Endocrine/Metabolic Alterations

1. Endocrine/Metabolic Alterations NUR 264 Pediatrics Angela Jackson, RN, MSN

2. Developmental Differences • The endocrine system is incompletely developed at birth • Less mature than any other body system • Pituitary gland is formed by the 4th month of gestation and measurable amounts of hormone can be detected • Newborn’s level of TSH is 10 times higher than levels seen in older children. Initial thyroid function tests cannot be interpreted using normal standards of childhood or adults

3. Endocrine Glands • Anterior pituitary • Posterior pituitary • Thyroid • Parathyroid • Adrenal cortex • Adrenal medulla • Ovaries • Testes • Pancreas

4. Growth Hormone Deficiency • Characterized by poor growth and short stature • Occurs equally in both sexes • May result from injury, destruction of the anterior pituitary gland by a brain tumor, infection, or irradiation, but is usually idiopathic

5. GHD: Pathophysiology • Hypothalamus secretes growth hormone-releasing hormone (GRH) • Production of growth hormone (GH) by the pituitary is stimulated • In GHD, the pituitary is unable to respond to the GRH, and GH is not produced

6. GHD: Clinical Manifestations • Short stature • Deteriorating or absent rate of growth • Higher weight to height ration • Delayed bone age (Determined by x-ray of the hand and wrist) • Increased fat in trunk area • Childlike face with a large, prominent forehead • High-pitched voice • Hypoglycemia • Micropenis and small testes in males • Delayed sexual maturation • Delayed dentition

7. GHD: Diagnosis • Family history • Review of previous growth records • Physical examination • Determination of growth rate • Radiographic bone studies • Baseline blood testing • Pituitary function testing

8. GHD: Treatment • Goal of treatment is to promote normal growth rates by administration of growth hormone • Growth hormone is given IM or SC • Treatment is discontinued once the epiphyseal growth plates have fused • Treatment is expensive ($20,000 to $30,000 / year, depending on dosage)

9. GHD: Potential Complications of Treatment • Slipped femoral epiphysis • Pseudotumor cerebri • Edema • Sodium retention

10. GHD: Nursing Management • Monitor growth • Maintain growth chart • Provide teaching to family concerning normal growth and development • Teach family proper medication administration techniques and side effects • Monitor medication dosages • Provide emotional support

11. Precocious Puberty • Breast development before the age of 7 in Caucasian girls and before the age of 6 in African-American girls • Development of secondary sex characteristics in boys less than 9 years old • Five times more common in girls • Idiopathic in girls, related to central nervous system abnormalities in boys

12. Precocious Puberty: Pathophysiology • Results from premature activation of the hypothalamic-pituitary-gonadal axis • Hypothalamus secretes gonadatrophin releasing hormone, which stimulates the pituitary to produce leutinizing hormone and follicle stimulating hormone. Estrogen or testosterone is also produced

13. Precious Puberty: Clinical Manifestations • Accelerated growth rate • Advanced bone age • Secondary sex characteristics • Acne • Body odor • May be emotionally labile, aggressive, and mood swings may occur • Potentially fertile

14. Precocious Puberty: Diagnosis • Physical exam and history • Tanner staging • Measurement of height and weight • X-rays for bone age, pelvic ultrasound for females to identify size of uterus and ovaries, CT, MRI or skull film to detect CNS lesions for males • Lab tests for LH, FSH, estradiol or testosterone • GnRH stimulation testing

15. Precocious Puberty: Treatment • Administration of luteinizing hormone – releasing hormone (Lupron) SC on a monthly basis • Surgery, radiation or chemotherapy if caused by CNS tumor • Treatment results in a decrease in growth rate, stabilization or regression of secondary sex characteristics • Puberty resumes when therapy is discontinued

16. Precocious Puberty: Nursing Management • Monitor growth • Provide psychological support • Teach parents about normal growth and development • Instruct parents that child’s mental age is congruent with chronologic age • Teach parents about medication administration and potential side effects

17. Diabetes Insipidus (DI) • Disorder of water regulation • Deficiency of ADH results in excretion of large amounts of dilute urine • Most often seen as a complication following head injury or cranial surgery to remove tumors of the hypothalamic-pituitary region • Other causes include vascular anomalies, infection, and genetic defect

18. DI: Clinical Manifestations • Polyuria • Polydipsia • Nocturnal enuresis • Urine output can range from a few liters to eighteen liters a day • Urine specific gravity is 1.005 or less, urine osmolarity is <200mmol/l • Serum sodium concentration and plasma osmolarity are elevated

19. DI: Diagnosis • UA for osmolarity, specific gravity, and sodium • Serum osmolarity, sodium and creatinine levels • Water deprivation test. Requires several hours to complete with close monitoring (I&O, weight, vital signs, hydration assessment, and urine and blood samples)

20. DI: Treatment • Goals of treatment include: antidiuresis, uninterrupted sleep, and increased ability to participate in school and other programs • Treated with daily replacement of ADH • Drug of choice is DDAVP, which is given intranasally or orally

21. DI: Nursing Management • Strict I&O and daily weight • Teach parents about the condition • Teach parents about lifelong need for medication and medication administration • Teach parents to monitor I&O and daily weights

22. Congenital Hypothyroidism (CH) • Present at birth • Reduced rate of metabolism caused by a low concentration of circulation thyroid hormones (T3 and T4) • More females than males are affected • Caused by a defect in the embryonic development of the thyroid gland, inborn error of thyroid hormone synthesis, and pituitary dysfunction • Thyroid gland is unable to produce T3 and T4 in response to increasing elevated levels of TSH secreted by the pituitary gland

23. Asymptomatic at birth Large posterior fontanel Umbilical hernia Constipation Prolonged jaundice Pallor hypothermia Enlarged tongue Hypotonia, hypoactivity Feeding difficulties Delayed mental responsiveness Cool, dry, scaly skin Swollen eyelids CH: Clinical Manifestations

24. CH: Diagnosis • Mandatory newborn screening • Low T4 and a high TSH indicate CH • Thyroid scan to evaluate for absence or ectopic placement of the thyroid gland

25. CH: Treatment • Goal of therapy is to quickly normalize thyroid function • Maintain the level of T4 in the upper half of the normal range and TSH in the normal range • Thyroid replacement with synthroid is initiated as soon as possible, starting dose of 10-15 mcg/kg/day • Close monitoring of thyroid function • Lifelong replacement is necessary to maintain normal metabolism

26. CH: Nursing Management • Monitor growth and development • Monitor lab values: every 2-4 weeks until thyroid function is within target range and medication dose is stabilized, every 3-4 months for first several years of life, every 6-12 months in adolescence • Teaching parents proper medication administration, side effects, importance of continuing medication for rest of child's life and importance of regular blood tests to monitor thyroid function

27. Questions??