Intravenous lidocaine reduces the propofol EC50 for loss of consciousness and intraoperative anesthetic consumption in gynecological laparoscopy: A randomized controlled trial.

TL;DR

In gynecological laparoscopy, intravenous lidocaine bolus with infusion reduced the propofol EC50 for loss of consciousness (3.32 vs 3.89 μg/mL) and decreased intraoperative propofol and remifentanil consumption compared to placebo.

Key findings

• Lidocaine pretreatment decreased propofol effect-site concentration needed for loss of consciousness by approximately 15%
• Intraoperative propofol consumption was reduced in the lidocaine group (8.62 vs 9.89 mg·kg⁻¹·h⁻¹)
• Remifentanil consumption was also lower with lidocaine (0.23 vs 0.27 μg·kg⁻¹·min⁻¹)
• Study used Dixon's up-and-down sequential method in a double-blind randomized controlled design with 60 patients

Why this matters at the bedside

Demonstrates a pharmacodynamic interaction between intravenous lidocaine and propofol that may reduce total anesthetic drug exposure during gynecological laparoscopy, with potential implications for anesthetic dosing strategies and adverse event reduction.