Adrenal Function in Critical Illness
Condition: Adrenal Insufficiency
MeSH terms: Adrenal Insufficiency; Critical Illness
Study type: Observational

Summary: 
      An appropriate hypothalamic-pituitary-adrenal (HPA) axis response is required to survive
      critical illness. Primary adrenal insufficiency, relative adrenal insufficiency, tissue
      resistance to glucocorticoids, ACTH deficiency and immune-mediated inhibition of the HPA axis
      may impair the secretion or action of glucocorticoids in critically ill patients. Adrenal
      insufficiency is estimated to occur in up to 77% of critically ill patients, but currently,
      there is no consensus on the diagnostic criteria for adrenal insufficiency in this setting,
      and standard testing does not discriminate among the aforementioned factors. We will study
      the incidence and natural history of adrenal insufficiency in critically ill patients to
      further define adrenal insufficiency and provide data to develop diagnostic tests. Clinical
      features and outcomes will be correlated with laboratory measurements of hormones, cytokines
      and glucocorticoid action. Healthy volunteers will undergo cortrosyn tests with measurement
      of free cortisol levels to develop a normative range for this endpoint.

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      Previous glucocorticoid use, if prolonged and supraphysiologic, also inhibits the HPA and can
      result in adrenal insufficiency. Patients with short intermittent courses of glucocorticoid
      administration have not been studied well, and may also be at risk. To gain further
      information about this group, patients receiving pulse glucocorticoid doses as part of bone
      marrow transplant regimens at the Clinical Center will also be studied.
    

Detailed description: 
      An appropriate hypothalamic-pituitary-adrenal (HPA) axis response is required to survive
      critical illness. Primary adrenal insufficiency, relative adrenal insufficiency, tissue
      resistance to glucocorticoids, ACTH deficiency and immune-mediated inhibition of the HPA axis
      may impair the secretion or action of glucocorticoids in critically ill patients. Adrenal
      insufficiency is estimated to occur in up to 77 percent of critically ill patients, but
      currently, there is no consensus on the diagnostic criteria for adrenal insufficiency in this
      setting, and standard testing does not discriminate among the aforementioned factors. We will
      study the incidence and natural history of adrenal insufficiency in critically ill patients
      to further define adrenal insufficiency and provide data to develop diagnostic tests.
      Clinical features and outcomes will be correlated with laboratory measurements of hormones,
      cytokines and glucocorticoid action. Healthy volunteers will undergo cortrosyn tests with
      measurement of free cortisol levels to develop a normative range for this endpoint. Patients
      with known adrenal insufficiency will also be studied to help determine the clinical utility
      of diagnostic tests among these different groups. Previous glucocorticoid use, if prolonged
      and supraphysiologic, also inhibits the HPA axis and can result in adrenal insufficiency.
      Patients with short intermittent courses of glucocorticoid administration have not been
      studied well, and may also be at risk. To gain further information about this group, patients
      receiving pulse glucocorticoid doses as part of bone marrow transplant regimens at the
      Clinical Center will also be studied.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        NIH patients with Cushing's syndrome, adrenal insufficiency, hepatitis, nephrotic syndrome
        surrounding community healthy volunteers
      
Keywords: ACTH; Cortisol; Natural History