31 results
Hyponatremia Diagnosis Algorithm
UOsm ≥ POsm - Vasopressin-Dependent
 • UNa < 20 mEq/L - Appropriate (↓ EABV)
Diagnosis Algorithm UOsm ... ≥ POsm - Vasopressin-Dependent ... Cortisol deficiency UOsm ... < POsm - Vasopressin-independent
Central vs Nephrogenic Diabetes Insipidus - Desmopressin Challenge
Give desmopressin (intranasal, SQ, IV) and monitor UOsm every
IV) and monitor UOsm ... • No Rise in UOsm ... < 45% rise in UOsm ... 15-50% rise in UOsm ... CDI • Rise in UOsm
Urine chemistry tests for the diagnostic evaluation of a patient with polyuria
UOsm <100 mOsm/Kg (H2O diuresis)
with polyuria UOsm ... nephrogenic) UOsm ... 2 × (Na + K) = UOsm ... × (Na + K) << UOsm ... diagnosis #nephrology #Uosm
Physiologic Approach to Hypotonic Hyponatremia
The next time you have a case of hypotonic hyponatremia, give the
• ADH Present (Uosm ... be high or low Uosm ... ADH Not Present (Uosm ... • ADH Present (Uosm ... ADH Not Present (Uosm
Hypernatremia - Diagnostic Evaluation Algorithm
Step 1: Consider history. Most patients presenting with hypernatremia are either very
Step 2: Check Uosm ... using initial Uosm
Pathophysiology Based Approach to Hyponatremia - Diagnostic Algorithm

Not the "classic" Volume based approach. 

#Hyponatremia #Algorithm #Pathophysiology
Differential #Nephrology #UOsm
Modified Hyponatremia Algorithm
Hypertonic Hyponatremia: Hyperglycemia, Mannitol, Urologic irrigants
Hypotonic Hyponatremia: 
 • ADH ON (UOsm > 100):
Hyponatremia: • ADH ON (UOsm ... wasting • ADH OFF (UOsm
Hyponatremia - Differential Diagnosis Algorithm
Hypovolemic - Give volume
Hypervolemic (Edematous) - Look for and treat underlying cause
) Euvolemic • UOsm ... Toast Diet • UOsm
Hyponatremia - Diagnostic Evaluation Algorithm

Step 1: Consider whether Posm may actually be normal or elevated
Step 2:
Consider whether Posm ... Step 2: Check Uosm
Causes of Polyuria - Differential Diagnosis Algorithm
Polyuria - Urine Output > 3L/day, Increased Urine Volume (>2ml/min)
Osmotic
Loss - DDAVP -> Uosm ... Insipidus - DDAVP -> Uosm