Initial management of blunt and penetrating neck trauma

Learning objectives.

By reading this article you should be able to:

• •Recall the key features that may indicate impending airway obstruction in a patient with acute neck trauma.
• •Explain the principles of managing a patient with a threatened airway resulting from neck trauma.
• •Distinguish the key features of the Advanced Trauma Life Support (ATLS) primary survey that are pertinent to patients with acute neck trauma.
• •Outline the next steps in management of acute neck trauma after completing the primary survey and securing the airway.

Key points.

• •The management of blunt and penetrating neck trauma can be complex and frequently requires close collaboration between anaesthesia and surgical teams.
• •Adherence to Advanced Trauma Life Support (ATLS) principles is fundamental, with an emphasis on early assessment of the airway.
• •The key principles of airway management are to identify any airway injuries and where possible ensure that the tip of the tracheal tube is positioned distal to the site of the injury without causing further airway trauma.
• •If airway injury is suspected, the best ways to secure the airway in a cooperative patient are by awake fibreoptic intubation or awake surgical tracheostomy under local anaesthesia.
• •Severe injuries require immediate surgical exploration. In less emergent situations CT scanning plays a valuable role in planning appropriate further management.

As a narrow conduit for the major blood vessels, aerodigestive tract, and neurological structures passing between the head and the torso, the neck is an especially hazardous area for traumatic injuries. Injuries in this area can be complex to manage, and airway management maybe particularly perilous.

Common causes of neck trauma include road traffic collisions (RTCs), sporting injuries, and interpersonal violence. Sadly, interpersonal violence is a global problem. Whilst reported rates are highest in South Africa, Central and South America, the incidence of interpersonal violence rates is increasing in Europe.^1,2 In the year ending March 2019, there were approximately 47,000 offences involving a knife or sharp object in England and Wales; the highest number since comparable data have been recorded (March 2011).³ It is becoming increasingly likely that anaesthetists, as part of a trauma or theatre team, will encounter patients with these complex and potentially life-threatening injuries.

Trauma to the neck can broadly be classified into blunt or penetrating injuries. Whilst these two mechanisms have different pathophysiologies and some important differences in management, there is a shared focus on early airway protection when needed. In this article we describe the relevant clinical anatomy common to both patterns of injury before separate discussion of blunt and penetrating neck trauma. We highlight important components of the Advanced Trauma Life Support (ATLS) primary survey pertinent to both types of injury, with a more detailed discussion of airway assessment and management.⁴ Whilst the recommendations we make are based on accepted international guidelines and evidence, we acknowledge that practice may vary internationally because of differences in available resources and training.

Clinical anatomy

When considering blunt and penetrating neck trauma, it is helpful to consider the relevant clinical anatomy. The platysma is a thin layer of skeletal muscle that attaches inferiorly to subcutaneous tissues overlying the superior parts of the pectoralis major. It extends superiorly covering the majority of the anterior and lateral neck, attaching to the inferior border of the mandible, contralateral muscle, and subcutaneous tissues of the lower face. A breach to this muscle layer defines penetrating neck injury.

Deep to the platysma lies the deep cervical fascia, which subdivides into the investing layer, the pretracheal layer, the prevertebral layer, and the carotid sheath. These fascial layers are continuous superiorly and inferiorly with the thoracic and cranial fascia. The facial layers are relevant to clinical practice because they can help to tamponade bleeding from damage to the vascular structures contained within. Their continuity with the mediastinum is relevant in oesophageal injuries, as mediastinitis can develop, with significant morbidity and mortality.

For penetrating neck injuries, it is helpful to have knowledge of the anatomical zones of injury first described by Monson and colleagues in 1969 (Fig. 1, Table 1).⁵ These zones identify underlying structures that can be potentially damaged. Whilst this schematic is useful, it is important to recognise that projectiles are capable of traversing the zones of the neck depending on their trajectory and therefore an entry wound in one zone does not rule out anatomical injury in another. Zone 1 injuries are associated with the highest mortality because of the density of vascular structures and proximity to the thoracic cavity. Fig. 2 is an image taken during operative exploration of a zone 1 penetrating injury associated with major haemorrhage in which the common carotid artery has been repaired. Historically, all breaches of the platysma warranted mandatory surgical exploration, but with the rapid evolution of advanced imaging modalities and interventional radiology, a more balanced conservative approach is now advocated.^6,7

Fig 1.

