Suppression of cough during emergence from general anesthesia: Laryngotracheal lidocaine through a modified endotracheal tube

Study Objective: To ascertain if coughing during emergence from general ane sthesia can be suppressed with a modified endotracheal tube. Design: Randomized, double-blind, controlled study. Setting: Operating rooms at a university hospital. Patients: 46 adult ASA physical status I, II, and III patients requiring el ective surgery. Interventions: Patients underwent general anesthesia with the laryngotrache al instillation of topical anesthesia (LITA (TM)) endotracheal tube (ETT). Thirty minutes before anticipated extubation, one investigator administered , via the LITA (TM) tube injection port onto the laryngotracheal mucosa, on e of the following according to randomized preselection: 2 mg/kg with 4 % l idocaine (Group I; n = 15); 4 mL with saline (Group 2; n = 16); and nothing (Control; n = 15). At the completion of surgery, with the patient adequate ly anesthetized, the oropharynx was gently suctioned, and the isoflurane wa s then turned off. When the isoflurane end-tidal concentration was : 0.2%, the neuromuscular block was reversed and the inspiratory oxygen concentrati on was increased to 100% while awaiting the return of spontaneous ventilati on. Measurements: An observer who was blinded to the study drug regimens judged the presence or absence of cough upon emergence, over a 1-minute period. T he observer noted the responses to the following verbal commands, in this o rder: 1) "open your eyes", 2) "grip my hand", and 3) "lift your head". Coug hing was defined as any evidence of irritation from having a tube in the tr achea. Blood samples for plasma lidocaine levels were taken at the time of extubation from patients who received lidocaine (Group 1). Main Results: Seventy-five Percent of Patients were found to have complete cough suppression upon emergence, while Group 2 (saline) had 14 % and Group 3 (the Control) only had 13 % suppression. Conclusions: The technique of l aryngotracheal topical lidocaine administered by the LITA (TM) tube can, in most cases, provide a smooth emergence from general anesthesia without cou ghing. (C) 2001 by Elsevier Science Inc.