Hypernatremia ☺️ Flashcards
Presentation
Investigation findings
-dehydration => AKI
-pituitary issue?
Thirst
Lethargy
Neurological dysfunction (dehydration of brain cells)
Dehydration
- Na => high
- Urea => high
- Urine Na and osmolality => high (retaining water)
Low ADH
- Na => high
- Urea, creatinine => high (water cannot be retained)
- Urine Na and osmolality => low (ALD action)
What regulates ECF volume
What happens when there is water loss
ECF volume regulated by Na
Loss of water
- greatest loss in ICF
- smaller loss in ECF (water moves out of the ICF => ECF before being lost)
- increased loss => concentration of plasma Na
What is water balance controlled by
What factors influence ADH secretion
ADH
Affected by
- osmolality
- ECF volume
- stress/trauma
- drugs
Differential diagnosis algorithm for hypernatremia
- high urine volume => high/low urine osmolality
- low urine volume => non renal loss/decreased intake
High urine volume and osmolality
-hypertonic Na solution
-osmotic diuresis
High urine volume and low urine osmolality
-central/peripheral DI
THESE ONLY LEAD TO HYPOVOLEMIA IF UNABLE TO INCREASE WATER INTAKE
Low urine volume Non renal loss -diarrhoea -burns -fever -hyperventilation
Decreased intake of water
How would you treat hypernatremia
- normovolemic
- hypovolemic
Address Na
Hypovolemic
-PO/IV dextrose fluids
Normovolemic
- PO/IV dextrose fluids
- treat underlying cause
- Central DI => desmopressin
- Peripheral DI => thiazides (paradoxical effect)
Hypervolemic
- PO/IV dextrose
- treat underlying cause => Na restriction