Diagram showing the anatomical zone of penetrating neck injury.

Table 1.

Anatomical definitions of zones of penetrating neck injury and anatomical structures at risk

Zone	Anatomical boundaries	Anatomical structures at risk
3	Superior boundary: skull base Inferior boundary: angle of the mandible	Pharynx Carotid arteries Internal jugular veins Cranial nerves Sympathetic chain Parotid gland
2	Superior boundary: angle of the mandible Inferior boundary: cricoid cartilage	Laryngotracheal complex Pharynx Oesophagus Carotid artery Jugular veins Vertebral arteries Spinal cord Vagus and phrenic nerves
1	Superior boundary: cricoid cartilage Inferior boundary: clavicles	Trachea Oesophagus Carotid artery Jugular veins Thoracic duct Spinal cord Cranial nerves Vertebral arteries

Fig 2.

Intraoperative picture during a neck exploration and repair of a patient's common carotid artery (A) for a zone 1 penetrating neck injury (B).

General principles

Ideally, patients with neck trauma should be managed in a major trauma centre as they often have concomitant injuries requiring 24-h specialty cover and resources not necessarily available in other centres. The major trauma team should be activated and ATLS guidelines on primary survey followed. An experienced anaesthetist and a head and neck surgeon should be involved at an early stage.

Mechanisms of injury are different in combat trauma compared with trauma in civilians. In combat trauma there is a greater preponderance of high-energy injuries (explosive devices, gunshot wounds).⁸ A variety of resources is available to guide decision-making in these challenging patients. The Joint Trauma System of the US military offers some perspective from combat experience.⁹ The principles of management outlined below still apply. Advice on iatrogenic airway trauma from medical instrumentation of the upper aerodigestive tract has been discussed recently in this journal and is not covered specifically here.¹⁰

Blunt neck trauma

Blunt neck trauma is comparatively rare within the context of the multiply injured patient as the neck is relatively shielded by the thoracic cage, cervical spine, and mandible.¹¹ Mechanisms of injury can be direct (e.g. a ‘clothesline injury’ or hanging attempt), or indirect high-energy injuries (e.g. resulting from blast injuries, an RTC, or sports injury).

A: Airway assessment

Priorities of the primary survey include identification of a threatened or obstructed airway, followed by definitive airway protection with a cuffed tracheal (or bronchial) tube, the tip of which should be sited distal to the site of injury if possible. Other immediate priorities include control of catastrophic haemorrhage and cervical spine immobilisation. Specific mechanisms of injury, ‘red flag’ symptoms and examination findings that should prompt the trauma team to suspect blunt neck trauma and impending airway obstruction are summarised in Table 2.

Table 2.

Mechanisms of injury, red flag symptoms, and red flag examination findings in patients with blunt neck trauma

Mechanisms of injury associated with blunt neck trauma	Red flag symptoms of blunt neck trauma	Red flag examination findings
Clothesline injury	Stridor	Respiratory distress
Road traffic collisions (particularly in unrestrained passengers)	Dysphonia	Ecchymosis of the neck
Strangulation	Dyspnoea	Surgical emphysema of the neck
Contact sports	Dysphagia	Tracheal deviation
Assault	Odynophagia	Haemoptysis
		Rapidly expanding neck haematoma

A: Airway management

Elements of previously published guidelines by national bodies on airway management in unanticipated difficult intubation and the critically ill may not apply or be appropriate in cases of neck trauma.^12,13 Blind placement of a tracheal tube or bougie distal to the glottis can inadvertently dislodge fractured cartilage or exit the trachea via a traumatic defect, thereby creating a false passage. Subsequent delivery of positive pressure into a false tract may distort anatomy further and even precipitate complete airway obstruction. Cricoid pressure can make laryngoscopy more challenging by displacing laryngotracheal fractures. It may also provoke or worsen existing airway bleeding, and may not compress the oesophagus effectively. Positive pressure ventilation via a face mask or supraglottic airway also carries a significant risk of creating an air leak from traumatic airway defects. In turn this may lead to progressive surgical emphysema and ultimately compromise the airway. Finally, conventional emergency front of neck access via cricothyroidotomy is likely to worsen already damaged anatomy; it is not recommended, particularly in cases of laryngotracheal injury or separation.¹⁴

