Randomized comparison of McGrath MAC videolaryngoscope, Pentax Airway Scope, and Macintosh direct laryngoscope for nasotracheal intubation in patients with manual in-line stabilization

  • Go Un Roh
  • Hyun Jeong Kwak
  • Kyung Cheon Lee
  • Sun Young Lee
  • Jong Yeop KimEmail author
Reports of Original Investigations



The objective of this study was to determine the clinical usefulness of videolaryngoscopes (VLs) by comparing the time to intubation (TTI) and the ease of intubation of McGrath MAC VL (MVL), Pentax Airway Scope VL (PVL), and Macintosh direct laryngoscope (DL) during nasotracheal intubation using manual in-line stabilization to simulate difficult airways.


One hundred and twenty patients were randomly assigned to the MVL group (n = 40), the PVL group (n = 40), and the DL group (n = 40). Nasotracheal intubation was performed using MVL, PVL, or DL, according to group assignments. The primary outcome was TTI and secondary outcomes were glottic view, ease of intubation, and bleeding.


The TTI was significantly shorter in the MVL group than in the DL group (45 sec vs 57 sec; difference in means: − 12; 95% confidence interval [CI], − 21 to − 3; P = 0.01). The percentage of glottic opening and Cormack Lehane grade were significantly superior in the MVL and the PVL groups compared with the DL group (both P < 0.001). The intubation difficulty scale and numeric rating scale regarding ease of intubation were also significantly lower in the MVL and PVL groups than in the DL group (all P < 0.007). The incidence of bleeding was significantly lower in the MVL group than in the DL group (3 vs 15, relative risk 0.2; 95% CI, 0.06 to 0.64; P = 0.001).


This study showed that both MVL and PVL provided better visualization of the glottis and easier intubation, with less additional manipulation than DL during nasotracheal intubation in simulated difficult airways. Additionally, use of the MVL significantly shortened the TTI compared with the DL.

Trial registration (NCT02647606); registered 6 January, 2016.

Comparaison randomisée des vidéolaryngoscopes McGrath MAC et Pentax Airway Scope et du laryngoscope avec lame Macintosh pour l’intubation nasotrachéale chez les patients avec stabilisation manuelle en ligne



L’objectif de cette étude était de déterminer l’utilité clinique des vidéolaryngoscopes (VL) en comparant le temps jusqu’à intubation (TTI) et la facilité d’intubation du VL McGrath MAC (MVL), du VL Pentax Airway Scope (PVL), et du laryngoscope avec lame Macintosh (DL) pour une intubation nasotrachéale avec stabilisation manuelle en ligne simulant des voies aériennes difficiles.


Cent vingt patients ont été aléatoirement alloués au groupe MVL (n = 40), au groupe PVL (n = 40) ou au groupe DL (n = 40). L’intubation nasotrachéale a été réalisée à l’aide du MVL, du PVL ou du DL selon l’attribution de groupe. Le critère d’évaluation principal était le TTI et les critères secondaires comprenaient la visualisation glottique, la facilité d’intubation et les saignements.


Le TTI était significativement plus court dans le groupe MVL que dans le groupe DL (45 sec vs 57 sec; différence de moyennes : -12; intervalle de confiance [IC] 95 %, -21 à -3; P = 0,01). Le pourcentage d’ouverture glottique et le grade de Cormack et Lehane étaient significativement supérieurs dans les groupes MVL et PVL par rapport au groupe DL (P < 0,001 pour les deux). L’échelle de difficulté d’intubation et l’échelle d’évaluation numérique concernant la facilité d’intubation étaient également significativement plus basses dans les groupes MVL et PVL que dans le groupe DL (tous P < 0,007). L’incidence de saignements était significativement plus basse dans le groupe MVL que dans le groupe DL (3 vs 15, risque relatif 0,2; IC 95 %, 0,06 à 0,64; P = 0,001).


Cette étude a démontré que le MVL et le PVL procuraient tous deux une meilleure visualisation glottique et une intubation plus facile, avec moins de manipulations supplémentaires qu’un DL pendant l’intubation nasotrachéale de voies aériennes difficiles simulées. En outre, l’utilisation d’un MVL a significativement réduit le TTI par rapport à un DL.

Enregistrement de l’étude (NCT02647606); enregistrée le 6 janvier 2016.


Conflicts of interest

None declared.

Editorial responsibility

This submission was handled by Dr. Philip M. Jones, Associate Editor, Canadian Journal of Anesthesia.

Author contributions

Go Un Roh and Jong Yeop Kim were involved in the study design, acquisition and interpretation of data, and writing of the manuscript. Hyun Jeong Kwak wrote the manuscript. Kyung Cheon Lee interpreted the data. Sun Young Lee analyzed the data.


No external funding, solely departmental source.


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Copyright information

© Canadian Anesthesiologists' Society 2019

Authors and Affiliations

  1. 1.Department of Anesthesiology and Pain Medicine, CHA Bundang Medical CenterCHA University School of Medicine, Bundang CHA General HospitalSeongnamKorea
  2. 2.Department of Anesthesiology and Pain MedicineGachon University, Gil Medical CenterIncheonKorea
  3. 3.Department of Anesthesiology and Pain MedicineAjou University School of MedicineSuwonKorea

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