In a 60-year-old woman with multiple sclerosis and a chronic suprapubic catheter who is in septic shock refractory to fluid resuscitation and norepinephrine/vasopressin, should I obtain an ACTH stimulation test, start a continuous dobutamine infusion, or initiate stress‑dose hydrocortisone with fludrocortisone?

Initiate Hydrocortisone Alone at 200 mg/Day

In this patient with refractory septic shock despite adequate fluid resuscitation (2.5 L crystalloids) and dual vasopressor therapy (norepinephrine and vasopressin), you should initiate intravenous hydrocortisone at 200 mg/day as a continuous infusion. Do not obtain an ACTH stimulation test, do not add fludrocortisone, and do not start dobutamine at this time.

Rationale for Hydrocortisone

This patient meets the clear indication for corticosteroid therapy: septic shock that remains refractory despite adequate fluid resuscitation and vasopressor therapy. The Surviving Sepsis Campaign 2016 guidelines explicitly recommend IV hydrocortisone at 200 mg/day when hemodynamic stability cannot be achieved with fluids and vasopressors alone 111112111. This is a weak recommendation with low-quality evidence, but the clinical scenario—persistent hypotension (BP 80/60) despite 2.5 L fluids and two vasopressors—clearly fits the criteria.

The mechanism is straightforward: In septic shock, relative adrenal insufficiency and glucocorticoid receptor resistance impair vascular responsiveness to catecholamines. Hydrocortisone restores vascular tone and enhances vasopressor responsiveness, potentially reducing catecholamine requirements and their associated complications (arrhythmias, myocardial ischemia) 3.

Recent evidence supports earlier hydrocortisone initiation. A 2026 study demonstrated that earlier addition of hydrocortisone as an adjunct to norepinephrine was associated with lower in-hospital mortality (37.3% vs 53.3%, adjusted HR 1.80, P=0.006), and delayed initiation increased mortality risk (HR 1.08 per hour delay, P<0.001) 4.

Why NOT ACTH Stimulation Test

Do not obtain an ACTH stimulation test. The guidelines explicitly recommend against using the ACTH stimulation test to identify which patients should receive hydrocortisone 11112111. This is a grade 2B recommendation.

The rationale is clear: The ACTH test does not reliably predict which patients will benefit from corticosteroids. The CORTICUS trial found similar hemodynamic responses to corticosteroids regardless of ACTH test results 5. Testing delays treatment and provides no actionable information—if the patient has refractory shock, they need hydrocortisone regardless of test results. The 2017 CIRCI guidelines acknowledge that while the high-dose (250 μg) ACTH test can diagnose adrenal insufficiency, it should not guide treatment decisions in septic shock 5.

Why NOT Fludrocortisone

Do not add fludrocortisone. While some studies suggest potential benefit from combining hydrocortisone with fludrocortisone, the guidelines recommend hydrocortisone alone at 200 mg/day 111112111. This is the evidence-based standard approach.

The controversy exists: A 2023 comparative effectiveness study found that hydrocortisone-fludrocortisone reduced the composite outcome of death/hospice discharge by 3.7% compared to hydrocortisone alone (P<0.001) 6, and a 2020 meta-analysis suggested lower 28-day mortality with the combination 7. However, these findings came after the 2016 guidelines and have not yet been incorporated into standard recommendations. The 2018 BMJ guideline notes that adding fludrocortisone "could be helpful, but that is highly speculative" 8.

In practice, start with hydrocortisone alone as per guidelines. If shock remains refractory after 24-48 hours of hydrocortisone, consider adding fludrocortisone 50 μg daily, but this is not the initial approach.

Why NOT Dobutamine

Do not start dobutamine now. Dobutamine is indicated only when there is evidence of persistent hypoperfusion despite adequate fluid loading and vasopressor use, specifically in the setting of myocardial dysfunction with elevated cardiac filling pressures and low cardiac output 111112111.

This patient has:

• Capillary refill time <2 seconds (normal, suggesting adequate peripheral perfusion)
• No mention of elevated lactate, oliguria, or other signs of persistent tissue hypoperfusion
• No documented cardiac dysfunction or low cardiac output

The guidelines are clear: dobutamine should be titrated to endpoints reflecting perfusion and discontinued if worsening hypotension or arrhythmias occur 111. Adding an inotrope to a hypotensive patient without documented cardiac dysfunction or hypoperfusion would be inappropriate and potentially harmful—it could worsen hypotension through vasodilation and increase myocardial oxygen demand.

If signs of persistent hypoperfusion emerge (elevated lactate >4 mmol/L, oliguria despite adequate MAP, cool extremities, altered mentation beyond baseline), then obtain echocardiography to assess cardiac function. Only if myocardial dysfunction is documented should you consider dobutamine 2.5-5 μg/kg/min, titrated up to 20 μg/kg/min as needed 99.

Practical Implementation

Hydrocortisone dosing:

• 200 mg/day as continuous IV infusion (preferred over bolus dosing per guidelines) 11112111
• Can give 50 mg IV bolus initially, then start infusion at 8.3 mg/hour
• Continue for 7 days or until vasopressors are no longer required
• Taper when vasopressors are discontinued 11112111

Monitoring:

• Blood glucose every 4-6 hours (treat hyperglycemia aggressively)
• Serum sodium and potassium daily
• Monitor for signs of adrenal insufficiency if steroids are stopped abruptly 8
• Reassess hemodynamics every 1-2 hours initially

Expected response: You should see improved vasopressor responsiveness within 6-24 hours, allowing gradual reduction in norepinephrine and vasopressin doses. If shock remains refractory after 48 hours of hydrocortisone, consider adding epinephrine as the next vasopressor 1111 or, based on emerging evidence, consider adding fludrocortisone 50 μg daily 67.

Common Pitfalls

• Delaying hydrocortisone while waiting for ACTH test results: This wastes time and provides no benefit. Start hydrocortisone immediately in refractory shock.
• Starting dobutamine for hypotension alone: Dobutamine is not a vasopressor—it's an inotrope that can worsen hypotension. Only use it for documented cardiac dysfunction with hypoperfusion.
• Abrupt steroid discontinuation: Always taper hydrocortisone when vasopressors are stopped to avoid rebound inflammation and hemodynamic instability 118.
• Inadequate glucose monitoring: Hydrocortisone causes hyperglycemia; check glucose frequently and treat aggressively.