Should morning cortisol levels be tested in a critically ill Intensive Care Unit (ICU) patient with severe trauma and potential adrenal insufficiency?

Testing Morning Cortisol in ICU Trauma Patients

Do not routinely test morning cortisol levels in critically ill ICU trauma patients, as corticosteroids are not recommended for major trauma and have shown no mortality benefit. 1

Evidence Against Routine Testing in Trauma

• The Society of Critical Care Medicine explicitly advises that corticosteroids are not recommended for patients with major trauma, as analysis of 19 trials showed no significant effect on mortality (RR 1.00,95% CI 0.89-1.13). 1

• This recommendation directly contradicts the approach used in septic shock, where adrenal testing and corticosteroid therapy have established roles. 1

When Testing May Be Considered

If you suspect true adrenal insufficiency (not just critical illness-related changes), proceed directly to ACTH stimulation testing rather than relying on morning cortisol alone:

• A single low morning cortisol level is suggestive but insufficient to definitively diagnose adrenal insufficiency. 2

• The 250-μg ACTH stimulation test is the recommended diagnostic test for evaluating adrenal insufficiency, as it helps differentiate between primary and secondary adrenal insufficiency. 2

• In critically ill patients without septic shock who have suspected adrenal insufficiency, measure random cortisol levels—a level <10 μg/dL may trigger need for glucocorticoid treatment. 3

Critical Distinction: Trauma vs. Septic Shock

The management differs dramatically based on the underlying condition:

• For septic shock: Use hydrocortisone 200 mg/day IV for patients not responsive to fluid and moderate-to-high-dose vasopressors, regardless of cortisol testing. 4, 1

• For trauma without septic shock: Do not use corticosteroids even if adrenal testing suggests insufficiency, unless the patient has hemodynamic instability refractory to standard resuscitation. 1

Research Context and Nuances

• One retrospective trauma study found that treatment of acute adrenal insufficiency reduced mortality by almost 50%, but this conflicts with the guideline-level evidence showing no benefit. 5

• A prospective trauma study showed 100% survival in patients with occult adrenal insufficiency who were NOT treated with steroids, suggesting that hemodynamically stable patients should not receive replacement therapy. 6

• The prevalence of low cortisol (<25 μg/dL) in trauma ICU patients ranges from 51-81%, peaking on days 4 and 8, but this represents a physiologic response rather than true insufficiency requiring treatment. 6

Common Pitfalls to Avoid

• Do not use the ACTH stimulation test to guide treatment decisions in septic shock—the European Society of Intensive Care Medicine explicitly recommends against this approach. 1

• Low albumin predicts low cortisol—hypoproteinemia (albumin ≤2.5 g/dL) is present in 37-60% of trauma ICU patients and causes falsely low total cortisol measurements. 6

• Do not confuse critical illness-related cortisol changes with true adrenal insufficiency—elevated cortisol in critical illness results from decreased cortisol breakdown rather than increased production. 3

Practical Algorithm

1. Is the patient in septic shock requiring vasopressors? If yes → Start hydrocortisone 200 mg/day without testing. 4, 1

2. Is the patient hemodynamically unstable despite adequate resuscitation? If yes → Consider 100 mg IV hydrocortisone immediately and perform ACTH stimulation test. 1

3. Is the patient hemodynamically stable? If yes → Do not test or treat, as survival is excellent without intervention. 6