Assessment of the proficiency and usability of direct laryngoscopy and video laryngoscopy

직접 후두경과 비디오 후두경의 숙련도 및 유용성 평가

  • Shin, Gyo-Seok (National Emergency Medical Center Gyeongbuk Emergency Medical Support Center) ;
  • Tak, Yang-Ju (Department of Paramedic Science, Korea National University of Transportation)
  • 신교석 (국립중앙의료원 경북응급의료지원센터) ;
  • 탁양주 (한국교통대학교 응급구조학과)
  • Received : 2019.03.13
  • Accepted : 2019.04.14
  • Published : 2019.04.30


Purpose: The aim of this study was conducted to assess the proficiency of both direct laryngoscopy and video laryngoscopy and the usefulness of each laryngoscope, thereby provide basic data for further education using video laryngoscopy. Methods: Forty one paramedic subjects participated in this study. Usability was measured with the System usability scale. The Macintosh direct laryngoscope and $C-MAC^{(R)}$ video laryngoscope were two instruments evaluated in the study. Results: Training with video laryngoscopy showed significantly better results within the categories of dental injury (p=.004), esophageal intubation (p=.001), and proper depth placement of intubation tubes (p=.019). The results of the System usability scale questionnaire and the degrees of visibility based on the Cormack & Lehane classification were also found to be better achieved with the video laryngoscopy (p=.000). Conclusion: This study suggests enhancing education with video laryngoscopy, which could reduce the risk of complications and duration of intubation while increasing the success rate among students and emergency medical technicians with little experience, rather than the existing method of only using direct laryngoscope, which requires considerable experience and skills.


Endotracheal intubation;Direct laryngoscope;Video laryngoscope;System usability scale

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Fig. 1. C-MAC® video laryngoscope(KARL STORZ GmbH & Co. KG, Germany)(left) and standard macintosh laryngoscope(right).

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Fig. 3. Airway Management Trainer 250000.

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Fig. 4. 7.5mm ET-tube.

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Fig. 5. Two-dimensional dot chart of intubation depth according to laryngoscopy type

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Fig. 6. Scatter plot of primary intubation time according to type of laryngoscopy

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Fig. 2. Video laryngoscope blade (top) and Macintosh laryngoscope blade(bottom).

Table 1. Intubation suitability of direct laryngoscopy and video laryngoscopy

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Table 2. Number of final intubation attempts and success rate of primary intubation

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Table 3. Mean procedural time according to intubation attempt

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Table 4. Cormack & Lehane classification

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Table 5. System usability scale

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