The anaesthetic management of facial trauma and fractures Nicholas J Chesshire David J W Knight

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1 The anaesthetic management of facial trauma and fractures Nicholas J Chesshire David J W Knight Key points All trauma patients should be managed according to the principles of ABC Maxillofacial trauma is associated with particular airway problems The airway in acute facial trauma victims is usually most safely secured with rapid sequence induction of anaesthesia and tracheal intubation. However, this may be inappropriate in some patients Specialized airway skills and equipment may be required The possibility of occult haemorrhage due to other injuries must never be forgotten Nicholas J Chesshire Consultant Anaesthetist, Department of Anaesthetics, Derbyshire Royal Infirmary, London Road, Derby DE1 2QY David J W Knight Specialist Registrar in Anaesthetics, Department of Anaesthetics, Queen s Medical Centre, Nottingham NG7 2UH In the field of maxillofacial trauma, the anaesthetist may be called upon to provide help in the treatment of the acutely injured patient on arrival to the accident and emergency department or in the semi-elective repair of fractures sustained previously. This article provides advice on the best approaches to dealing with these problems and the alternatives available. The acutely injured patient In the UK, the epidemiology of trauma has changed dramatically since legislation on seat belts and drinking and driving. These changes have been most notable in the field of head injury and maxillofacial trauma. The overall incidence of complex pan-facial trauma may have decreased, but an increase in violent crime and associated facial injuries has easily compensated for this. The management of any traumatized patient is based on the principles of ABC, i.e. airway, breathing and circulation. When maxillofacial trauma has occurred, particular problems may be encountered in securing the airway and oxygenation and these will be reviewed in detail. Associated injuries frequently cause breathing and circulation difficulties. Life-threatening hypovolaemia is rarely seen in uncomplicated maxillofacial trauma, but occurs in 1 4% of isolated mid-face fractures. Causes of airway difficulty Airway obstruction The mechanism of trauma itself may obstruct the airway due to gross disruption of facial anatomy or the presence of a foreign body such as a knife or fence post. Blood, broken teeth and generalized oedema may also compromise the airway. Alternatively, the administration of opiates, underlying cerebral trauma or drug and alcohol intoxication can reduce the ability of the trauma victim to maintain an adequate airway. These factors often occur in combination. Uncooperative/intoxicated patients Many patients with maxillofacial trauma are uncooperative, not only due to previous drug and alcohol ingestion, but also to underlying hypoxaemia, pain or cerebral trauma. This often prevents utilisation of airway management techniques that require patient co-operation, such as awake intubation. Full stomach A full stomach with concurrent risk of aspiration should be assumed and precautions such as rapid sequence induction with cricoid pressure or, if appropriate, awake intubation before induction of anaesthesia, are mandatory. Disruption of normal anatomy Even minor maxillofacial trauma can cause enough anatomical distortion to prevent an adequate mask seal and so make mask ventilation impossible. Basic airway adjuncts such as oral or nasal airways may actually cause further trauma or be contra-indicated and so be lost as an aid to airway management. Cervical spine protection High velocity trauma, e.g. road traffic accidents, has a relatively high incidence of associated cervical spine injury. Thus, cervical spine immobilisation should be achieved at all times during management of the airway. This may complicate matters further. Management of the airway Airway management should begin with an assessment of the speed with which a definitive airway needs to be secured, knowledge of airway equipment that is readily available, and a plan of action if primary airway manoeuvres fail. 108 British Journal of Anaesthesia CEPD Reviews Volume 1 Number The Board of Management and Trustees of the British Journal of Anaesthesia 2001

2 Airway assessment in patients with facial injuries follows the same principles as in any traumatized patient; the clinical features of respiratory obstruction, hypoventilation, hypoxaemia or coma indicate the need for urgent intervention. Simple airway manoeuvres Many routine airway manoeuvres may not be possible in maxillofacial trauma due to anatomical disruption or poor patient co-operation. It should be remembered that agitation is often due to hypoxaemia and correction of this may convert a difficult patient to one who co-operates fully with airway management. Fully conscious patients will often present in the most favourable position to maintain their own airway and may fiercely resist attempts to lay them supine. Obtunded patients may benefit greatly from a simple jaw thrust and left lateral positioning to allow blood and