4. Clinical Signs of Hyponatrema
Nausea, vomiting, anorexia, muscle
cramps, confusion, and lethargy, and
culminate ultimately in seizures and coma.
Seizures are quite likely at [Na+] of 113
mEq/L or less.
9. Diagnostic Criteria for Syndrome
of Inappropriate Secretion of ADH
Hypotonic hyponatremia
Inappropriately elevated urine osmolality
(usually >200 mOsm/kg)
Elevated urine [Na+] (typically > 20 mEq/L)
Clinical euvolemia
Normal adrenal, renal, cardiac, hepatic, and
thyroid function
Correctable with water restriction
10.
11. Total Body [Na+] Deficit
= (desired plasma [Na+]-measured plasma [Na+])
×TBW
12. Emergency Treatment of Severe
Hyponatremia
Although specific or general treatment of
hyponatremia for the condition discussed may be
initiated in the ED, there is generally little
urgency to address the hyponatremia
immediately when [Na+] is 120 mEq/L.
If hyponatremia is severe (<115 mEq/L or when
the patient is symptomatic), treatment should be
initiated.
13. Emergency Treatment of Severe
Hyponatremia
Situations that warrant consideration of emergent
treatment are hypovolemic patients and patients
in extremis, (e.g., mental status changes or
coma). In hypovolemic patients, the [Na+] deficit
should be calculated and replaced with normal
saline solution.
Urine electrolytes are useful only before
beginning treatment and therefore should be
collected in the ED.
The rise in [Na+] should be no greater than 0.5
to 1.0 mEq/L per hour.