Diagnostic Approach to Hypernatremia - Flowchart
Diagnostic Approach to Hypernatremia - Flowchart Hypernatremia Hypernatremia
«Flowchart»

Serum Na >145 mEq/L

Serum Na >145 mEq/L

Serum Na >145 mEq/L

Hypertonic fluid administration
Salt ingestion
Hyperalimentation

Hypertonic fluid administration
Salt ingestion
Hyperalimentation

Hypertonic fluid administration
Salt ingestion
Hyperalimentation



Assess volume status

Assess volume status

Assess volume status

Hypovolemia
(water and salt deficit)
TBW ↓↓
TBS ↓

Hypovolemia
(water and salt deficit)
TBW ↓↓
TBS ↓

Hypovolemia

↓ ↓
↓ Hypovolemia

Euvolemia
(pure water deficit)
TBW ↓↓
TBS normal

Euvolemia
(pure water deficit)
TBW ↓↓
TBS normal

Euvolemia

↓ ↓
Euvolemia

Hypervolemia
(net sodium gain)
TBW ↓ or normal
TBS ↑↑

Hypervolemia
(net sodium gain)
TBW ↓ or normal
TBS ↑↑

Hypervolemia

↓
↑ ↑ Hypervolemia

End

End

End

Nephrogenic or Central DI

Nephrogenic or Central DI

Nephrogenic or Central DI

Check urine Na

Check urine Na

Check urine Na

UNa <20
Extrarenal loss
Usually low UOP

UNa <20
Extrarenal loss
Usually low UOP

Na

U(Na) <20

UNa >20
Renal loss
Usually high UOP

UNa >20
Renal loss
Usually high UOP

Na

U(Na) >20

Check urine Osm

Check urine Osm

Check urine Osm

Uosm/Posm >1
Extrarenal loss
Usually low UOP

Uosm/Posm >1
Extrarenal loss
Usually low UOP

osm osm

U(osm)/P(osm) >1

Uosm/Posm <1
Renal loss
Usually high UOP

Uosm/Posm <1
Renal loss
Usually high UOP

osm osm

U(osm)/P(osm) <1