Adrenal failure in neurological and septic critically ill patients

Introduction

Adrenal failure (AF) is known to develop during the course of sepsis and to adversely affect the prognosis of the patients. Neurological critically ill patients may additionally be susceptible to development of AF due to disruption of the hypotalamic–pituitary–adrenal axis.

Objectives

To determine the response to the corticotropin stimulation test with low dose (1 μg) and high dose (249 μg) in septic patients and to compare the frequency of AF in the neurological and non-neurological subsets.

Materials and methods

Patients admitted to an ICU from May 2002 to November 2004, with septic shock, additionally registered whether they had associated neurological diseases (head trauma, acute cerebrovascular disorders, postoperative) or not, were submitted to the corticotropin stimulation test. A baseline cortisol level was first obtained, then patients received an intravenous injection of 1 μg corticotropin (low dose) followed 60 min later by an injection of 249 μg (high dose). The cortisol level was obtained 60 min after low-dose and high-dose corticotropin. The difference between the higher and baseline cortisol level was registered as Δmax. We defined AF when the baseline cortisol level was lower than 25 μg/dl or Δmax was lower than or equal to 9 μg/dl. The EPiINFO version was used for data analysis, and P < 0.05 was considered significant.

Results

Eighty-two patients were enrolled, 47 were female. The mean age was 71. The overall rate of baseline cortisol level lower than 25 μg/dl was 79.3% (65/82) and Δmax lower than or equal to 9 μg/dl was 19.5% (16/82). The cortisol levels were significantly higher in the neurological group than in the non-neurological group, as presented in Table 1. The frequency of cortisol level lower than 25 μg/dl was similar in the neurological and non-neurological disease groups (33/43 vs 32/39 – odds ratio 1.37 [95% confidence interval, 0.41–4.83]), but the frequency of Δmax < 9 μg/dl was higher in the neurological patients (9/39 vs 7/43), although non-statistically significant (P = 0.2).

Table 1 Table 1

Conclusion

Patients with septic and neurological diseases have higher baseline and post-corticotropin cortisol levels than non-neurological patients, but the frequency of AF is similar between both groups.