Hyponatremia resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Definition
Causes
Life Threatening Causes
Conditions that may cause death or permanent disability within the next 24 hours
Common Causes
Management
IV V1, V2 antagonistConivaptan, oral V2
receptors
Tolvaptan for resistant cases
| Serum sodium < 135 | |||||||||||||||||||||||||||||||||||||||||||||
| Plasma osmolality | |||||||||||||||||||||||||||||||||||||||||||||
| Hypotonic < 280 | Isotonic/Hypertonic (Pseudohyponatremia) > 280 | ||||||||||||||||||||||||||||||||||||||||||||
| Assess volume status | Osmotically active compounds, glucose, protein, lipid, hypertonic fluid i.e. mannitol, sorbitol | ||||||||||||||||||||||||||||||||||||||||||||
| Hypovolemia | Hypervolemia | Euvolemia | Treat the cause | ||||||||||||||||||||||||||||||||||||||||||
| Spot urine Na < 10, BUN/Creatinine > 20:1, Urine osmolality > 450 | Same as hypovolemia, Spot urine Na < 10, BUN/Creatinine > 20:1, Urine osmolality > 450 | Spot urine Na > 20, BUN/Creatinine < 20:1, Urine osmolality > 300 | |||||||||||||||||||||||||||||||||||||||||||
| GI, Renal losses, Dehydration, Diuretics, Adrenal insufficiency, cerebral salt wasting syndrome | Heart failure Cirrhosis Renal failure | Urine osmolality > 300 | Urine osmolality 50-100 | ||||||||||||||||||||||||||||||||||||||||||
| (a) Normal saline; (b) If neurological sign/symptoms 3% hypertonic saline, and furosemide | Treat the etiology | SIADH, Hypothyroidism | Compulsive water drinking | ||||||||||||||||||||||||||||||||||||||||||
| Fluid restriction Demeclocycline (if fluid restriction fails) | |||||||||||||||||||||||||||||||||||||||||||||