In the trauma bay, the algorithm is drilled into us from day one: A is for Airway, with simultaneous cervical spine protection. For decades, the gold standard for achieving this has been Manual In-Line Stabilisation (MILS) during endotracheal intubation. The premise is deeply intuitive—if the cervical spine is potentially unstable, we must rigidly restrict motion to prevent catastrophic secondary cord injury.
However, a growing body of high-quality evidence - culminating in the recent paradigm-shifting guidelines from the Association of Anaesthetists (Wiles et al., 2024) and supported by extensive 2026 systematic reviews - is forcing the trauma community to confront an uncomfortable truth: our rigid adherence to MILS might be causing more harm than good.
For clinicians managing the airway in real-time, and for candidates preparing for the Advanced Trauma Life Support (ATLS) written assessment, it is time to re-examine the balance of risks during trauma intubation.
The Problem with MILS: A Guaranteed Difficult Airway
The fundamental issue with MILS is anatomical. A normal, unobstructed view of the glottis via Direct Laryngoscopy (DL) relies on aligning the oral, pharyngeal, and laryngeal axes. This alignment is best achieved in the "sniffing" position - which involves cervical flexion and atlanto-occipital extension.
By aggressively maintaining a neutral, immobile cervical spine, MILS inherently prevents this alignment. The evidence is unequivocal: applying MILS significantly degrades the laryngeal view. It dramatically increases the incidence of Cormack-Lehane Grade 3 and 4 views, prolongs intubation times, and increases the rate of failed intubations.
We have essentially traded a theoretical risk of spinal cord compression for a very real, documented risk of failure to oxygenate.
Hypoxia vs. Secondary Cord Injury: Reassessing the Threat
The historical fear of secondary spinal cord injury during airway management was largely based on cadaveric studies and worst-case assumptions, rather than robust clinical outcomes. Modern kinematic studies and extensive clinical reviews paint a different picture:
Movement is Inevitable: No technique, including MILS or rigid collars, completely eliminates cervical spine movement during laryngoscopy.
The Cord is Resilient: The slight degree of movement associated with careful intubation has rarely been proven to cause clinically significant neurological deterioration, even in the presence of unstable fractures.
- Hypoxia is Lethal: In trauma patients—particularly those with concurrent traumatic brain injury (TBI) - even brief episodes of hypoxia or hypercapnia from a prolonged, difficult intubation cause immediate, irreversible secondary brain injury.
The modern consensus is clear: securing a definitive airway and maintaining oxygenation takes absolute precedence over rigid cervical motion restriction. If MILS is preventing a view of the vocal cords, the stabilisation must be immediately relaxed to allow for cautious optimal positioning.
Videolaryngoscopy (VL)
The debate between securing the airway and protecting the spine has largely been resolved by technology. Recent systematic reviews from 2026 reiterate that Videolaryngoscopy, particularly with hyperangulated blades, is the most consistently advantageous option for airway instrumentation under cervical motion restriction.
VL allows the clinician to "look around the corner," providing excellent glottic views without the need to forcefully align the anatomical axes. It reduces the applied lifting force on the base of the tongue, thereby generating significantly less movement at the upper cervical segments compared to direct Macintosh laryngoscopy.
ATLS Relevance
While clinical practice is rapidly evolving towards VL and a more pragmatic approach to cervical motion restriction, candidates taking the ATLS written examination must understand how to answer within the strict framework of the 11th Edition guidelines:
Airway Always Comes First: If you are presented with a scenario where an airway cannot be secured due to cervical spine precautions, the correct answer is always to prioritize the airway. You may carefully remove the anterior portion of a collar or relax MILS if it is impeding a lifesaving intubation.
Failed Airway with Suspected C-Spine Injury: If oxygenation cannot be maintained and an endotracheal tube cannot be passed despite adjuncts, the algorithm still points toward a surgical airway (cricothyroidotomy) as the definitive backup, rather than forcibly extending a known unstable neck.
Additional Resource For a deeper dive into the clinical realities of managing these complex cases, consider this highly relevant presentation: Anaesthesia Clinical Effectiveness: Airway Management in C-Spine Injuries. This video provides an excellent summary of the recent Association of Anaesthetists guidelines and the evolving best practices for suspected cervical spine injuries.
References
Wiles, M. D., et al. (2024). Association of Anaesthetists guidelines: airway management in patients with suspected cervical spine injury. Anaesthesia.
- American College of Surgeons. (2025). Advanced Trauma Life Support (ATLS) Student Course Manual (11th ed.).