Comparison of the Effects of Inhaled and Injectable Lidocaine on Postoperative Complications and Hemodynamic Responses to Endotracheal Intubation in Adults

Abstract

Background: Airway management is an important procedure for adequate oxygenation and ventilation, opening a pathway between the environment and the lungs to allow air to flow. Several complications can occur after endotracheal intubation, leading to functional loss. The use of intravenous lidocaine is another preventive measure to reduce the incidence of postoperative airway complications, which is commonly used by anesthesiologists. This study aimed to "determine and compare the effects of inhaled and injectable lidocaine on postoperative complications and hemodynamic responses to endotracheal intubation in adults with ENT surgery."
Methods: This study is a quasi-experimental study conducted in 2025 at Amiralam Hospital, Tehran, on 150 patients with head and neck surgery. Patients were selected on a convenience basis and then randomly assigned to three groups: injectable lidocaine (n = 50), nebulizer (n = 50), and a control group (n = 50). Patients in the inhaled lidocaine group received 4% inhaled lidocaine (5 ml) 15 min before anesthesia induction. Patients in the intravenous lidocaine group received 1.5 mg/kg of lidocaine 90 seconds before intravenous intubation. However, patients in the control group did not receive lidocaine. The hemodynamic status of patients was assessed and recorded at intervals during anesthesia and postoperative intubation complications. Data were analyzed using SPSS version 25 software.
Results: The average age of patients in the nebulizer (47.52±13.64), injectable (49.16±11.64), and control (46.52±13.13) groups (P>0.05). Based on statistical tests, the mean blood oxygen level as well as the mean systolic, diastolic, and mean blood pressure of the patients in the injection group were higher than those in the nebulizer group at the time intervals immediately, one minute, three minutes, and five minutes after intubation (P<0.05). The prevalence of impaired blood oxygen saturation and bradycardia in the nebulizer group was higher than that in the injection group, while the prevalence of laryngospasm and coughing after surgery was higher in the injection group than in the nebulizer group (P<0.05).
Conclusion: The use of both injectable and nebulized lidocaine methods immediately before intubation reduces hemodynamic responses and postoperative complications. Also, each of the nebulized and injectable lidocaine has a better effect on a number of items of hemodynamic status and complications after intubation of patients. Accordingly, the use of lidocaine is recommended in patients undergoing ear, throat, and nose surgery under general anesthesia.