title: The low-dose corticotropin stimulation test in acute traumatic and non-traumatic brain injury: incidence of hypo-responsiveness and relationship to outcome.
abstract: OBJECTIVE
  To investigate adrenal responses to the low-dose corticotropin (ACTH) stimulation test in acute traumatic or non-traumatic brain injury (BI) and to assess its value in predicting outcome.
  
  
  METHODS
  Prospective study. SETTING. Intensive care unit (ICU) in a university hospital.
  
  
  METHODS
  Seventy-five patients with acute BI, with a median age of 45 years were investigated. BI was due to trauma ( n=51), ischemic stroke ( n=17), subarachnoid hemorrhage ( n=4) or intracerebral hemorrhage (n=3).
  
  
  METHODS
  Blood was taken on day 16 (median) after admission to the ICU to determine baseline cortisol and ACTH. Thereafter, a low-dose stimulation test (LDST) was performed: 1 microg of tetracosactrin was injected and 30 min later a second blood specimen was obtained to measure stimulated cortisol. Patients having a stimulated cortisol below 500 nmol/l were defined as non-responders to the LDST.
  
  
  RESULTS
  Median baseline and stimulated cortisol were 491 nmol/l and 690 nmol/l, respectively. The median increment in cortisol was 154 nmol/l (range 5-579 nmol/l). Mean ACTH was 46+/-21 pg/ml. Ten (13%) patients were non-responders to the LDST; these had a higher mortality rate compared to patients with adequate cortisol production (70 vs 32%, p=0.034). Logistic regression analysis revealed that APACHE II ( p<0.001), Glasgow Coma Scale (GCS) ( p=0.04) and age ( p=0.02) were independent outcome predictors. In contrast, the increment in cortisol ( p=0.26) did not add to outcome prediction.
  
  
  CONCLUSIONS
  Adrenal hypo-responsiveness in the setting of acute traumatic or non-traumatic BI is not an independent outcome predictor in the presence of high APACHE II, low GCS and older age.
authors.affiliation: Department of Critical Care Medicine, Evangelismos Hospital, Medical School, National and Kapodistrian University of Athens, 10675 Athens, Greece. idimo@otenet.gr
authors.forename: Ioanna
authors.initials: I
authors.lastname: Dimopoulou
authors.forename: Stylianos
authors.initials: S
authors.lastname: Tsagarakis
authors.forename: Evangelia
authors.initials: E
authors.lastname: Douka
authors.forename: Maria
authors.initials: M
authors.lastname: Zervou
authors.forename: Andreas T
authors.initials: AT
authors.lastname: Kouyialis
authors.forename: Urania
authors.initials: U
authors.lastname: Dafni
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Thalassinos
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
mesh_terms: D000293:Adolescent; D000304:Adrenal Cortex Function Tests; D000309:Adrenal Insufficiency / Q000175:diagnosis / Q000453:epidemiology*; D000324:Adrenocorticotropic Hormone; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000175:diagnosis* / Q000401:mortality; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D015994:Incidence; D020300:Intracranial Hemorrhages / Q000175:diagnosis* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000401:mortality
chemical_list: D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone