78 Laryngeal Trauma Flashcards
What is the incidence of external laryngeal trauma?
What is the incidence of external laryngeal trauma?
External laryngeal trauma is rare and occurs with an estimated incidence of 1 in 137,000 inpatient admissions and 1 in 30,000 emergency room visits. Laryngeal injuries in the pediatric patient are even more uncommon and account for <0.5% of trauma admission compared to 1% of adult trauma admissions. The occurrence of blunt trauma injuries has decreased in the past several decades due to improved automobile safety. However, the incidence of penetrating trauma has increased with a rise in violent crimes.
What anatomic features are protective against laryngeal trauma?
What anatomic features are protective against laryngeal trauma?
- Surrounding structures: Multiple surrounding structures shield the larynx and provide protection from external trauma. These structures include the mandible superiorly, the sternum and clavicles inferiorly, the sternocleidomastoid muscles laterally, and the vertebrae posteriorly. Anterior soft tissue including strap muscles provides minimal protection from anteriorly directed force. In pediatric patients, the larynx is located higher in the neck in relation with the mandible and is thus further protected.
- Laryngeal mobility: The larynx is mobile in multiple directions, most prominently in the lateral plane, but also in the anterior/posterior and superior/inferior planes. This mobility allows it to be pushed out of the way by external forces.
- Tissue pliability: In adults, ossification of the larynx increases the chances of fracture in the setting of blunt trauma. In children, laryngeal cartilages remain pliable and are consequently more resistant to fracture.
3 Discuss the etiology of external laryngeal trauma.
Blunt trauma occurs as the result of an anterior force compressing the larynx against the fixed vertebral column. These injuries classically result from motor vehicle accidents and occur when the hyperextended neck is thrust onto the dashboard or steering wheel during rapid deceleration. Another subset of these injuries are “clothesline” injuries in which a thin horizontal structure (e.g., barbed wire fence) is struck.
The severity of trauma is variable and depends on multiple factors. The speed at which the patient is traveling is key because injury severity is generally proportional to velocity. The size and configuration of the surface against which the neck makes contact is also important to consider because a larger force distributed over a smaller surface area is more likely to result in penetrating trauma rather than blunt trauma.
Penetrating trauma more commonly occurs as a result of violent crime and military conflict. The energy of the penetrating object is an important factor in determining the potential for airway injury. Any additional information regarding the penetrating object is helpful as it can help predict the extent of collateral damage.
4 What are the main symptoms and signs of blunt laryngeal trauma?
Physical exam may range from the asymptomatic to the critically ill and symptoms alone may not denote severity. Dysphonia, dysphagia, pain, and difficulty breathing are the most common initial symptoms. Patients may present with mild symptoms and progress to airway compromise over minutes to hours due to progressive edema, hematoma or instability of the laryngotracheal framework. Observation is recommended if history and physical are at all concerning. A disrupted airway may present with cervical crepitus, particularly in the patient who has been managed with positive pressure ventilation. In these critically ill patients, look for/anticipate pneumomediastinum, pneumothorax, and worsening respiratory status. Note that these patients are often at risk for cervical spine and vascular trauma as well. Loss of anatomic landmarks on neck palpitation may indicate hyoid or laryngeal fracture, or hematoma. Hemoptysis is indicative of mucosal disruption at the least.
5 Discuss the management of acute airway compromise following laryngeal trauma.
The first step in airway management is to determine whether the patient displays signs and symptoms of impending airway compromise such as stridor, dyspnea, respiratory distress, or aphonia. If a patient exhibits signs of airway compromise, a secure airway must be obtained as soon as possible. There are several methods that are appropriate to secure the airway in the setting of laryngeal trauma including intubation, tracheostomy, and cricothyroidotomy.
Several factors must be taken into consideration when choosing which method will be used to secure the airway, including patient stability and injury severity. Control of the airway should occur in the emergency room or, when possible, the operating room to allow for optimal direct and endoscopic evaluation. For endotracheal intubation to proceed, the larynx and trachea must be clearly intact and in continuity to prevent mucosal disruption, laryngotracheal separation, false passage of the endotracheal tube surrounding soft tissue, and further respiratory compromise. It is important to note that intubation should be performed by an experienced physician to help prevent intubation-related trauma (Figure 78-1).
Cricothyroidotomy is reserved for those patients with a rapidly deteriorating airway, those who do not meet the optimal conditions for intubation, or those patients in whom tracheostomy is not possible due to patient factors or availability of physicians experienced in the surgical airway. Cricothyroidotomy is dependent on continuity of the cricoid and trachea. Cricothyroidotomy should subsequently be converted to a tracheostomy to prevent the development of subglottic stenosis. Following emergent management of the airway, these patients should undergo endoscopic evaluation of the aerodigestive tract in the operating room.
6 Discuss important aspects of the evaluation and management of a stable patient with external laryngeal trauma.
A.
History:
1.
Mechanism of injury: Be suspicious in the setting of high velocity impact directed anteriorly to the neck.
2.
Temporal evolution: Determine if symptoms are getting worse.
