The Takeaway

"During colonoscopy, the addition of intravenous lidocaine to propofol-based sedation reduced propofol consumption, shortened awakening time, mitigated post-procedural pain and enhanced patient satisfaction"

Physiology Refresh

Lidocaine targets voltage-gated sodium channels located in the cell membranes of nerve fibers. By binding to these channels, lidocaine blocks the influx of sodium ions, which are crucial for the propagation of action potentials — the electrical signals that carry pain messages to the brain.

This blockade halts the transmission of pain signals, preventing them from reaching the brain and resulting in a numbing effect in the localized area. The overall result is that pain sensation is either significantly diminished or completely eliminated for the duration of the drug’s effect.

Abstract

Introduction: Intravenous lidocaine is a promising complementary strategy for sedation during surgical procedures. We performed a systematic review and meta-analysis to compare intravenous lidocaine with placebo as an adjuvant to propofol-based sedation in patients undergoing colonoscopy.

Methods: We searched MEDLINE, Embase and Cochrane databases for randomised controlled trials comparing sedation with propofol and lidocaine vs. propofol and placebo in patients undergoing colonoscopy. The primary outcome was total propofol dose. A random-effects model was used to estimate the mean differences and risk ratios.

Results: We included eight trials with 520 patients. Compared with placebo, intravenous lidocaine reduced propofol consumption during the procedure (mean difference (95%CI): -42.93 mg (-62.89 to -22.97)); shortened awakening time (mean difference (95%CI): -3.38 minutes (-5.92 to -0.84)); reduced post-procedural pain scores (mean difference (95%CI): -1.38 (-2.72 to -0.04)); and increased patient satisfaction scores (mean difference (95%CI): 0.50 (0.30 to 0.70)). There were no significant differences between the groups in procedure duration; endoscopist satisfaction scores; and risk of hypoxia or hypotension.

Discussion: In patients undergoing colonoscopy, the addition of intravenous lidocaine to propofol-based sedation reduced propofol consumption, shortened awakening time, mitigated post-procedural pain and enhanced patient satisfaction compared with placebo. Although the findings are statistically significant, clinical relevance and cost-effectiveness are unclear.

Excerpts

despite its well-established efficacy, propofol may be associated with complications and haemodynamic adverse events, especially in procedures requiring higher doses

Compared with placebo, intravenous lidocaine reduced propofol consumption; shortened awakening time; reduced post-procedural pain scores; and increased patient satisfaction

Subgroup analysis by use of short-acting opioids showed significant subgroup interactions for post-procedural pain score (test for subgroup differences with p < 0.01) and procedure duration (test for subgroup differences with p = 0.08), where lidocaine provided a greater reduction in pain scores and procedure duration in the subgroup that did not receive a short-acting opioid.

Lidocaine use significantly decreased the total amount of propofol required for sedation (mean difference: - 43 mg), corresponding to a 19% reduction compared with the mean dosage required in the placebo group.

Discomfort during colonoscopy is mainly attributed to visceral nociception caused by colonic distension and traction. Lidocaine effectively alleviates visceral pain and does not affect propofol requirements when there is no nociceptive stimulus

this propofol-sparing effect with lidocaine did not reduce the occurrence of intraprocedural cardiorespiratory events of propofol, such as hypoxia or hypotension, since their risk did not differ significantly between both groups.

While it is imperative for physicians to recognise and manage toxicity, further studies are required to investigate appropriate dosing, drug interactions and the applicability of this approach in patients with higher surgical risk.

Citation

Barbosa EC, Aguirre JM, Bertoldi PFE, Santo P, Baraldo S, Nau AL, Meine GC. Intravenous lidocaine with propofol-based sedation for colonoscopy: a systematic review and meta-analysis with trial sequential analysis. Anaesthesia. 2025 Mar 18. doi: 10.1111/anae.16563. Epub ahead of print. PMID: 40102176.

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