENSION
MENSTRUAL DISTURBANCE
CARPAL TUNNEL SYNDROME
MAY HAVE GOITER-ESP IODINE DEFICIENCY OR HASHIMOTOS
HYPOTHYROIDISM
RISK FACTORS
FAMILY HX OF AUTOIMMUNE DISEASE
EG DM 1, OVARIAN FAILURE CELIAC SJOGRENS VITILIGO .PERNICIOUS ANEMIA
AGE
POSTPARTUM
AUTOIMMUNE DISEASE
HEAD/NECK RADIATION
RX OF HYPOTHYROID
PT ON LITHIUM OR IODINE CONTAINING AMIODARONE
HYPOTHY
IMPORTANT FACT
EXPECT LIPIDS TO BE ELEVATED IN HYPOTHYROID PTS,
TREAT LIPIDS IF STILL ELEVATED AFTER TSH <10 MIU/L
DRUG CLEARANCE REDUCED IN HYPOTHYROIDISM
LIPID CLEARANCE DECREASED
R/O HYPOTHYROID BEFORE DIAGNOSING SIADH IN HYPONATREMIC PT
HYPOTHYRO
DIAGNOSTIC TESTING
TSH ELEVATED
(EXCEPT IN PITUITARY OR HYPOTHALAMIC HYPOTHYROIDISM-NORMAL OR UNDETECTABLE TSH)
T4 LOW
T3 LO OR NORMAL -may not test this
ANTI TPO -HASHIMOTO 90-100%/GRAVES 85%
buttaro
Anti-TPO antibodies are found in 90% to 100% of patients with Hashimoto thyroiditis and in less than 85% of patients with Graves disease
DIFF DIAGNOSIS
IDA-SAME SX
SLEEP APNEA
ANOREXIA
GAD
SLE
UPTODATE:
RECOVERY FROM NONTHYROIDAL ILLNESS ELEVATED TSH- REPEAT TSH T3 T4 AFTER 4 WEEKS
PITUITARY ADENOMAS
PRIMARY ADRENAL IINSUFFICIENCY
TYHROID SCREENING
AAFP - PERIODIC ASSST OF THYROID FUNCTION IN OLDER WOMEN -NO AGE
ACP WOMEN >50
ATA AND AACE SCREEN ANYONE AT RISK- FAM HISTORY , T1D, AUTOIMMUNE DISEASE,RADIATION TO NECK , THYROID SURGERY AND ANYONE OVER 60
nodules in thyroid disease
Nodules are classified as hot, warm, or cold according to the concentration of iodine isotope in the nodule in comparison with the rest of the thyroid gland. Hot nodules are usually but not always benign. Most cold nodules (solid or cystic) are benign; however, most malignant neoplasms also appear as cold nodules.
Ultrasonography is used to evaluate the anatomy of the thyroid gland and to differentiate solid from cystic nodules
HYPOTHYROID PHARM PTPX
LEVOTHYROXINE
1.7 MCG/KG/DAY
VARIES FOR EACH PT
START WITH 50 MCG/DAY DOSAGE INCREASE Q 4-6 WEEKS
30-40 YO =100MCG DAY
EPOCRATES
START 1.6 MCG/KG /DAY THEN 4-6 WEEKLY INCREASE BY 12.5-50 MCG INTERVALS ADJUST ACCORDING TO TFT
RARELY NEED > 300MCG /DAY
HYPOTHY PHARM PTPX
PT WITH ISCHEMIC HEART DISEASE ,, ATRIAL FIB , ELDERLY
START AT 12.5 -25 MCG DAILY
INCREASE BY 25 MCG Q 8 WEEKS
HYPO NON PHARM
TAKE ON EMPTY STOMACH 30-60 MINUTES BEFORE BREAKFAST
OR 2-4 HOURS AFTER LEAST MEAL
DONT TAKE ANTACIDS
LIFELONG THERPAY
RED FLAGS
THYROID STORM
IF ON BETA BLOCKERS MONITOR PULSE, LESS THAN 50 ->120 BPM CONTACT PROVIDER
AGRANULOCYTOSIS
HYPO PPTX
REFERRALS
PREGNANCY
UNSTABLE ISCHEMIC HEART DISEASE
MYXEDEMA COMA
NEED RADIOACTIVE IODINE THERAPY
DEVELOP GOITER OR NODULE
NO CHANGE IN SX AFTER LEVOHYROXINE TREATMENT
ER IF HF ANGINA RAPID ATRIAL FIB
THYROID GLAND PPTX
FUNCTION
REGULATES BODY TEMP
METABOLISM
HEART RATE
MAKES TWO HORMONES T3 TRIIODOTHYRONINE
T4 THYROXINE
THHYROID DISORDER TYPES PPTX
HYPERTHYROIDISM
GRAVES
HASHIMOTOS DX-CHROMO 6
GOITER AND THYROID NODULES
THYROID CANCER
THYROID PPTX
EPIDEMIOLOGY
60% UNAWARE OF CONDITION
FEMALES 5-8 X MORE LIKELY
1 IN 8 WOMEN WILL GET TTHYROID DISORDER
USU LIFELONG + NEED MEDS
UNDIAGNOSED THYROID DISORDER > RISK OF MISCARRIAGE, DEVELOPMENTAL D/O AND PRE TERM LABOR
HYPERTHYROID PPTX
LAB RESULTS
COMPS
LOW TSH
ELEVATED T4 & T3
WOMEN>60
FAMILY HISTORY
PERNICIOUS ANEMIA
T1D & T2D
FOODS HIGH IN IODINE (KELP)
PRIMARY RENAL INSUFFICIENCY
