Hemodynamic effects of topical lidocaine on the laryngoscope blade and trachea during endotracheal intubation: a prospective, double-blind, randomized study.

Purpose: Minimizing hemodynamic changes during the peri-intubation period is a concern for anesthesiologists. We investigated the effect of lidocaine sprayed on the laryngoscope blade and trachea on hemodynamics during direct laryngoscopic intubation.

Methods: Seventy-two patients were randomly allocated to one of four groups: 10% lidocaine was sprayed either on the laryngoscope blade (group L), on the trachea (group V), or on the laryngoscope blade and the trachea (group LV). No lidocaine was used in group C. Anesthesia was induced in all patients with remifentanil (effect site concentration: 4.0 ng/ml) and propofol (effect site concentration 4.0 μg/ml) continuous infusion using a target control infusion (TCI) device. Mean arterial pressure (MAP) and heart rate (HR) were recorded during the peri-intubation period.

Results: Changes in MAP and HR over time were markedly different among the four groups (P < 0.05). MAP at 1 min post-intubation was significantly lower in groups L, V, and LV than in group C (86.1 ± 12.7, 85.3 ± 12.6, and 83.7 ± 13.1 vs. 106.3 ± 22.9 mmHg, P < 0.01). Maximum MAP values were lower in groups L and LV than in group C (P < 0.05). HRs at 1, 2, and 3 min post-intubation were lower in group LV than in group C (70.4 ± 9.0 vs. 84.2 ± 15.3; 64.0 ± 8.1 vs. 79.2 ± 15.4; 61.6 ± 8.3 vs. 77.2 ± 14.5 beats/min, P < 0.01, respectively).

Conclusions: Lidocaine sprayed on the laryngoscope blade and/or trachea reduced the hemodynamic response to laryngoscopic intubation during the post-intubation period following anesthetic induction with remifentanil and propofol using a TCI device.