Adrenal insufficiency in septic shock: what should one do at the present time?

Introduction

In the past years many studies have demonstrated the occurrence of relative adrenal insufficiency and immunologic and hemodynamic effects of low-dose hydrocortisone in septic shock. Despite this evidence, the optimal approach to ensure the diagnoses is not yet clear.

Methods

We conducted a prospective cohort study in two ICUs from March 2003 to March 2004. The patients who developed septic shock and were under mechanical ventilation had their serum cortisol measured. The diagnoses of septic shock were made in accordance with the criteria proposed by ACCP/SCCM. The hydrocortisone was administrated every 6 hours (200 mg intravenously daily) during 7 days or less, according to the hemodynamic response and the relationship with the serum cortisol level (≤ 25 μg/dl). Two criteria were used to make the diagnoses: serum cortisol level ≤ 25 μg/dl and the weaning of vasoative drugs in the first 24 hours or dose reduction in at least 50%. The APACHE II score and SOFA score were used to evaluate the seriousness.

Results

Fifty-nine patients were evaluated. Average age was 69 years, 30 (50.8%) were male. The average APACHE II score was 24 and the SOFA score on the first day was 10.5. The average plasma cortisol was 27.5 μg/dl (4–114). Cortisol ≤ 25 μg/dl was identified in 30 (50.8%) patients. The weaning from vasoative drugs or the dose reduction in at least 50% was observed in 25 patients. The sensitivity of a baseline cortisol ≤ 25 μg/dl associated with hemodynamic response to predict adrenal insufficiency was 83.3% (95% confidence interval; 72.5–94). According to this criterion, relative adrenal insufiency was diagnosed in 33.8% in this group.

Conclusion

Adrenal insufiency appears to be common in septic shock patients. Hemodynamic response to hydrocortisone linked to a serum cortisol ≤ 25 μg/dl seems to be a good way to make the diagnosis. Until we have the best cut-off value of serum cortisol and a definitive response about the validity of the corticotropin test in septic patients, the clinical response to corticosteroids should be taken into consideration to make that diagnosis.