28 results
Causes of Polyuria - Differential Diagnosis
Excess Intake of Water:
 • Primary polydipsia (a.k.a. "psychogenic polydipsia")
 •
- Differential ... Diagnosis Excess ... Solute (a.k.a. osmotic ... • Central Dl (Low ... #nephrology
Causes of Hypernatremia - Differential Diagnosis Algorithm
Hypernatremia - Excess free water loss, Serum Sodium >145 mmol/L
High
Diagnosis Algorithm ... administration • Osmotic ... diuresis (see Polyuria ... mannitol, glucosuria Low ... Hypernatremia #Nephrology
Causes of Polyuria - Differential Diagnosis Algorithm
Polyuria - Urine Output > 3L/day, Increased Urine Volume (>2ml/min)
Osmotic
- Differential ... Diagnosis Algorithm ... Volume (>2ml/min) Osmotic ... #Nephrology #Differential ... #Diagnosis #Algorithm
Polyuria - Differential Diagnosis Algorithm
Polyuria = >3L Urine output / 24 hours
Urine osmolality = 2 (Na
Polyuria - Differential ... Diagnosis Algorithm ... nutrition), Azotemia LOW ... #Differential # ... #nephrology
Causes of Hypernatremia - Differential Diagnosis
Inadequate water intake:
 • Lack of access to water
Extrarenal hypotonic fluid
Hypernatremia - Differential ... Diagnosis Inadequate ... Diuretics • Osmotic ... #Diagnosis #Causes ... #nephrology #sodium
Hypokalemia Differential Diagnosis Algorithm

Low intake 
• poor oral intake 

Renal loss 
• Medication 
• Hypomagnesemia 
•
Hypokalemia Differential ... Diagnosis Algorithm ... Low intake ... Hypomagnesemia • Osmotic ... #Diagnosis #Algorithm
Workup for Hypophosphatemia - Differential Diagnosis Framework
Rule out spurious hypophosphatemia: paraproteinemia, acute leukemia
Measure Urine Fractional Excretion
Hypophosphatemia - Differential ... Diagnosis Framework ... • Normal or Low ... syndrome, CA Inh., Osmotic ... Workup #phosphate #nephrology
Hypernatremia - Differential Diagnosis Workup Algorithm

1) Check Urine Osmolality:
 > 600 mOsm/kg - Implies extrarenal mechanism
Hypernatremia - Differential ... Diagnosis Workup ... • Euvolemic (Low ... Hypovolemic: Diuretics, osmotic ... #Algorithm #nephrology
Urine chemistry tests for the diagnostic evaluation of a patient with polyuria
UOsm <100 mOsm/Kg (H2O diuresis)
tests for the diagnostic ... a patient with polyuria ... + K) << UOsm - Osmotic ... #differential # ... diagnosis #nephrology
Causes of Hyponatremia - Differential Diagnosis Algorithm
Hypovolemia, UNa > 20: 
 • Renal losses, Diuretic excess,
Hyponatremia - Differential ... Diagnosis Algorithm ... alkalosis, Ketonuria, Osmotic ... #Diagnosis #Algorithm ... #Causes #nephrology