Cortisol responses at baseline and after corticotropin in acute aneurysmal subarachnoid haemorrhage: a prospective study

Measurements of total plasma cortisol (TPC) in the acute phase of aneurysmal subarachnoid haemorrhage (aSAH) have suggested a high incidence of adrenal insufficiency (AI).To compare TPC and free plasma cortisol (FPC) measurements in acute aSAH and to assess whether rates of diagnosis of AI based on TPC and FPC criteria were discordant.A prospective, observational study of 20 patients admitted within 7 days of aSAH to a tertiary intensive care unit. Cortisol binding globulin (CBG), TPC and FPC levels were measured at baseline, and cortisol profiles at 30 and 60 minutes after administration of 250_g corticotropin.Compared with controls, the mean baseline FPC (46 nmol/L [SD, 48 nmol/L] v 9 nmol/L [SD, 6 nmol/L],