INTRODUCTION

This tutorial builds on ATOTW (541) ‘Airway Management in Patients with Maxillofacial Trauma Part 1’.

Part 1 discusses the relevant anatomical components of maxillofacial trauma and their impact on the airway and provides a comprehensive approach to emergency and elective airway assessment of patients with maxillofacial injuries.

Part 2 continues with a practical and detailed description of important basic and advanced airway management techniques. Proficiency in fundamental airway skills is essential, whereas advanced techniques require extensive training and experience. A discussion of postoperative airway management is included.

Knowledge of difficult airway management guidelines and the use of rescue airway techniques and devices is essential. The recommendations are based on challenges associated with specific airway and facial injuries, standardised airway protocols and current literature. It is important to recognise that the anaesthetist will often have to balance competing priorities when caring for patients with maxillofacial trauma. Reconciliation of these priorities, and therefore, final airway management techniques used, is not prescriptive but requires an individualised approach dependent on the clinical scenario.

BASIC AIRWAY MANAGEMENT

Emergency Airway Management

Patient Positioning

Patient positioning for airway management in cases of maxillofacial trauma is multifaceted and differs significantly between the acute and elective scenarios. An acutely compromised airway may require rapid securing of a definitive airway as an emergency life-saving measure. This immediate intervention can be performed regardless of the patient’s position.

Careful consideration is required to ensure both airway and spinal safety. Airway maintenance remains the first and foremost goal in the American College of Surgeons’ Advanced Trauma Life Support protocol. All measures should be taken to protect spinal integrity as far as possible, however, ensuring adequate oxygenation is the most important goal. Patient positioning aimed at achieving airway patency and ensuring spinal immobilisation can result in conflicting objectives.

Placing unconscious, unintubated patients in the left lateral decubitus position may aid drainage of blood and secretions, reducing the risk of aspiration and alleviating airway obstruction. Importantly, it is possible to maintain spinal alignment in this position. The supine position maintains spinal alignment but can lead to airway obstruction in patients with maxillofacial fractures and carries an increased risk of vomiting and aspiration.¹

A seated position reduces oedema, improves airway patency and assists with fluid drainage from the airway. The semi-Fowler’s position with a 308 head elevation is reasonable for traumatic brain and chest injuries, reducing intracranial pressure and supporting respiratory function.² Awake patients with partial airway obstruction may adopt a forward-leaning position to mitigate airway compromise and aid passive drainage of fluids.

Notably, prehospital management of suspected traumatic spinal cord injuries (TSCIs) remains an evolving field. The traditional recommendation for complete spinal immobilisation using a semi-rigid or rigid neck collar is losing favour globally due to concerns about efficacy and potential complications. Additionally, an awake, cooperative patient can protect their cervical spine. In a recent literature review, Arejan HR et al.³ noted a lack of consensus regarding spinal immobilisation in patients with suspected TSCl. They emphasised the need for future prospective studies with large sample sizes in real-life settings to provide clear and evidence-based data on this topic.

Provision of Supplemental Oxygen

Various oxygen delivery devices are available for supplemental oxygen administration. Among these, humidified high-flow nasal oxygenation (HFNO) proves beneficial for acutely injured maxillofacial trauma patients by enhancing oxygenation and maintaining an open airway.⁴ However, it is important to note that HFNO is contraindicated in cases of base of skull fractures due to the risk of clinically significant pneumocephalus.

For more detailed information on HFNO, refer to ATOTW #437.

Hypoxia is a potential cause of correctable altered mental states. Uncooperative patients can hinder the provision of supplemental oxygen, and sedation in critically ill patients can lead to inadequate respiration or airway obstruction. In this scenario, consideration of a definitive airway is warranted.

Pre-oxygenation is an important aspect of the preparation for advanced airway management. Utilising a breathing circuit and face mask with minimal downward pressure, along with waveform capnography, can help avoid complications associated with bag-mask ventilation (BMV) and confirm adequate ventilation.

Simple Airway Maintenance Techniques

Basic airway manoeuvres, along with the use of suctioning equipment and airway adjuncts, play a crucial role in maintaining a clear, patent airway.

Non-Invasive Ventilation

BMV is a life-saving manoeuvre in difficult airway management. A 2-person technique is recommended for a better mask seal and success.⁵ Care must be taken to avoid displacing fractured segments, which can worsen airway obstruction. Avoid using excessive pressure, as this can force air into the subdural space in the presence of skull base fractures.

For more detailed information on difficult BMV, refer to ATOTW #321.

Elective Airway Management Techniques

Patient Positioning

Elective airway management permits meticulous positioning to optimise airway visualisation and access while minimising potential complications. It is essential to consider whether the patient requires C-spine immobilisation. While awake, patients may be able to protect their C-spine, but when unconscious, manual in-line stabilisation is recommended.

Provision of Supplemental Oxygen

Pre-oxygenation is essential in preparing for advanced airway management. Using a breathing circuit with a face mask, complemented by waveform capnography, is advised. Unless contraindicated, HFNO can be advantageous during intubation, particularly for apnoeic oxygenation, extending the duration of apnoea before arterial oxygen desaturation occurs.

