Metabolism/Endocrine + Genetic

Describe the endocrine system

• Composed of glands, tissues, or clusters of cells that produce & release hormones in a negative feedback system (hypothalamus & nervous system)

  • Hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, gonads (ovaries & testes), and islets of langerhans located in pancreas

• Most glands develop during 1st trimester of gestation → development incomplete @ birth

Describe the hypothalamus

• Center of brain

• Communicates messages of central autonomic nervous system to endocrine system organs/glands to maintain homeostasis

Describe the pituitary gland (anterior and posterior)

• Connected to hypothalamus by stem-like structure

• Affects growth and gland functions

Describe the thyroid gland

• Front of neck, just below larynx

• 2 lobes connected by an isthmus

• Produces 2 hormones: Thyroxine (T4) & Triiodothyronine (T3)

Describe parathyroid glands

• 2 glands embedded on posterior side of each lobe of thyroid gland

• Produces parathyroid hormone (PTH) & responsible for calcium regulation

Describe adrenal glands

• Outer (cortex) portion & an inner (medulla) portion

• On top of each kidney

Describe the pancreas

• In the abdomen, just behind the stomach, near the duodenum

• As an endocrine gland, it secretes both insulin and glucagon

Describe the reproductive glands (ovaries & testes)

• Produces several steroidal sex hormones = produces & regulate changes in the male and female body at puberty

What are the common lab and diagnostic testing used for endocrine disorders?

• Newborn metabolic screening

• Serum chemistry

• Random and timed serum hormone testing

• Growth hormone stimulation testing

• Blood glucose (fasting, random and OGTT), HgA1C

• Urine testing (ketone, glucose, 24‐hour collections)

• Hemoglobin A1c

• Genetic testing

• Water deprivation study = looks at serum sodium and urine osmolarity

• Bone age radiographs

• Imaging studies—CT, MRI, nuclear medicine, ultrasonography

What are the different pituitary disorders?

• Growth hormone deficiency

• Precocious puberty

• Delayed Puberty

• Diabetes insipidus

• Syndrome of inappropriate antidiuretic hormone secretion

Describe growth hormone deficiency (dwarfism)

• Causes poor growth & short stature

• Growth hormone = stimulates linear growth, bone mineral density, & body tissue growth

Describe the assessment for growth hormone deficiency

• Height at or below 3rd percentile on standard growth chart

• Delayed puberty

• Child like face

• Chubby build = inc amt of fat around face and abdomen

• Delayed skeletal maturation

What is the management for growth hormone deficiency?

• Supplemental GH

• Treat underlying problem (remove tumors)

• GH therapy

• Biosynthetic GH by subq injection

Describe precocious and delayed puberty

• Precocious puberty

  • Child develops sexual characteristics before usual age of pubertal onset

    • Girls = < 8 years

    • Boys = < 9 years

  • If untreated child becomes fertile due to rapid growth

• Delayed puberty

  • Girls = breasts are not developed by 12

    • Normal range = 10-12

  • Boys = no testicular enlargement or scrotal changes by 14

    • Normal range = 11-14

What is the management for precocious and delayed puberty?

• Educate about physical changes

• Teach how to correctly use prescribed meds

• Help child w/ self-esteem issues related to rate of growth & development of secondary sexual characteristics

• Promote age-appropriate physical development & pubertal progression

Describe diabetes insipidus (DI) and the different types

• Def: Hypofunction of posterior pituitary gland

  • The body doesn't properly regulate water balance, leading to excessive thirst and frequent, dilute urination

• Types:

  • Nephrogenic DI = lack of response to ADH

  • Central DI = deficient production of ADH

Describe the s/s of DI in different age groups

• Infants = poor feeding, failure to thrive, fussiness, frequent saturated diapers

• School age & teen = irritability, polydipsia, polyuria, craving for cold water, enuresis (urinary incontinence), nocturia

• All ages = vomiting, constipation, fevers, dry skin, weight loss

How do we manage DI?

• Diet low in solutes (low sodium & protein)

• Monitor for signs of impending dehydration or fluid imbalance = urine output, fluid intake, daily weights

• Comfort irritable child & use distraction methods during water deprivation test = assesses kidney function

• Meds = desmopressin (DDAVP), hydrochlorothiazide (microzide) + chlorpropamide

Describe syndrome of inappropriate antidiuretic hormone (SIADH)

Excessive secretion of ADH → water retention, electrolyte imbalance, dec serum sodium

What are the s/s of SIADH?

• N/v, seizures, headache, muscle cramps, weakness

• Weight gain w/ no external visible edema

• Personality changes = irritability, combativeness, confusion, drowsiness, hallucinations, stupor, coma

• ↑ BP, ↓ urine output

• Fluid & electrolyte imbalance (as sodium levels decrease → lethargy, confused)

What is the management for SIADH?

