Updates on Management of Airway Trauma

Abstract

Airway trauma can be broadly classified as blunt or penetrating trauma. Each of these categories can be considered in the context of direct injury to the airway itself versus compromise or threat to the airway caused by the proximity of an injury in the neck. Injury to the airway can occur at one or more levels. Maxillofacial trauma can compromise the upper airway; direct injury to the neck can compromise the airway from the hypopharynx to the trachea; and injuries to the thorax can disrupt the lower trachea, main stem bronchi, or other smaller bronchi. The approach to airway management is dictated by the clinical presentation of the patient and the best judgment of the operator. Penetrating injuries commonly fracture the mandible followed by the maxilla and zygoma, orbit and nasal bones. They are usually associated with severe bleeding, hematoma formation and airway obstruction. Tissue, teeth or bone fragments can also obstruct the airway. Blunt injury to the larynx commonly fractures the thyroid cartilage which can distort and also obstruct the airway making intubation difficult. The mortality is around 11%. Cricoid injuries are less frequent. They can be associated with injury to the recurrent laryngeal nerve which can paralyse the vocal cords. Cricoid pressure can cause complete airway obstruction in an unsuspected cricoids injury. Mortality from cricoid injury is 43%. In the trauma resuscitation room, all patients who have been subjected to significant blunt trauma should be assumed to have a C-spine injury until it has been excluded. The primary focus for trauma stabilization or resuscitation in the field is airway, breathing (ventilation), circulation, (the ABCs) and spinal stabilization. Airway compromise, respiratory failure, and shock can coexist following trauma. Prehospital care of airway patients addresses the spectrum of clinical conditions faced in emergency departments, critical care units, and operating rooms, forced positive pressure with bag-mask ventilation and rapid transport may be the only options available. Endotracheal intubation has been considered the gold standard for definitive airway management, but the diverse skill levels found in prehospital care and the use of extraglottic airway devices have challenged this idea. All trauma patients are considered to be at high risk for aspiration. Compromised airway protection from head injury or from intoxication, prone position, and a non fasted state make aspiration a paramount concern. When applying awake intubation techniques, adequate sedation and topical anesthesia should be used to prevent gagging and emesis. If the patient vomits during awake intubation, there is increased risk of aspiration because of the topical anesthesia of the supraglottic area and the vocal cords. Most trauma patients can maintain and protect their airways and exhibit adequate or correctable oxygenation and ventilation. This is the most important of the decisions facing the airway manager. A patient may appear stable at the time of evaluation, but deterioration can be predicted as a natural course of the injuries. Preventing morbidity or mortality as it relates to trauma airway management refers to delaying intubation rather than to a mishap occurring during intubation. It is better to err on the side of intubating early and securing a potentially threatened airway than observing the patient with a false sense of security born from adequate oxygenation and ventilation at that moment. The purpose of observation is to see whether obstruction or airway failure ensues, but if either occurs, the results may be disastrous. The ideal intravenous induction agent for emergency airway management should be smooth and rapidly acting, painless on injection, permit optimum intubating conditions, and be devoid of cardiovascular, respiratory, and cerebral excitatory side effects. Neuromuscular blocking agents are required in emergency for two specific circumstances. They may be needed to facilitate tracheal intubation in the emergency department or prior to arrival in the hospital to provide oxygenation and ventilation to the unstable patient. Although many neuromuscular blocking drugs exist, only succinylcholine and rocuronium are recommended for rapid sequence induction in the trauma and other emergency situations. Despite solid direct laryngoscopic technique, inadequate glottic exposure results from the additive effect of poor C-spine mobility, reduced mouth opening, and oral secretions and blood. The modern difficult airway manager should have a device designed to overcome these limitations and see around corners. Many options exist, although video laryngoscopy has shown the most promise, resulting in improved laryngeal views.

Video laryngoscopy should be considered early as a backup or principal intubating device for significantly difficult trauma airways. Optically enhanced devices, such as the Airtraq, are understudied in trauma populations, although, early data suggest the Airtraq may be effective for patients requiring C-spine precautions.