secretions to drain away from the oropharynx. A unique but life-saving manoeuvre in mid-face fracture is to grasp and pull forward a posteriorly displaced and mobile fractured maxilla, in order to open a previously obstructed airway. Oral/nasal intubation Patients who are unable to maintain their own airway and/or need the institution of positive pressure ventilation for other reasons (such as suspected raised intracranial pressure or impending respiratory failure) need a definitive airway secured. The above factors may well make this difficult. The techniques utilised will depend on the experience and expertise of the anaesthetist and at all times a plan B must be considered should failure be encountered. An experienced anaesthetist must be available, as it is often hard to assess how difficult intubation will be. The presence of a suspected basal skull fracture will preclude the use of the nasal approach to the trachea. Otherwise, either route can be chosen, depending on the technique utilized and patient factors, e.g. site of injuries. Battles sign (retroauricular haematoma) and periorbital haematoma ( Racoon eyes ) are common clinical signs of base of skull fracture. General anaesthesia Rapid sequence induction of anaesthesia with rigorous preoxygenation and cricoid pressure remains the technique of first choice in all trauma patients providing that there is no obvious reason to suppose that direct laryngoscopy will be impossible. Fortunately, most genuine grade IV Cormack and Lehane laryngoscopies can be predicted and correspond to those patients with gross anatomical disruption or foreign body invasion. Bearing in mind that the intubation is likely to be difficult, rather than impossible, the most experienced anaesthetist available should be present and all equipment must be rigorously checked. Difficult intubation adjuncts should be available such as a selection of different tubes and laryngoscope blades and most importantly, a gum elastic bougie. A plan of action involving a failed intubation drill must be practised and agreed upon, and in the event of failure to intubate and ventilate facilities for cricothyroid puncture and oxygenation should be available. There are many other useful aids now marketed which should be considered for a difficult intubation trolley available in all accident departments. These include McCoy laryngoscopes, laryngeal mask airways, ventilating bougies and specific cricothyrotomy cannulas. Simple facilities for jet ventilation are not expensive and can be extremely useful if oxygenation becomes difficult due to an airway problem. Several case reports have demonstrated the use of the Bullard laryngoscope in facial trauma. This is a rigid laryngoscope with a fibre-optic viewing channel and guide wire which is preloaded with an endotracheal tube. Unfortunately, most UK anaesthetists are unfamiliar with these more specialized equipment options. Intubation under general anaesthesia with neuromuscular paralysis remains the technique most well practised and is the first that should be considered in maxillofacial trauma. Clearly, if it is felt that intubation via direct laryngoscopy is very likely to fail then another method of securing the airway must be sought. Some may advocate the use of inhalation induction of anaesthesia in order to maintain spontaneous ventilation in the face of a difficult airway. Theoretically, this avoids the possibility of a can t intubate can t ventilate scenario. In experienced hands, this may be a useful technique, but is often practically difficult in uncooperative patients. The airway may well obstruct during lighter planes of anaesthesia and hypoxaemia often rapidly ensues in traumatized patients. Regurgitation of gastric contents may occur and be aspirated along with blood already in the airway. Once a deep plane of anaesthesia is achieved, one is still faced with the problem of how to intubate the trachea. Awake intubation If extreme difficulty in laryngoscopy is anticipated, awake intubation must be considered. The major benefit is that the airway is maintained reducing the chance of further catastrophic deterioration in oxygenation and the aspiration of gastric contents. A degree of patient co-operation is essential for awake intubation British Journal of Anaesthesia CEPD Reviews Volume 1 Number

3 and this may preclude its use in aggressive or intoxicated patients. However, those with progressing airway difficulties will often tolerate a significant amount of discomfort to obtain relief from their distressing symptoms. Local anaesthesia is usually applied to the airway mucosa by means of spray, injection, or nebulizer together with topical vasoconstrictors. Sedation is generally contra-indicated in these patients due to respiratory compromise, full stomach and/or reduced level of consciousness. Having achieved a reasonable level of local anaesthesia, various methods of intubation can be employed. Gentle rigid laryngoscopy can be performed but most practitioners would use a fibre-optic intubating laryngoscope as the method of first choice. However, after trauma, the presence of blood and other matter in the airway can make