Serum and salivary cortisol in the diagnosis of adrenal insufficiency and as a predictor of the outcome in patients with severe sepsis.

OBJECTIVES To compare salivary with serum total cortisol in patients with severe sepsis, postoperative patients and healthy controls. MATERIALS AND METHODS Serum total cortisol was determined by chemiluminescence immunoassay; salivary cortisol was determined by enzyme immunoassay. RESULTS In patients with severe sepsis, median concentration of salivary cortisol was 14.0 and 2.6 higher than that of postoperative patients and healthy subjects. In postoperative patients, salivary cortisol was 5.4 times higher than in control patients. Serum total cortisol was also higher in patients with severe sepsis than in controls and postoperative patients. This increment, however, was much lower (2.33 and 1.64, respectively). Patients with a salivary cortisol greater than 7.2 µg/dL had a mortality rate of 80%, a statistically significant result when compared with the group with lower cortisol levels (Z = 2.38 and p < 0.05). CONCLUSIONS Salivary cortisol in critically ill patients may be a better laboratory indicator of cortisol levels than serum total cortisol.