Endocrine and Electrolyte Imbalances Notes

Summary:

This Endocrine and Electrolyte Imbalances note discusses the endocrine system, including its organs and glands, hormones, negative feedback mechanisms, and various disorders such as Sheehan syndrome, hypersecretion and hyposecretion disorders, and pituitary tumors. It also covers electrolyte imbalances like hypernatremia and hyponatremia and their causes and treatments. This Endocrine and Electrolyte Imbalances note further provides information on several endocrine disorders, including Cushing’s syndrome, hyperaldosteronism, pheochromocytoma, congenital adrenal hyperplasia, adrenal tumors, calcium disorders, and thyroid disorders such as Graves’ disease and toxic multinodular goiter. Diagnostic and treatment options for each disorder are also discussed.

Excerpt:

Endocrine and Electrolyte Imbalances

PROLACTINOMA

• HYPERPROLACTINEMIA
• Non-cancerous pituitary tumor (the most common)
• The causes:

• Pituitary adenoma (micro/macro)
• Pituitary stalk damage (Craniopharyngioma, Meningioma), Infiltration—Sarcoidosis
  (multisystem granulomatous disorder), Pituitary stalk-section (Head Injury, Surgery)
• Drugs—first-gen antipsychotics, antidepressants, Metoclopramide, Cimetidine, Estrogen,
  Opiates, Marijuana
• Physiological—pregnancy, breastfeeding

• Sx: reduced libido, amenorrhea, galactorrhea, erectile dysfunction, gynecomastia, osteopenia, bitemporal hemianopsia, etc

**Prolactin is antagonistic with estrogen and testosterone

**Estrogen (OCP) can increase Prolactin levels

• Diagnostic: (1)Prolactin: <5,000: other causes, >5,000: prolactinoma, (2) BEST: MRI

• Tx: (1) Dopamine agonist (Cabergoline, Bromocriptine), refer to Endo, (2) Surgery (Transsphenoidal resection)

GROWTH HORMONE-PRODUCING TUMORS
• ACROMEGALY
o Most common cause: Pituitary Adenoma
o Hypersecretion of GH
o “Gigantism” in children
o MCC of death: Hypertrophic Cardiomyopathy with CHF
o Sx: Frontal bossing, spade-like hands, thick greasy skin, thickened palms, increased shoe size, heteronymous hemianopsia
o Complications: Diabetes Mellitus,  Colon Cancer Risk, Sleep Apnoea, Carpal Tunnel Syndrome, Osteoarthritis, Hypertension
o Diagnostics: (1) GH measurement after OGTT (glucose suppresses GH levels; if GH not suppressed by glucose→acromegaly diagnosis) **measurement of baseline GH is not adequate since some px may have normal baseline GH; (2) IGF-1—anabolic,  bone and tissue growth; (3) Pituitary MRI
o Tx: Pituitary microsurgery (Transsphenoidal resection), Radiation, Bromocriptine (dopamine agonist; if prolactin co-secretion), Octreotide (Somatostatin analog)