Endocrinology

Question 1

When is hypoglycemia common in neonates? What are the abnormal levels?

Answer 1

first 3 days of life. abnormal is less than 45mg/dL or less than 55w/ sx’s

Question 2

DDx of hypoglycemia?

Answer 2

shock, heart failure, intoxication, metabolic d/o, hormone deficiency (GH, glucagon, catecholamines)

Question 3

Pathway of steroid production

Answer 3

hypothalamus makes CRH–stimulates pituitary to release ACTH–stimulates adrenal cortex to release cortisol

Question 4

What is the dz characterized by the absence of cortisol production from birth?

Answer 4

Congenital adrenal hyperplasia

Question 5

What are signs/sx’s of Congenital Adrenal Hyperplasia (CAH) at birth?

Answer 5

ambiguous genitalia, hypo NA, hyper K, vomiting, dehydration, acidosis

Question 6

What is the MCC of CAH?

Answer 6

21-hydroxylase deficiency

Question 7

What is Addison’s dz? S/Sx’s?

Answer 7

autoimmune destruction of adrenal cortex: hyperpigmentation, salt craving, hypotension, hypoglycemia, shock

Question 8

When is parathyroid hormone secreted and what does it do?

Answer 8

secreted when Ca is low, it increases Ca and decreases phosphate

Question 9

What is hypoparathyroid, s/s, and is seen in which d/o?

Answer 9

low Ca, high phosphate (causes neonatal tetany which can also be from cow’s milk), seen in DiGeorge syndrome

Question 10

Panhypopituitarism causes deficiency in what hormones? What is the tx?

Answer 10

low GH, T4/T3, cortisol, ADH (causes hypernatremia & diabetes insipidus), low sex hormones. Replace all hormones to tx.

Question 11

How is diabetes defined in terms of values?

Answer 11

Fasting BG >126 or >200 2hrs after meals

Question 12

What is the most common endocrine disease in children?

Answer 12

Type I Diabetes

Question 13

Sx’s of diabetes and ketosis?

Answer 13

polyuria, polyphagia, polydipsia, vomiting, abd pain, fatigue, dehydration, decreased mental status,

Question 14

How do you define diabetic ketoacidosis with lab values?

Answer 14

arterial pH < 7.25, arterial bicarb <15, ketonuria/ketonemia

Question 15

When/where does the thyroid develop in the embryo?

Answer 15

4th week in the 3rd and 4th pharyngeal pouches

Question 16

If a TSH is high on a neonatal screen does this ALWAYS indicate hypothyroidism?

Answer 16

Not always, TSH surge can result in false positives

Question 17

Fetal hypothyroidism results in what deformity?

Answer 17

absent distal femoral epiphysis

Question 18

What is secondary hypothyroidism?

Answer 18

defective TSH synthesis in pituitary or hypothalamus

Question 19

What is the rate of congenital hypothyroidism, which sex does it affect more?

Answer 19

1 in 3500-4000, girls 2x’s more than boys

Question 20

What are signs and symptoms of congenital hypothyroidism?

Answer 20

lg fontanelles, poor feeding, jaundice, hypothermia, macroglossia, umbilical hernia, constipation, hoarse cry, lethargy, myxedema

Question 21

What are signs of acquired hypothyroidism?

Answer 21

same as congenital but >6mos old, deceleration of linear growth (ht)

Question 22

What are causes of congenital hypothyroidism?

Answer 22

90% is thyroid dysgenesis; Down syndrome, toxoplasmosis, iodine def (maternal) are others

Question 23

What are causes of acquired hypothyroidism?

Answer 23

drug-induced–hyperthyroid meds, Li, iodine def., Hashimoto’s, irradiation

Question 24

What are complications of hypothyroidism?

Answer 24

MC is decreased linear growth. Also impaired intellect, chronic constipation, SCFE

Question 25

What is a complication of overtreatment of hypothyroidism w/levothyroxine?

Answer 25

early closure of cranial sutures

Question 26

Most cases (95%) of hyperthyroidism are d/t what?

Answer 26

Graves disease

Question 27

What is the epidemiology of hyperthyroidism?

Answer 27

1 out of 5000. 5x’s more in girls. onset in teens, family hx, other endocrine d/o’s.

Question 28

What are 4 drugs to treat hyperthyroidism?

Answer 28

propranolol & idodide (acute), PTU & methimazole (long-term)

Question 29

Which hyperthyroid tx is preferred during Pg?

Answer 29

PTU

Question 30

When is radioactive idodine (I-131) used to treat hyperthyroid?

Answer 30

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)

Question 31

What are sx’s of neonatal hyperthyroidism?

Answer 31

arrhythmias, exophthalmos, heart failure, craniosynostosis, cog. defects, rebound hypothyroidism

Question 32

What is TSI, what does it do, what is a complication in Pg?

Answer 32

TSI = thyroid stimulating immunoglobulin, binds to receptors & mimics TSH, causes hyperthyroid after birth

Question 33

When is hypoglycemia normal in neonates?

Answer 33

the first 3 days of life, otherwise s is ABnormal