114 results
Polyuria - Differential Diagnosis Algorithm
Urine Output > 3L /day
Water Diuresis (Urine Osm <100 mOsm/kg)
 • Primary
<100 mOsm/kg) ... Central Diabetes Insipidus ... Nephrogenic Diabetes Insipidus ... 100-200 mOsm/kg ... Diagnosis #Algorithm #causes
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 ... differential #algorithm #causes
Central vs Nephrogenic Diabetes Insipidus - Desmopressin Challenge
Give desmopressin (intranasal, SQ, IV) and monitor UOsm every
Nephrogenic Diabetes Insipidus ... IV) and monitor UOsm ... • No Rise in UOsm ... < 45% rise in UOsm ... Nephrogenic #Diabetes #Insipidus
Causes of Polyuria - Differential Diagnosis Algorithm
Polyuria - Urine Output > 3L/day, Increased Urine Volume (>2ml/min)
Osmotic
Causes of Polyuria ... Loss - DDAVP -> Uosm ... Central Diabetes Insipidus ... - DDAVP -> Uosm ... Diagnosis #Algorithm #Causes
Hypernatremia Differential Diagnosis Algorithm - Diabetes Insipidus Workup

Step #1 - Consider the history
Step #2 - Assess
Algorithm - Diabetes Insipidus ... #2 - Assess the Uosm ... Sodium #nephrology #insipidus
Diabetes Insipidus vs Syndrome of Inappropriate ADH (SIADH) - Comparison Table

Diabetes Insipidus - Inadequate ADH
SIADH -
Diabetes Insipidus ... Table Diabetes Insipidus ... #Diabetes #Insipidus ... Symptoms #Diagnosis #Endocrinology
Urine chemistry tests for the diagnostic evaluation of a patient with polyuria
UOsm <100 mOsm/Kg (H2O diuresis)
with polyuria UOsm ... polydipsia • Diabetes insipidus ... 2 × (Na + K) = UOsm ... × (Na + K) << UOsm ... diagnosis #nephrology #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 ... considered likely, the cause
Causes of Hypernatremia - Differential Diagnosis
Inadequate water intake:
 • Lack of access to water
Extrarenal hypotonic fluid
Causes of Hypernatremia ... Central diabetes insipidus ... Nephrogenic diabetes insipidus ... Differential #Diagnosis #Causes
Polyuria - Differential Diagnosis Algorithm
Polyuria = >3L Urine output / 24 hours
Urine osmolality = 2 (Na
osmolality > 300 mosm ... osmolality < 100 mosm ... kg • Diabetes Insipidus