Effect of local infiltration with oxytocin on hemodynamic response to surgical incision and postoperative pain in patients having open laparoscopic surgery under general anesthesia.

Abstract

Preemptive analgesia encompasses different perioperative interventions that have the final aim of decreasing postoperative pain and improving recovery. Recently, peripheral analgesic effects of oxytocinergic modulation have been suggested. In this regard, we tested the potential analgesic effects of subcutaneous oxytocin (OT) infiltration in patients submitted to laparoscopic cholecystectomy. Thirty patients with similar general characteristics and medical physical conditions were evaluated. The patients were assigned by simple random selection to one of three groups: (a) OT group (n=10), which received preincisional subcutaneous OT (4µg/4 ml saline) in the surgical sites for trocar placements; (b) Lidocaine group (n=10), which received subcutaneous lidocaine 1% (4ml) in the surgical sites; and (c) Control group (n=10), which did not receive any treatment. Then we measured the effect of those treatments on the hemodynamic variations produced as responses to the surgical incisions and trocar insertions (open port placements using the Hasson technique). Moreover, we assessed the intensity of postoperative pain with the visual analogue scale during recovery and 24hr after surgery. Hemodynamic parameters were stable in both intervention groups (subcutaneous OT and lidocaine) during the surgical incisions and trocar placements, whereas a most likely sympathetic activation due to trocar insertions (open port placements) was not blunted in the placebo group. Furthermore, postoperative pain was diminished in both OT and lidocaine groups when compared to the control group. Preincisional subcutaneous OT administration reduced the hemodynamic response produced by the latter. Furthermore, OT also diminished postoperative pain.