IRREGULAR HR
GRAVES OPTHALMOLOGY
OSTEOPOROSIS
MENSTRUAL ABNORMALITIES
FERTILITY ISSUES
HIGH THYR PPTX
ASST FINDINGS
WEIGHT LOSS
INCREASED APPETITE
RAPID HR
FEELING SHAKY OR NERVOUS
DIARRHEA
CLAMMY SKIN/SWEATING
HYPER THYROID CAUSES -PPTX
OVERACTIVE THYROID NODULES
THYROIDIITIS
TOO MUCH IODINE
TOO MUCH LEVOTHYROXINE
PITUITARY TUMOR
REFERRAL
HIGH T3 & T4
REFER TO ENDOCRINOLOGY
GRAVES DX-PPTX SX
AUTOIMMUNE DISORDER
RESULTS IN EXCESSIVE THYROID HORMONE
SX
PROPTOSIS
LIGHT SENSITIVITY
DIPLOPIA
BLURRED VISION
DRY EYE
RED THICKENED ROUGH SKIN -GRAVES DERMOPATHY OR PRETIBIAL MYXEDEMA
THYROID STORM PPTX
DAIGNOSIS
ACUTE LIFE THREATENING COMPLICATION OF HYPERTHYROIDISM W A MORTALITY RATE OF 8-25% DESPITE ADVANCEMENT
AGITATION
HYPERPYREXIA
TACHYCARDIA
ARRHYTMIAS
ABDOMINAL PAIN
VOMITING /JAUNDICE
BURCH WARTOFSKY POINT SCALE
THYROID STORM ICU RX
THERAPY TO BLOCK CONVERSION OF T3 & T4
IODINATED RADIOCONTRAST AGENT
GLUCOCORTICOID , PTU, METHIMAZOLE
PROPANOLOL-(CROSSES BLOOD BRAIN BARRIER AS LIPID SOLUBLE-GOOD FOR MIGRAINE)
BILE ACID SEQUESTRANT-REDUCES ENTEROHEPATIC RECYCLING OF THYROID HORMONE
DIAGNOSTICS
TYHROID PPTX
IMAGING
USS
RADIOUPTAKE THYROID SCAN-CALL IT RUTS
DOPPLER BLOOD FLOW MEASUREMENTS (USS) MAY BE ORDERED IF RUTS CONTRAINIDCATED, PREGNANCY ALLERGY BREASTFEEDING,
GRAVES INFERNO-INCREASED BLOOD FLOW
LABS
CBC LFTS BASELINE FOR METHIMAZOLE
ESR
T3 T4 TSH
LAB FINDINGS
T3&T4 -HIGH HYPER
T3& T4-LOW IS HYPO
TSH -LOW IS HYPER, HIGH IS HYPO
TSI-THYROID STIMULATING IMMUNOGLOBULIN-ANTIBODY THAT TELLS THE THYROID TO INCREASE ACTIVITY AND RELEASE THYROID HORMONE INTO BLOOD STREAM
HYPERHYROID
PHARM PPTX
THIONAMIDES
METHIMAZOLE (MMI,TAPAZOLE) 5-20 MG PO Q8H AS START DOSE
THEN 5-10 MG PO QD
Initial: Individualize initial dose based on clinical status and gland size; free T4 levels may be used to guide initial therapy (Ref):
Free T4 levels 1 to 1.5 times ULN: 5 to 10 mg once daily.
Free T4 levels >1.5 to 2 times ULN (or iodine-induced thyrotoxicosis): 10 to 20 mg once daily.
Free T4 levels >2 times ULN: 20 to 40 mg/day. To achieve euthyroidism more quickly and reduce GI-related adverse effects, may give in 2 to 3 divided doses (especially with doses >30 mg/day) (Ref).
HYPER PHARM PPTX
PROPANOLOL
10-40 MG Q 6
OR ATENOLOL 25-100 Q6H
CAUTION W BRONCHOSPASM HF PREGNANCY
NON PHARMRX-PPTX
REF ENDOCRINE IF
GRAVES OPTHALMOPATHY
RX RADIO IODINE THERAPY IODINE rX IS IODINE 131 TO DESTROY THYROID TISSUE
thyroi outpatient uptodate
Serum TSH normal – No further testing performed
•Serum TSH high – Free T4 added to determine the degree of hypothyroidism
•Serum TSH low – Free T4 and T3 added to determine the degree of hyperthyroidism
if young woman w amenorrhea and fatigue-suspect pituitary or hypothalamic dx- do tsh and free t4
if pt has symptoms - test serum free T4 anyway even if TSH normal
recommended because a TSH only could miss 3.8 % with secondary , central or TSH mediated hyperthyroidism
sickness- can have low concentrations of binding proteins
meds that affect thyroid function
hi concentrations of free fatty acids that displace thyroid hormones from binding proteins
on levo- can assess TSH only
ANTITHYROID ANTIBODIES
GRAVES, HASHIMOTOS
HASHIMOTOS -AL HAVE ELVATED TPO NOT NECESSARY
THIRD GEN TSI STUDIES 97/99 SPE,SEN FOR GRAVES-NOT NEC TEST IF RADIO UPTAKE SCAN HAS BEEN DONE
Last changed7 months ago