Influences of hydrocortisone therapy on arginine vasopressin plasma levels in septic shock.

Concomitant hydrocortisone and arginine vasopressin therapy increases arginine vasopressin plasma levels and may improve survival in septic shock. The objective of this post hoc analysis of a prospective study was to determine whether hydrocortisone therapy increases arginine vasopressin plasma levels in patients with septic shock. Forty-five patients were included into the study, of whom 23 (51.1%) received a hydrocortisone infusion because of escalating vasopressor dosages. Median arginine vasopressin plasma levels did not differ between patients treated with and without hydrocortisone therapy [4.2 (2.2-6.2) vs. 4.3 (2.7-6.1) pmol/L] both in a bivariate (p = 0.43, Mann-Whitney U-test) and a logistic regression model adjusted for differences in disease severity (p = 0.38). No association was further detected between hydrocortisone therapy and arginine vasopressin plasma levels in an adjusted linear regression model [β-coefficient, -0.57 (-1.86-0.73), p = 0.39]. We conclude that increased arginine vasopressin plasma levels during concomitant arginine vasopressin and hydrocortisone therapy in septic shock result from reduced arginine vasopressin clearance and not increased arginine vasopressin secretion or interaction of hydrocortisone with the arginine vasopressin assay.