Immediate airway management of patients with neck trauma differs depending on whether impending airway obstruction is thought likely or not. Patients with or deemed at high risk of impending obstruction require definitive airway management, outlined below. Patients who are physiologically stable and who do not have any ‘red flags’ (Table 2) can undergo fibreoptic nasoendoscopic examination by an appropriately trained clinician. Further assessment with a contrast enhanced CT scan is considered necessary by many centres in order to accurately diagnose neck injuries.¹⁵

If less significant injuries are identified (e.g. minor mucosal injury without cartilage exposure, minor endolaryngeal haematoma, or laceration), conservative management may be appropriate. Patients managed conservatively should receive humidified air or humidified supplemental oxygen, if supplemental oxygen is needed. If an appropriate humidification device is not available, saline nebulisers can be used every 2–4 h. Conservative management also includes voice rest. Proton pump inhibitors are advised to suppress gastric acid production and prevent exacerbation of upper aerodigestive tract injuries by gastro-oesophageal reflux. Feeding via a nasogastric tube may also be needed. Ideally, conservative management should be within a critical care environment with continuous monitoring and close observation. The airway should be re-examined at least every 24 h with a flexible nasoendoscope for the first 5 days, and more frequently if there are any additional concerns. Clinicians with advanced airway skills and appropriate equipment must be immediately available. Detailed subsequent management of the stable airway should be directed by head and neck surgical specialists and is beyond the scope of this article.

Management of impending airway obstruction in blunt neck trauma

In this scenario, conventional rapid-sequence induction, direct laryngoscopy, and tracheal intubation can be challenging. These interventions may be associated with significant complications such as creating a false passage with the tracheal tube, displacement of laryngotracheal fractures, displacement of haematomas, and restarting of airway haemorrhage.^15,16 Any of these complications may rapidly cause uncorrectable airway obstruction.

Airway management plans should be tailored to the individual patient, the skills of the team, and the equipment available. The evidence base informing these decisions is largely observational and it is important to recognise that individual decision-making involves a risk/benefit assessment of the patient.¹⁴ A briefing to outline the proposed airway management strategy is very important and should be undertaken before induction of anaesthesia. This should include discussion of options in the event of failure of the primary technique and allocation of key tasks. Writing this on a white board means all of the team have a shared mental model of what is about to happen. The different options for airway management that are relevant to specific situations are discussed below.

Cervical spine immobilisation is indicated in most patients with blunt trauma to the neck until radiological investigations have ruled out unstable injuries. Usually, cervical spine immobilisation is maintained during the process of securing the airway. However, in the presence of failed intubation or failed oxygenation, it is reasonable to temporarily discontinue cervical spine precautions in order to prevent potentially devastating complications, such as hypoxic brain injury and death.

When formulating an airway plan it is important to recognise that the conventional ‘plan d’ for a ‘can't intubate can't oxygenate’ scenario in the form of surgical cricothyroidotomy may be more technically challenging because of distorted anatomy.¹³ It also has the potential to exacerbate laryngotracheal injury. If possible, it is strongly advisable to have a head and neck surgeon present at the earliest opportunity.

If the patient is cooperative

• 1.Awake fibreoptic intubation

Benefits of this technique include keeping the patient breathing spontaneously, maintaining airway tone, and being able to directly visualise trauma. It also facilitates placement of the tracheal tube under direct vision distal to any pathology, thereby minimising the risks of exacerbating the initial injury.

In our experience, awake fibreoptic intubation may prove challenging in this scenario. Additional maxillofacial trauma may lead to blood in the airway and make visualisation of structures difficult. Spinal immobilisation means the patient is likely to be positioned supine. The team should consider the risks and benefits of sitting the patient up in the semi-recumbent position. Alternatively, the whole bed can be tilted head up if the team feels it is essential for spinal alignment to be maintained. Cervical spine immobilisation can be maintained with manual in-line stabilisation. Topical local anaesthesia with or without sedation carries the risk of worsening airway obstruction, so the team should prepare for this eventuality. If the patient is agitated, the team should reconsider whether this mode of securing the airway remains appropriate.