B.
Physical exam:
1.
Head and neck exam: Bony and soft tissue trauma, voice quality, respiratory effort, loss of landmarks, crepitus
2.
Associated injuries: Neurological, vascular, or spinal injuries
C.
Flexible laryngoscopy: Damage to mucosa of supraglottis, damage to vocal folds (mucosal tears, hematoma, exposed muscle or cartilage), vocal fold mobility
D.
Definitive management:
1.
Nonsurgical management
a.
Appropriate for “reversible injuries” due to blunt trauma: endolaryngeal edema, hematoma, contusion, abrasion, non-displaced fractures and small lacerations. These patients commonly have dysphonia, neck pain and tenderness to palpation.
b.
Observe for 12–24 hours following injury. +/- Steroids; +/- Proton Pump Inhibitor; +/- Cool mist.
c.
Controversy regarding plating/repairing all laryngeal framework fractures. Some authors prefer plating even non-displaced fractures due to concerns of displacement over time.
2.
Surgical management: Goal is preservation of airway patency and function. Earlier intervention is associated with better outcomes. Surgical approach may require some or all of the following:
a.
Midline thyrotomy
b.
Repair of mucosal lacerations, muscle disruption, cartilage repair
c.
Stenting may or may not be used. Surgeon experience/preference will determine this.
d.
Repair laryngeal skeletal fractures with wires, sutures, plating. Plating may be difficult in the more cartilaginous pediatric larynx.
7 What is the preferred imaging modality for the assessment of laryngeal trauma?
In the patient with a stable airway, CT scan is the preferred imaging modality due to its fast acquisition and adequate imaging of the larynx and surrounding structures. It is important to note that airway management should not be delayed for imaging. Imaging is particularly helpful in patients with blunt injury in whom it is difficult to ascertain severity of injury and/or when the continuity of the endolarynx/trachea is unknown.
8 What associated injuries should be ruled out in laryngeal trauma patients?
A.
Cervical spine injury: Based on the National Emergency X-Radiography Utilization Study (NEXUS) criteria, laryngeal trauma qualifies as a “distracting injury” and cervical radiography is indicated to evaluate for the presence of cervical spine injuries. Since a CT scan may be obtained to evaluate the larynx, a cervical spine protocol may be added.
B.
Pharyngeal/Esophageal Injuries:
•
Infrequent in penetrating and blunt laryngeal injuries (4% to 6%) but potentially catastrophic
•
Rigid esophagoscopy recommended in all patients undergoing surgical treatment of external airway injuries
•
Barium esophagram may also be useful in nonsurgical patients.
9 Propose an algorithm for evaluation and management of external laryngeal trauma.
See Figure 78-2.
10 What anatomic factors affect laryngeal trauma in the pediatric patient?
There are several differences between the pediatric larynx and adult larynx that affect laryngeal trauma in the pediatric population. Some of these factors are protective, but some also convey increased risk. First, the larynx lies at the level of C3 in young children and descends gradually until the age of three when it takes on a more adult location at the level of C6. The relatively high location of the pediatric larynx provides some additional protection afforded by the overhanging mandible. Another protective feature of the pediatric larynx is its pliability. Compared to an adult larynx, which is relatively rigid due to ossification, the pediatric larynx remains pliable. The flexibility allows for compression without fracture in the setting of external blunt trauma.
Conversely, the child’s larynx is relatively smaller than the adult airway, which translates to greater potential compromise from edema. Furthermore, the submucosal tissue in a pediatric patient is loosely adherent to the underlying perichondrium when compared to the adult, resulting in the potential for greater soft tissue injury, edema, and hematoma formation. This combination of factors translates to greater risk of airway compromise in these patients despite the protective factors discussed above.
11 Discuss the etiology of internal laryngeal trauma.
The predominant cause of internal laryngeal trauma is iatrogenic injury related to endotracheal intubation. The injury can result from the act of intubation or the presence of an endotracheal tube: risk factors include prolonged intubation, excessive endotracheal tube (ET) size, intubation in the emergency setting, and intubation without neuromuscular blockade. Acute complications include mucosal lacerations, arytenoid dislocation, and tracheal rupture, among others. Trauma related to prolonged intubation is the result of long-standing excessive pressure from the ET or the cuff, leading to tissue necrosis, inflammation, and subglottic stenosis from scar formation. Longer duration correlates with greater histologic damage.
There are several locations that are at risk for injury from prolonged intubation, including the narrowest portions of both the adult and pediatric airway—the glottis and subglottis, respectively. In children, intubation injury in the subglottis can result in subglottic stenosis. In adult patients, damage at the level of the glottis generally occurs posteriorly and can result in posterior glottic stenosis and even bilateral vocal cord immobility (Figure 78-3).
12 What is the incidence of subglottic stenosis following endotracheal intubation?
The incidence in pediatric patients (those most at risk) ranges from approximately 1% to 8%. More recent reports indicate an incidence between 0% and 2%. Of patients with acquired subglottic stenosis, approximately 90% of cases are due to endotracheal intubation.
