Background: Two wounds are created after abdominal surgery. The surgical insult to the peritoneal cavity and viscera has not been emphasized as a target for interventions. In animal models vagotomy blunts the intraperitoneal response to induced inflammation. This is not feasible in humans. However a transient chemical afferentectomy after colectomy by using neuraxial blockade (epidural) and intraperitoneal blockade may be possible. We investigated the effects of intraoperative instillation and postoperative infusion of intraperitoneal local anesthetic (IPLA) on recovery parameters after colectomy, in the setting of an established enhanced recovery after surgery (ERAS) program.
Methods: Double blinded, randomized, placebo controlled design. The study group (IPLA) received instillation of intraperitoneal ropivacaine (75 mg) before dissection and postoperative infusion of 0.2% solution at 4 mL/hour for 3 days continuously. The placebo group (NS) was treated as above with 0.9% saline solution. All patients were cared for under ERAS standardized perioperative care. Epidural infusion was stopped on day 2. Patients were discharged from day 3 onwards once criteria met. Perioperative data, surgical recovery score (SRS), complications, and length of stay were recorded. Systemic cytokines response, neuroendocrine parameters, pain measures and opioid use data were collected. Patients were followed up for 60 days.
Results: Sixty patients were recruited. Patients were equivalently matched at baseline. There were no local anesthetic related adverse events. The complication rate, including anastomotic leak rate, was equivalent between groups. IPLA group had better SRS scores for the duration of intraperitoneal infusion. Pain and opioid use was reduced in the IPLA group. Systemic cytokine and cortisol response was diminished in the IPLA group. IPLA group had consistently higher systemic ropivacaine levels than placebo group.
Conclusion: Instillation and infusion of intraperitoneal ropivacaine after colectomy improves early surgical recovery. This was associated with a blunting of postsurgical systemic cytokines and cortisol. Patients also had significantly reduced pain and opioid use over and above the effect of an epidural infusion. Therefore a transient chemical afferentectomy with clinical benefit is possible with this method. A longer IPLA infusion duration needs to be studied. This study is registered at clinicaltrials.gov and carries the ID number NCT00722709.