15 results
Hypernatremia Diagnosis and Workup

Step 1 . Repeat the sodium concentration.
Step 2.  Check plasma osmolality.
NORMAL PLASMA
Repeat the sodium ... EUVOLEMIC • SIADH ... • psychogenic polydipsia ... HYPERVOLEMIC • CHF ... #Algorithm #Nephrology
Volume Based Approach to Hyponatremia
Hypovolemic, Serum uric acid >4
 • Urine Na <20: Extra-renal losses
 •
to Hyponatremia ... uric acid <4 • SIADH ... deficiency, Primary polydipsia ... algorithm #diagnosis ... #sodium #low #nephrology
Hyponatremia Treatment Algorithm

CHF, Cirrhosis - Fluid restriction
SIADH - Fluid restriction
 - Consider salt tablets if etiology
Hyponatremia Treatment ... Algorithm CHF ... Fluid restriction SIADH ... diuresis) 1° polydipsia ... #Treatment #Algorithm
Hyponatremia - Differential Diagnosis Algorithm
Hypovolemic - Give volume
Hypervolemic (Edematous) - Look for and treat underlying cause
Hypovolemic - Give volume ... underlying cause (CHF ... - Primary Polydipsia ... , SSRIs) - SIADH ... diagnosis #nephrology #sodium
Physiologic Approach to Hypotonic Hyponatremia
The next time you have a case of hypotonic hyponatremia, give the
than the normal volume-based ... algorithm Urine ... poor response to volume ... , Renal Sodium loss ... intake (Primary polydipsia
Modified Hyponatremia Algorithm
Hypertonic Hyponatremia: Hyperglycemia, Mannitol, Urologic irrigants
Hypotonic Hyponatremia: 
 • ADH ON (UOsm > 100):
Algorithm Hypertonic ... OFF (UNa > 30): SIADH ... 100): Primary polydipsia ... , Low solute intake ... #sodium #nephrology
Hyponatremia - Diagnostic Evaluation Algorithm

Step 1: Consider whether Posm may actually be normal or elevated
Step 2:
Evaluation Algorithm ... Check Uosm and/or Urine ... Step 3: Assess volume ... tests Step 5: If SIADH ... #Diagnosis #Workup
Hypernatremia - Differential Diagnosis Workup Algorithm

1) Check Urine Osmolality:
 > 600 mOsm/kg - Implies extrarenal mechanism
Differential Diagnosis Workup ... Algorithm 1) ... Check Urine Osmolality ... mechanism 2) Volume ... #sodium
Primary Polydipsia
Definition: Excessive volitional water intake
Epidemiology:
 • 6-20% of patients with psychiatric disorders - Most commonly
hypothalamic thirst center ... Pseudohyponatremia, SIADH ... intoxication Initial Workup ... Osm, Serum Sodium ... , Urine Sodium
Hyponatremia - Differential Algorithm
Isotonic Hyponatremia: Hyperlipidemia, Hyperproteinemia, Recent TURP
Hypotonic Hyponatremia: 
 • Hypovolemia: Diuretics/Nephropathies, Vomiting, Diarrhea,
Algorithm Isotonic ... • Euvolemia: SIADH ... Potomania, Psychogenic polydipsia ... Alcohol MH/CCF ... causes #nephrology #sodium