PURPOSE: Compare salivary cortisol dosage, considered to have a good correlation with serum free cortisol, with total serum cortisol in critical care patients.
METHODS: We studied 47 patients, grouped in 2 different categories: 27 with severe sepsis (SS) and 20 stable pos operative patients (PO) in their last day on intensive care unit (ICU). We include 19 normal controls for comparison. Salivary and serum cortisol were measured on admission in the septic group and in the morning before ICU discharge in the pos operative patients. All the patients and controls also had serum protein (albumin) measured. Salivary cortisol: measured with microplate enzime immunoassay (EIA) by Diagnostic Systems Laboratories® (DSL® –Webster, Texas). Serum total cortisol: measured with Immulite® chemiluminescent immunoassay by Diagnostic Product Corporation® (DPC® –Los Angeles, CA).Serum albumin: measured with Vitros® “dry chemistry” bromcresol green albumin method, by Ortho-Clinical Diagnostics® (J & J® –Rochester NY).
RESULTS: Median salivary cortisol was 14 times higher in SS patients than controls while this difference in median total plasmatic cortisol was only the double (p<0.05) (Table 1). Serum protein levels were uniformly below 2g/L in SS patients.
CONCLUSION: We conclude that salivary cortisol, a broadly available method but still not routinely used, can be a better method to assess hypothalamic-pituitary-adrenal axis in critical care patients, in which serum total cortisol is greatly influenced by low levels of protein, a common complication of these patients.
CLINICAL IMPLICATIONS: Salivary cortisol can become a good , easy and confiable test for the diagnosis of adrenal insufficiency in critical care patients. It is still necessary to determine normal salivary cortisol levels in these patients to establish this criteria.
DISCLOSURE: Eduardo Sad, None.