How should adrenal insufficiency be diagnosed and managed in a postpartum woman who presents within weeks of delivery with fatigue, nausea, vomiting, abdominal pain, hypotension, hyponatremia, and hypoglycemia, especially after severe obstetric hemorrhage, prolonged hypotension, or a difficult labor?

Postpartum Adrenal Insufficiency: Diagnosis and Management

Immediate Recognition and Emergency Treatment

In a postpartum woman presenting with hypotension, nausea, vomiting, abdominal pain, hyponatremia, and hypoglycemia—especially after severe obstetric hemorrhage—administer hydrocortisone 100 mg IV bolus immediately and begin 0.9% isotonic saline 1 L over the first hour without waiting for diagnostic confirmation. 1, 2

Clinical Triggers Requiring Immediate Action

• Severe postpartum hemorrhage (>5000 mL blood loss) is the most critical risk factor for acute Sheehan's syndrome presenting as adrenal crisis 3
• Hypotension (often <90/60 mmHg) with tachycardia and shock 1, 2
• Severe nausea and vomiting that fails to improve with standard antiemetics 1, 3
• Altered mental status ranging from confusion to obtundation or coma 1, 4
• Hypoglycemic seizures particularly within the first 24 hours to 2 weeks postpartum 4, 5
• Lactation failure followed by hyponatremia-related symptoms on postpartum days 8-9 3

Critical Laboratory Findings

• Hyponatremia is present in 90% of cases and may be severe 6, 1, 3, 5
• Hypoglycemia especially in the acute postpartum period 7, 4, 5
• Hyperkalemia occurs in only ~50% of primary adrenal insufficiency cases, so its absence does not exclude the diagnosis 6, 1
• Serum cortisol <250 nmol/L (<9 µg/dL) with elevated ACTH confirms primary adrenal insufficiency 6, 1
• Serum cortisol <400 nmol/L (<14 µg/dL) with low or inappropriately normal ACTH suggests secondary adrenal insufficiency (Sheehan's syndrome) 8

First-Hour Emergency Protocol

Immediate Interventions (Do Not Delay)

1. Draw blood for cortisol, ACTH, electrolytes, glucose, creatinine before treatment if feasible, but never postpone therapy 1, 2
2. Administer hydrocortisone 100 mg IV bolus—this dose provides both glucocorticoid and mineralocorticoid activity by saturating 11β-hydroxysteroid dehydrogenase type 2 1, 2
3. Begin aggressive fluid resuscitation with 0.9% isotonic saline 1 L IV over the first hour 1, 2
4. If IV access cannot be rapidly established, give hydrocortisone 100 mg IM as backup 1

Alternative Hydrocortisone Regimen

• Hydrocortisone 50 mg IV or IM every 6 hours (total 200 mg/day) if continuous infusion is unavailable 1, 2

Ongoing Management (First 24-48 Hours)

Continued Therapy

• Continue hydrocortisone 200 mg per 24 hours as continuous IV infusion (preferred) or 50 mg IV/IM every 6 hours 1, 2
• Provide total of 3-4 L isotonic saline or 5% dextrose-in-saline over 24-48 hours with frequent hemodynamic monitoring 1, 2
• Monitor serum electrolytes every 4-6 hours initially to guide fluid management and detect hypernatremia 1, 2
• Check blood glucose frequently, especially given the postpartum hypoglycemia risk 1, 2

Supportive Care

• Admit to ICU or high-dependency unit for persistent hypotension or severe presentation 1, 2
• Provide gastric stress-ulcer prophylaxis 1, 2
• Administer low-dose heparin for DVT prophylaxis 1, 2
• Treat any precipitating infections with appropriate antimicrobials 1, 2

Distinguishing Primary vs. Secondary Adrenal Insufficiency

Primary Adrenal Insufficiency (Rare in Postpartum)

• Unilateral adrenal infarction can cause primary adrenal insufficiency in pregnancy 7
• Hyperpigmentation of skin creases, scars, or mucous membranes indicates markedly elevated ACTH 1
• Hyperkalemia present in ~50% of cases 6, 1
• Serum cortisol <250 nmol/L with markedly elevated ACTH (>300 pg/mL) is diagnostic 1, 8

Secondary Adrenal Insufficiency (Sheehan's Syndrome—Most Common Postpartum)