Simple Airway Maintenance

Figure 1 describes techniques utilised to maintain a clear and patent airway during induction.

Figure 1. Techniques of airway maintenance for patients with maxillofacial trauma.

Non-Invasive Ventilation

Careful BMV remains a crucial manoeuvre during challenging airway management, benefiting from a 2-person technique to enhance mask seal and overall success.

ADVANCED AIRWAY MANAGEMENT

General Anaesthesia

Rapid sequence induction allows for quick and safe intubation but avoids cricoid pressure with C-spine or laryngeal injuries.⁶ Elective sequence induction is for low aspiration risk and uncomplicated airway management.

Awake Approaches

An awake approach requires patient cooperation as well as adequate anaesthesia of the entire airway. Airway anaesthesia for awake intubations is achieved by topical application of a local anaesthetic (LA) agent onto airway mucosa and regional anaesthetic techniques. The presence of blood and secretions in the airway can dilute the LA, causing inadequate anaesthesia. Airway nerve blocks are often impractical in maxillofacial trauma. Internal approaches to glossopharyngeal and superior laryngeal nerve blocks necessitate sufficient mouth opening for adequate visualisation and access. While glossopharyngeal nerve blocks using an external approach can be performed with the head in neutral position, recurrent laryngeal nerve and superior laryngeal nerve blocks using an external approach require a degree of neck extension.

Figure 2. Comparison between advanced airway management under general anaesthesia and awake techniques.

In scenarios of C-spine injury or a difficult airway is anticipated, it is advantageous for the patient to be awake, alert, breathing spontaneously, and maintaining his or her airway. If a patient becomes uncomfortable and anxious, minimal sedation can be used with extreme caution, as it may lead to respiratory depression and airway obstruction.⁷ The Difficult Airway Society (DAS) recommends using a single sedative agent as the safest approach.⁸ If necessary, introducing a second agent only if an additional anaesthetist is present to oversee the sedation separately from the anaesthetist performing the procedure (see Figure 2).⁸

Tracheal Intubation Under General Anaesthesia

Endotracheal intubation provides a definitive, secure airway for critically ill patients and facilitates GA. However, maxillofacial trauma often complicates conventional laryngoscopy. While direct laryngoscopy (DL) requires C-spine manipulation for optimal glottis visualisation, video laryngoscopy (VL) offers a safer alternative with substantially reduced C-spine manipulation. An inter-incisor distance of less than 3 cm predicts difficult DL, whereas specific video laryngoscope blades require only 1.8–2 cm for effective insertion.⁹ Additionally, alternative and complementary devices and techniques exist for visualising the glottis and larynx during intubation, e.g., video-assisted fibreoptic intubation (VAFI, see below).

In specific maxillofacial procedures, where unobstructed access to the oral cavity is crucial, standard orotracheal intubation is not recommended. Oral endotracheal tubes (ETTs) have the potential to interfere with dental occlusion and mandibulomaxillary fixation (MMF). Unless contraindicated, nasotracheal intubation is a viable option in these circumstances. However, nasotracheal intubations may not be suitable for certain injuries or procedures. Complex craniofacial, nasal, and maxillary reconstructions necessitate surgical access to the mouth and nose. In such cases, alternative techniques, such as retromolar intubation, submental intubation and surgical airways, may be considered.

Video-Assisted Fibreoptic Intubation

Despite the utilisation of VL, tracheal intubation remains a challenging procedure in patients with significant maxillofacial trauma. Using alternative techniques, such as VAFI, can enhance success rates.¹⁰ VAFI involves using a video laryngoscope while introducing a fibrescope preloaded with a tracheal tube. By utilising both video screens, this approach optimises the glottic view during intubation. Alternative devices for laryngoscopy (Figure 3) can also be used in a similar way in these scenarios.

Figure 3. Alternative devices for laryngoscopy.

Retromolar Intubation

Following standard orotracheal intubation, the ETT is positioned in the retromolar space, secured with sutures to the molar tooth on the maxillary side and held at the angle of the mouth with tape. A reinforced ETT is preferred, and the size of the retromolar space must be assessed preoperatively.

Submental Intubation

Following standard orotracheal intubation, the ETT is passed through a tunnel created on the floor of the mouth in the submental area. The pilot balloon of the ETT is passed through the tunnel first. Then the ETT is disconnected from the breathing circuit, the connector removed, the lumen occluded, and the ETT passes through the floor of the mouth. It is important to pre-oxygenate before disconnection and closely monitor the patient throughout, as hypoxia may occur if apnoea becomes prolonged. Confirm correct tube positioning before securing the ETT with a suture. It is not appropriate for post-operative ventilation and must be reversed at the end of surgery.

Awake Tracheal Intubation

Variations of the Awake Intubation Technique

Awake intubation can be performed using direct or VL or using a fibreoptic scope (see Figure 4).

