Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock

Objective: To investigate plasma concentrations of adrenomedullin in patients with septic shock and the potential association of these concentrations with relaxation of vascular tone. Design: Prospective, case series. Setting: Department of Emergency and Critical Care Medicine, Nara Medical University. Patients: Twelve patients who fulfilled the clinical criteria for severe sepsis or septic shock (as defined by the Members of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee) and 13 healthy volunteers. Interventions: Arterial blood samples were obtained via a 20-gauge cannula inserted into each patient's radial artery. Measurements and Main Results: After extraction and purification, plasma adrenomedullin was measured by radioimmunoassay. Systemic vascular resistance index, pulmonary vascular resistance, cardiac index, and stroke volume index were determined with a thermodilution catheter. The mean plasma concentration of adrenomedullin was markedly higher in patients than in controls (226.1 ± 66.4 [SEM] vs. 5.05 ± 0.21 fmol/mL, p