Management of Electrolyte Abnormalities in Classical CAH

Immediate Fludrocortisone Adjustment

The American Academy of Pediatrics recommends increasing fludrocortisone from 50 to 100 micrograms daily in children with electrolyte derangements, as the current dose is clearly insufficient given the electrolyte abnormalities 1
Most children and younger patients with primary adrenal insufficiency require 50-200 µg fludrocortisone daily, with children often needing higher doses than adults 1
Monitor serum electrolytes within 3-5 days after dose adjustment to assess response 1

The Endocrine Society recommends a glucocorticoid dose of 6-10 mg/m² body surface area for children with CAH, and the current total hydrocortisone dose is appropriate 1
The three-times-daily dosing schedule is acceptable, though ensure the first dose is given immediately upon waking and the last dose at least 6 hours before bedtime 1

A potassium level of 6.0 mmol/L requires urgent treatment while awaiting fludrocortisone effect, according to the Mayo Clinic Proceedings 2, 3
Consider oral sodium bicarbonate if concurrent metabolic acidosis is present, as this promotes potassium excretion 2
Ensure adequate sodium intake through diet while increasing fludrocortisone dose 1, 4

Recheck electrolytes (sodium, potassium) within 3-5 days after fludrocortisone increase 1
Monitor blood pressure at each visit, as excessive fludrocortisone can cause hypertension 1
If hypertension develops, reduce fludrocortisone dose but do not discontinue 1

Sodium should normalize to >135 mmol/L and potassium should decrease to 3.5-5.0 mmol/L within days of appropriate fludrocortisone dosing 1

Do not attribute electrolyte abnormalities to inadequate glucocorticoid dosing alone—this is a mineralocorticoid deficiency requiring fludrocortisone adjustment 1
Avoid reducing fludrocortisone dose if mild hypertension develops; instead, restrict dietary salt intake first 1