Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Excessive ADH

• Risk Factors (CONDITIONS

• Increased IntraTHORACIC Pressure

• head Injury

• tumors

• Stroke

• Meningitis

• TB

Risk Factors

• Meds

• SSRI’s

• Opioids

• Anesthetics

• Chemotherapy

• Fluroquinolone Abx

Pathophysiology

• Urine

Urine Output- LOW

Specific Gravity- HIGH

Osmolarity- HIGH

Early Clinical Manifestations

• Anorexia

• Nausea

• Malaise

Progression of Clinical Manifestations

• Headache

• Irritability

• Confusion

• Weakness

• Muscle Cramps

Weigh Gain, Oliguria, DECREASED Serum Sodium

Diagnostics

• Urine Chemistry

Volume- LOW

• Osmolarity HIGH

• Specific Gravity HIGH

• Sodium HIGH

• Potassium HIGH

Diagnostics

• Serum Chemistry

Sodium LOW

Osmolarity LOW

Goals of Tx

ID Cause

Restrict Fluid Volume

Restore normal osmolarity and Electrolytes (HypoNatremia)

Reduce Cerebral Edema

Management

• Fluid Balance

• Fluid Restriction: Less than 1000ml/day

• Severe Hyponatremia

  • HYPERtonic fluids (3% Sodium Chloride)

• Diuretics given carefully to increase Urine Output

Demeclocycline (Declomycin)

may be used to Increase Urine Output

• often used in malignancy when other Tx aren’t effective

• Tetracycline

• 900-1200 mg/day

• Delayed Onset (Days -2 weeks)

Lithium

Blocks renal response to ADH

• less effective than Demeclocycline

• 600-1800 mg/day

• Toxic Side Efffects

• Drug/Drug interactions

Vasopressin Antagonist

(Tolvaptan, Convaptan)

• Promotes water excretion WITHOUT Sodium Loss

• Does Rapidly increase Sodium Levels

• Beneficial for SIADH + HF

Furosemide

Increases Water Excretion from kidneys

• can cause sodium excretion

• MONITOR S/S Hyponatremia and REPORT TO DR

  • N/V

  • Anorexia

Complications

Hyponatremia

• Seizures and Coma

• Increased Intracranial pressure

Water Intoxication

Cerebral Edema

Pulmonary Edema

Monitor

HTN, tachycardia, hypothermia

Pulmonary Edema and HF

Interventions

• Fluid Restriction, Daily Weight, I&O

• Admin 3% saline via Central Line

• Demeclocycline

• REPORT AMS

• Seizure Precautions