Efficacy and safety of intravenous lidocaine for postoperative analgesia and recovery after surgery: a systematic review with trial sequential analysis

Background: Improvement of postoperative pain and other perioperative outcomes remain a significant challenge and a matter of debate among perioperative clinicians. This systematic review aims to evaluate the effects of perioperative i.v. lidocaine infusion on postoperative pain and recovery in patients undergoing various surgical procedures. Methods: CENTRAL, MEDLINE, EMBASE, and CINAHL databases and ClinicalTrials.gov, and congress proceedings were searched for randomized controlled trials until May 2014, that compared patients who did or did not receive continuous perioperative i.v. lidocaine infusion. Results: Forty-five trials (2802 participants) were included. Meta-analysis suggested that lidocaine reduced postoperative pain (visual analogue scale, 0 to 10 cm) at 1-4 h (MD -0.84, 95% CI -1.10 to -0.59) and at 24 h (MD -0.34, 95% CI -0.57 to -0.11) after surgery, but not at 48 h (MD -0.22, 95% CI -0.47 to 0.03). Subgroup analysis and trial sequential analysis suggested pain reduction for patients undergoing laparoscopic abdominal surgery or open abdominal surgery, but not for patients undergoing other surgeries. There was limited evidence of positive effects of lidocaine on postoperative gastrointestinal recovery, opioid requirements, postoperative nausea and vomiting, and length of hospital stay. There were limited data available on the effect of systemic lidocaine on adverse effects or surgical complications. Quality of evidence was limited as a result of inconsistency (heterogeneity) and indirectness (small studies). Conclusions: There is limited evidence suggesting that i.v. lidocaine may be a useful adjuvant during general anaesthesia because of its beneficial impact on several outcomes after surgery.