title: Intracuff 160 mg alkalinized lidocaine reduces cough upon emergence from N2O-free general anesthesia: a randomized controlled trial.
abstract: OBJECTIVE
  Chemical and mechanical irritation of the tracheal mucosa influences the incidence of cough at emergence from general anesthesia, potentially leading to significant postoperative complications. This study evaluates the benefits of endotracheal tube (ETT) intracuff alkalinized lidocaine during N2O-free general anesthesia by 1) assessing the in vitro effect of alkalinization on lidocaine diffusion kinetics across the cuff's membrane and 2) evaluating, in a randomized controlled clinical trial, the impact of 160 mg of intracuff alkalinized lidocaine on cough upon emergence from anesthesia for surgery lasting > 120 min.
  
  
  METHODS
  In the in vitro study, diffusion kinetics of various intracuff alkalinized lidocaine amounts (40, 80, and 160 mg) were compared to their non-alkalinized lidocaine controls. In the clinical trial, 80 adult patients (American Society of Anesthesiologists physical status I-III) undergoing urological or gynecological surgery expected to last > 120 min and scheduled for N2O-free general anesthesia were enrolled. The ETT cuffs (high-volume, low-pressure) were filled with either 160 mg of alkalinized lidocaine or a comparable volume of 0.9% saline. The primary outcome was the incidence of cough upon emergence from anesthesia. Sore throat, hoarseness, and postoperative nausea and vomiting were evaluated as secondary outcomes.
  
  
  RESULTS
  Our in vitro study confirmed that alkalinization increases lidocaine diffusion across the membrane of ETT cuffs and suggested that the lidocaine diffusion rate is associated with the initial intracuff lidocaine quantity. Our clinical trial demonstrated that, compared with the saline group, 160 mg of intracuff alkalinized lidocaine reduced the incidence of cough upon emergence from N2O-free general anesthesia (76% vs 34%, respectively; difference 42%; 95% confidence interval, 21% to 62%; P < 0.001) while having no clinical impact on secondary outcomes.
  
  
  CONCLUSIONS
  The use of 160 mg of intracuff alkalinized lidocaine is associated with a decreased incidence of cough upon emergence from N2O-free general anesthesia > 120 min. This trial was registered at www.clinicaltrials.gov (NCT01774292).
authors.affiliation: Department of Anesthesiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Houssine
authors.initials: H
authors.lastname: Souissi
authors.affiliation: Department of Anesthesiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Fréchette
authors.affiliation: Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Murza
authors.affiliation: Department of Anesthesiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Masse
authors.affiliation: Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Éric
authors.initials: É
authors.lastname: Marsault
authors.affiliation: Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Sarret
authors.affiliation: Department of Anesthesiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada.
authors.forename: Frédérick
authors.initials: F
authors.lastname: D'Aragon
authors.affiliation: Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada. alexandre.parent2@usherbrooke.ca.
authors.forename: Alexandre J
authors.initials: AJ
authors.lastname: Parent
authors.affiliation: Department of Anesthesiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, J1H 5N4, QC, Canada. yanick.sansoucy@usherbrooke.ca.
authors.forename: Yanick
authors.initials: Y
authors.lastname: Sansoucy
mesh_terms: D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D000779:Anesthetics, Local / Q000494:pharmacology; D003371:Cough / Q000517:prevention & control*; D004867:Equipment Design; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods; D008012:Lidocaine / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D017693:Sodium Bicarbonate / Q000008:administration & dosage
chemical_list: D000779:Anesthetics, Local; D017693:Sodium Bicarbonate; D008012:Lidocaine