this extremely difficult. Alternatively, blind nasal or oral intubation is often possible and is helped in the awake patient by listening down the tube for breath sounds emanating from the trachea. A laryngeal mask airway can be placed under local anaesthesia and then used as a port for the fibre-optically guided or blind passage of a small endotracheal tube. The intubating laryngeal mask airway can also be used. Various light wand and lighted stylets have been marketed for difficult intubation and are useful in the awake patient, as they require minimal mouth opening, but few UK anaesthetists are experienced in their use. Retrograde intubation may also be of value, in which a guide wire or catheter is passed into the trachea through the cricothyroid membrane and then up into the pharynx. The tube is then passed downwards over the guide. Commercial kits are available to facilitate this. Whichever technique is chosen will depend upon the expertise of the operator, the equipment available and patient factors. Surgical airway This may be the only viable option if intubation is impossible and ideally should consist of a tracheostomy performed awake under local anaesthesia. This may present practical problems if the patient is uncooperative of if there is gross swelling or anatomical disruption of the cervical structures. It may have to be performed in the sitting position if the patient cannot maintain an airway supine. Surgical access to the trachea may be necessary urgently after induction of anaesthesia and a failure to intubate or ventilate adequately. In these circumstances, the quickest life-saving manoeuvre is to cannulate the trachea through the cricothyroid membrane and oxygenate via this route. Specific cannulas are designed for this purpose and should be available as venous cannulas are extremely prone to kinking and have no direct means of connection to a breathing system. Jet ventilation is the ideal mode of ventilation through a cannula due to the small bore of the tube ; extreme care must be taken to watch for signs of barotrauma, particularly if exhalation is also obstructed. Conversion to a definitive tracheostomy must proceed as soon as possible. Haemorrhage Persistent hypotension in a patient with apparently isolated maxillofacial trauma should always prompt the resuscitation team to look for an occult cause of haemorrhage. Profuse bleeding from facial injuries can be very difficult to deal with due to the complex vascular supply to the area involving branches of both the internal and external carotid arteries. Cerebral trauma In a recent study, cerebral injury was the most common lifethreatening factor in cases of maxillofacial trauma (more common than airway compromise). It should, therefore, be remembered that initial resuscitation in an agitated patient should be aimed at preventing secondary brain injury and that computerised tomography of the cranium should be performed early. The semi-elective repair of maxillofacial fractures If surgical or anaesthetic intervention is not required for other problems associated with the trauma, maxillofacial fracture repair is often delayed until swelling has subsided, intoxication has passed and the effects of any head injury can be properly assessed. Also, repair can be scheduled for a time when experienced medical and theatre staff are readily available during daylight hours. The treatment of facial fractures follows the principles of all fracture management, i.e. debridement of open injuries, reduction (open or closed), fixation (internal or external), immobilisation and functional rehabilitation. Most commonly, fractures are fixed internally using microplating instruments. External fixators and long-term immobilisation are used less often. A simple understanding of the classification of the injuries and functional anatomy is useful when planning anaesthesia. Classification of facial fractures Common facial injuries may involve fracture to one or more of the bones of the facial skeleton. For example, mandibular fractures often occur alone whereas orbital or midface fractures 110 British Journal of Anaesthesia CEPD Reviews Volume 1 Number

4 commonly require fixation of multiple components of the skull. The functional effect of the injury is most important to the anaesthetist, but the fractures themselves can be classified according to their anatomical position or displacement. Mandibular fractures These vary in site and relative incidence, i.e. condylar neck 35%, angle 20%, body 20%, parasymphysis 13%, symphysis 11% and coronoid 1%. Midface fractures The midface comprises the maxilla, zygoma, palatine, nasal, lacrimal, inferior concha, pterygoid plate of sphenoid, vomer and ethmoid. Rene Le Fort developed the following classification in 1901 after applying direct trauma to cadaveric heads: Le Fort I: Le Fort II: Le Fort III: low level fractures pyramidal or sub-zygomatic fractures high level or supra-zygomatic fractures Le Fort III fractures are often associated with base of the skull fractures. Other fractures The classification of zygomatic fractures is shown in Table 1. Others include naso-ethmoidal and orbital fractures. The