title: Comparison of the force applied on oral structures during intubation attempts by novice physicians between the Macintosh direct laryngoscope, Airway Scope and C-MAC PM: a high-fidelity simulator-based study.
abstract: We examined whether the use of Airway Scope (AWS) and C-MAC PM (C-MAC) decreased the force applied on oral structures during intubation attempts as compared with the force applied with the use of Macintosh direct laryngoscope (DL).
  
  
  
  Prospective cross-over study.
  
  
  
  A total of 35 novice physicians participated.
  
  
  
  We used 6 simulation scenarios based on the difficulty of intubation and intubation devices.
  
  
  
  Our primary outcome measures were the maximum force applied on the maxillary incisors and tongue during intubation attempts, measured by a high-fidelity simulator.
  
  
  
  The maximum force applied on maxillary incisors was higher with the use of the C-MAC than with the DL and AWS in the normal airway scenario (DL, 26 Newton (N); AWS, 18 N; C-MAC, 52 N; p<0.01) and the difficult airway scenario (DL, 42 N; AWS, 24 N; C-MAC, 68 N; p<0.01). In contrast, the maximum force applied on the tongue was higher with the use of the DL than with the AWS and C-MAC in both airway scenarios (DL, 16 N; AWS, 1 N; C-MAC, 7 N; p<0.01 in the normal airway scenario; DL, 12 N; AWS, 4 N; C-MAC, 7 N; p<0.01 in the difficult airway scenario).
  
  
  
  The use of C-MAC, compared with the DL and AWS, was associated with the higher maximum force applied on maxillary incisors during intubation attempts. In contrast, the use of video laryngoscopes was associated with the lower force applied on the tongue in both airway scenarios, compared with the DL. Our study was a simulation-based study, and further research on living patients would be warranted.
authors.affiliation: Department of Emergency Medicine, Fukui Prefectural Hospital, Fukui, Japan.
authors.forename: Taizo
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: Department of Emergency Medicine, Tokyo Bay Urayasu/Ichikawa Medical Center, Noguchi Hideyo Memorial International Hospital, Urayasu, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiga
authors.affiliation: Department of Emergency Medicine, Tokyo Bay Urayasu/Ichikawa Medical Center, Noguchi Hideyo Memorial International Hospital, Urayasu, Japan.
authors.forename: Yosuke
authors.identifier: 0000-0002-0473-9617
authors.initials: Y
authors.lastname: Homma
authors.affiliation: Department of Emergency and Critical Care Medicine, University of Tsukuba Hospital, Tsukuba, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Koyama
authors.affiliation: Department of Emergency Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Goto
mesh_terms: D000328:Adult; D002983:Clinical Competence; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D007180:Incisor; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D020704:Laryngoscopes; D007828:Laryngoscopy / Q000295:instrumentation*; D008297:Male; D008348:Manikins; D008437:Maxilla; D011446:Prospective Studies; D013314:Stress, Mechanical
keywords: ACCIDENT & EMERGENCY MEDICINE; ANAESTHETICS; MEDICAL EDUCATION & TRAINING