14 results
Volume Based Approach to Hyponatremia
Hypovolemic, Serum uric acid >4
 • Urine Na <20: Extra-renal losses
 •
Renal losses, Cerebral ... uric acid <4 • SIADH ... deficiency, Primary polydipsia ... #algorithm #diagnosis ... #sodium #low #nephrology
Modified Hyponatremia Algorithm
Hypertonic Hyponatremia: Hyperglycemia, Mannitol, Urologic irrigants
Hypotonic Hyponatremia: 
 • ADH ON (UOsm > 100):
Algorithm Hypertonic ... OFF (UNa > 30): SIADH ... Reset osmostat, Cerebral ... 100): Primary polydipsia ... #sodium #nephrology
Cerebral Salt Wasting vs SIADH - Pathophysiology 
1) Neurological event
2) Sodium loss from tubules
3) Naturiesis →
Cerebral Salt Wasting ... Neurological event 2) Sodium ... → Increased urine ... Pathophysiology #diagnosis #nephrology ... #hyponatremia #
Hyponatremia Differential Diagnosis Algorithm - Utilizing Uric Acid 
ADH promotes Urea/uric acid excretion along with water
Hyponatremia Differential ... Diagnosis Algorithm ... Sodium 4) Serum ... Low Uric Acid → SIADH ... #nephrology #sodium
Physiologic Approach to Hypotonic Hyponatremia
The next time you have a case of hypotonic hyponatremia, give the
normal volume-based algorithm ... Urine Na+K / serum ... Insufficiency, Cerebral ... intake (Primary polydipsia ... #nephrology
Hypernatremia Diagnosis and Workup

Step 1 . Repeat the sodium concentration.
Step 2.  Check plasma osmolality.
NORMAL PLASMA
Repeat the sodium ... EUVOLEMIC • SIADH ... • psychogenic polydipsia ... Diagnosis #Workup #Algorithm ... #Nephrology
Hyponatremia - Differential Diagnosis Algorithm
Hypovolemic - Give volume
Hypervolemic (Edematous) - Look for and treat underlying cause
Diagnosis Algorithm ... - Primary Polydipsia ... , SSRIs) - SIADH ... #diagnosis #nephrology ... #sodium
Primary Polydipsia
Definition: Excessive volitional water intake
Epidemiology:
 • 6-20% of patients with psychiatric disorders - Most commonly
hypothalamic thirst center ... Pseudohyponatremia, SIADH ... Osm, Serum Sodium ... , Urine Sodium ... diagnosis #management #nephrology
A lazy man's classification of hyponatremia
There are two possible approaches to the diagnosis of hyponatremia: .
serum osmolality, urine ... osmolality and urinary sodium ... the patient has SIADH ... or cerebral salt ... #Algorithm #Differential
Hyponatremia - Differential Algorithm
Isotonic Hyponatremia: Hyperlipidemia, Hyperproteinemia, Recent TURP
Hypotonic Hyponatremia: 
 • Hypovolemia: Diuretics/Nephropathies, Vomiting, Diarrhea,
Algorithm Isotonic ... • Euvolemia: SIADH ... Potomania, Psychogenic polydipsia ... diagnosis #causes #nephrology ... #sodium #low