This topic was selected because an evidence synthesis beats a textbook on it: the trials disagree, or the guidance has moved recently.
THE EVIDENCE
What each source contributes, and how strong it is
Study design first — a cohort and a randomised trial do not carry the same weight.
Design
Year
Journal
What it found
Meta-analysis
2018
The Cochrane database of systemati
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine
Randomised trial
2025
JAMA
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut
Review
2019
British journal of anaesthesia
Systemic lidocaine has antinociceptive effects in both acute and chronic pain
Meta-analysis
2010
Drugs
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use,
Randomised trial
2012
The Clinical journal of pain
Perioperative lidocaine in breast cancer surgery reduced persistent pain at three
Review
2018
Drugs
At commonly recommended doses lidocaine's therapeutic index is very high and plasma
6 resolved citations behind this deck; every point above traces to one of them.
WHERE THE GUIDANCE SITS
What the guidelines and pooled evidence say
2 findings, each on the slide that follows.
The Cochrane database of systematic reviews 2018
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine on early postoperative pain very low quality, with infusion…
Drugs 2010
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use,
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use, brought first flatus up to 23 hours earlier and shortened stay…
WHERE THE GUIDANCE SITS
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine
Meta-analysis · The Cochrane database of systemati
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine on early postoperative pain very low quality, with infusion regimens varying from 1 to 5 mg/kg/h and no consistent stopping point.
Continuous Intravenous Perioperative Lidocaine Infusion for Postoperative Pain and Recovery in Adults, The Cochrane database of systematic reviews 2018 · PMID 29864216
WHERE THE GUIDANCE SITS
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use,
Meta-analysis · Drugs
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use, brought first flatus up to 23 hours earlier and shortened stay by about 1.1 days, but had no effect in tonsillectomy, hip arthroplasty or coronary bypass.
Impact of Intravenous Lidocaine Infusion on Postoperative Analgesia and Recovery From Surgery: A Systematic Review of Randomized Controlled Trials, Drugs 2010 · PMID 20518581
WHAT THE TRIALS FOUND
Where randomised evidence moved the question
2 findings, each on the slide that follows.
JAMA 2025
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut function at 72 hours after minimally invasive colon resection (57.3%…
The Clinical journal of pain 2012
Perioperative lidocaine in breast cancer surgery reduced persistent pain at three
Perioperative lidocaine in breast cancer surgery reduced persistent pain at three months from 47.4% to 11.8% and reduced the area of secondary…
WHAT THE TRIALS FOUND
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut
Randomised trial · JAMA
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut function at 72 hours after minimally invasive colon resection (57.3% versus 59.0%) and none of eleven secondary outcomes differed.
Intravenous Lidocaine for Gut Function Recovery in Colonic Surgery, JAMA 2025 · PMID 39602290
The largest trial of the indication lidocaine is most often given for, and it was negative.
Intravenous Lidocaine for Gut Function Recovery in Colonic Surgery, JAMA 2025 · PMID 39602290
WHAT THE TRIALS FOUND
Perioperative lidocaine in breast cancer surgery reduced persistent pain at three
Randomised trial · The Clinical journal of pain
Perioperative lidocaine in breast cancer surgery reduced persistent pain at three months from 47.4% to 11.8% and reduced the area of secondary hyperalgesia.
Perioperative Intravenous Lidocaine Decreases the Incidence of Persistent Pain After Breast Surgery, The Clinical journal of pain 2012 · PMID 22699129
THE NUMBERS
In breast surgery it reduced persistent pain at three months
36 patients randomised.
A striking result in a small trial — worth knowing, and worth treating as hypothesis-generating.
Perioperative Intravenous Lidocaine Decreases the Incidence of Persistent Pain After Breast Surgery, The Clinical journal of pain 2012 · PMID 22699129
IN PRACTICE
What the cohorts and reviews add
2 findings, each on the slide that follows.
British journal of anaesthesia 2019
Systemic lidocaine has antinociceptive effects in both acute and chronic pain
Systemic lidocaine has antinociceptive effects in both acute and chronic pain states, acting via multiple mechanisms beyond sodium channel blockade,…
Drugs 2018
At commonly recommended doses lidocaine's therapeutic index is very high and plasma
At commonly recommended doses lidocaine's therapeutic index is very high and plasma concentrations stay well below cardiotoxic and neurotoxic…
IN PRACTICE
Systemic lidocaine has antinociceptive effects in both acute and chronic pain
Review · British journal of anaesthesia
Systemic lidocaine has antinociceptive effects in both acute and chronic pain states, acting via multiple mechanisms beyond sodium channel blockade, including silencing ectopic discharges and suppressing inflammation.
Molecular Mechanisms of Action of Systemic Lidocaine in Acute and Chronic Pain: A Narrative Review, British journal of anaesthesia 2019 · PMID 31303268
IN PRACTICE
At commonly recommended doses lidocaine's therapeutic index is very high and plasma
Review · Drugs
At commonly recommended doses lidocaine's therapeutic index is very high and plasma concentrations stay well below cardiotoxic and neurotoxic thresholds, which is the basis for judging its benefit-risk against other analgesic strategies.
Perioperative Use of Intravenous Lidocaine, Drugs 2018 · PMID 30117019
THE NUMBERS
In spinal surgery the analgesic effect is consistent
Eight trials, 692 patients, mean difference in pain score.
Benefit is procedure-specific: present in spine and abdominal surgery, absent after hip arthroplasty.
IN THE ROOM
What this changes about the next case
Colour is the strength of the evidence behind each step, not the urgency.
1
1
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine on early postoperative pain very low quality, with infusion regimens varying from 1 to 5 mg/kg/h and no consistent stopping point.
