Sufentanil EC50 for Endotracheal Intubation with Aerosol Inhalation of Lidocaine

Abstract Background: Nebulized lidocaine combined with opioid drugs was a classical implementation for awake intubation or rigid bronchoscopy. In this study, aerosol inhalation of carbonated lidocaine combined with sufentanil was accomplished prior to induction of anesthesia, to dig out whether the dosage of sufentanil could less or not, and the sufentanil EC50 for endotracheal intubation under these drugs combination.Methods: Intravenous injection of sufentanil starting at 0.5 μg/kg. Then sufentanil dosages were increased/decreased (step-size 0.05 μg/kg for sufentanil) using Dixon and Massey up and down method in the next patient depending upon previous patient's response within 3 min after intubation. The observation was terminated after 8 reflexes. The hemodynamic indexes were recorded.Results: The EC50 and EC95 of sufentanil with aerosol inhalation of lidocaine for endotracheal intubation was found to be 0.232 μg/kg (95% CI: 0.187-0.270 μg/kg) and 0.447 μg/kg (95% CI: 0.364-0.703 μg/kg). 55.88% out of 34 patients showed hemodynamic index change <20% of baseline during endotracheal intubation.Conclusion: Aerosol inhalation of lidocaine could reduce the dosage of sufentanil for endotracheal intubation. The advantages in lidocaine inhalation for airway anesthesia by ultrasonic atomizer could be recommended in patients who need more stable hemodynamic changes.Trial registration: Chinese Registry of Central Trial, ChiCTR-IOR-17014198. Registered 28 December 2017, http://www.chictr.org.cn/showprojen.aspx?proj=22301