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  • Evaluation of the McGrath MAC and Macintosh laryngoscope for tracheal intubation in 2000 patients undergoing general anaesthesia: the randomised multicentre EMMA trial study protocol

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Anaesthesia
Protocol
Evaluation of the McGrath MAC and Macintosh laryngoscope for tracheal intubation in 2000 patients undergoing general anaesthesia: the randomised multicentre EMMA trial study protocol
  1. Marc Kriege1,
  2. Christian Alflen1,
  3. Irene Tzanova2,
  4. Irene Schmidtmann3,
  5. Tim Piepho1,
  6. Ruediger R Noppens1,4
  1. 1 Department of Anaesthesiology, University Medical Centre of the Johannes, Gutenberg University, Mainz, Germany
  2. 2 Department of Anaesthesiology, Christophorus Hospital, Coesfeld, Germany
  3. 3 Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
  4. 4 Department of Anesthesia and Perioperative Medicine, Western University, London, Ontario, Canada
  1. Correspondence to Dr Ruediger R Noppens; ruediger.noppens{at}lhsc.on.ca

Abstract

Introduction The direct laryngoscopy technique using a Macintosh blade is the first choice globally for most anaesthetists. In case of an unanticipated difficult airway, the complication rate increases with the number of intubation attempts. Recently, McGrath MAC (McGrath) video laryngoscopy has become a widely accepted method for securing an airway by tracheal intubation because it allows the visualisation of the glottis without a direct line of sight. Several studies and case reports have highlighted the benefit of the video laryngoscope in the visualisation of the glottis and found it to be superior in difficult intubation situations. The aim of this study was to compare the first-pass intubation success rate using the (McGrath) video laryngoscope compared with conventional direct laryngoscopy in surgical patients.

Methods and analysis The EMMA trial is a multicentre, open-label, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath video laryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of successful first-pass intubation is 95% in the McGrath group and 90% in the Macintosh group. Each group must include a total of 1000 patients to achieve 96% power for detecting a difference at the 5% significance level. Successful intubation with the first attempt is the primary endpoint. The secondary endpoints are the time to intubation, attempts for successful intubation, the necessity of alternatives, visualisation of the glottis using the Cormack & Lehane score and percentage of glottic opening score and definite complications.

Ethics and dissemination The project was approved by the local ethics committee of the Medical Association of the Rhineland Palatine state and Westphalia-Lippe. The results of this study will be made available in the form of manuscripts for publication and presentations at national and international meetings.

Trial registration number ClinicalTrials.gov NCT 02611986; pre-results.

  • adult anaesthesia
  • airway management
  • video laryngoscope
  • macintosh laryngoscope
  • difficult airwayd
  • intubation

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/

https://doi.org/10.1136/bmjopen-2017-016907

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    Footnotes

    • Contributors MK and RRN designed the trial and prepared the manuscript. TP, IT and CA participated in designing the EMMA trial. IS wrote the statistical analysis plan and estimated the sample size. None of the authors have financial interests or received honoraria or paid expert testimony. None of the authors have any personal relationships with people or organisations that could inappropriately influence (bias) this work. The authors alone are responsible for the content and writing of the paper.

    • Competing interests None declared.

    • Patient consent Obtained.

    • Ethics approval Medical Association of the State of Rhineland Palatinate, Germany, Registration Nr.: 837.296.15 (10064); NCT 02611986.

    • Provenance and peer review Not commissioned; externally peer reviewed.