Endocrine Abstracts

Critical illnesses are characterized by increased systemic cortisol availability, a vital part of the stress response. ‘Relative adrenal failure’ (later termed critical illness-related corticosteroid insufficiency or CIRCI) is a condition in which the systemic availability of cortisol is assumed to be insufficiently high to face the stress of the illness, and is most typically thought to occur in the acute phase of septic shock. Researchers suggested that CIRCI can be diagnosed by a suppressed incremental cortisol response to an injection of adrenocorticotropic hormone, irrespective of the baseline plasma cortisol concentration. This concept triggered several randomized clinical trials on the impact of large ‘stress doses’ of hydrocortisone to treat CIRCI, which gave conflicting results. Recent novel insights in the response of the hypothalamus-pituitary-adrenal axis to acute and prolonged critical illnesses challenge the concept of CIRCI, as currently defined, as well as the current practice guidelines for diagnosis and treatment. These novel insights will be presented and integrated within a novel conceptual framework that can be used to re-appreciate adrenocortical function and dysfunction in the context of critical illness. This novel conceptual framework opens perspectives for further research and for preventive and/or therapeutic innovations.