Care must be taken to ensure that on advancing the tracheal tube the bevel does not disrupt laryngeal tears or displaced cartilaginous fractures. In our experience, using a size 6.0 lubricated tracheal tube that fits snugly on the fibreoptic scope or has a curved tip, for example a Parker Flex-Tip, can help prevent this.¹⁷

• 2.Tracheostomy under local anaesthetic

This is a commonly used strategy in this setting and considered by some the gold standard as it maintains spontaneous ventilation and allows direct visualisation of anatomical structures between the skin and trachea. It can help to stop bleeding in addition to establishing a definitive airway.⁸ Tracheostomy is preferred to a surgical cricothyroidotomy as it offers a more definitive airway and is safer in the context of laryngotracheal separation. During the procedure, anatomical layers are dissected, allowing any laryngotracheal injury to be seen and the tracheostomy to be sited away from this. It can be technically challenging and a clinician with the required skill set may not be immediately available.

• 3.Inhalation induction of anaesthesia

This would appear to carry some of the benefits described above such as maintenance of both spontaneous ventilation and airway tone. However, inhalation induction of anaesthesia in adults with a precarious airway is often slow and unpredictable; therefore it is not recommended in this setting.¹⁸

• 4.High-flow nasal oxygen

The role of high-flow nasal oxygen (HFNO) to assist airway management in blunt and penetrating neck trauma is unclear. Whilst there may be some benefit in slowing or preventing hypoxia during airway interventions, there is a risk of dislodging airway clots or worsening surgical emphysema. Evidence from healthy volunteers suggests using HFNO increases mean airway pressure by approximately 1 cmH₂O for every 10 L min⁻¹ of flow.¹⁹ Therefore, flows of <30 L min⁻¹ are more likely to be safe; flow rates exceeding this carry increasing risk. HFNO may not be available in all emergency departments and setting it up could potentially distract the trauma team from other priorities. In summary, at lower flow rates, HFNO can be considered as an adjunct for oxygenation during the definitive airway management strategies outlined above. When used, it is important that the team, including the head and neck surgeon, are familiar with its risks and benefits.

If the patient is not cooperative or the team considers the above approaches unsuitable

Perform a modified rapid-sequence induction without cricoid pressure and using fibreoptic intubation to visualise and bypass any laryngotracheal injury.

Cricoid pressure is not advised as it may displace fractures of the proximal laryngotracheal complex. Videolaryngoscopy has theoretical benefits as it allows visualisation of the oral cavity, oropharynx, and supraglottis whilst minimising the displacing force that would be required to obtain this view directly. Whilst direct laryngoscopy may have benefits if there is blood in the airway, there is no consensus on whether, in the context of blunt trauma to the neck, video or direct laryngoscopy is superior. Ultimately, we would not recommend adopting an unfamiliar technique in an already challenging situation.

Once the glottic aperture is seen, a flexible fibreoptic bronchoscope preloaded with a snugly fitting tracheal tube can be introduced through the glottis, facilitating direct visualisation of distal injuries. The well lubricated tracheal tube can then be cautiously railroaded over the fibreoptic scope, ensuring the cuff is inflated distal to any injuries. Applying positive pressure ventilation before securing a tracheal tube distal to the injury should be avoided if possible. If bag-mask ventilation is required because of significant hypoxia before the tracheal tube has been placed, we recommend minimising airway pressures as much as possible.

B: Assessment and management of ventilation

Patients should be assessed for the presence of life-threatening thoracic injury. These injuries may be directly related to the neck trauma itself, such as tracheobronchial injury causing a tension pneumothorax or independent of the neck injury, such as direct trauma to the chest wall and underlying viscera. Any such life-threatening injuries should be managed according to the ATLS primary survey approach.

C: Assessment and management of circulation

Isolated blunt trauma to the neck alone is unlikely to cause significant haemorrhage. Patients with signs of cardiovascular compromise should undergo immediate resuscitation and control of major haemorrhage where applicable. Activation of a major haemorrhage protocol may be required and alternative sources of traumatic blood loss should be looked for and managed appropriately. If major haemorrhage is suspected, tranexamic acid should be given as soon as possible.²⁰ Neurogenic shock should be considered if the patient remains hypotensive despite exclusion of blood loss.

