What is the acute management of a patient presenting with hypoglycemia and hyponatremia, suspected adrenal insufficiency?

Acute Management of Hypoglycemia and Hyponatremia with Suspected Adrenal Insufficiency

Immediately administer 100 mg IV hydrocortisone bolus and infuse 0.9% saline at 1 L/hour without waiting for diagnostic confirmation—treatment of suspected adrenal crisis must never be delayed by diagnostic procedures. 1, 2

Immediate Emergency Actions (First 15 Minutes)

Draw blood samples before steroid administration if feasible, but do not delay treatment:

• Obtain serum cortisol, ACTH, sodium, potassium, glucose, and creatinine 1
• If peripheral IV access cannot be achieved quickly, give hydrocortisone 100 mg intramuscularly without delay 3

Administer hydrocortisone 100 mg IV bolus immediately to saturate 11β-HSD type 2 receptors and achieve mineralocorticoid effect 1

Begin rapid isotonic saline infusion:

• Infuse 0.9% saline at approximately 1 L over the first hour 1, 2
• Plan for 3–4 L total isotonic saline or 5% dextrose in isotonic saline over 24 hours 1

Correct hypoglycemia urgently:

• Administer IV dextrose if glucose is low (hypoglycemia occurs particularly in children but can occur at any age) 1, 4
• Monitor glucose frequently as cortisol deficiency impairs counter-regulatory mechanisms 4

Ongoing Management (First 24–48 Hours)

Continue parenteral hydrocortisone:

• Give 100–300 mg/day as continuous IV infusion OR 1
• Give 100 mg IV/IM boluses every 6 hours 1

Monitor hemodynamics and electrolytes frequently:

• Continue isotonic saline at slower rate for 24–48 hours 1
• Measure serum electrolytes every 4–6 hours to avoid fluid overload 1
• Hyponatremia will correct with hydrocortisone and saline; do not restrict fluids 2

Address precipitating causes:

• Obtain cultures and initiate antibiotics if infection suspected 1
• Consider ICU or high-dependency unit admission depending on severity 1
• Provide gastric stress ulcer prophylaxis and low-dose heparin 1

Critical Diagnostic Considerations

Adrenal insufficiency presents identically to SIADH in 90% of cases:

• Both show euvolemic hypo-osmolar hyponatremia with inappropriately high urine osmolality and elevated urinary sodium 2
• The cosyntropin stimulation test is medically necessary to distinguish these conditions, as treatment differs fundamentally 2, 5
• Adrenal insufficiency requires glucocorticoid replacement; SIADH requires fluid restriction 2

Do not rely on electrolyte patterns alone:

• Hyperkalemia is present in only ~50% of adrenal insufficiency cases 1, 2, 6
• When vomiting is present, hypokalemia (not hyperkalemia) occurs because GI losses mask aldosterone deficiency 6
• Hyponatremia may be only marginally reduced in some cases 2

Interpret pre-treatment cortisol and ACTH if obtained:

• Basal cortisol <250 nmol/L (<9 µg/dL) with elevated ACTH in acute illness is diagnostic of primary adrenal insufficiency 1, 2
• Basal cortisol <400 nmol/L (<14 µg/dL) with elevated ACTH generates strong suspicion 1, 2
• Low cortisol with low or inappropriately normal ACTH indicates secondary adrenal insufficiency 2

Transition to Oral Therapy (Days 2–3)

Taper parenteral glucocorticoids over 1–3 days:

• Begin tapering when precipitating illness permits 1
• Restart fludrocortisone when hydrocortisone dose falls to <50 mg/day 1

Transition to maintenance oral replacement:

• Hydrocortisone 15–25 mg daily in divided doses (typically 10 mg at 7 AM, 5 mg at noon, 2.5–5 mg at 4 PM) 1, 2
• For primary adrenal insufficiency, add fludrocortisone 50–200 µg daily 1, 2
• Ensure unrestricted sodium salt intake 2

Confirmatory Testing After Stabilization

Perform cosyntropin stimulation test once stable (if diagnosis uncertain):

• Administer 0.25 mg (250 µg) cosyntropin IV or IM 2
• Measure serum cortisol at baseline, 30 minutes, and optionally 60 minutes 2
• Peak cortisol <500 nmol/L (<18 µg/dL) confirms adrenal insufficiency 2
• Peak cortisol >550 nmol/L (>18–20 µg/dL) excludes adrenal insufficiency 2

Determine etiology if primary adrenal insufficiency confirmed:

• Measure 21-hydroxylase autoantibodies (positive in ~85% of autoimmune cases) 2
• If antibodies negative, obtain adrenal CT to evaluate for hemorrhage, tumor, tuberculosis, or infiltration 2
• In males with negative antibodies, measure very-long-chain fatty acids to screen for adrenoleukodystrophy 2

Common Pitfalls to Avoid

Never delay treatment for diagnostic testing in clinically unstable patients—mortality is high if adrenal crisis goes untreated 1, 2

Do not assume SIADH without excluding adrenal insufficiency—the cosyntropin test is mandatory when both conditions are in the differential 2, 5

Do not use dexamethasone for acute crisis management unless you specifically need to preserve the ability to measure cortisol later—dexamethasone lacks mineralocorticoid activity and is inadequate for primary adrenal insufficiency 2

Recognize that normal basal ACTH and cortisol on admission do not exclude adrenal insufficiency—provocation testing may be necessary after recovery from hyponatremia 7

Patient Education Before Discharge

Provide emergency preparedness:

• Prescribe hydrocortisone 100 mg IM injection kit with self-injection training 2, 3
• Issue medical alert bracelet or necklace indicating adrenal insufficiency 1, 2, 3
• Educate on stress-dosing: double or triple dose during illness, fever, or physical stress 2

Arrange mandatory endocrine follow-up for long-term management, annual screening for associated autoimmune conditions, and prevention of future crises 1, 2