26 results
Causes of Polyuria - Differential Diagnosis
Excess Intake of Water:
 • Primary polydipsia (a.k.a. "psychogenic polydipsia")
 •
- Differential Diagnosis ... Solute (a.k.a. osmotic ... diuresis): • ... • Central Dl (Low ... #Causes #nephrology
Hypernatremia - Differential Diagnosis Workup Algorithm

1) Check Urine Osmolality:
 > 600 mOsm/kg - Implies extrarenal mechanism
- Differential Diagnosis ... Workup Algorithm ... • Euvolemic (Low ... , osmotic (solute ... #nephrology #sodium
Causes of Hypernatremia - Differential Diagnosis Algorithm
Hypernatremia - Excess free water loss, Serum Sodium >145 mmol/L
High
- Differential Diagnosis ... administration • Osmotic ... diuresis (see Polyuria ... mannitol, glucosuria Low ... Hypernatremia #Nephrology
Causes of Hypernatremia - Differential Diagnosis
Inadequate water intake:
 • Lack of access to water
Extrarenal hypotonic fluid
- Differential Diagnosis ... concentrating defect: • Diuretics ... • Osmotic diuresis ... #Differential #Diagnosis ... #Causes #nephrology
Hypernatremia Classification and Features According to Volume Status
 - Hypervolemic hypernatremia - Cushing's syndrome, Primary hyperaldosteronism,
hypernatremia - Osmotic ... diuretic, Loop ... diuresis - Extrarenal ... Classification #Features #Diagnosis ... Comparison #Table #Nephrology
Causes of Polyuria - Differential Diagnosis Algorithm
Polyuria - Urine Output > 3L/day, Increased Urine Volume (>2ml/min)
Osmotic
- Differential Diagnosis ... Volume (>2ml/min) Osmotic ... Diuresis Urine ... #Nephrology #Differential ... #Diagnosis #Algorithm
Hypomagnesemia - Etiologies by Mechanism

Decreased GI Uptake 
 - Poor dietary intake (particularly common in alcoholics)
Hypokalemia - Osmotic ... diuresis - ... #Differential #Diagnosis ... #Low #Magnesium ... Classification #Causes #Workup
Workup for Hypophosphatemia - Differential Diagnosis Framework
Rule out spurious hypophosphatemia: paraproteinemia, acute leukemia
Measure Urine Fractional Excretion
Workup for Hypophosphatemia ... - Differential Diagnosis ... syndrome, CA Inh., Osmotic ... diuresis Dr. ... #phosphate #nephrology
Polyuria - Differential Diagnosis Algorithm
Polyuria = >3L Urine output / 24 hours
Urine osmolality = 2 (Na
Diagnosis Algorithm ... mosm/kg • Solute Diuresis ... nutrition), Azotemia LOW ... #Differential #Diagnosis ... #Algorithm #nephrology
Causes of Hypokalemia
Transcellular Shifts:
 - Alkalosis, Increased plasma insulin (treatment of diabetic ketoacidosis), ß-Adrenergic agonists, Hypokalemic
plasma insulin (treatment ... thiazide-like diuretics ... , Osmotic diuresis ... #differential #diagnosis ... #nephrology