D: Assessment and management of disability

Patients may have a depressed level of consciousness secondary to associated traumatic brain injury, secondary brain injury, or substance intoxication. Other important signs to look for and exclude are hemiparesis secondary to a traumatic vascular injury and associated stroke, and pupillary miosis and ptosis from ipsilateral sympathetic chain injury. Profound respiratory compromise without thoracic injury may suggest a high spinal cord injury. Examination of the upper limbs to exclude brachial plexus injury is also recommended.

E: Further assessment and management

An i.v. contrast-enhanced CT scan is usually indicated. This will provide important information on the presence of significant injuries affecting the aerodigestive and vascular structures of the neck.¹⁵ When present, these injuries usually require surgical repair, the details of which are beyond the scope of this article.

Penetrating neck trauma

Penetrating neck injury can be challenging to assess and manage. An entry wound that looks relatively innocuous can be associated with a devastating projectile trajectory through the densely packed anatomical structures of the neck. All breaches of the platysma muscle layer of the neck warrant detailed further assessment and investigation. Multiple injuries and higher velocity injuries, such as gunshot or blast injury, are associated with a higher mortality.^21,22 If possible, retained sharp foreign bodies such as a knife or a screwdriver should only be removed in theatre, as removing them may precipitate life-threatening haemorrhage.

A: Airway assessment and management

As with blunt neck injury, the priorities in penetrating neck injury are to assess for a compromised airway and to formulate an appropriate management plan. All patients with ongoing bleeding, clinical instability, expanding neck haematomas, signs of airway obstruction, or depressed level of consciousness will require definitive airway protection.

Management of impending airway obstruction in penetrating neck trauma

As with blunt neck trauma this needs tailoring to the individual patient and the skills of the team caring for them. Strategies for different clinical scenarios are outlined below.

If the patient has a large open wound communicating directly with the trachea

1. Direct placement of the tracheal tube through the deficit guided by a fibreoptic scope may be possible in this setting. This will avoid the need to navigate challenging proximal airway anatomy and also allow direct visualisation of any trauma distal to the tracheal entry wound.

If the patient has a smaller/non-communicating wound and is cooperative

• 1.Awake fibreoptic intubation carries the benefits of maintaining spontaneous ventilation and visualising airway injury as described earlier. This has the potential to be technically challenging in the presence of haematoma or surgical emphysema distorting normal anatomy. Blood can easily obstruct the view so an endoscope with a suction channel is preferred.
• 2.Awake surgical tracheostomy under local anaesthetic may be the preferred strategy, particularly if there has been major distorting injury to the face making a nasal/oral intubation route prohibitively difficult. This approach can be technically challenging with injury deforming normal anatomy and it has the potential to exacerbate haemorrhage.

If the patient has a smaller/non-communicating wound and is not cooperative

• 1. Modified rapid-sequence induction without cricoid pressure and using direct laryngoscopy or videolaryngoscopy to facilitate fibreoptic intubation (as described in the blunt neck trauma airway section above) enables airway injuries to be seen directly and avoided when siting the tracheal tube.

Cervical spine immobilisation in penetrating neck trauma

In contrast to blunt neck trauma, cervical spine cord damage is rare with penetrating neck trauma, and routine immobilisation is not recommended, particularly as it can impair the adequate assessment and management of injuries.²³ The US Eastern Association for the Surgery of Trauma has published guidance on this topic.²⁴ They recommend that cervical immobilisation is only necessary in cases of penetrating trauma when there is a mechanism of injury compatible with spinal cord or column injury, and either a neurological deficit is present or it has not been possible to exclude a neurological deficit on clinical examination, such as in a patient with a depressed conscious level.

B: Assessment and management of ventilation

Penetrating injuries in all zones of the neck can compromise respiratory function. It is especially important to exclude a haemothorax, a pneumothorax, or both in patients with zone 1 or zone 2 injuries. If present, thoracostomies and intercostal drains are indicated.

