The Child with Endocrine Dysfunction

ENDOCRINE SYSTEM

  • Functionality: Controls and regulates metabolism.

  • Distribution of Endocrine Glands:
      - Hypothalamus
      - Pineal gland
      - Pituitary gland
      - Thyroid gland
      - Parathyroid glands
      - Thymus
      - Adrenal glands
      - Pancreas
      - Ovaries
      - Testes

  • Connection to Other Systems:
      - The hypothalamus is the link between the autonomic nervous system (ANS) and the endocrine system.

  • System Components:
      - Sender Cells: Cells that send chemical messages using hormones.
      - Target Cells/Organs: Organs that receive chemical messages (e.g., liver, kidneys, thyroid, gonads).
      - Transport Medium: The environment through which chemicals are transported from the site of synthesis to the site of cellular action.
      - Hormone Definition: A chemical substance that exerts a physiologic controlling effect on other cells.
      - Feedback Control: Mechanisms of hormone production and secretion can be either positive or negative.

ENDOCRINE SYSTEM OVERVIEW

  • Hormones from Anterior Pituitary:
      - Growth hormone (GH)
      - Adrenocorticotropic hormone (ACTH)
      - Thyroid-stimulating hormone (TSH)
      - Gonadotropic hormones (FSH and LH)
      - Prolactin (PRL)
      - Melanocyte-stimulating hormone (MSH)

  • Target Organs:
      - Mammary glands, adrenal cortex, thyroid, gonads, skin, kidneys, uterus.

PITUITARY GLAND

  • Overview: Responsible for regulating many other glands; consists of two lobes with unique functions:
      - Anterior Lobe (Adenohypophysis):
        - Known as the "master gland"; regulated by hypothalamic hormones.
      - Posterior Lobe (Neurohypophysis):
        - Different hormones are secreted compared to the anterior lobe.

HORMONES AND FUNCTIONS

Anterior Pituitary Hormones

  • Thyrotropin (TSH): Stimulates thyroid gland.

  • Growth Hormone (GH): Increases blood glucose levels and promotes overall growth.

  • Corticotropin (ACTH): Promotes secretion from adrenal cortex.

  • Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH): Affect gonadal function.

  • Prolactin (PRL): Stimulates mammary gland function.

Posterior Pituitary Hormones

  • Oxytocin:
      - Functions: Uterine contractions, milk letdown, orgasm facilitation, social recognition:
      - Dysfunction results in issues like benign prostatic hyperplasia in males and absence of milk letdown in females.

  • Vasopressin (ADH):
      - Functions: Water conservation, electrolyte balance, blood vessel constriction; dysfunction can lead to Diabetes Insipidus.
      - Dysfunction Details: Under secretion results in excessive urination and thirst.

KEY POINTS OF ENDOCRINE SYSTEM

  • Immature at birth; hormonal secretion varies throughout the day.

  • Regulates activity of cells and organs for growth and metabolism.

  • Maintains homeostasis via connections between ANS and the pituitary gland.

  • Feedback mechanisms regulate the system (positive and negative).

  • Diagnosis often requires laboratory tests and imaging.

PRECOCIOUS PUBERTY

  • Definition: Early sexual development marked by the appearance of secondary sex characteristics.

  • Boys: Before age 9; Girls: Before age 8 (90% idiopathic).

  • Consequences: Accelerated bone growth and early fusion of growth plates, potentially leading to reduced adult height.

  • Therapeutic Management:
      - Objective: Preserve adult health and reverse premature secondary sex characteristics.
      - Treatment includes monthly synthetic LHRH (subcutaneous).
      - Considerations include risk of sexual abuse, teasing, and family support.

DIABETES INSIPIDUS

  • Description: Principal disorder of the posterior pituitary; arises from dysfunction or under secretion of ADH.

  • Types: Nephrogenic vs. central DI.

  • Symptoms: Polyuria and polydipsia (insatiable thirst, excessive urination).

  • Diagnostic Evaluation: Water deprivation test (monitor dehydration).

  • Management:
      - DDAVP (synthetic vasopressin, intranasal), monitor for dilutional hyponatremia.
      - Fluid restriction aimed at balancing fluids.
      - Nursing Management: Family education and monitoring urine specific gravity.

SYNDROME OF INAPPROPRIATE ANTIDIURETIC HORMONE SECRETION (SIADH)

  • Resulting from hypersecretion of ADH, leading to inability to excrete free water.

  • Etiology includes infection, hydrocephalus, or brain tumors.

  • Symptoms: Fluid retention, hypotonicity, possibly stupor and seizures.

  • Diagnostic Criteria: Low urine output, Na < 135mmol/L, high urine specific gravity.

  • Management: Correcting the underlying cause, achieving fluid balance, and careful hyponatremia correction.
      - Important monitoring including weight, neurological checks, and Na levels.

DIABETES INSIPIDUS vs SIADH

Diabetes Insipidus (High and Dry)

  • Symptoms Include: Increased urination (polyuria), nocturia, increased thirst (polydipsia), hypernatremia, low urine specific gravity < 1.005, elevated serum osmolality > 300 mOsm/kg.

SIADH (Low and Wet)

  • Symptoms Include: Decreased urination, excessive thirst, fluid retention, hypertension, hyponatremia < 125 mEq/L, high urine specific gravity > 1.030, decreased serum osmolality < 280 mOsm/kg.

GROWTH HORMONE DEFICIENCY

  • Description: Insufficient production or secretion of GH, leading to poor growth and short stature.

