Hypothalamic-pituitary-adrenal axis dysfunction in critically ill patients with traumatic brain injury: Incidence, pathophysiology, and relationship to vasopressor dependence and peripheral interleukin-6 levels

OBJECTIVETo investigate hypothalamic-pituitary-adrenal axis function in patients requiring mechanical ventilation for traumatic brain injury and to assess the relation of hypothalamic-pituitary-adrenal axis abnormalities with vasopressor dependence and peripheral cytokine levels. DESIGNProspective s...

Full description

Saved in:

Bibliographic Details
Published in:	Critical care medicine Vol. 32; no. 2; pp. 404 - 408
Main Authors:	Dimopoulou, Ioanna, Tsagarakis, Stylianos, Kouyialis, Andreas T, Roussou, Paraskevi, Assithianakis, Georgios, Christoforaki, Marietta, Ilias, Ioannis, Sakas, Damianos E, Thalassinos, Nikolaos, Roussos, Charis
Format:	Journal Article
Language:	English
Published:	Hagerstown, MD by the Society of Critical Care Medicine and Lippincott Williams & Wilkins 01-02-2004 Lippincott
Subjects:	Adrenocorticotropic Hormone - pharmacology Adult Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy Biological and medical sciences Brain Injuries - blood Brain Injuries - diagnosis Brain Injuries - physiopathology Corticotropin-Releasing Hormone Critical Illness Female Humans Hydrocortisone - blood Hydrocortisone - pharmacology Hypothalamo-Hypophyseal System - physiopathology Incidence Intensive care medicine Interleukin-6 - blood Male Medical sciences Pituitary-Adrenal System - physiopathology Prospective Studies Vasoconstrictor Agents - pharmacology Human Intensive care primary adrenal dysfunction Endocrine gland Critically ill Low dose Cytokine Central nervous system traumatic brain injury human corticotropin releasing hormone test Trauma interleukin-6 Encephalon Incidence low-dose corticotropin stimulation test Interleukin 6 Dependence Pituitary gland Corticotropin Resuscitation
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	OBJECTIVETo investigate hypothalamic-pituitary-adrenal axis function in patients requiring mechanical ventilation for traumatic brain injury and to assess the relation of hypothalamic-pituitary-adrenal axis abnormalities with vasopressor dependence and peripheral cytokine levels. DESIGNProspective study. SETTINGGeneral intensive care unit in a university teaching hospital. PATIENTSForty patients (33 men and 7 women) with moderate to severe traumatic brain injury (mean age, 37 ± 16 yrs) were studied the day after termination of mechanical ventilation (7–60 days after trauma). INTERVENTIONSFirst, a morning blood sample was obtained to measure baseline cortisol, corticotropin, interleukin-6, and tumor necrosis factor alpha. Subsequently, 1 μg of synthetic corticotropin was injected intravenously, and 30 mins later, a second blood sample was drawn to determine stimulated plasma cortisol. Based on data derived from healthy volunteers, patients having stimulated cortisol levels <18 μg/dL were defined as nonresponders to the low-dose stimulation test. Thirty-one patients underwent also a human corticotropin releasing hormone test. MEASUREMENTS AND MAIN RESULTSIn traumatic brain injury patients, mean baseline and low-dose stimulation test-stimulated cortisol levels were 17.2 ± 5.4 μg/dL and 24.0 ± 6.6 μg/dL, respectively. The median increment in cortisol was 5.9 μg/dL. Basal corticotropin levels ranged from 3.9 to 118.5 pg/mL. Six of the 40 patients (15%) failed the low-dose stimulation test. The human corticotropin releasing hormone test (performed in 26 responders and five nonresponders) revealed diminished cortisol release only in the low-dose stimulation test nonresponder patients. Corticotropin responses to corticotropin releasing hormone were consistent with both primary (three patients) and/or secondary (two patients) adrenal dysfunction. In retrospect, nonresponders to the low-dose stimulation test more frequently required vasopressors (6/6 [100%] vs. 16/34 [47%]; p = .02) and for a longer time interval (median, 0 vs. 293 hrs; p = .006) compared with responders. Furthermore, nonresponders had higher interleukin-6 levels compared with responders (56.03 vs. 28.04 pg/mL; p = .01), whereas tumor necrosis factor alpha concentrations were similar in the two groups (2.42 vs. 1.55 pg/mL; p = .53). CONCLUSIONSAdrenal cortisol secretion after dynamic stimulation is deficient in a subset of critically ill patients with moderate to severe head injury. This disorder is associated with prior vasopressor dependency and higher interleukin-6 levels.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0090-3493 1530-0293
DOI:	10.1097/01.CCM.0000108885.37811.CA