title: Airway topicalisation in morbidly obese patients using atomised lidocaine: 2% compared with 4%.
abstract: We evaluated the technique of airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in morbidly obese patients using two doses of local anaesthetic. Morbidly obese patients were allocated to receive either 2% or 4% lidocaine (40 ml) for oral airway anaesthesia using an atomiser with high oxygen flow. Patients were carefully sedated using midazolam and fentanyl. Outcomes included patient tolerance to airway manipulation, haemodynamic parameters, and serial plasma lidocaine concentrations. In all, 27 patients were enrolled in the study (2% cohort n = 14, 4% cohort n = 13). Patient characteristics and time for topicalisation and airway management were similar. Haemodynamic parameters did not change significantly. Tolerance to insertion of the Ovassapian airway, bronchoscopy, and tracheal tube positioning was excellent (12 vs 12 patients, 12 vs 12 patients, and 8 vs 12 patients had no response, respectively, 2% vs 4%). Differences did not reach statistical significance. Peak plasma lidocaine concentration was significantly lower in the 2% group (2.8 (0.8) microg.ml(-1) compared with 6.5 (1.0) microg.ml(-1), p < 0.05). Airway anaesthesia using atomised lidocaine for awake fibreoptic intubation in the morbidly obese is efficacious, rapid, and safe. Compared with 4% lidocaine, the 2% dose provides acceptable intubating conditions in most cases and produces lower plasma lidocaine levels.
authors.affiliation: Department of Anaesthesia, McGill University Health Center - Royal Victoria Hospital Site, 687 Pine Ave. W., Montreal, QC, H3A 1A1, Canada. paul.wieczorek@mail.mcgill.ca
authors.forename: P M
authors.initials: PM
authors.lastname: Wieczorek
authors.forename: T
authors.initials: T
authors.lastname: Schricker
authors.forename: B
authors.initials: B
authors.lastname: Vinet
authors.forename: S B
authors.initials: SB
authors.lastname: Backman
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D005336:Fiber Optic Technology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D007442:Intubation, Intratracheal / Q000379:methods*; D008012:Lidocaine / Q000008:administration & dosage* / Q000097:blood; D008297:Male; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000150:complications* / Q000503:physiopathology
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D006993:Hypnotics and Sedatives; D008012:Lidocaine; D008874:Midazolam; D005283:Fentanyl