Hypoadrenalism following trauma: is sepsis always necessary?

PURPOSE OF THE STUDY: Trauma patients can exhibit the systemic inflammatory response syndrome (SIRS) without evidence of infection. SIRS from infection has been associated with hypoadrenalism. We hypothesized that hypoadrenalism can accompany SIRS from trauma without infection. To investigate this further, we performed a retrospective study of trauma patients admitted to the ICU at our rural academic level 1 trauma center from October 2003- June 2005, with measurement of blood cortisol in the first 7 days after injury (N=33). We determined the incidence of hypoadrenalism based on serum cortisol levels and performed a univariate analysis to delineate factors associated with hypoadrenalism. Significant Findings: Twelve of 33 (36.6 %) were diagnosed with hypoadrenalism on mean ICU day 2.8. SIRS was documented in 92% of hypoadrenal patients vs. 52% of patients without hypoadrenalism (p=0.021). No patient had evidence of invasive infection. Younger age and higher ISS were also associated with hypoadrenalism. There were no gender differences identified, although most patients in the study were male. There was a trend toward higher etomidate use in the hypoadrenal group, although this was not statistically significant.
CONCLUSIONS: Trauma patients who demonstrate SIRS early in their ICU course may exhibit hypoadrenalism without infection. Younger age and higher ISS also appear to be associated with this alteration. Further study is needed to determine the true incidence of this condition, and to better delineate which trauma patients are most susceptible.