thyroid Flashcards
gens plus à risque d’avoir une TSH débalancée 4 (dans énoncé)
personnes âgées
femmes en période postpartum
patients avec ANTCD de fibrillation auriculaire
patients atteints d’une endocrinopathie
comment palper la thryoide
placez-vous derrière le patient et demandez-lui d’avaler
risk factors for thryoid dz 6
Women >45yo
Postpartum
Radiation
Drug-induced (lithium, amiodarone)
Autoimmune disease (eg. DM1)
Strong family history of thyroid disease
hypot4 sx 8 6M + 2
Mood: Depression
Memory
Motor: Fatigue/Lethargy
Mass: Weight gain
Metabolism: Cold intolerance
Menstrual irregularities
Constipation
Dry skin
hypert4
Palpitations/ tachycardia/ atrial fibrillation
Widened pulse pressure
Nervousness and tremor
Heat intolerance
Weight loss
Muscular weakness
Usually goiter is present
what is a high tsh, meaning and other tests to do
TSH high (>4-5mU/L) - Possible Primary Hypothyroidism
FT4 to determine degree of hypothyroidism
Anti-TPO Ab once
what is a low tsh, meaning and other tests to do
TSH low (<0.2mU/L) - Possible Primary Hyperthyroidism
Free T4 and T3 to determine degree of hyperthyroidism
if no obvious cause for hyper T4 what to order
Thyrotropin receptor antibodies (TRAb)
Radioactive iodine uptake (contraindicated in pregnant/breastfeeding)
Ultrasound with thyroidal blood flow
if nodules what to do
échographie + fine needle aspiration PRN
hypot4 ddx primaire
Primary
Chronic autoimmune thyroiditis
Iatrogenic (thyroidectomy, radioiodine therapy, external radiation)
Iodine deficiency/excess
Drugs - thionamides, lithium, amiodarone, interferon-alfa, interleukin-2, perchlorate, tyrosine kinase inhibitors
Infiltrative diseases
Transient hypothyroidism
Congenital thyroid disease
hypot4 central
TSH or TRH deficiency
hyperT4 2 broad categories
normal or high iodine uptake
vs
near absent iodine uptake
hyperT4 normal or high iodine uptake
graves
hashitoxicosis
toxic multinodular goiter
pituitary adenoma
when to treat subclinical hypoT4 7
Consider treatment if TSH≥20mU/L (BMJ 2019), asx
symptomatic
or risk (elevated Anti-TPO Ab, Goiter, strong family history of autoimmune, pregnancy)
Consider treatment in infertility
when to treat subclinical hypert4 5
Consider treatment if TSH <0.1 mIU/L and
Symptomatic (palpitations, tremor, nervousness)
> 65yo
Comorbidities such as heart disease or osteoporosis
Postmenopausal (<65yo) and not taking estrogen/bisphosphonates
txhypoT4
Levothyroxine
aka synthroid
avoid giving synthroid when TSH level is …. risk of ….3
Avoid TSH <0.1mIU/L
Risk of thyrotoxicosis - A-fib and osteoporosis
when to repeat TSH
q 3-4mo and then yearly
Myxedema coma signs and symptoms 7
Altered mental status,
hypoventilation,
hypothermia,
hypotension,
bradycardia,
hyponatremia,
hypoglycemia
myxedeme coma tx
Treat aggressively (mortality 40%)
Levothyroxine (T4) loading dose 200-400mcg IV, then 1.6mcg/kg/day IV
Liothyronine (T3) 5-20mcg followed by 2.5-10mcg q8h given with T4
Glucocorticoids (hydrocortisone 100mg IV q8-12h x2d) until coexisting adrenal insufficiency can be excluded
Supportive measures (fluids etc)
two thyroid emergencies
thyroid storm (aka tooo much T3 T4 ) going cray cray in your boday
myxedema coma - no T3 and T4
thyroid storm sx
Hyperthermia, tachycardia, No/Vo/Do, dehydration, delirium, coma
hyperT4 graves tx
Thionamides
1) Methimazole (MMI) in non preganant pt
2) Propylthiouracil – PTU (grossesse))
Elevated TSH, rule out
pituitary gland tumour
thyroid storm tx
B-Blockers (Propranolol 60-80mg q4-6h)
o PTU 200mg PO q4h
o Iodine solution (delayed 1h after PTU)
o Iodinated radiocontrast
o High-dose IV hydrocortisone 100mg IV q8h
hyperT4 sx control rx
beta blocker
atenolol 25-50 mg die
