Efficacy of Alkalinized Lidocaine in the Endotracheal Tube Cuff on the Incidence of Coughing During Emergence

Overview

This study is designed to compare the efficacy of endotracheal tube cuffs pre-filled with alkalinized lidocaine on the: * incidence of coughing during emergence of general anesthesia * time needed for emergence following a desflurane-based anesthesia * incidence of sore throat after extubation. The investigator's hypothesis is that the use of endotracheal tube cuffs pre-filled with alkalinized lidocaine will reduce the incidence of coughing by 50% relative to a control group following a desflurane-based anesthesia.

Emergence is an important period of general anesthesia during which several problems can occur. Coughing, hypertension, tachycardia and agitation have been observed during emergence of general anesthesia. Desflurane is a newer volatile agent allowing early recovery from anesthesia. This agent has led to earlier discharge and more rapid resumption of normal activities after surgery. However, an incidence of coughing around 70% has been reported after a desflurane-based anesthesia. Different techniques and drugs have been studied to reduce coughing during emergence. Among others, the role of lidocaine given intravenously, topically, or intracuff has been studied. Intracuff lidocaine has been shown to increase the tolerance to the endotracheal tube without reducing the swallowing reflex. However, lidocaine slowly diffuses across the tube's cuff. The addition of bicarbonates is required to increase its diffusion to the underlying tracheal tissue. Alkalinization of lidocaine allows the diffusion of 65% of its neutral base form over a period of 6 hours. In vitro studies have demonstrated that the optimal time for local anesthetic diffusion through the cuff may vary from 90 to 180 minutes. Due to its low onset, this technique would be appropriate for long-duration surgeries. Pre-filling the endotracheal tube cuffs with alkalinized lidocaine at least 90 minutes before intubation could be appropriate for surgeries expected to last less than two hours. This study will assess the efficacy of pre-filling endotracheal tube cuffs with alkalinized lidocaine to prevent coughing during emergence in short-duration surgeries.