Endocrine

Hypoglycemia

Acute Condition

• AACN Definition: Blood glucose levels less than 50 mg/dL.
• Beta Blockers: Can mask early cardiac symptoms; monitor for changes in consciousness.
• Symptoms Progression:
  • Early: Cardiovascular signs.
  • Late: Central nervous system involvement.
• Symptoms: Rapid heart rate, palpitations, sweating, blurred vision, altered mental status, seizures, or coma.
• Treatment: Administer glucose—typically D50% (25g IV).

Osmolality

Definition: A measure of solute concentration (serum or urine), expressed as solute particles per kilogram.

• Normal Range: 275–295 mOsm/kg.
• Hypo-osmolarity: Less than 275 mOsm/kg.
• Hyper-osmolarity: Greater than 295 mOsm/kg.
• Factors Influencing Serum Osmolality: Changes in sodium, blood urea nitrogen (BUN), and glucose levels.

Diabetic Ketoacidosis (DKA)

Key Characteristics:

• Occurs more frequently in younger individuals, particularly those with type 1 diabetes.
• Primary Cause: Infection is the most common trigger.
• Metabolic Changes:
  • Decreased insulin levels and elevated blood sugar.
  • Increased production of ketones.
  • Serum osmolality may be normal or elevated.
  • Increased anion gap and BUN.
  • Serum potassium may appear normal or elevated, but total body potassium is depleted.
  • No insulin production.
  • Blood sugar exceeds 250 mg/dL.

Onset: Rapid development, typically within 1–2 days.

Fluid Loss: Estimated at 4–6L, often requiring 8–10L of fluid replacement within 24 hours.

Symptoms: Kussmaul respirations—deep and labored breathing.

Treatment: Administer insulin, followed by aggressive fluid replacement therapy.

Hyperglycemic Hyperosmolar Syndrome (HHS)

Common Demographic: Typically occurs in older adults with type 2 diabetes.

• Key Features:
  • No ketone production or acidosis.
  • Markedly elevated blood sugar levels (>600 mg/dL).
  • Increased urine output, high serum osmolality (>350), elevated BUN, and potassium levels.
  • Some insulin is still produced.

Progression: Develops gradually over weeks.

Fluid Loss: Estimated at 6–9L; usually requires replacement exceeding 10L within 24 hours.

Symptoms:

• Rapid, shallow breathing.
• Severe low blood pressure.

Treatment: Start with fluid replacement, followed by insulin therapy.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)

Overview: Excessive water retention due to increased ADH levels.

Causes:

• Viral pneumonia.
• Cancers (lung, pancreas, thymus, prostate, lymphatic).
• Neurological issues (head trauma, tumors, surgery).

Symptoms:

• Concentrated urine with low output.
• Decreased serum sodium.

Treatment:

• Phenytoin to inhibit ADH secretion.
• Fluid restriction.
• Diuretics.
• Sodium replacement (done gradually).

Diabetes Insipidus (DI)

Overview: Excessive water loss due to reduced ADH levels.

Causes:

• Medications: Can be triggered by phenytoin.
• Neurological Issues: Head trauma, hypoxia, tumors.
• Kidney-Related: Renal failure or decreased osmotic pressure.

Symptoms:

• Diluted urine.
• Elevated serum sodium.

Complications:

• Hypovolemia due to excessive urination (6–24L/day).
• Hypovolemic shock and low blood pressure.

Treatment:

• Vasopressin (synthetic ADH).
• Thiazide diuretics.