As per recent research conducted in the Department of Anesthesiology and Intensive Care Medicine, Lovran, Croatia, the postoperative regional analgesia helped to maintain immune system among patients who went through total knee replacement (TKR).

Surgical stress and pain after the surgical treatment initiate a pro-inflammatory response which leads to a decrease in body immunity. The low immunity may enhance postoperative complications like lengthening of wound healing and infections. Two components of cellular immunity; natural killer (NK) cells and T lymphocytes play an essential role in maintaining immunity. Therefore, Sandra Velcic Brumnjak and colleagues attempt to preserve and regain cytotoxic potential of NK cells, NKT cells, T lymphocytes and their sub-populations via three types of postoperative analgesia among patients after TKR. The evaluation of which analgesic approach is more useful to strengthen the immune system was also done.

A total of 40 patients were selected for the analysis. These patients were randomly assigned to three groups. Group one patients obtained epidural analgesia; group two patients obtained femoral and sciatic nerve block and group three received systemic multi-modal analgesia. The pain was measured before, immediately after surgery, 24 h and 72 h post-treatment. At the same time point, blood samples were accumulated for peripheral blood mononuclear cells isolation. Flow cytometry was used to detect and assess NKT, NK and T lymphocytes frequencies along with their perforin expression.

A reduction in severe pain was seen in group 1 and 2 as compared to group 3. also, the NKT, NK and T lymphocytes frequencies along with their perforin expression were considerably higher in group 1 and group 2 as compared to group 3. the group one exhibited better outcomes as compared to other two groups, and this reflects a considerable efficacy of regional epidural anaesthesia.