Selective neurogenic blockade and perioperative immune reactivity in patients undergoing lung resection.

Objective: This double-blind, prospective, randomized, controlled trial examined the effects of thoracic epidural block and intravenous clonidine and opioid treatment on the postoperative Th1/Th2 cytokine ratio after lung surgery. The primary endpoint was the interferon γ (IFN-γ; Th1 cytokine)/interleukin 4 (IL-4; Th2 cytokine) ratio. Secondary endpoints were reductions in pain and incidence of pneumonia.
Methods: Sixty patients were randomized into three groups to receive remifentanil intravenously (remifentanil group, n=20), remifentanil and clonidine intravenously (clonidine group, n=20), or ropivacaine epidurally (ropivacaine group, n=20). Pain was assessed using a numerical rating scale (NRS). Cytokines were measured using a cytometric bead array.
Results: Patients in the ropivacaine group (thoracic epidural block) had a significantly lower IFN-γ/IL-4 ratio at the end of surgery than those in the remifentanil group and clonidine group. There were no significant between-group differences in the IFN-γ/IL-4 ratio at other time-points. There were no differences in NRS scores at any time-point. No patient developed pneumonia.
Conclusion: Intraoperative thoracic epidural block decreased the IFN-γ/IL-4 ratio immediately after lung surgery, indicating less inflammatory stimulation during surgery.