C: Assessment and management of circulation

Adequate venous access should be secured in all penetrating neck injuries, either with large bore peripheral i.v. cannulae or a large bore central vein access, for example with a sheath introducer or haemodialysis catheter. Sites remote from the area of injury, such as the femoral or subclavian veins, are recommended for central venous access. Blood should immediately be sent for cross-match, coagulation profile, and full blood count. Physiological evidence of hypovolaemic shock should prompt activation of the major haemorrhage protocol, resuscitation with appropriate blood products, and treatment with tranexamic acid. Detailed guidance on the management of major haemorrhage is available and should be followed.²⁵

Sterile gauze and digital pressure should be applied to any neck wound with ongoing bleeding. If this fails to achieve haemostasis, a 20 FG Foley catheter can be used to stem the bleeding.²⁶ This is done by inserting the catheter tip into the bleeding wound, carefully advancing it along the wound tract and then inflating the catheter balloon with 10–15 ml sterile water until resistance is felt. If this is attempted, the catheter must be cross-clamped to prevent ongoing bleeding through it.

D: Assessment and management of disability

Zone 3 injuries have the highest risk of cranial nerve and brain injury. Assessment of conscious level and for the presence of focal neurological deficits should be performed. When possible, these assessments should be performed before the administration of any sedative medications. Information from these assessments may help understanding of the trajectory of the penetrating injury and as a result suggest which other neurological structures may be at risk of damage.

E: Further assessment and management

Patients who are physiologically unstable or have signs of upper aerodigestive tract or vascular injury listed in Table 3 should be urgently transferred to an operating theatre as surgical exploration is indicated.

Table 3.

Hard signs of vascular and aerodigestive tract injury after penetrating neck trauma

Hard signs of vascular injury	Hard signs of aerodigestive tract injury
Uncontrolled haemorrhage	Airway compromise
Rapidly expanding neck haematoma	Massive subcutaneous emphysema
Hypovolaemic shock not responsive to resuscitation	Bubbling or sucking neck wounds
	Large volume haematemesis
	Large volume haemoptysis

Management of patients with soft signs of injury who are haemodynamically stable remains an area of controversy.^6,7 Previous management algorithms recommending mandatory surgical exploration depending on zones of injury have now been replaced in some centres by a ‘no zones approach’ and use of early CT scanning with CT-angiography protocols. This individually tailored management approach provides better delineation of injuries within the neck and will reduce the number of negative surgical explorations performed. The strategy of early CT scanning reflects current practice in the management of major trauma in other anatomical regions.

A detailed description of further surgical management is beyond the scope of this article but may include a combination of open surgical repair of damaged structures, interventional radiology, or a conservative management for more minor injuries.

Conclusion

Despite an increasing incidence of interpersonal violence including knife crime, blunt and penetrating neck trauma remain relatively rare occurrences, even in most major trauma centres. These injuries can present significant challenges to the trauma team. The key principles of airway management in these patients are early recognition of impending airway obstruction, avoidance, where possible, of positive pressure face mask ventilation and to attempt, when necessary, to place the tip of a tracheal tube distal to the site of the injury. A collaborative approach with experienced surgical colleagues is crucial.

Declaration of interests

The authors declare that they have no conflicts of interest.

Acknowledgements

Mr Rory O'Conner, consultant in major trauma and maxillofacial surgery at Nottingham University Hospitals NHS Trust, for his assistance with clinical imaging.

Dr Joshua M. Tobin MD, adjunct clinical associate professor, Department of Anesthesiology Perioperative and Pain Medicine at Stanford University Medical Center USA, for his insights into the international management of blunt and penetrating neck trauma.

MCQs

The associated MCQs (to support CME/CPD activity) will be accessible at www.bjaed.org/cme/home by subscribers to BJA Education.

Biographies

James Shilston FRCA FFICM is a dual trainee in anaesthesia and intensive care medicine in the East Midlands, UK.

David L Evans FRCA is an RAF consultant anaesthetist at Nottingham University Hospitals NHS Trust, which is a regional major trauma centre covering a population of around 4 million people. He also provides military medical support to multiple theatres of conflict including Afghanistan.

Anthony Simons FRCS-ORL HNS is a consultant head and neck surgeon based at Nottingham University Hospitals NHS Trust who has an interest in airway and head and neck oncology

David A Evans FRCA is a consultant anaesthetist at Nottingham University Hospitals NHS Trust with interests in major trauma and head and neck anaesthesia

Matrix codes: 1B02, 1C01, 2A01, 2A02, 3A01, 3A02, 3A10