Intraoperative thoracic epidural anaesthesia attenuates stress-induced immunosuppression in patients undergoing major abdominal surgery

Abstract

Background: Intraoperative stress may suppress the adaptive immune system. Abolished proinflammatory lymphocyte function is associated with higher risk of infection and postoperative complications. We hypothesized that thoracic epidural anaesthesia (TEA) reduces intraoperative stress and thus attenuates lymphocyte decrease and impairment of proinflammatory lymphocyte function.

Methods: Fifty-four patients undergoing major abdominal surgery who had a thoracic epidural catheter inserted were studied. In the TEA-I group, this catheter was used for intraoperative analgesia, whereas the TEA-P group received systemic opioids during surgery. In both groups, patient-controlled epidural analgesia was used for postoperative pain management. Blood samples for immune analyses were obtained before induction of anaesthesia, 2 h after skin incision, and at days 1 and 4 after surgery. Lymphocyte subpopulations, expression of human leucocyte antigen (HLA)-DR on monocytes, plasma concentrations of interleukin (IL)-10, interferon-gamma (IFN-gamma), and IL-12, and concanavalin-A-stimulated concentrations of IFN-gamma and IL-10 were measured. Intraoperative data including bispectral index and plasma concentrations of epinephrine/cortisol were analysed; APACHE-II, SAPS II, and additional postoperative data were documented.

Results: Plasma concentrations of epinephrine and cortisol were significantly lower in the TEA-I patients during surgery. IFN-gamma/IL-10 ratio was significantly higher in the TEA-I group from 2 h after skin incision until day 1. Lymphocyte numbers and T-helper cells were significantly higher in the TEA-I group at day 1, whereas no significant differences were detected among IL-12, HLA-DR, and postoperative clinical course.

Conclusions: Intraoperative use of thoracic epidural catheter reduced stress response and prevented stress-induced perioperative impairment of proinflammatory lymphocyte function.