title: High-dose lidocaine reduces airway mucus transport velocity in intubated anesthetized dogs.
abstract: BACKGROUND
  Assessment of mucociliary clearance with displacement of charcoal markers in the central airways needs a bronchoscopic procedure and thus local anesthesia of the upper airways. However, the effects of lidocaine administration on mucus transport in airways are inconclusive. Therefore, detailed information is needed to establish the effects of high- and low-dose lidocaine administration.
  
  
  OBJECTIVE
  To study the dose-dependent effect of instillation of lidocaine on mucus transport velocity (MTV) in intubated, anaesthetized dogs.
  
  
  METHODS
  Displacement of a charcoal spot in time was studied with a bronchoscope in 10 anaesthetized dogs before and after administration of respectively 5 and 10 ml of either 2% lidocaine (n=5) or NaCl 0.9% (n=5). In addition, mucus viscoelastic properties were determined.
  
  
  RESULTS
  No significant differences in MTV were observed after administration of 5 ml of NaCl (8.2+/-3.2 mm/min) or 2% lidocaine (6.7+/-3.8 mm/min) compared to baseline values. By contrast, MTV was reduced after administration of 10 ml of 2% lidocaine (1.9+/-1.0 mm/min; P<0.05 vs. baseline and 5 ml of 2% lidocaine vs. controls, P=0.0035), but not after 10 ml of NaCl (6.2+/-2.1 mm/min). A trend towards an increased mucociliary clearability index was observed for the lidocaine-treated group as compared to the control group (P=0.07). The cough clearability index was not different between groups (P=0.89).
  
  
  CONCLUSIONS
  High-dose lidocaine reduces MTV. Therefore, only low-dose lidocaine administration should be applied in the bronchoscopic procedure for assessment of MTV.
authors.affiliation: Respiratory Muscle Research Unit, Laboratory of Pneumology and Respiratory Division, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium. Rik.Grosselink@uz.kuleuven.ac.be
authors.forename: Rik
authors.initials: R
authors.lastname: Gosselink
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Gayan-Ramirez
authors.forename: Els
authors.initials: E
authors.lastname: Houtmeyers
authors.forename: Kristel
authors.initials: K
authors.lastname: de Paepe
authors.forename: Marc
authors.initials: M
authors.lastname: Decramer
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001980:Bronchi / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004548:Elasticity / Q000187:drug effects; D007442:Intubation, Intratracheal; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D009093:Mucus / Q000187:drug effects*; D014783:Viscosity / Q000187:drug effects
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine