Intravenous lidocaine decreased the median effective concentration of sufentanil for tracheal intubation in obese patients undergoing bariatric surgery in a recent study.
Sufentanil is widely used to inhibit hemodynamic responses induced by tracheal intubation. However, using sufentanil during anesthesia induction is associated with reduced heart rate and blood pressure. Intravenous lidocaine attenuates hemodynamic responses without cardiovascular inhibition and may help reduce the required sufentanil dose.
A study in the journal Drug Design, Development and Therapy assessed the effect of intravenous lidocaine on the median effective concentration (EC50) of sufentanil for endotracheal intubation in obese patients.
Study Population and Method
The study was a prospective, randomized, double-blind, and up-and-down sequential allocation trial. Fifty obese patients undergoing bariatric surgery were randomized in a 1:1 ratio to the lidocaine group or the normal saline group. Patient characteristics were similar between the two groups at baseline.
Optimizing Anesthesia Induction With Target-Controlled Infusion
A target-controlled infusion of propofol and sufentanil was used for anesthesia induction. Once the target concentration of propofol and sufentanil was achieved, lidocaine at 1.5 mg/kg or the same volume of normal saline was infused over 3 minutes. Tracheal intubation was performed 3 minutes after the end of the lidocaine or normal saline infusion.
Effect of Lidocaine on Median Effective Concentration of Sufentanil
The dose of sufentanil in the lidocaine group was significantly reduced compared to that in the normal saline group [25 (25–28.8) μg vs. 20 (17.8–23) μg, respectively; P < 0.001]. The use of intravenous lidocaine significantly reduced the EC50 of sufentanil (EC50: 0.36 ng/mL; 95% CI: 0.31–0.41 ng/ mL) compared to normal saline (EC50: 0.50 ng/mL; 95% CI: 0.43–0.62 ng/mL). There was a 28% reduction in the EC50 of sufentanil by intravenous lidocaine.
A total of 38 patients (18 in the lidocaine group and 20 in the saline group) completed the study.
Hemodynamics During Study Period
The hemodynamics were stable in both groups during the study period. Mean arterial blood pressure (MAP) and heart rate (HR) values were not significantly different between the two groups at different time points. The two groups had similar values of MAP and HR at baseline.
In conclusion, adjunct intravenous lidocaine injection at a dose of 1.5 mg/kg significantly reduced the EC50 of sufentanil for tracheal intubation in obese patients undergoing bariatric surgery.
Dong, J., Yuan, X. Q., He, C., & Tu, F. (2023b). Intravenous lidocaine decreased the median effective concentration of sufentanil for tracheal intubation in obese patients. Drug Design Development and Therapy, Volume 17, 2431–2439. https://doi.org/10.2147/dddt.s415872