Steroid Inhibition of Cytokine-Mediated Vasodilation After Warm Heart Surgery

Abstract

Background Peripheral vasodilation, a potentially adverse effect of warm heart surgery, may be mediated by the perioperative release of cytokines. Corticosteroids may abolish cytokine production and vasodilation. We investigated cytokine production and its inhibition by steroids in patients undergoing elective coronary bypass surgery. Methods and Results Twenty-five patients undergoing coronary bypass surgery with normothermic cardiopulmonary bypass received either preoperative steroid (Solumedrol 250 mg IV, n=16) or no steroid (n=9, control group). Blood samples were obtained serially for 24 hours and assayed for interleukin-6 (IL-6), tumor necrosis factor (TNF), and interleukin-8 (IL-8). In the control patients, the IL-6, TNF, and IL-8 levels were elevated postoperatively and peaked between 3 and 6 hours after surgery (IL-6, 1330±295 [mean±SEM] pg/mL; TNF, 18.4±9.8 pg/mL; and IL-8, 150±51 pg/mL). Cytokine release was abolished in patients receiving preoperative corticosteroid (IL-6, 75±38 pg/mL; TNF, 2.6±0.5 pg/mL; and IL-8, 33±6.7 pg/mL; P <.05). Patients receiving steroid premedication had higher arterial pressure, lower cardiac index, and higher systemic vascular resistance, indicating less vasodilation. Conclusions Our findings demonstrate that cytokine production occurs after normothermic cardiopulmonary bypass. Preoperative administration of steroids abolishes cytokine release and vasodilation.