2
2
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use, brought first flatus up to 23 hours earlier and shortened stay by about 1.1 days, but had no effect in tonsillectomy, hip arthroplasty or coronary bypass.
3
3
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut function at 72 hours after minimally invasive colon resection (57.3% versus 59.0%) and none of eleven secondary outcomes differed.
4
4
Perioperative lidocaine in breast cancer surgery reduced persistent pain at three months from 47.4% to 11.8% and reduced the area of secondary hyperalgesia.
5
5
Systemic lidocaine has antinociceptive effects in both acute and chronic pain states, acting via multiple mechanisms beyond sodium channel blockade, including silencing ectopic discharges and suppressing inflammation.
The oral-boards stem on the next slide puts these into one scenario.
KEY TAKEAWAYS
What to carry into the next case
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine
The Cochrane database of systematic reviews 2018
In the ALLEGRO trial, 2% intravenous lidocaine did not improve return of gut
JAMA 2025
Systemic lidocaine has antinociceptive effects in both acute and chronic pain
British journal of anaesthesia 2019
In abdominal and ambulatory surgery, lidocaine infusion reduced pain and opioid use,
Drugs 2010
The Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine
Questions I'll ask you in the room
How does your plan change if the patient is not optimised?
What is the physiology behind what we just did?
Talk me through the trade-off you made there.
What would make you abandon this plan and do something else?
Oral boards stem
A 62-year-old is having an open right hemicolectomy on an enhanced recovery pathway without an epidural, and the resident asks whether to run intravenous lidocaine.
Board questions
1. For intravenous lidocaine given at commonly recommended perioperative doses, describe its therapeutic index and where plasma concentrations sit relative to cardiotoxic and neurotoxic thresholds, and state what that comparison is used for.
Show answer
At commonly recommended doses lidocaine's therapeutic index is very high and plasma concentrations stay well below cardiotoxic and neurotoxic thresholds, which is the basis for judging its benefit-risk against other analgesic strategies.
The safety case for perioperative lidocaine is a margin argument: at recommended doses plasma levels sit well below the cardiotoxic and neurotoxic thresholds, which is what lets you weigh it against other analgesic strategies.
Perioperative Use of Intravenous Lidocaine, Drugs 2018 · PMID 30117019
2. In the ALLEGRO trial, 2% intravenous lidocaine was studied after minimally invasive colon resection. State the primary outcome, the result including both group rates, and what happened to the trial's secondary outcomes.
Show answer
The primary outcome was return of gut function at 72 hours, and lidocaine did not improve it: 57.3% versus 59.0%. None of the eleven secondary outcomes differed either.
ALLEGRO is a clean negative trial: no improvement in 72-hour gut function and no difference in any of eleven secondary outcomes.
Intravenous Lidocaine for Gut Function Recovery in Colonic Surgery, JAMA 2025 · PMID 39602290
3. A systematic review of randomised trials of intravenous lidocaine infusion found benefit in some operations and not others. Name the surgical settings where benefit was seen, quantify the effect on first flatus and on length of stay, and name the three operations in which no effect was found.
Show answer
In abdominal and ambulatory surgery lidocaine infusion reduced pain and opioid use, brought first flatus up to 23 hours earlier and shortened stay by about 1.1 days, but it had no effect in tonsillectomy, hip arthroplasty or coronary bypass.
Lidocaine is not a general-purpose analgesic: in this review the benefit sat in abdominal and ambulatory surgery and vanished in tonsillectomy, hip arthroplasty and coronary bypass.
Impact of Intravenous Lidocaine Infusion on Postoperative Analgesia and Recovery From Surgery: A Systematic Review of Randomized Controlled Trials, Drugs 2010 · PMID 20518581
4. A Cochrane review of 68 trials and 4,525 patients assessed continuous perioperative intravenous lidocaine infusion for early postoperative pain. State the quality of evidence it assigned, describe how much the infusion regimens varied, and explain what that combination prevents you from specifying at the bedside.
Show answer
The Cochrane review found the evidence for lidocaine on early postoperative pain very low quality, with infusion regimens varying from 1 to 5 mg/kg/h and no consistent stopping point. Very low quality evidence plus that spread of regimens means the review cannot specify an infusion rate or a stopping point to use.
Sixty-eight trials and 4,525 patients still left this at very low quality evidence, with rates from 1 to 5 mg/kg/h and no consistent stopping point, so whatever regimen you run is not one the evidence pins down.
Continuous Intravenous Perioperative Lidocaine Infusion for Postoperative Pain and Recovery in Adults, The Cochrane database of systematic reviews 2018 · PMID 29864216
The bottom lineThe Cochrane review of 68 trials and 4,525 patients found the evidence for lidocaine
Sources
[1] Continuous Intravenous Perioperative Lidocaine Infusion for Postoperative Pain and Recovery in Adults, The Cochrane database of systematic reviews 2018 · PMID 29864216 open
[2] Intravenous Lidocaine for Gut Function Recovery in Colonic Surgery, JAMA 2025 · PMID 39602290 open
[3] Molecular Mechanisms of Action of Systemic Lidocaine in Acute and Chronic Pain: A Narrative Review, British journal of anaesthesia 2019 · PMID 31303268 open
[4] Impact of Intravenous Lidocaine Infusion on Postoperative Analgesia and Recovery From Surgery: A Systematic Review of Randomized Controlled Trials, Drugs 2010 · PMID 20518581 open
[5] Perioperative Intravenous Lidocaine Decreases the Incidence of Persistent Pain After Breast Surgery, The Clinical journal of pain 2012 · PMID 22699129 open
[6] Perioperative Use of Intravenous Lidocaine, Drugs 2018 · PMID 30117019 open