The Effects of Intravenous Lidocaine and Alfentanil on Airway Irritability and Hemodynamic Stability during Inhaled Induction with Desflurane: A Randomized Double-Blinded Studdy

Background: Because desflurane can cause airway irritability when used to induce anesthesia, drugs aimed at reducing airway irritability. This study investigated the possible differences between lidocaine and alfentanil on the decrease in the airway irritability during desflurane inhaled induction. Methods: 75 patients (25 in each groups) were assigned randomly to induce anesthesia with inhaled desflurane. The breathing circuit was primed with desflurane 6% in 50% O2 and 50% . After pretreatment with 2% lidocaine (1 mg/kg), or alfentanil (10/kg), or saline (7 ml) intravenously 2 minutes before inducing anesthesia, each patient breathed the gas mixture through a tight fitting facemask. The time to loss of consciousness, cough, laryngospasm, excitatory movement and hemodynamics were checked before and after inhalation. Results: The time to loss of consciousness, cough and excitatory movement were lower significantly between in the control group and other groups, but there was no difference between the 2% lidocaine and alfentanil groups. The blood pressure and heart rate were lower in the alfentanil group, but the heart rate was similar. Conclusions: These results explain that intravenous 2% lidocaine appears to be useful. However, Intravenous alfentanil can also reduce the airway irritability and stabilize the hemodynamics significantly when desflurane is used to induce anesthesia.