Suppression of cough during emergence from general anesthesia: laryngotracheal
lidocaine through a modified endotracheal tube.
Author(s): Diachun CA, Tunink BP, Brock-Utne JG.
Affiliation(s): Department of Anesthesia, Stanford University School of Medicine, Stanford, CA
94305-5640, USA. Carol_Diachun@urmc.rochester.edu
Publication date & source: 2001, J Clin Anesth. , 13(6):447-51
STUDY OBJECTIVE: To ascertain if coughing during emergence from general
anesthesia 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 elective
surgery.
INTERVENTIONS: Patients underwent general anesthesia with the laryngotracheal
instillation of topical anesthesia (LITA) endotracheal tube (ETT). Thirty minutes
before anticipated extubation, one investigator administered, via the LITA tube
injection port onto the laryngotracheal mucosa, one of the following according to
randomized preselection: 2 mg/kg with 4% lidocaine (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 adequately anesthetized, the oropharynx was gently
suctioned, and the isoflurane was then turned off. When the isoflurane end-tidal
concentration was < or =0.2%, the neuromuscular block was reversed and the
inspiratory oxygen concentration was increased to 100% while awaiting the return
of spontaneous ventilation.
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. The observer
noted the responses to the following verbal commands, in this order: 1) "open
your eyes", 2) "grip my hand", and 3) "lift your head". Coughing was defined as
any evidence of irritation from having a tube in the trachea. 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 laryngotracheal topical lidocaine administered by
the LITA tube can, in most cases, provide a smooth emergence from general
anesthesia without coughing.
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