BackgroundNebulized lidocaine reduced stress response for endotracheal intubation. However, the impact of novel lidocaine aerosol inhalation for intubation by ultrasonic atomizer was unclear. Hence, we designed aerosol inhalation of lidocaine by ultrasonic atomizer, to seek whether the dosage of sufentanil for intubation could be less or not.MethodsIntravenous injection of sufentanil started at 0.5 mu g/kg, and sufentanil dosage was increased/decreased (step-size 0.05 mu g/kg for sufentanil) using Dixon's up and down method. The observation was terminated after 8 reflexes.ResultsThe EC50 and EC95 of sufentanil with lidocaine by ultrasonic atomizer for intubation were found to be 0.232 mu g/kg (95% CI: 0.187-0.270 mu g/kg) and 0.447 mu g/kg (95% CI: 0.364-0.703 mu g/kg). 55.88% out of 34 patients showed hemodynamic index change <20% of baseline during intubation.ConclusionAerosol inhalation of lidocaine by ultrasonic atomizer reduced the dosage of sufentanil for endotracheal intubation. Lidocaine inhalation by ultrasonic atomizer for airway anesthesia with minimal dosage of sufentanil could be recommended, particularly in patients who need more stable hemodynamic changes or spontaneous respiration.Trial registrationChinese Registry of Central Trial, ChiCTR-IOR-17014198.Registered 28 December 2017.