Abstract

Introduction: Traumatic brain injury is a cause of death in adult populations. Adrenal insufficiency has a great impact on the prognosis of patients with traumatic brain injury. However there is a lack of consensus regarding the diagnostic criteria of adrenal insufficiency. Our aim was to assess adrenal function in patients with moderate to severe traumatic brain injury. Materials and Methods: In a multicenter case-series study, 50 patients, aged 15 to 70 years, with moderate to severe traumatic brain injury were enrolled from 4 intensive care units in Tehran. Adrenal function was assessed using the 1 and 250µg ACTH stimulation tests. Results: The incidence of adrenal insufficiency in the first 10 days after traumatic brain injury varied from 34% to 82%, based on various definitions of adrenal insufficiency. More cases of adrenal insufficiency were detected by 1µg ACTH stimulation test compared to the basal cortisol and 250µg ACTH tests. Since the gold standard insulin stimulation test is regarded as potentially dangerous in the acute phase of post traumatic brain injury, the sensitivity and specificity of the stimulation tests could not be assessed. Kappa test showed no agreement between the two tests (Kappa=0.17). The incidence of hypotension and vasopressor requirement was higher in patients diagnosed by the 250µg ACTH test. Baseline cortisol had linear correlation with the 60-minute cortisol of both the 1 and 250µg ACTH tests (P<0.0001). Conclusion: The prevalence and associated morbidity of adrenal insufficiency in patients with traumatic brain injury warrant early diagnosis of subclinical cases by dynamic stimulation tests and judicious corticosteroid therapy.