Cervical Spine Movement and Ease of Intubation Using Truview or McCoy Laryngoscope in Difficult Intubation

Airway management in patients with suspected or confirmed cervical spine injury: Guidelines from the Difficult Airway Society (DAS), Association of Anaesthetists (AoA), British Society of Orthopaedic Anaesthetists (BSOA), Intensive Care Society (ICS), Neuro Anaesthesia and Critical Care Society (NACCS), Faculty of Prehospital Care and Royal College of Emergency Medicine (RCEM)

BACKGROUND

There are concerns that airway management in patients with suspected or confirmed cervical spine injury may exacerbate an existing neurological deficit, cause a new spinal cord injury or be hazardous due to precautions to avoid neurological injury. However, there are no evidence-based guidelines for practicing clinicians to support safe and effective airway management in this setting.

METHODS

An expert multidisciplinary, multi-society working party conducted a systematic review of contemporary literature (January 2012-June 2022), followed by a three-round Delphi process to produce guidelines to improve airway management for patients with suspected or confirmed cervical spine injury.

RESULTS

We included 67 articles in the systematic review, and successfully agreed 23 recommendations. Evidence supporting recommendations was generally modest, and only one moderate and two strong recommendations were made. Overall, recommendations highlight key principles and techniques for pre-oxygenation and facemask ventilation; supraglottic airway device use; tracheal intubation; adjuncts during tracheal intubation; cricoid force and external laryngeal manipulation; emergency front-of-neck airway access; awake tracheal intubation; and cervical spine immobilisation. We also signpost to recommendations on pre-hospital care, military settings and principles in human factors.

CONCLUSIONS

It is hoped that the pragmatic approach to airway management made within these guidelines will improve the safety and efficacy of airway management in adult patients with suspected or confirmed cervical spine injury.

Laryngoscopes for difficult airway scenarios: a comparison of the available devices

INTRODUCTION

According to the American Society of Anesthesiologists, the incidence of difficult intubation in the operating room is 1.2-3.8%; however, in emergency conditions, this rate is higher and reaches even 5.3%. Successful emergency airway management is an essential component of the modern practice of medicine.

AREAS COVERED

The aim of the study is to review the literature regarding different devices used to perform endotracheal intubation (Macintosh, Miller, and McCoy laryngoscopes; ETView, GlideScope, TruView, Airtraq, McGrath MAC, Pentax AWS, Trachlight, Shikani, and Bullard) and discuss their clinical and experimental role in difficult airway management.

EXPERT COMMENTARY

Owing to the development of medical technology, there are an increasing number of videolaryngoscopes and other devices facilitating endotracheal intubation in difficult airway scenarios, including cardiopulmonary resuscitation, cervical spine injury, or face-to-face intubation. Each of these devices may bring benefits in the form of increasing the intubation effectiveness, as well as shortening the procedure, provided that the person performing intubation is familiar with the use of the device.

Fluoroscopic Comparison of Cervical Spine Motion Using LMA CTrach, C-MAC Videolaryngoscope and Macintosh Laryngoscope

Objective

Endotracheal intubation should be performed with care when cervical spine (C-spine) injury is suspected. The aim of this study was to evaluate the movement of the C-spine using fluoroscopy during intubation with Laryngeal Mask Airway (LMA) CTrach, C-MAC videolaryngoscope and Macintosh laryngoscope.

Methods

This was a single-centre, prospective, observational, controlled trial. In total, 22 surgical patients aged 18-65 years planned to undergo operation under general anaesthesia, were enrolled. X-ray images of the C-spine were obtained using fluoroscopy with the patients' head in a neutral position. All patients underwent laryngoscopy using a Macintosh blade, LMA CTrach and C-MAC videolaryngoscope, and fluoroscopic images of the C-spine were obtained. All the patients were intubated at the last laryngoscopy simulation (using the C-MAC). The atlanto-occipital distance (AOD) and angles between C₀C₁, C₀C₂, C₀C₃, C₀C₄, C₁C₂ and C₂C₃ lines were measured and compared between each device.

Results

The mean AOD was measured as 20.4 mm in a neutral position, which decreased to 13.1, 17.2 and 12.3 mm after the insertion of the Macintosh laryngoscope, LMA CTrach and C-MAC videolaryngoscope, respectively. The differences were significant (p<0.001). Moreover, significant difference was noted in C₀C₂, C₀C₃ and C₁C₂ angles with the insertion of the three devices (p<0.001). The LMA CTrach resulted in significantly lesser C-spine movements in C₀C₂, C₀C₃ and C₀C₄ angles compared to the Macintosh laryngoscope and C-MAC videolaryngoscope (p<0.001).

Conclusion

The LMA CTrach resulted in lesser C-spine movements compared to Macintosh laryngoscope and C-MAC videolaryngoscope. In case of the C-spine injury, LMA CTrach may be preferred and may cause fewer traumas during endotracheal intubation.