Evaluation of function of pituitary gland in patients with septic shock and the effect of low-dose corticosteroid therapy

Introduction

There is evidence for the usefulness of low-dose corticosteroids for relative adrenal insufficiency in septic shock. Treatment with low-dose corticosteroid was found to have beneficial effects on hemodynamics and outcome. Relative adrenal insufficiency is often diagnosed by the adrenocorticotropic hormone (ACTH) stimulation test, but it is impossible to evaluate the function of the whole hypothalamus-pituitary-adrenal axis, so there might be possibility to miss the patients who need steroids due to disability of pituitary gland or hypothalamus.

Objectives

We proposed a corticotropine releasing hormone (CRH) stimulation test to evaluate the function of the pituitary gland in patients with septic shock. We also examine the usefulness of low-dose corticosteroid in a nonresponder to the CRH stimulation test.

Methods

One hundred micrograms of CRH is administered to a patient with septic shock. A patient was recognized to be a responder when the plasma concentration of ACTH raised up to 30 pg/dl or three times as high as the control level. For nonresponders, hydrocortisone of 200 mg/day was administered. We evaluated the 28-day mortality and the degree of reduction of cathecolamine and vasopressin, considered as an improvement in the circulatory status in each group.

Results

Of 13 septic patients, three patients were determined as responders and 10 as nonresponders to the CRH stimulation test. For the latter group, hydrocortisone was used for nine patients and, particularly, there were four patients who responded to the ACTH stimulation test in this group. The 28-day survival rate was 33% (1/3) for responders and 60% (6/10) for nonresponders, 66% survived for 28 days who were given low-dose corticosteroid. We could reduce the dose of cathecolamine and vasopressin during 72 hours after the administration of hydrocortisone. Dopamine 7.0 ± 6.6 to 2.0 ± 3.0 μg/kg/min (P = 0.077), dobutamine 1.8 ± 2.4 to 1.0 ± 2.0 μg/kg/min (P = 0.086), noradrenaline 0.106 ± 0.088 to 0.004 ± 0.013 μg/kg/min (P = 0.085) and vasopressin 0.13 ± 0.25 to 0.0 ± 0.0 U/kg/hour (P = 0.232).

Discussion

Based on this study, it is suggested that there are patients who need stress doses of corticosteroid due to malfunction of the pituitary gland even though they responded adequately to the ACTH stimulation test. We used hydrocortisone in all nonresponders. For further details, administration of hydro-cortisone should be examined by randomized, double blind-test, but we think it is too critical to leave the nonreactive patient without corticosteroid.

Conclusion

We propose that the CRH stimulation test is useful to assess the function of the pituitary gland of patients with septic shock.