• Massive postpartum hemorrhage (>5000 mL), impaired consciousness on arrival, and hysterectomy are key risk factors 3
• Lactation failure is an early clinical clue, typically followed by hyponatremia-related symptoms on postpartum days 8-9 3
• Normal skin coloration (no hyperpigmentation) because ACTH is low 1
• Hyperkalemia is absent because aldosterone secretion is preserved 1
• Serum cortisol <400 nmol/L with low or inappropriately normal ACTH suggests secondary adrenal insufficiency 8
• Median time to presentation: 7.9 days for adrenal insufficiency, 4 days for diabetes insipidus, 18 days for hypothyroidism 9

Diagnostic Workup (After Stabilization)

Confirmatory Testing

• Cosyntropin stimulation test: administer 0.25 mg (250 µg) IV or IM, measure cortisol at baseline, 30, and 60 minutes 6, 1, 8
• Peak cortisol <500 nmol/L (<18 µg/dL) confirms adrenal insufficiency 6, 1, 8
• Peak cortisol >550 nmol/L (>18-20 µg/dL) excludes adrenal insufficiency 1, 8

Etiologic Evaluation for Primary Adrenal Insufficiency

• Measure 21-hydroxylase autoantibodies—positive in ~85% of autoimmune Addison's disease 6, 1, 8
• If autoantibodies negative, obtain CT or MRI of adrenals to evaluate for infarction, hemorrhage, tumor, or infiltrative disease 1, 8, 7
• In males, measure very-long-chain fatty acids to screen for adrenoleukodystrophy 6, 1

Evaluation for Sheehan's Syndrome

• MRI of pituitary may show serial changes including acute infarction, empty sella, or pituitary necrosis 9
• Assess other pituitary hormones: TSH, free T4, prolactin, LH, FSH 9, 4
• Isolated ACTH deficiency can occur without panhypopituitarism 4

Transition to Maintenance Therapy

Tapering Protocol

• Taper parenteral glucocorticoids over 1-3 days once the precipitating illness permits oral intake 1, 2
• Double the usual oral hydrocortisone dose for 24-48 hours postpartum after uncomplicated delivery 6
• Resume fludrocortisone only when hydrocortisone dose falls below 50 mg per day in primary adrenal insufficiency 1

Long-Term Replacement for Primary Adrenal Insufficiency

• Hydrocortisone 15-25 mg daily in divided doses (e.g., 10 mg at 7:00 AM, 5 mg at 12:00 PM, 2.5-5 mg at 4:00 PM) 6, 1, 8
• Fludrocortisone 50-200 µg daily for mineralocorticoid replacement 6, 1, 8
• Unrestricted sodium salt intake is essential 6, 1

Long-Term Replacement for Secondary Adrenal Insufficiency

• Hydrocortisone 15-25 mg daily in divided doses 1, 8
• No fludrocortisone required because aldosterone production is preserved 1
• If concurrent hypothyroidism, start glucocorticoids several days before thyroid hormone to prevent precipitating crisis 1, 8

Monitoring for Resolution (Postpartum Adrenal Infarction)

• Adrenal insufficiency from unilateral adrenal infarction may resolve at approximately 16 months postpartum 7
• Test for HPA axis recovery at 3 months after maintenance therapy in isolated central adrenal insufficiency 8

Critical Pitfalls to Avoid

• Never delay treatment for diagnostic confirmation—mortality increases with treatment postponement 6, 1, 2
• Do not rely on hyperkalemia to diagnose adrenal insufficiency—it is present in only ~50% of cases 6, 1
• Do not add separate mineralocorticoid (fludrocortisone) during acute crisis—high-dose hydrocortisone provides adequate mineralocorticoid activity 1
• Do not attribute persistent hyponatremia to pregnancy-related vomiting alone—failure to correct hyponatremia despite adequate IV hydration should raise suspicion for adrenal insufficiency 7
• Do not start thyroid hormone before glucocorticoids in patients with multiple pituitary hormone deficiencies 1, 8

Patient Education and Prevention

• Provide emergency injectable hydrocortisone 100 mg IM kit with self-injection training 1, 2
• Instruct patients to wear medical alert bracelet or necklace indicating adrenal insufficiency 1, 2
• Educate on stress-dosing: double or triple oral dose during illness, fever, or physical stress 1, 2
• For subsequent pregnancies: increase maintenance dose in latter stages of pregnancy, give hydrocortisone 100 mg IM at onset of labor, followed by 200 mg per 24 hours IV infusion or 50 mg IM every 6 hours until after delivery 6, 1