Comparison of intubating conditions between induction with target-controlled infusion (TCI) of remifentanil and propofol with or without a topical lignocaine spray in elective surgery for adults

Background & objective: Intubation without muscle relaxants is indicated in certain situations. The aim of this study was to compare intubating conditions without muscle relaxants between a combination of induction using target-controlled infusion (TCI) remifentanil and propofol with a topical lignocaine spray and TCI remifentanil and propofol alone in elective surgery. Methodology: Sixty patients, aged 18 to 65 years with ASA I and II classification, were randomized into two groups: the RPL group (n = 30), which received 10 puffs of 10% lignocaine spray over the glottic area before induction followed by TCI remifentanil 4 ng/ml and TCI propofol 4 µg/ml for induction, and the control group (n = 30), which received 10 puffs of topical spray of normal saline before a similar technique of induction. The intubating conditions were assessed using a C-Mac video laryngoscope. Hemodynamic changes and the percentage of patients who required rescue muscle relaxants were recorded. Results: The RPL group showed a significantly higher percentage of easy laryngoscopic procedures (96.7% vs. 56.7%; P < 0.01) and open vocal cord positions (86.7% vs. 56.7%; P = 0.028) than the control group. However, there were no significant differences in overall intubating conditions, requirements for rescue muscle relaxants, or hemodynamic changes between the two groups. Conclusion: A combination of TCI remifentanil and TCI propofol with a topical lignocaine spray facilitated better intubating conditions without muscle relaxants compared to this combination without topical lignocaine. Abbreviations: Cet: effect-site concentration, Cpt: target plasma concentration, ETT: Endotracheal tube, LOC: loss of consciousness, NS: Normal saline, TCI: Target-controlled infusion, Keywords: Muscle Relaxants; Remifentanil; Propofol; Lignocaine; Vocal Cord Citation: Khan SN, Wan Hassan WMN, Seevaunnatum P, Mazlan MZ, Hassan MH. Comparison of intubating conditions between induction with target-controlled infusion (TCI) of remifentanil and propofol with or without a topical lignocaine spray in elective surgery for adults. Anaesth. pain intensive care 2025;29(2):163-169. DOI: 10.35975/apic.v29i2.2699 Received: August 10, 2024; Reviewed: September 26, 2024; Accepted: September 26, 2024