Perioperative intravenous lidocaine infusion for postoperative pain control: a meta-analysis of randomized controlled trials.
BACKGROUND
Various strategies have been proposed for postoperative pain control. Among those, intravenous lidocaine infusion (IVLI) has gained in interest. However, its clinical benefit remains unclear. This systematic review is an evaluation of the analgesic efficacy and safety of IVLI during general anesthesia.


METHODS
A systematic search was performed using MEDLINE, EMBASE, Cochrane, and SCOPUS databases, likewise, grey literature. The review included all randomized controlled trials that used a placebo or any comparator and evaluated IVLI during general anesthesia for any type of surgery. Primary outcomes were pain control and opioid requirement. Secondary outcomes were mortality, length of stay, ileus recovery time, nausea/vomiting, and adverse events. Random effects models were used and heterogeneity was assessed using the I2 index.


RESULTS
From 5,472 citations retrieved, 29 studies involving a total of 1,754 patients met eligibility. At six hours postoperatively, intravenous lidocaine infusion reduced pain at rest (weighted mean difference [WMD]-8.70, 95% confidence intervals [CI] -16.19 to -1.21), during cough (WMD -11.19, 95% CI -17.73 to -4.65), and during movement (WMD -9.56, 95% CI -17.31 to-1.80). Intravenous lidocaine infusion also reduced opioid requirement (morphine) (WMD -8.44 mg, 95% CI -11.32 to -5.56), time to first flatus (WMD -7.62 hr, 95% CI-10.78 to -4.45), time to first feces (WMD -10.71 hr, 95% CI -16.14 to -5.28), nausea/vomiting (risk ratios = 0.71, 95% CI 0.57-0.90), and hospital length of stay (WMD -0.17 days, 95% CI -0.41 to 0.07). Abdominal surgery was strongly associated with benefit. For the 12 studies that systematically screened adverse events, the incidence of cardiac and neurologic adverse events was comparable. Eight studies observed toxic plasma levels.


CONCLUSIONS
Perioperative IVLI reduced postoperative pain and opioid requirement, as well as ileus recovery time, hospital length of stay, and nausea/vomiting. Intravenous lidocaine infusion was effective mainly in abdominal surgery populations. Considering that toxic levels were detected and that adverse events were not systematically screened for in most studies, dose and safety of IVLI should be established before recommending its use.
Département d'Anesthésiologie, Division de Soins Intensifs, Centre Hospitalier Affilié Universitaire de Québec, Hôpital de l'Enfant-Jésus, Université Laval, Quebec,QC G1J 1Z4, Canada.
Louise
L
Vigneault
Alexis F
AF
Turgeon
Dany
D
Côté
François
F
Lauzier
Ryan
R
Zarychanski
Lynne
L
Moore
Lauralyn A
LA
McIntyre
Pierre C
PC
Nicole
Dean A
DA
Fergusson
D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000768:Anesthesia, General / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007262:Infusions, Intravenous; D007902:Length of Stay; D008012:Lidocaine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010149:Postoperative Pain / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D008012:Lidocaine