The routine anesthesia induction strategy for cardiac surgery is to decrease stress response during endotracheal intubation by using large doses of opioids. However, high doses of opioids often leads to persistent and recurrent hypotension in patients from the anesthesia induction period to the beginning of the surgery. Patients scheduled to accept cardiac surgery often have severe concomitant disease. Hemodynamic fluctuation might lead to disastrous events. Anesthesia induction for such patients should not only provide adequate depth of anesthesia to decrease the stress response of endotracheal intubation, but also make hemodynamics stable after tracheal intubation.
The aim of the induction is to decrease stress response of endotracheal intubation. It is also important to keep hemodynamics stable during and after the induction period. Previous studies have shown that topical anesthesia can provide excellent superior supraglottic and subglottic local anesthetic effects and can significantly reduce the dosage of intravenous anesthetics. Therefore, it is significant to explore whether the combination of topical anesthesia and intravenous anesthetics could decrease the stress response of endotracheal intubation and keep hemodynamics stable during and after the induction period.