In their overall assessment of the devices studied, the AP’s rated the Macintosh most difficult device to use in each scenario. However, when assessing their confidence in the use of each device for tracheal intubation procedures, they rated the three laryngoscopes similarly. This rating probably reflects the familiarity of the AP’s with the Macintosh laryngoscope. A number of important limitations exist regarding this study. Firstly, we acknowledge that the potential for bias exists, as it is impossible to blind the AP’s to the device being used. Secondly, this study was carried out in experienced users of

the Macintosh laryngoscope. Inhibitors,research,lifescience,medical The findings may differ if studies in APs prior to their attaining competence with the Macintosh device. Thirdly, this is a manikin study, and may not adequately mimic clinical conditions, particularly in the emergency setting. A particular issue of particular relevance in the emergency setting Inhibitors,research,lifescience,medical is the risk of fogging and contamination of the lens by INCB024360 molecular weight secretions and/or blood, especially in the traumatized airway. Therefore, these findings need to be confirmed

and extended in clinical studies before definitive conclusions can be drawn. Careful consideration Inhibitors,research,lifescience,medical would also have to be given to the cost implications of introducing these more expensive laryngoscopes into the pre-hospital emergency care setting. Finally, the relative efficacies of these devices in comparison to other promising devices such as the Airtraq® [39,40], McCoy® [41], McGrath®[19], TruView® [42], LMA CTrach® [14] or Bonfils® [43] have not been determined. We focused on the Glidescope® and AWS® devices in Inhibitors,research,lifescience,medical this study due to the fact that these are portable devices that can easily be included in the equipment

used by AP’s. Nevertheless, further comparative studies are needed with other alternative laryngoscopy devices in order to find the optimal alternatives to the Macintosh laryngoscope. Conclusion The Glidescope® Inhibitors,research,lifescience,medical and AWS® devices appears to possess advantages over the conventional Macintosh laryngoscope when used by AP’s in normal and simulated difficult intubation scenarios. The AWS® performed best overall, and demonstrates considerable promise in this context. Further clinical studies are necessary to confirm these initial positive findings. Abbreviations ANOVA: analysis of variance; ETT: endotracheal Terminal deoxynucleotidyl transferase tube; SD: standard deviation; VAS: Visual analogue scale. Competing interests Pentax Ltd provided the AWS® device and the disposable blades free of charge for this study. Authors’ contributions SN and CM conceived of the study, and participated in its design and execution and helped to draft the manuscript. AM, JO’D, and BDH participated in the study, recruited participants, and helped to draft the manuscript.