Self-pressurized air-Q® intubating laryngeal airway versus the LMA® Classic™: a randomized clinical trial

  • Sang Hee Ha
  • Min-Soo Kim
  • Jiwoo Suh
  • Jong Seok Lee
Reports of Original Investigations



The self-pressurized air-Q® (air-Q SP) intubating laryngeal airway is a relatively new supraglottic airway (SGA) device. The intracuff pressure of air-Q dynamically equilibrates with the airway pressure and adjusts to the patient’s pharyngeal and periglottic anatomy, potentially providing improved airway fit and seal. The aim of this prospective randomized study was to compare the clinical performance of air-Q to the LMA® Classic™ SGA.


Adult patients requiring general anesthesia for elective surgery were prospectively enrolled and randomly assigned to either air-Q SP or the LMA Classic SGA. Oropharyngeal leak pressure (primary endpoint), success rate, insertion features (insertion time, ease of insertion, requirement for device manipulation), sealing function, gastric insufflation, bronchoscopic view, and oropharyngeal complications at device insertion and following its removal (sore throat, dysphagia, dysphonia) were compared.


The mean (standard deviation [SD]) oropharyngeal leak pressure just after insertion was similar in the air-Q SP and LMA [16.8 (4.9) vs 18.6 (5.5) cm H2O, respectively; mean difference, 1.8 cm H2O; 95% CI, −0.5 to 4.2; P = 0.13] and did not differ at ten minutes following device insertion. Median [interquartile range (IQR)] peak inspiratory pressure just after insertion was lower in the air-Q SP (11.0 [10.0-13.0] vs 13.0 [11.0-14.0] cmH2O, median difference, 1.0 cm H2O; 95% CI, 0.0 to 2.0; P = 0.03) but no difference was observed at ten minutes. The median [IQR] insertion time was faster with the air-Q SP (15.9 [13.6-20.3] sec vs 24 [21.2-27.1] sec; median difference, 8.1 sec; 95% CI, 5.6 to 9.9; P < 0.001) and improved bronchoscopic viewing grade were seen with the air-Q SP immediately after insertion (P < 0.001). No differences between the groups were observed with respect to the rate of successful insertion at first attempt, overall insertion success rate, ease of insertion, and complications.


The air-Q SP had similar leak pressures but a faster insertion time and superior bronchoscopic viewing grade when compared with the LMA Classic. The air-Q SP is a suitable alternative to the LMA Classic in adult patients and may be a superior conduit for tracheal intubation.

Trial registration (NCT02206438). Registered 1 August 2014.

Étude clinique randomisée du masque laryngé d’intubation Self-pressurized air-Q® versus le LMA® Classic MD



Le masque laryngé d’intubation Self-pressurized air-Q® (air-Q SP) est un dispositif pour voie respiratoire supraglottique (VRS) relativement nouveau. La pression à l’intérieur du coussinet de l’air-Q s’équilibre de façon dynamique avec la pression des voies respiratoires et s’adapte à l’anatomie pharyngée et périglottique du patient, procurant une meilleure étanchéité et un meilleur moulage aux voies aériennes. L’objectif de cette étude prospective randomisée était de comparer les performances cliniques de l’air-Q et du dispositif supraglottique LMA® ClassicMD.


Des adultes nécessitant une anesthésie générale pour chirurgie élective ont été recrutés de façon prospective et randomisés dans le groupe de dispositif pour VRS air-Q SP ou dans le groupe LMA Classic. La pression de fuite oropharyngée (critère d’évaluation principal), le taux de succès, les caractéristiques de l’insertion (temps d’insertion, facilité d’insertion, nécessité de manipulation du dispositif, insufflation gastrique, vue en bronchoscopie et complications oropharyngées à l’insertion et après le retrait [mal de gorge, dysphagie, dysphonie]) ont été comparés.


La pression de fuite oropharyngée moyenne (écart-type [ET]) juste avant l’insertion a été semblable pour l’air-Q SP et le LMA (respectivement 16,8 [4,9] contre 18,6 [5,5] cmH2O; différence des moyennes, 1,8 cmH2O; IC à 95 %, -0,5 à 4,2; P = 0,13] et n’était pas différente 10 minutes après l’insertion du dispositif. La pression inspiratoire maximum médiane (écart interquartile [IQR]) immédiatement après l’insertion était inférieure dans le groupe air-Q SP (11,0 [10,0-13,0] contre 13,0 [11,0-14,0] cmH2O, différence médiane, 1,0 cmH2O; IC à 95 %, 0,0 à 2,0; P = 0,03) mais aucune différence n’a été observée à dix minutes. Le temps d’insertion médian [IQR] a été plus court avec l’air-Q SP (15,9 [13,6-20,3] secondes contre 24 [21,2-27,1] s; différence des médianes, 8,1 s; IC à 95 %, 5,6 à 9,9; P < 0,001) et un meilleur niveau de vision bronchoscopique a été constaté avec l’air-Q SP immédiatement après l’insertion (P < 0,001). Aucune différence n’a été observée entre les groupes concernant les taux de succès des insertions à la première tentative, le taux global de succès des insertions, la facilité d’insertion et les complications.


L’air-Q SP avait des pressions de fuite similaires, mais un temps d’insertion plus rapide et une meilleure visualisation bronchoscopique comparativement au LMA Classic. L’air-Q SP est une option acceptable pour remplacer le LMA Classic chez les patients adultes et peut s’avérer supérieur pour une intubation trachéale.

Enregistrement de l’essai clinique (NCT02206438). Enregistré le 1er août 2014.


Conflicts of interest and source of funding

The authors have no funding or conflicts of interest to disclose.

Editorial responsibility

This submission was handled by Dr. Steven Backman, Associate Editor, Canadian Journal of Anesthesia.

Author contributions

Sang Hee Ha and Jong Seok Lee contributed substantially to all aspects of this manuscript, including conception and design, acquisition, analysis, and interpretation of data and drafting the article. Min-Soo Kim contributed substantially to the conception and design, acquisition, and analysis. Jiwoo Suh contributed substantially to the acquisition of data.


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Copyright information

© Canadian Anesthesiologists' Society 2018

Authors and Affiliations

  • Sang Hee Ha
    • 1
    • 2
  • Min-Soo Kim
    • 1
  • Jiwoo Suh
    • 1
  • Jong Seok Lee
    • 1
    • 2
  1. 1.Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research InstituteYonsei University College of MedicineSeoulKorea
  2. 2.Department of Anesthesiology and Pain Medicine, Yonsei University College of MedicineGangnam Severance HospitalSeoulKorea

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