• I&O, fluid restrictions (give certain meds w/ meals), irrigate oral tubes w/ normal saline

• Nutrition status (high in sodium and protein)

• Assess LOC, seizure precautions

• Evaluate for fluid retention = edema in dependent areas, lungs to detect overhydration, skin turgor

• Discharge instructions = daily weights, avoid excessive fluid intake (“hidden” fluids in food), urine output

Describe diabetes insipidus vs SIADH

• Diabetes insipidus

  • High and dry

  • Inc urination

  • Hypernatremia

  • Dec urine osmolality

  • Dehydration, thirst

• SIADH

  • Low and wet

  • Dec urination

  • Hyponatremia

  • Inc urine osmolality

  • Fluid retention, weight gain, inc BP

What are the different thyroid disorders?

• Hypothyroidism

• Hyperthyroidism

Describe hypothyroidism

• Congenital or acquired

• Thyroid gland is underactive & secretes too little thyroid hormone for body to function normally

• If untreated → goiter (enlargement of thyroid gland)

• Risk factors = downs, maternal hypothyroidism

What are the s/s of hypothyroidism in infants?

• Prolonged jaundice

• Constipation

• Lethargy

• Hypotonia

• Macroglossia (large tongue)

• Umbilical hernia

What are the s/s of hypothyroidism as child grows/matures?

• Severe mental retardation

• Short stature, delayed milestones, delayed dentition

• Weight gain, hypotonia

• Puffy face, brittle hair, mottled skin

• Protruding abdomen, umbilical hernia

What are the s/s of hypothyroidism in older children?

• Bradycardia

• Fatigue

• Hypothermia

• Facial puffiness

• Heavy or irregular menstrual cycles

• Constipation

How do we diagnose hypothyroidism?

• Cord blood, heel-stick = TSH values

• Serum sample = ↓ T4 & ↑ TSH

• Thyroid gland scan = cause of congenital hypothyroidism

How do we manage hypothyroidism?

• Thyroid hormone replacement therapy = levothyroxine sodium (synthroid) + iodine supplementation

• Discharge = med compliance, monitor child’s growth, weight gain, & developmental milestone progression, follow-up T4 & TSH labs

• Monitor = growth @ regular intervals, thyroid levels, signs of hypo- or hyperfunction (changes in vital signs, thermoregulation, & activity level)

Describe hyperthyroidism

• Hyperfunction of thyroid gland → excessive levels of circulating thyroid hormones

• Grave’s disease = most common cause of hyperthyroidism

  • Autoimmune disorder that causes excessive amount of thyroid hormone to be released in response to human thyroid stimulator immunoglobulin

• Diagnosis: ↑ T3 and T4, ↓ TSH

What are the s/s of hyperthyroidism?

• Goiter (causes dysphagia)

• Raised, thickened skin over shins, back of feet, back, hands, or face

• Swollen, reddened, bulging eyes (exophthalmos)

• Sudden onset of severe restlessness & irritability, fever, diaphoresis, severe tachycardia (signs of thyroid storm) → REPORT

What is the management for hyperthyroidism?

• ↓ thyroid hormone levels:

  • Antithyroid meds

  • Radioactive iodine therapy

  • Subtotal thyroidectomy

  • Beta-blocking agents (inderal) = to relieve tachycardia, restlessness, tremors

• Discharge = follow treatment regimens, routine blood tests, promote low-stress & pressure environment

What is the difference btw hypo and hyperthyroidism?

• Hypothyroidism

  • Fatigue

  • Constipation

  • Cold intolerance

  • Weight gain

  • Dry, thick skin, edema of face, eyes and hands

• Hyperthyroidism

  • Anxiety

  • Diarrhea

  • Heat intolerance

  • Weight loss

  • Smooth, velvety skin

What are the different adrenal gland disorders?

• Congenital adrenal hyperplasia

• Cushing syndrome

• Addison disease

Describe congenital adrenal hyperplasia

• Group of autosomal recessive inherited disorders → inability to produce cortisol & aldosterone

• Excessive amount of corticosteroid-releasing hormone secreted from hypothalamus + adrenocorticotropic hormone (ACTH) from anterior pituitary

  • Overproduction of ACTH → overexcretion of androgens

What are the s/s of congenital adrenal hyperplasia?

• Cortisol deficiency = failure to thrive, weight loss, weakness, N&V, poor appetite, hypoglycemia, cool, clammy skin, dizziness, confusion

• Aldosterone deficiency = vomiting, poor feeding, lethargy, dehydration, skin hyperpigmentation, fatigue

How do we manage congenital adrenal hyperplasia?