latter may involve the rim, floor, roof or walls or the orbit. Isolated fractures or the medial wall or floor can occur and are termed blow-out fractures. Principles of anaesthesia for facial fracture repair General anaesthesia is almost invariably required for the repair of facial fractures and all the usual general principles of anaesthetic management are employed. The security of the airway is of particular relevance in view of the following points: (i) intubation may be difficult due to anatomical distortion of the facial structures and residual swelling; (ii) the airway is shared between surgeon and anaesthetist; and (iii) endotracheal tube placement may interfere with surgical management. Good communication is vital between surgeon and anaesthetist prior to deciding on the appropriate technique for Table 1 Classification of zygomatic fractures Type 1 Type 2 Type 3 Type 4 Type 5 Type 6 Type 7 Undisplaced fracture Arch fracture only Tripod malar fracture (frontozygomatic suture intact) Tripod malar fracture (frontozygomatic suture distracted) Pure blowout fracture Orbital rim fracture involving zygoma only Comminuted and other fractures Fig. 1 Classification of Le Fort fractures. I: low level fractures, II: pyramidal or sub-zygomatic fractures, III: high level or supra-zygomatic fractures. securing the airway. A full pre-operative airway assessment and knowledge of the anatomical disruption present will allow an estimate of ease of intubation to be made. Many patients with facial fractures find mouth opening difficult. However, this is often due to pain or trismus and may not cause difficulty in laryngoscopy once anaesthesia is induced. If difficult intubation is anticipated, the options are a careful inhalational induction of anaesthesia with laryngoscopy under deep anaesthesia, or to secure the airway awake. With the increasing dissemination of fibre-optic endoscopy skills, many would now advocate awake fibre-optic intubation. Other difficult airway adjuncts must be available as described above. In the rare event of a total loss of the airway, then a surgical airway may be necessary. Intermaxillary fixation (IMF) is frequently employed intraoperatively for midface and mandibular fractures to produce a template for the fracture reduction and may remain in place for some time postoperatively. This is becoming less common as modern microplating techniques provide good immobilization of the fracture site. IMF precludes the use of an oral tube unless there is a large gap between the teeth. Therefore, nasotracheal intubation is commonly required for mandibular and midface fractures. However, this route may not be available if basal skull fracture is present (common in Le Fort III injuries) or if fractures of the naso-ethmoidal complex are to be plated. British Journal of Anaesthesia CEPD Reviews Volume 1 Number

5 In these circumstances, either a tracheostomy must be formed or the technique of sub-mental intubation must be employed. This technique, first described in 1986, involves the surgeon making a submental skin incision adjacent to the lower border of the mandible and blunt dissecting into the floor of the mouth. A tube may then be passed through the tissues and into the larynx if direct laryngoscopy is straight-forward. Alternatively, a tracheal tube already in situ can be exteriorised through the hole if the universal connector is removed. After extubation, the submental incision is simply repaired. This technique may be associated with less morbidity than tracheostomy. The surgical fixation of multiple facial fractures may be prolonged and the usual steps should be taken to keep the patient warm and well monitored. Moderate controlled hypotension is useful to improve operative conditions but care must be taken to restore the blood pressure prior to closure to ensure haemostasis. Extubation must be planned carefully. A generally safe technique is to allow the patient to regain consciousness and airway reflexes prior to extubation and to ensure that the airway is clear. If IMF is in place, then a nasopharyngeal airway can be useful to maintain a clear airway. Tools for releasing the IMF must be immediately available in the event of loss of the airway or severe vomiting. Patients with IMF should be recovered and nursed in a high dependency area. Key references Arekian L, Rosen D, Klein Y, Peled M, Michaelson M, Laufer D. Life-threatening complications and irreversible damage following maxillofacial trauma. Injury 1998; 29: Gabbott DA. Recent advances in airway technology. BJA CEPD Rev 2001; 1: Ghouri A, Bernstein C. Use of Bullard laryngoscope blade in patients with maxillofacial injuries. Anaesthesiology 1996; 84: 490 Gillespie MB, Eisele DW. Outcomes of emergency surgical airway procedures in a hospital-wide setting. Laryngoscope 1999; 109: King H. Airway management of patients with maxillofacial trauma. Acta Anaesthesiol Sin 1996; 34: Magennis M, Shepherd J, Hutchinson I, Brown A. Trends in facial injury. BMJ 1998; 316: Vaughan RS. Predicting difficult airways. BJA CEPD Rev 2001; 1: 44 7 See multiple choice questions British Journal of Anaesthesia CEPD Reviews Volume 1 Number