During the first 3 days after birth, serum calcium concentrations normally decline in response to withdrawal of the maternal calcium supply via the placenta. transient hypoparathyroidism : Hypocalcemia caused by suppresses fetal PTH release in the neonatal period in infants of mothers with hyperparathyroidism and hypercalcemia. Hypomagnesemia may cause a secondary hypoparathyroidism, which responds poorly to therapies other than magnesium replacement. Neonatal tetany from excessive phosphate intake classically in a 1week-old to 1month- old infant who is fed cow's milk. Hyperphosphatemia ↓ calcium symptomatic hypocalcemia. Cow's milk: ↑ calcium& phosphorus than human milk. phosphate retention, as occurs in renal failure, produces hypocalcemia. The etiology of hypocalcemia 1. clinical presentation 2. serum ionized calcium 3. phosphate 4. alkaline phosphatase 5. PTH (preferably at a time when the calcium is low) 6. magnesium 7. albumin 8. X-rays of the long bones and hands and knees are important if the problem occurs after the neonatal period. If the PTH concentration is not elevated appropriately relevant to a low serum calcium, hypoparathyroidism (transient, primary, or caused by hypomagnesemia) is present. Vitamin D stores can be estimated by measuring serum 25-hydroxyvitamin D. Treatment severe tetany or seizures from hypocalcemia : IV calcium gluconate (1 - 2 mL/kg of 10% solution) slowly over 10 minutes+ cardiac ECG monitor for bradycardia, may be fatal. Long-term treatment of hypoparathyroidism : 1. vitamin D , 1,25-dihydroxyvitamin D.
365 Nelson Last Minute 2. calcium . keep the serum calcium in the lower half of the normal range to avoid hypercalcemia ( nephro-calcinosis and pancreatitis) . SEXUAL PRECOCITY Classification Sexual precocity (precocious puberty) is classically defined as secondary sexual development occurring before the age of 9 years in boys or 8 years in girls. The lower limit of normal puberty may be 7 years in white girls and 6 years in African American girls. the mean age at which girls exhibit Tanner II breast development (the-larche) is 10 years for white girls and 9 years for African American girls (normal range 8- 13 years). The mean age at which girls exhibit Tanner II pubic hair development is 9 years for white girls and 10.5 years for African American girls. Menarche usually occurs at 12.2 and 12.9 years (range 10-15 years). The normal developmental sequence is thelarche followed closely by pubarche and finally menarche 2 to 3 years later. In boys, the first normal event is enlargement of testes followed by appearance of pubic hair (long diameter of the testis >2.5 cm, volume >4 mL). The first distinction regarding puberty is that of central versus peripheral.
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- Fall '17
- Hypoglycemia, short stature, Precocious puberty