• Stop excessive adrenal secretions of androgens & monitor for acute adrenal crisis

  • Adrenal crisis in newborn = vomiting, lethargy, feeding difficulties

• Meds = replacement glucocorticoids: mineralocorticoid, hydrocortisone

• Steroids in injectable form (solu-cortef, decadron) → EMERGENCY SITUATIONS

• Discharge = lifelong treatment, proper admin, take child to ER (if med cannot be given), alert bracelet

Describe cushing syndrome

• Result of extended exposure to high levels of cortisone

• Causes = adrenal tumor or prolonged steroid therapy

What are the s/s of cushing syndrome?

• Weight gain (pendulous abdomen)

• Moon face & facial flushing

• Buffalo hump (fat pad between shoulders)

• Purple striae

• Muscle wasting & fatigue

• Fragile skin (easy bruising, poor healing)

• Mood changes (depression, psychosis)

• Irregular periods / erectile dysfunction

How do we manage cushing’s syndrome?

• Meds = steroid therapies (@ lowest possible level), cortisol production inhibitors, radiation therapy

• Surgical intervention if tumors present

• Discharge = med admin, inform that cushing-like appearance will dec, signs of adrenal insufficiency, med alert bracelet

Describe addison disease

• Deficiency in adrenal steroids, glucocorticoids (cortisol), mineralocorticoids (aldosterone)

• Causes: destruction of adrenal glands by immune system, hemorrhage, surgical removal, dysfunction of hypothalamus/pituitary gland

• S/s:

  • Hypo-natremia, glycemia, tension

  • Hyperkalemia and hyperpigmentation

  • Water loss

  • Adrenal crisis

Describe polycystic ovary syndrome (PCOS)

• Ovarian androgen excess

• Complications: infertility, insulin resistance, DM, CVD

• Management:

  • Oral contraceptives = normalizes hormone levels

  • Oral insulin sensitizing drugs = metformin

What are the different types of diabetes?

• Type 1

• Type 2

• Diabetic ketoacidosis

  • Secondary to certain conditions (CF, cushing syndrome, genetic = down syndrome)

• Gestational diabetes

Describe diabetes type 1

• Autoimmune disease that arises when child w/ particular genetic makeup is exposed to precipitating event (infection, virus, diet)

• S/S: Polyuria, polydipsia, polyphagia

• Management:

  • Insulin replacement therapy = given daily

  • Subq injections or portable insulin pump

Describe diabetes type 2

• Body’s resistance to recognizing and utilizing insulin

• “Adult onset,” ↑ in young people

• Risk factors = family hx of type 2 in 1st/2nd degree relative, race/ ethnicity (Native American, African, Latino, Asian, Pacific Islander), GDM

• Management: diet and inc activity, oral hypoglycemic meds

What is the s/s of diabetes type 2?

• Asymptomatic until routine exam reveals ↑ BG or complications

• Numbness or burning sensation of the feet, ankles, and legs

• Blurred or poor vision

• Impotence, Fatigue, Headache, sleep apnea

• Poor wound healing

• Obesity, Unexplained weight loss

What is the diagnosis criteria for diabetes?

• Fasting bg >126 mg/dl

• Random bg > 200mg/dl

• Hba1c > 6.5%

Describe diabetic ketoacidosis (DKA)

• Complex combination of hyperglycemia, ketosis, & acidosis from severely deficient insulin in type 1 or 2

• Abnormal metabolism of carbs, protein, & fat → high glucose levels → DKA

• Leading cause of death in children with type 1 DM

What are s/s of DKA?

• N/v, abdominal pain

• Lethargy, confusion, altered LOC

• Kussmaul respirations (deep, labored breathing)

• Fruity smelling breath

• Signs of dehydration (↓ skin turgor, dry mucosa)

• Polyuria, polydipsia

• Ketones in urine & blood

• Untreated = coma & death

What is the criteria to diagnose DKA?

• BG > 250 mg/dL, ketonuria, or ketonemia with serum bicarbonate level < 18 mEq/L

• Blood pH < 7.34 (indicates acidosis)

What is the management for DKA?

• Restore fluid volume

• Return child to glucose-utilization state by inhibiting lipolysis

• Replace body electrolytes

• Correct acidosis, restore acid-base balance

Describe down’s syndrome or trisomy 21

• Individuals that have three copies of chromosome 21 = genetic condition

• Characteristics:

  • Some degree of intellectual disability

  • Specific facial features

  • Associated with other health problems = cardiac defects, visual and hearing impairment, intestinal malformations, and increased susceptibility to infections

What lab and diagnostic tests should be done for those with down syndrome?

• Genetic testing (pre- and postnatal)

• Echocardiogram: to detect cardiac defects

• Sleep apnea testing

• Vision and hearing screening: to detect vision and hearing impairments

• Thyroid hormone level: to detect thyroid disease

• Cervical radiographs: to assess for atlantoaxial instability (too much mobility in the neck causing spinal cord compression)

• Ultrasound: to assess for structural malformations