High incidence of decreased cortisol reserve in brain-dead potential organ-donors

To investigate the adrenocortical function in brain-dead, potential organ donors, 36 patients (27 men, 9 women) with severe brain injury (BI), having a mean age of 42 ± 18 years were studied. Group A, consisted of 20 BI patients who did not develop brain-death (BD), and group B, was comprised of 16 BI patients who became brain-dead. Of these, seven patients were admitted in the hospital after clinical BD. In all patients (group A and group B), a morning blood sample was obtained upon admission in the ICU to determine baseline plasma cortisol levels. Subsequently, 1 μg of corticotropin (ACTH, synacthen) was administered intravenously and a second blood sample was drawn 30 min following the injection. In group B patients, the same procedure was repeated the morning following the confirmation of BD. Patients having a cortisol level of at least 18 μg/dl following the administration of ACTH were defined as responders. After the occurrence of BD, group B patients had significantly lower values for baseline (8.8 ± 6.3 vs 17.0 ± 6.6 μg/dl, P < 0.001) and stimulated (16.8 ± 6.5 vs. 23.9 ± 5.7 μg/dl, P = 0.001) plasma cortisol levels compared to group A patients. Hormonal data of the nine brain-dead patients studied upon admission in the ICU and after the occurrence of BD were the following: baseline plasma cortisol 23.8 ± 12.0 vs 7.1 ± 4.3 μg/dl, P = 0.008, and stimulated plasma cortisol 28.9 ± 10.5 vs 16.0 ± 4.4 μg/dl, P = 0.01. Thirteen group B patients (81%) and two group A patients (10%) were non-responders to synacthen (P < 0.0001). In group B patients, baseline and stimulated cortisol concentrations were significantly related (r = 0.72, P = 0.002), whereas there was no correlation between baseline cortisol and the increment in cortisol (r =-0.33, P = 0.21). In conclusion, adrenal cortisol secretion following dynamic stimulation is deficient in a substantial proportion of brain-dead patients. This finding calls for reconsideration of corticosteroid replacement therapy, at least in a subset, of brain-dead potential organ donors.