Stress doses of hydrocortisone in high-risk patients undergoing cardiac surgery: effects on interleukin-6 to interleukin-10 ratio and early outcome

Abstract

Background: Severe systemic inflammation (systemic inflammatory response syndrome) associated with cardiac surgery often leads to a worse short-term and long-term outcome. Stress doses of hydrocortisone have been successfully used to improve outcome of CS. The interleukin (IL)-6 to IL-10 ratio is associated with outcome after trauma and major surgery.

Objective: To evaluate immunologic effects (especially IL-6 to IL-10 ratio) of stress doses of hydrocortisone in a high-risk group of patients after cardiac surgery with cardiopulmonary bypass.

Design: Prospective, randomized, double-blinded, placebo-controlled trial.

Setting: Cardiovascular intensive care unit of a university hospital.

Patients: High-risk patients (n = 36) undergoing CS.

Intervention: Stress doses of hydrocortisone or placebo.

Main outcome measures: IL-6 to IL-10 ratio and other markers of systemic inflammation at predefined time points; short-term clinical outcome.

Results: The two study groups did not differ with regard to demographic data. The patients from the hydrocortisone group (n = 19) had significantly lower levels of IL-6 and higher levels of IL-10, resulting in an attenuated change in IL-6/IL-10 ratio (28.7 [6.4/128.7] vs. 292.8 [6.5/534.6] 4 hours after cardiopulmonary bypass; p < 0.001). Patients in the hydrocortisone group had a shorter duration of catecholamine support (1 [1/2] vs. 4 [2/4.5] days; p = 0.02), a shorter length of stay in the intensive care unit (2 [2/3] vs. 6 [4/8] days; p = 0.001), and a lower incidence of postoperative atrial fibrillation (26% vs. 59%; p = 0.04).

Conclusions: Stress doses of hydrocortisone attenuate the evolution of IL-6/IL-10 ratio in patients with systemic inflammatory response syndrome after CS, which seems to be associated with an improved outcome. The immunologic effects of hydrocortisone may thus be both, inhibitory (IL-6) and permissive (IL-10), regarding the immune response.