Nebulized bupivacaine attenuates the heart rate response following tracheal intubation

Study Objective: To determine whether nebulized bupivacaine attenuates the acute hemodynamic response to laryngoscopy and intubation. Design: Prospective, randomized, placebo-controlled study. Setting: Operating room at a university medical center. Patients: 40 health ASA physical status I and II patients scheduled for minor surgical procedures. Interventions: Patients were randomized to receive 4 ml of a nebulized solution of either saline (n = 20) or 0.75% bupivacaine (n = 20) 15 minutes before induction of anesthesia. On completion of the aerosol treatment, fentanyl 1.5 μg/kg was given intravenously (IV), and 3 minutes later anesthesia was induced with thiopental sodium 5 mg/kg IV and succinylcholine 1.5 mg/kg IV. Laryngoscopy was begun 60 seconds after induction, and the trachea was intubated at 90 seconds. Anesthesia was maintained with 50% nitrous oxide in oxygen following intubation, and 1% isoflurane was administered at 180 seconds. Measurements and Main Results: Heart rate (HR) and blood pressure were recorded automatically every 30 seconds for 5 minutes. Bupivacaine significantly attenuated HR ( p < 0.05) but not the hypertensive response to laryngoscopy and intubation. Conclusion: Nebulized 0.75% bupivacaine was only partially effective in blunting the hemodynamic response to tracheal intubation.