Impact of intravenous lidocaine infusion on postoperative analgesia and recovery from surgery: a systematic review of randomized controlled trials.

Postoperative pain continues to be inadequately managed. While opioids remain the mainstay for postoperative analgesia, their use can be associated with adverse effects, including ileus, which can prolong hospital stay. A number of studies have investigated the use of perioperative intravenous lidocaine infusion for improving postoperative analgesia and enhancing recovery of bowel function. This systematic review was performed to determine the overall efficacy of intravenous lidocaine infusion on postoperative analgesia and recovery from surgery in patients undergoing various surgical procedures. We searched the databases of MEDLINE, CINAHL and the Cochrane Library from 1966 to December 2009. We searched for randomized controlled comparisons of lidocaine infusion with placebo in the surgical setting and reporting on postoperative analgesia and other aspects of patient recovery from surgery. The quality of all included studies was assessed using the Modified Oxford Scale. Information on postoperative pain intensity and analgesic requirements was extracted from the trials and compared qualitatively. Other relevant data such as return of bowel function, length of hospital stay, intraoperative anaesthetic requirement and adverse effects were also compared. Sixteen trials were included. A total of 395 patients received intravenous lidocaine with 369 controls. In open and laparoscopic abdominal surgery, as well as in ambulatory surgery patients, intravenous perioperative infusion of lidocaine resulted in significant reductions in postoperative pain intensity and opioid consumption. Pain scores were reduced at rest and with cough or movement for up to 48 hours postoperatively. Opioid consumption was reduced by up to 85% in lidocaine-treated patients when compared with controls. Infusion of lidocaine also resulted in earlier return of bowel function, allowing for earlier rehabilitation and shorter duration of hospital stay. First flatus occurred up to 23 hours earlier, while first bowel movement occurred up to 28 hours earlier in the lidocaine-treated patients. Duration of hospital stay was reduced by an average of 1.1 days in the lidocaine-treated patients. Administration of intravenous lidocaine infusion did not result in toxicity or clinically significant adverse events. Lidocaine had no impact on postoperative analgesia in patients undergoing tonsillectomy, total hip arthroplasty or coronary artery bypass surgery. In conclusion, intravenous lidocaine infusion in the perioperative period is safe and has clear advantages in patients undergoing abdominal surgery. Patients receiving lidocaine infusion had lower pain scores, reduced postoperative analgesic requirements and decreased intraoperative anaesthetic requirements, as well as faster return of bowel function and decreased length of hospital stay. Further studies are needed to assess whether lidocaine has a beneficial effect in patients undergoing other types of surgery and to determine the optimum dose, timing and duration of infusion of lidocaine in this setting.