Impact Of Lidocaine Infusion On The Recovery Of Bowel Function In Patients Undergoing Colorectal Surgery

Objective: The purpose of this experiment was to investigate the beneficial effects of perioperative systemic lidocaine on postoperative pain, gastrointestinal motility and inflammatory response on colorectal surgery.Methods: A total number of forty ASAⅠ～Ⅱpatients undergoing colorectal surgery were assigned randomly to lidocaine or placebo treatment. Before induction of general anesthesia, an intravenous lidocaine bolus (1.5 mg/kg) was administered followed by a continuous lidocaine infusion (2mg/kg/h) until 2 hours postoperatively. Patients in the contrast group received an equal volume of saline. Each group was induced with propofol 1 mg/kg, vecuronium 0.15mg/kg, fentanyl 5μg/kg, midazolam 0.1 mg/kg. Anesthesia was maintained with propofol 3mg/kg/h infusion and isoflurane(adjusted according to the bispectral index and arterial blood pressure). Fentanyl was administered when the end-tidal concentration of isoflurane was above 1.0 MAC and the arterial blood pressure increased more than 15% of the preinduction value or heart rate was greater than 100 beats/min. BIS was kept between 40 and 50. Blood samples were drawn before induction, 2 hours after incision, and 2, 24hours after surgery. Plasma concentration of IL-6 was measured. Fentanyl consumption during and after surgery, end-tidal concentration of isoflurane every 15 minutes, VAS scores, flatus time, defecation time, and length of hospital stay were recorded.Results: (1) Patients in lidocaine group required less fentanyl intraoperatively than those in contrast group (6.82±0.79) vs (8.35±0.86)μg/kg,(p<0.001). (2) Fentanyl consumption in the PCA was much less in the lidocaine group in the first postoperative day, (262.75±118.29) vs(397.50±143.60)μg, P<0.01. But the difference was not significant in the second postoperative day. (3) The first flatus time after operation was significantly shorter in lidocaine group,(56.70±11.51)vs(69.60±11.13) hours, P<0.001. But the first defecation time was similar in two groups. The length of hospital stay was shorter in lidocaine group, (7.60±0.60)vs(8.45±0.83)days. (4) The end-tidal concentrations of isoflurane were lower in the lidocaine group at each time point. (5) The resting and moving VAS scores were significantly lower in lidocaine group in 2 hours, 6 hours after operation, 12AM and 6PM in the first postoperative day. (6) Plasma concentrations of IL-6 were significantly lower in lidocaine group in 2 hours after incision and 2 hours after operation. No side effects of lidocaine were seen in either groups.Conclusions: (1) Perioperative lidocaine infusion led to a significant reduction in requirement of fentanyl and isoflurane in anesthesia, and it also improved the quality of postoperative analgesia with less fentanyl consumption. (2) Lidocaine significantly suppressed surgery-induced inflammatory response and attenuated the plasma level of IL-6. (3) Lidocaine significantly accelerated the recovery of bowel function and shortened length of hospital stay. Systemic lidocaine may thus provide a convenient and inexpensive approach to improve outcome for patients undergoing colorectal surgery.