What is the recommended hydrocortisone dosing regimen for an adrenal crisis in adults (initial IV bolus and subsequent maintenance) and in children (dose per square meter), including alternative dosing if hydrocortisone is unavailable?

Hydrocortisone Dosing for Adrenal Crisis

For adults in adrenal crisis, administer hydrocortisone 100 mg IV bolus immediately, followed by a continuous infusion of 200 mg over 24 hours; for children, give hydrocortisone 2 mg/kg IV bolus followed by 2 mg/kg every 4 hours or a weight-based continuous infusion. 1, 2, 3

Adult Dosing Protocol

Immediate Emergency Treatment

• Administer hydrocortisone 100 mg IV or IM bolus without delay—do not wait for diagnostic testing, though blood should be drawn for cortisol and ACTH levels before treatment begins. 2, 3, 4
• This initial 100 mg bolus saturates 11β-HSD type 2 enzymes to provide critical mineralocorticoid activity, which is essential since high-dose hydrocortisone is needed to achieve mineralocorticoid effects in adrenal crisis. 3
• Simultaneously begin aggressive fluid resuscitation with 0.9% normal saline—infuse 1 liter over the first hour. 3, 4

Continuous Maintenance Phase

• Immediately after the bolus, initiate continuous IV infusion of hydrocortisone 200 mg over 24 hours (approximately 8.3 mg/hour). 1, 2, 3
• Alternative regimen if continuous infusion is impractical: hydrocortisone 50 mg IV or IM every 6 hours (totaling 200 mg/24 hours). 1, 3
• Continue IV hydrocortisone at 200 mg/24 hours for 24-48 hours or until the patient is clinically stable and able to tolerate oral intake. 1, 3

Important note: Continuous infusion is strongly preferred over intermittent bolus dosing because it provides superior maintenance of physiologic cortisol concentrations and avoids the peaks and troughs that result in suboptimal cortisol profiles. 2, 5

Transition to Oral Therapy

• Once the patient can tolerate oral intake and the precipitating illness is controlled, transition to oral hydrocortisone at double the patient's usual maintenance dose for 48 hours. 1, 3
• If recovery is complicated or the patient experienced major stress, continue doubled oral doses for up to one week before tapering back to standard maintenance dosing. 1, 3

Pediatric Dosing Protocol

Initial Emergency Treatment

• Administer hydrocortisone 2 mg/kg IV bolus at the onset of crisis or at induction if surgery-related. 1, 2
• Begin hourly blood glucose monitoring, as children with adrenal insufficiency are more vulnerable to hypoglycemia than adults. 1

Maintenance Phase

• Postoperatively or during ongoing crisis: hydrocortisone 2 mg/kg IV or IM every 4 hours. 1
• Alternative: weight-based continuous infusion of hydrocortisone if there is evidence of instability or sepsis. 1
• When enteral intake is established, administer double the normal maintenance dose of hydrocortisone for 48 hours, then reduce to standard dosing once stability is achieved. 1

Alternative Glucocorticoid if Hydrocortisone Unavailable

Dexamethasone Dosing

• Dexamethasone 8 mg IV provides glucocorticoid activity comparable to approximately 200 mg hydrocortisone and supplies adequate coverage for roughly 24 hours due to its long-acting properties. 2
• Critical limitation: Dexamethasone lacks mineralocorticoid activity and is therefore inadequate as the sole agent for stress dosing in primary adrenal insufficiency—it should not be used alone in this setting. 1, 2
• If dexamethasone must be used temporarily, ensure aggressive saline resuscitation and plan to transition to hydrocortisone as soon as available. 2

Critical Supportive Measures

• Continue slower IV saline infusion for 24-48 hours after the initial liter to maintain adequate hydration. 3
• Identify and treat the precipitating cause—infection accounts for the majority of adrenal crises. 3, 4
• Monitor serum sodium, potassium, glucose, and creatinine; expect hyponatremia, hyperkalemia, and prerenal azotemia. 3
• For patients with primary adrenal insufficiency, add fludrocortisone 0.05-0.2 mg daily once oral intake resumes, as they require mineralocorticoid replacement. 3

Common Pitfalls to Avoid

• Never delay treatment of suspected adrenal crisis for diagnostic testing—postponement markedly increases mortality. 2, 3
• Avoid intermittent bolus dosing when continuous infusion is feasible, as bolus regimens produce suboptimal cortisol profiles with significant peaks and troughs. 2, 5
• Never use dexamethasone alone for primary adrenal insufficiency due to lack of mineralocorticoid activity. 1, 2
• Do not abruptly stop stress-dose steroids—always taper gradually over 48 hours to one week depending on clinical recovery. 3
• Prevent medication errors and omissions on hospital wards, as these are documented contributors to adrenal crises; ensure uninterrupted stress-dose administration. 2

Special Pediatric Considerations

• No child with adrenal insufficiency should be fasted for more than 6 hours. 1
• Blood glucose should be checked every hour until enteral intake is resumed after surgery or during acute illness. 1
• Particular care is required in children with both diabetes insipidus and adrenal insufficiency, as cortisol is required to excrete a water load—strict fluid balance with adequate cortisol replacement is mandatory to avoid hyponatremia. 1