Figure 4. Variations of the awake intubation technique.¹¹

Awake Fibreoptic Intubation

This is an essential skill in airway management of the anticipated or known difficult airway. Awake fibreoptic intubation (AFOI) requires controlled and well-prepared conditions, an experienced and skilled clinician and a cooperative patient. AFOI is usually reserved for elective airway management.

For more information on AFOI, refer to ATOTW #201.

Despite the potential of a fibrescope to facilitate intubation without any manipulation of the C-spine, their use is often limited by the availability of equipment and operator skill.

Suction-Assisted Laryngoscopy and Airway Decontamination Technique

The main objective of the suction-assisted laryngoscopy and airway decontamination (SALAD) technique is to keep the airway clear during emergency airway management. Laryngoscopy in these circumstances is often complicated by the presence of blood, gastric contents, secretions and other contaminants. DuCanto et al.¹² created an airway simulation tool that presents students with the dynamic challenges associated with emergency airway management. It involves positioning a rigid suction catheter in the upper oesophagus and stabilising it to the left of the laryngoscope. Continuous suctioning is thought to allow better visualisation of the airway while limiting airway contamination.

Surgical Airway

Front-of-neck access (FONA) refers to surgical techniques used to gain access to the trachea via the anterior aspect of the neck. Tracheostomy and cricothyroidotomy can be performed either under GA or with an awake approach. However, anatomical distortion of the neck, accompanied by the presence of oedema and haematomas, can complicate FONA.

Tracheostomy

Indications:

• Airway obstruction above the glottis;
• Laryngotracheal injuries;
• Complex craniofacial, nasal and maxillary reconstructions;
• Anticipated airway obstruction after extubation; and
• Prolonged (postoperative) ventilation.

For more information on tracheostomy, refer to ATOTW #241.

Cricothyroidotomy

Needle and surgical cricothyroidotomies provide transtracheal access through the cricothyroid membrane. They serve as a rescue strategy when attempts to oxygenate and ventilate the patient supraglottically have failed. Leading airway societies continue to debate the preferred technique for emergencies, recognising the merits of both methods. While some practitioners consider needle cricothyroidotomy to be faster and simpler to execute, the DAS endorses surgical cricothyroidotomy in its guidelines.¹³

Importantly, emergency transtracheal oxygenation is only a temporary measure and conversion to a device facilitating ventilation is performed once haemodynamic stability is achieved.

For more information on cricothyroidotomy, refer to ATOTW #114.

Supraglottic Airway Devices

These devices offer a less invasive method of maintaining the airway. They can provide a leak-free seal above the glottis that facilitates both spontaneous and controlled ventilation but, despite design advances in second-generation devices, do not guarantee airway protection from soiling. In maxillofacial trauma, supraglottic airway devices (SADs) are used as temporary rescue airways before establishing a definitive airway. However, with some maxillofacial injuries, it may not be possible to insert a SAD; in these scenarios, the recommended back up plan is FONA (see Figure 5).

Figure 5. Placement of the endotracheal tube.^7,14

Difficult Airway Management

The DAS guidelines for the management of unanticipated difficult intubation in adults (2015) provide a useful strategy in the event of an unanticipated difficulty with tracheal intubation.¹³

POSTOPERATIVE AIRWAY MANAGEMENT

The DAS’s 2011 guidelines include an extubation algorithm. Postoperative extubation decisions should consider patient and surgical factors and be made in consultation with the surgical team on a case-by-case basis (see Figure 6).

Figure 6. Patient and surgical factors affecting the decision on extubation postoperatively.

Key Aspects for Emergence and Extubation

• Ensure immediate availability of all airway equipment, including the difficult airway trolley, anaesthetic drugs, and emergency drugs.
• Minimise coughing and bucking.
• Extubate the patient only once they are fully awake.
• Gently remove nasal ETTs.
• Wire cutters or scissors should be immediately available in both the operating room and recovery area.
• Avoid applying excessive pressure with a face mask following extubation.
• Ensure the surgical team remains present until successful extubation and stable patient condition.

Postoperative Airway Complications

Complications related to extubation can occur either immediately or be delayed. Upper airway obstruction due to oedema or haematoma formation may occur abruptly or insidiously. Obstruction from haematoma formation is more likely with surgery involving the neck and the floor of the mouth. A haematoma is managed with urgent decompression by removal of all clips and sutures and manual evacuation of the haematoma with a rigid suction catheter.

The DAS has presented a comprehensive strategy for addressing postoperative airway obstruction after thyroid surgery.¹⁵ The established consensus guidelines offer a systematic method for the prompt detection and management of haematoma development. These guidelines are also applicable and beneficial in managing similar complications after specific maxillofacial surgical procedures (see Figure 7).

Figure 7. DESATS acronym adapted from the DAS guidelines on the management of post-thyroid surgery haematoma formation.¹⁵

Obstruction may persist after decompression due to the secondary venous congestion induced by the haematoma. Airway management should be expected to be much more challenging than the initial management.

CHECKLISTS FOR AIRWAY MANAGEMENT

See Figures 8–10.

Figure 8. Emergency airway management.

Figure 9. Checklist for emergency airway management.

Figure 10. Checklist for elective airway management.