Endocrinology Flashcards
When is hypoglycemia common in neonates? What are the abnormal levels?
first 3 days of life. abnormal is less than 45mg/dL or less than 55w/ sx’s
DDx of hypoglycemia?
shock, heart failure, intoxication, metabolic d/o, hormone deficiency (GH, glucagon, catecholamines)
Pathway of steroid production
hypothalamus makes CRH–stimulates pituitary to release ACTH–stimulates adrenal cortex to release cortisol
What is the dz characterized by the absence of cortisol production from birth?
Congenital adrenal hyperplasia
What are signs/sx’s of Congenital Adrenal Hyperplasia (CAH) at birth?
ambiguous genitalia, hypo NA, hyper K, vomiting, dehydration, acidosis
What is the MCC of CAH?
21-hydroxylase deficiency
What is Addison’s dz? S/Sx’s?
autoimmune destruction of adrenal cortex: hyperpigmentation, salt craving, hypotension, hypoglycemia, shock
When is parathyroid hormone secreted and what does it do?
secreted when Ca is low, it increases Ca and decreases phosphate
What is hypoparathyroid, s/s, and is seen in which d/o?
low Ca, high phosphate (causes neonatal tetany which can also be from cow’s milk), seen in DiGeorge syndrome
Panhypopituitarism causes deficiency in what hormones? What is the tx?
low GH, T4/T3, cortisol, ADH (causes hypernatremia & diabetes insipidus), low sex hormones. Replace all hormones to tx.
How is diabetes defined in terms of values?
Fasting BG >126 or >200 2hrs after meals
What is the most common endocrine disease in children?
Type I Diabetes
Sx’s of diabetes and ketosis?
polyuria, polyphagia, polydipsia, vomiting, abd pain, fatigue, dehydration, decreased mental status,
How do you define diabetic ketoacidosis with lab values?
arterial pH < 7.25, arterial bicarb <15, ketonuria/ketonemia
When/where does the thyroid develop in the embryo?
4th week in the 3rd and 4th pharyngeal pouches
If a TSH is high on a neonatal screen does this ALWAYS indicate hypothyroidism?
Not always, TSH surge can result in false positives
Fetal hypothyroidism results in what deformity?
absent distal femoral epiphysis
What is secondary hypothyroidism?
defective TSH synthesis in pituitary or hypothalamus
What is the rate of congenital hypothyroidism, which sex does it affect more?
1 in 3500-4000, girls 2x’s more than boys
What are signs and symptoms of congenital hypothyroidism?
lg fontanelles, poor feeding, jaundice, hypothermia, macroglossia, umbilical hernia, constipation, hoarse cry, lethargy, myxedema
What are signs of acquired hypothyroidism?
same as congenital but >6mos old, deceleration of linear growth (ht)
What are causes of congenital hypothyroidism?
90% is thyroid dysgenesis; Down syndrome, toxoplasmosis, iodine def (maternal) are others
What are causes of acquired hypothyroidism?
drug-induced–hyperthyroid meds, Li, iodine def., Hashimoto’s, irradiation
What are complications of hypothyroidism?
MC is decreased linear growth. Also impaired intellect, chronic constipation, SCFE
What is a complication of overtreatment of hypothyroidism w/levothyroxine?
early closure of cranial sutures
Most cases (95%) of hyperthyroidism are d/t what?
Graves disease
What is the epidemiology of hyperthyroidism?
1 out of 5000. 5x’s more in girls. onset in teens, family hx, other endocrine d/o’s.
What are 4 drugs to treat hyperthyroidism?
propranolol & idodide (acute), PTU & methimazole (long-term)
Which hyperthyroid tx is preferred during Pg?
PTU
When is radioactive idodine (I-131) used to treat hyperthyroid?
for pts who cannot tolerate or don’t respond to meds, 90% cure rate, not for Pg or lactating women, not for young children (cancer risk)
What are sx’s of neonatal hyperthyroidism?
arrhythmias, exophthalmos, heart failure, craniosynostosis, cog. defects, rebound hypothyroidism
What is TSI, what does it do, what is a complication in Pg?
TSI = thyroid stimulating immunoglobulin, binds to receptors & mimics TSH, causes hyperthyroid after birth
When is hypoglycemia normal in neonates?
the first 3 days of life, otherwise s is ABnormal
