Nebulized tetracaine attenuates the hemodynamic response to tracheal intubation

Background : Local anesthetics, principally lidocaine, are commonly administered in an attempt to blunt the hemodynamic response to tracheal intubation. There are no prior investigations evaluating the use of tetracaine in this setting.
Methods : In the present study, 30 female patients (ASA HI) scheduled for elective surgery were randomized to receive inhaled nebulized tetracaine 0.5 mg/kg or nebulized saline. Subsequently, anesthesia was induced with thiopental 5mg/ kg and succinylcholine 1.0 mg/kg. Sixty seconds later, the trachea was intubated. Vital signs were recorded at intubation and at 1-minute intervals for the next 5 minutes.
Results : Patients treated with tetracaine had a significantly ( P <0.05) lower mean heart rate at intubation and all subsequent times. Similarly, there were significant differences ( P <0.05) in mean arterial pressure between tetracaine and control patients at all times post-intubation except at 2 minutes. The inhalation of nebulized tetracaine produced no adverse side effects.
Conclusion : We conclude that nebulized tetracaine significantly attenuates the hemodynamic response to tracheal intubation.