American Journal of Respiratory and Critical Care Medicine Vol 173. pp. 934, (2006)
© 2006 American Thoracic Society
Association between Adrenal Insufficiency and Ventilator Weaning
To the Editor:
We read with great interest the recent article by Huang and Lin (1) showing that, in patients with adrenal insufficiency, a stress dose of hydrocortisone improves the success of ventilator weaning in the intensive care unit. The authors state that they cannot explain the result from a physiologic point of view. Based on findings in critically ill patients with septic shock, they speculate that hydrocortisone supplementation increases the weaning success by improving hemodynamic stability.
We would like to propose another mechanism by which stress dose steroids might positively affect the weaning trial. The weaning process constitutes a stressful situation for the organism. Recent research suggests that cytokine production is not restricted to injurious, inflammatory, and infectious insults, but that cytokines are also elaborated in large amounts in response to physical or psychologic stressors (2). Our group (3) and others (4) have shown that critically ill patients with high cortisol levels have lower interleukin (IL)-6 concentrations. Animal studies suggest that cytokines, in particular tumor necrosis factor- and IL-6, may depress the contractility of the diaphragm and of the peripheral muscles (5, 6). Thus, at least from a theoretical point of view, hydrocortisone supplementation may increase weaning success not only by providing hemodynamic stability but also by suppressing cytokine concentrations.
Regardless of the underlying pathophysiology, the study of Huang and coworkers is of extreme originality and has significant clinical implications.
Ioanna Dimopoulou
Attikon University Hospital, Athens University Medical School Athens, Greece
FOOTNOTES
Conflict of Interest Statement: I.D. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript.
REFERENCES
- Huang C-J, Lin H-C. Association between adrenal insufficiency and ventilator weaning. Am J Respir Crit Care Med 2006;173:276280.[Abstract/Free Full Text]
- Turnbull AV, Rivier CL. Regulation of the hypothalamic-pituitary-adrenal axis by cytokines: actions and mechanisms of actions. Physiol Rev 1999;79:171.[Abstract/Free Full Text]
- Dimopoulou I, Tsagarakis S, Kouyialis AT, Roussou P, Assithianakis G, Christoforaki M, Ilias I, Sakas DE, Thalassinos N, Roussos C. Hypothalamic-pituitary-adrenal dysfunction in critically ill patients with traumatic brain injury: incidence, pathophysiology, and relationship to vasopressor dependence and peripheral interleukin-6 levels. Crit Care Med 2004;32:404408.[CrossRef][Medline]
- Hoen S, Asehnoune K, Brailly-Tabart S, Mazoit JX, Benhamou D, Moine P, Edouard AR. Cortisol response to corticotropin stimulation in trauma patients: influence of hemorrhagic shock. Anesthesiology 2002;97:807813.[CrossRef][Medline]
- Reid MB, Lannergren J, Westerblad H. Respiratory and limb muscle weakness induced by tumor necrosis factor-alpha: involvement of muscle myofilaments. Am J Respir Crit Care Med 2002;166:479484.[Abstract/Free Full Text]
- Janssen SP, Gayan-Ramirez G, Van den Bergh A, Herijgers P, Maes K, Verbeken E, Decramer M. Interleukin-6 causes myocardial and skeletal muscle atrophy in rats. Circulation 2005;111:9961005.[Abstract/Free Full Text]
Copyright © 2006 American Thoracic Society
|