What endocrine emergencies should be considered in a critically ill patient with a history of Coronary Artery Disease (CAD), Coronary Artery Bypass Graft (CABG), and Traumatic Brain Injury (TBI), who recently had a respiratory infection and shock?

Endocrine Emergencies in Critically Ill Patients with CAD, CABG, TBI, Respiratory Infection, and Shock

The most critical endocrine emergency to consider in this patient is Critical Illness-Related Corticosteroid Insufficiency (CIRCI), which presents with hypotension refractory to fluid resuscitation and vasopressors—a clinical picture that demands immediate empiric treatment with IV hydrocortisone without waiting for diagnostic confirmation. 1, 2

Critical Illness-Related Corticosteroid Insufficiency (CIRCI)

Clinical Presentation and Diagnosis

This patient's presentation of shock following respiratory infection in the context of critical illness creates a high-risk scenario for CIRCI. The condition is characterized by dysregulated systemic inflammation from inadequate glucocorticoid-mediated anti-inflammatory activity. 1

Key clinical features to assess immediately include:

• Cardiovascular: Hypotension refractory to fluid resuscitation, decreased sensitivity to catecholamines, requirement for high-dose or multiple vasopressors 1, 2
• Neurological: Confusion, delirium, or altered mental status 1
• Gastrointestinal: Nausea, vomiting, intolerance to enteral nutrition 1
• Laboratory findings: Hypoglycemia, hyponatremia, hyperkalemia (though hyperkalemia occurs in only ~50% of cases), metabolic acidosis 1, 3

Diagnostic Approach

Do not delay treatment for diagnostic testing if the patient is hemodynamically unstable. 2, 3 However, if time permits before initiating hydrocortisone:

• Draw baseline cortisol and ACTH levels immediately 2, 3
• A random plasma cortisol <10 μg/dL suggests CIRCI 1, 2
• A delta cortisol <9 μg/dL after cosyntropin (250 μg) administration defines CIRCI 1, 2

Critical pitfall: The ACTH stimulation test should NOT be used to decide whether to treat septic shock with hydrocortisone—clinical criteria (vasopressor-dependent hypotension despite adequate fluid resuscitation) should guide treatment decisions. 1, 4

Immediate Management

For septic shock not responsive to fluid and moderate-to-high-dose vasopressor therapy:

• Administer hydrocortisone 200 mg/day IV (50 mg every 6 hours or continuous infusion) immediately 1, 2, 4
• Continue for at least 3 days at full dose 1, 4
• Taper gradually over 6-14 days when vasopressors are discontinued, rather than stopping abruptly 2, 4
• Monitor glucose levels closely as hydrocortisone worsens hyperglycemia 2

Important distinction: Do NOT use corticosteroids for sepsis without shock—this provides no benefit and is not recommended. 1, 4

Secondary Adrenal Insufficiency from Prior Steroid Exposure

Given the patient's history of TBI and potential prior corticosteroid use, consider iatrogenic secondary adrenal insufficiency. 3, 5

High-risk indicators:

• Any patient taking ≥20 mg/day prednisone or equivalent for ≥3 weeks who develops unexplained hypotension should be presumed to have adrenal insufficiency until proven otherwise 3
• Recent steroid exposure for TBI management or other conditions 3

If adrenal crisis is suspected (not just CIRCI):

• Give 100 mg IV hydrocortisone immediately without waiting for testing 2, 3
• Infuse 0.9% saline at 1 L/hour (at least 2L total) 3
• Continue hydrocortisone 200-300 mg/day as continuous infusion or divided doses 2, 5

Thyroid Storm (Less Likely but Must Consider)

While less probable given the clinical scenario, thyroid storm can present with fever, tachycardia, altered mental status, and cardiovascular instability in critically ill patients. 6

Key distinguishing features:

• Marked tachycardia out of proportion to fever
• Hyperthermia (often >40°C)
• Agitation, delirium, or psychosis
• Gastrointestinal symptoms (diarrhea, nausea, vomiting)

If suspected, check TSH and free T4 urgently, but do not delay treatment. 6

Diabetic Ketoacidosis (DKA)

In patients with known or undiagnosed diabetes, infection can precipitate DKA. 6

Diagnostic criteria:

• Hyperglycemia (glucose >250 mg/dL)
• Metabolic acidosis (pH <7.3, bicarbonate <18 mEq/L)
• Ketonemia or ketonuria

Algorithmic Approach to This Patient

Step 1: Assess hemodynamic status

• If hypotension refractory to fluids and vasopressors → Presume CIRCI

Step 2: Draw baseline labs before treatment (if stable enough)

• Cortisol, ACTH, electrolytes, glucose
• Do NOT delay treatment if unstable 2, 3

Step 3: Initiate empiric hydrocortisone

• 200 mg/day IV (50 mg q6h or continuous infusion) 1, 2, 4
• Continue for ≥3 days at full dose 4

Step 4: Monitor response

• Vasopressor requirements should decrease
• Blood pressure should stabilize
• Monitor glucose closely 2

Step 5: Taper when stable

• Begin taper when vasopressors discontinued 4
• Taper over 6-14 days, not abruptly 2, 4

Critical pitfall to avoid: Never stop hydrocortisone abruptly—this can cause hemodynamic deterioration from rebound inflammation. 4