Summary: For the those of you who are following along on weekly basis we are going to start a review of the endocrine system. I am going to continue to work through each section in it’s entirety rather than bouncing from topic to topic. I think that adds some continuity to the review and it is easier for you to follow along. At some point I would also like to create a short review test for each section and doing them together will better facilitate this. Anyway, lets get started Thyroid - Hyperthyroidism Primary vs Secondary Primary hyperthyroidism is when the problem is within the thyroid. Secondary hyperthyroidism is when the problem is with something else in the body which is affecting the thyroid like the pituitary or hypothalamus Graves disease is the most common cause of hyperthyroidism. It is an auto immune disease in which the body creates antibodies that bond to the TSH receptor thereby forcing the thyroid into excessive production. Amiodarone may cause thyrotoxicosis Clinical Presentation As a physician assistant with acute clinical skills you will of course be keeping an eye out for symptoms of hyperthyroidism. It is quite a list! If you picture someone who has had a lot caffeine for a long period of time a good number of the symptoms will come easy to you. So here’s the list. Eyes stare lid lag with downward gaze upper eyelid retraction diplopia Ophthalmopathy -- which means any eye disease Grave’s disease 20-40% of pts will have chemosis conjunctivitis exophthalmos or proptosis Heart Tachycardia AFib Palpitations Chest pain Skin Fine hair warm moist onycholysis myxedema Mental changes irritability nervousness fatigue heat intolerance sweating changes in weight increase in appetite loose stool frequent urination muscle cramps changes in menstruation fine resting tremor hyperreflexia goiter bruit hypokalemic periodic paralysis lasting 7-72 hours typically in Asian and Native American Men following oral or IV carbohydrates or excessive exercise Chronic symptoms include osteoporosis clubbing finger swelling hypercalcemia decreased libido Thyroid storm very rare but severe risk factors stressful illness thyroid surgery radioactive iodine treatment symptoms fever tachycardia vomiting/diarrhea dehydration muscle weakness confusion Believe it or not this is where I decided to stop listing symptoms. It could still continue quite a ways. Labs & Studies Being a good physician assistant you will want to understand the relationships between the hypothalamus, pituitary and the thyroid in order to understand what the lab work should look like. At this point I am not branching out into video or graphic design so here is a link to a decent review of the the hypthalmic pituitary thyroid axis. Hyperthyroid blood work TSH (thyroid stimulating hormone) decreased (almost all the time) T4 (thyroxine) elevated T3 (triiodothyronine ) elevated Free T4 elevated Free T4 index elevated ESR elevated TSH receptor antibody elevated in Graves disease hypercalcemia Radioactive iodine uptake scan will be elevated in Graves disease U/S may be helpful Treatment Beta blockers are the first line of treatment and propranolol is the one you will hear about with hyperthyroidism and thyroid storm Methimazole and propylthiourcial (PTU) will actually control hyperthyroidism and is used to prepare patients for surgery or as treatment in someone who can not do either iodine ablation or have surgery. Radioactive Iodine ablation Surgical removal Digoxin to treat AFib Warfarin to treat clotting with AFib ------------------------------------------------------------------------------------------------------------------------- If you are preparing for the PANRE/PANCE check back for weekly updates.
