Enda Pediatric Hc Bsa Dosing

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name: enda-pediatric-hc-bsa-dosing
description: Recommends initiating hydrocortisone replacement at a total starting dose of 8 mg/m2 body surface area per day, given in three or four divided doses, for children with confirmed primary adrenal insufficiency (PAI). Use when starting glucocorticoid therapy in pediatric PAI patients, adjusting the dose according to individual clinical response, growth, and need for stress coverage.
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# Treat Children with PAI Using Hydrocortisone with BSA-Based Dosing

## STEP 1 — Gather Information
Confirm PAI diagnosis with low cortisol response to ACTH stimulation test and elevated ACTH; assess for aldosterone deficiency (renin, aldosterone); measure weight and height to calculate body surface area (BSA); review growth parameters, weight, blood pressure, and signs of glucocorticoid over- or under-replacement.

## STEP 2 — Rule In / Rule Out
Is PAI biochemically confirmed (subnormal cortisol peak after 250 µg ACTH with elevated ACTH)?  
- Yes → proceed to Step 3.  
- No → consider secondary adrenal insufficiency, transient causes, or non‑adrenal etiologies; do not initiate glucocorticoid replacement pending further evaluation.

## STEP 3 — Classify or Stratify
Determine if the child has concomitant aldosterone deficiency (elevated plasma renin with low aldosterone) requiring fludrocortisone replacement; if yes, plan mineralocorticoid therapy in addition to glucocorticoid dosing.

## STEP 4 — Decide
Start hydrocortisone at 8 mg/m2/day divided into three or four doses (largest dose upon waking, subsequent doses spaced 4–6 hours apart, last dose not later than 4–6 hours before bedtime); adjust dose based on clinical wellbeing, growth velocity, blood pressure, and signs of over- (weight gain, Cushingoid features, hypertension) or under-replacement (fatigue, hypotension, hyperpigmentation, poor growth).

## Clinical Guardrails / Mimics / Pitfalls
Do not use synthetic long‑acting glucocorticoids (e.g., dexamethasone, prednisolone) as first‑line in children; avoid dosing based solely on weight without BSA calculation; do not adjust dose based on plasma ACTH levels; avoid exceeding 20 mg/m2/day in infants or 15–17 mg/m2/day in adolescents without clear clinical indication; ensure patient/family education on stress dosing and emergency injection kit.

## Concrete Clinical Example
A 4‑year‑old boy (weight 16 kg, height 100 cm, BSA ≈0.78 m2) with newly diagnosed PAI (low cortisol after 250 µg ACTH, high ACTH) and normal aldosterone. Starting hydrocortisone dose = 8 mg/m2/day × 0.78 m2 ≈ 6.2 mg/day, given as 2 mg at 08:00, 2 mg at 12:00, and 2.2 mg at 16:00. After two weeks, weight gain is appropriate and no Cushingoid signs; dose maintained.

**Source:** Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, DOI:10.1210/jc.2015-1710