Relative adrenocorticoid insufficiency exists and should be treated.

The issue of relative adrenocortical insufficiency (RAI) in septic shock is confused and uncertain. Multiple definitions of RAI have been proposed, but it is most commonly defined as an increment of less than 250 nmol/L in total serum cortisol level after administration of 250 microg corticotropin. RAI is associated with an increased risk of death, after adjustment for other factors that might independently influence risk. It is likely that the definition of RAI, if it exists, will be modified in the future, based on research that measures the level of free serum cortisol (the active fraction), rather than total serum cortisol (as currently measured). There is strong, but not overwhelming, evidence that administration of low doses of hydrocortisone to patients with septic shock, especially those with RAI, improves survival.