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 micrograms/kg was given intravenously (i.v.), and 3 minutes later anesthesia was induced with thiopental sodium 5 mg/kg i.v. and succinylcholine 1.5 mg/kg i.v.. 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.