Background: Analysis of serum cortisol concentrations in patients with appropriate adrenocortical function and acute non-critical illness, in three periods of the day (11.30-15.00; 15.00-18.30; 18.30-22.00).
Patients and method: One hundred and thirteen patients(40, 38 and 35, respectively) were evaluated at the Emergency Department. Every patient had a definite diagnosis.
Results: In each period, minimum and mean serum cortisol concentrations were:8-8-8 microg/dl(220,8-220,8-220,8 nmol/l) and 27,8-24,1-29,3 microg/dl (767,3-665,2-808,7 nmol/l). No statistically significant differences were found between period means. A quarter of patients did not show serum cortisol concentrations >= 18 microg/dl (496,8 nmol/l).
Conclusions: Inpatients with acute disease, a random cortisol concentration below 8 microg/dL (220,8 nmol/L) is a strong presumptive evidence of adrenocortical insufficiency.