  • Causes: Isolated or could be secondary to brain tumors or congenital issues.

  • Management: Growth hormone replacement, preferably administered at night via injection. Family education about the disorder and GH administration is essential.

DIAGNOSTICS FOR ENDOCRINE FUNCTION

  • Laboratory Tests: Serum hormone levels and stimulation tests.

  • Bone Age Scan: X-ray of the left wrist; indicators of ossified bones help assess delay or precocious ossification.

THYROID FUNCTION

  • Functions: Regulates basal metabolic rate (BMR), growth, tissue differentiation.

  • Hormone Types Produced:
      - Thyroxine (T4)
      - Triiodothyronine (T3)
      - Calcitonin

HYPOTHYROIDISM vs HYPERTHYROIDISM

Hypothyroidism Symptoms:

  • Dry hair, hair loss, cold intolerance, weight gain, slow heartbeat, goiter, constipation.

  • Clinical consequences may include infertility and risks of miscarriage.

Hyperthyroidism Symptoms:

  • Bulging eyes, puffy face, heat intolerance, rapid heartbeat, weight loss, diarrhea.

  • Clinical consequences may include irregular menstrual cycles.

JUVENILE HYPOTHYROIDISM

  • Types: Congenital (screened at birth) and acquired.

  • Symptoms: Puffiness, constipation, lethargy, and poor feeding in infants.

  • Management: Skin care, administration of thyroxine therapy (e.g., Synthroid), use of stool softeners for constipation.

LYMPHOCYTIC THYROIDITIS (Hashimoto's Disease)

  • Most common thyroiditis in children and adolescents.

  • Symptoms: Signs of hypothyroidism; treatment revolves around management of symptoms.

HYPERTHYROIDISM (Graves Disease)

  • Clinical manifestations include exophthalmos and thyroid storms; requires careful therapeutic management:
      - Medications: Antithyroid drugs (e.g., Tapazole) with monitoring for infection risks.
      - Possible surgical interventions (subtotal thyroidectomy or radioiodine ablation).

GOITER

  • Description: Hypertrophy/enlargement of the thyroid gland.

  • Types: Congenital and acquired.

  • Symptoms: Enlarged thyroid gland; management involves symptom alleviation and normalization of thyroid levels.

THYROTOXICOSIS

  • Definition: Crisis state caused by sudden hormone release; can be life-threatening.

  • Management: Antithyroid drugs, beta-blockers; nursing focus on maintaining homeostasis and monitoring vitals.

HYPERPARATHYROIDISM

  • Causes: Primary or secondary (e.g., renal disease).

  • Management strategies will vary based on etiology; nursing focus on patient care and education.

DISORDERS OF ADRENAL FUNCTION

  • Include: Acute adrenal insufficiency, Addison Disease, Cushing syndrome, congenital adrenal hyperplasia, pheochromocytoma.

ADDISON DISEASE (Primary Adrenal Insufficiency)

  • Rare in children; symptoms include hyperkalemia and hyponatremia.

  • Management: Replacement of glucocorticoids and mineralocorticoids.

CUSHING SYNDROME

  • Cause: Excess circulating cortisol.

  • Signs: Cushingoid features, hypertension, immunocompromise.

  • Management: Varies based on root causes; encompassing nursing care.

CONGENITAL ADRENAL HYPERPLASIA

  • Cause: Reduced enzyme activity leading to high ACTH levels and virilization symptoms.

  • Management: Glucocorticoids, mineralocorticoids, sodium supplementation, and monitoring during stress.

PHEOCHROMOCYTOMA

  • Rare catecholamine-secreting tumor; diagnosed via imaging (CT, MRI); managed with surgical intervention.

DIABETES MELLITUS (DM)

  • Type 1 DM: Peaks in early childhood/adolescence; destruction of pancreatic beta cells leading to insulin deficiency.
      - Diagnostic criteria: HgA1C > 6.5%, random glucose > 200 mg/dL.

  • Type 2 DM: Related to insulin resistance; incidence rising with obesity.
      - Diagnostic criteria: Elevated glucose > 160 mg/dL (fasting) or > 200 mg/dL (random).

TYPE 1 DM PATHOPHYSIOLOGY:

  • In fasting: Fat/protein mobilization, liver converts fats to ketones.

  • Post-meal: Pancreas secretes insulin for glucose regulation.

DIABETES MELLITUS TYPE 1: DIABETIC KETOACIDOSIS (DKA)

  • Description: Inability to utilize ketones due to insulin deficiency.

  • Manifestations: Hyperglycemia, acidosis, polyuria.

  • Management Protocol: Prioritize hydration, monitor cardiorespiratory status, administer insulin post-rehydration, monitor electrolytes and urine for ketones.

DKA PATHOPHYSIOLOGY:

  • Insulin deficiency leads to impaired metabolism of fats, proteins, and carbohydrates; cellular starvation occurs.

NURSING CLINICAL PEARL:

  • "Cool and clammy, give some candy"—if the diagnosis between hypoglycemia and hyperglycemia is uncertain, treat as hypoglycemia first by administering carbs.

LONG-TERM COMPLICATIONS OF DM:

  • Effects of hyperglycemia on vascular system (retinopathy, nephropathy, neuropathy, cardiovascular disease).

  • Management: Comprehensive approach with insulin therapy, nutrition management, and responsible monitoring.
      - Emphasize importance of continuous education and involvement of a diabetes nurse educator.