13 What are other causes of internal laryngeal trauma?
Caustic injections and inhalational burns are two other causes of internal laryngeal injury. The larynx is involved in 40% of caustic ingestions. Thermal injury of the larynx occurs in 30% of burn patients. These injuries tend to produce more severe stenosis compared to postintubation trauma.
14 What is arytenoid dislocation?
Arytenoid dislocation is a rare injury that can occur as the result of external laryngeal trauma with disruption of the laryngeal framework or more commonly as a result of upper aerodigestive tract instrumentation (intubation). Dislocation occurs either anteriorly or posteriorly. Anterior dislocation results from anterior displacement of the cartilage during laryngoscope or ET insertion, whereas posterior cartilage displacement can result from forces applied by the ET as it passes through the glottis. Another possibility includes extubation with an inflated cuff, which translates posteriorly directed forces on the cartilage.
15 How common is arytenoid dislocation?
Arytenoid dislocation is extremely rare with an estimate incidence of 0.1% of tracheal intubations.
16 How does an arytenoid dislocation present?
Common presenting symptoms include dysphonia, vocal fatigue, cough, and inability to project the voice due to reduced vocal cord mobility. Some patients may also experience swallow dysfunction. In the acute phase after laryngeal trauma, the patient may also note sore throat or pain with swallowing.
Flexible fiber-optic laryngoscopy and/or videostroboscopy demonstrates diminished ispilateral vocal cord movement with abnormal position of the arytenoid cartilage as well as a height discrepancy between the vocal cords (CT scans may also reveal incorrect position of the arytenoid cartilage). Laryngeal electromyography can distinguish vocal cord paralysis from arytenoid dislocation as paralysis will be associated with the absence of electrical activity and arytenoid dislocation should be associated with normal electrical activity.
17 Describe treatment for arytenoid dislocation.
Early intervention is recommended to prevent joint ankylosis. Microlaryngoscopy with arytenoid repositioning is effective in the majority of patients who undergo this treatment. Voice therapy as adjunctive treatment is also helpful.
Discuss the etiology of external laryngeal trauma.
Discuss the etiology of external laryngeal trauma.
Blunt trauma occurs as the result of an anterior force compressing the larynx against the fixed vertebral column. These injuries classically result from motor vehicle accidents and occur when the hyperextended neck is thrust onto the dashboard or steering wheel during rapid deceleration. Another subset of these injuries are “clothesline” injuries in which a thin horizontal structure (e.g., barbed wire fence) is struck.
The severity of trauma is variable and depends on multiple factors. The speed at which the patient is traveling is key because injury severity is generally proportional to velocity. The size and configuration of the surface against which the neck makes contact is also important to consider because a larger force distributed over a smaller surface area is more likely to result in penetrating trauma rather than blunt trauma.
Penetrating trauma more commonly occurs as a result of violent crime and military conflict. The energy of the penetrating object is an important factor in determining the potential for airway injury. Any additional information regarding the penetrating object is helpful as it can help predict the extent of collateral damage.
What are the main symptoms and signs of blunt laryngeal trauma?
What are the main symptoms and signs of blunt laryngeal trauma?
Physical exam may range from the asymptomatic to the critically ill and symptoms alone may not denote severity. Dysphonia, dysphagia, pain, and difficulty breathing are the most common initial symptoms. Patients may present with mild symptoms and progress to airway compromise over minutes to hours due to progressive edema, hematoma or instability of the laryngotracheal framework.
Observation is recommended if history and physical are at all concerning. A disrupted airway may present with cervical crepitus, particularly in the patient who has been managed with positive pressure ventilation. In these critically ill patients, look for/anticipate pneumomediastinum, pneumothorax, and worsening respiratory status. Note that these patients are often at risk for cervical spine and vascular trauma as well. Loss of anatomic landmarks on neck palpitation may indicate hyoid or laryngeal fracture, or hematoma. Hemoptysis is indicative of mucosal disruption at the least.
Discuss the management of acute airway compromise following laryngeal trauma.
Discuss the management of acute airway compromise following laryngeal trauma.
The first step in airway management is to determine whether the patient displays signs and symptoms of impending airway compromise such as stridor, dyspnea, respiratory distress, or aphonia. If a patient exhibits signs of airway compromise, a secure airway must be obtained as soon as possible. There are several methods that are appropriate to secure the airway in the setting of laryngeal trauma including intubation, tracheostomy, and cricothyroidotomy.
Several factors must be taken into consideration when choosing which method will be used to secure the airway, including patient stability and injury severity. Control of the airway should occur in the emergency room or, when possible, the operating room to allow for optimal direct and endoscopic evaluation. For endotracheal intubation to proceed, the larynx and trachea must be clearly intact and in continuity to prevent mucosal disruption, laryngotracheal separation, false passage of the endotracheal tube surrounding soft tissue, and further respiratory compromise. It is important to note that intubation should be performed by an experienced physician to help prevent intubation-related trauma (Figure 78-1).
Cricothyroidotomy is reserved for those patients with a rapidly deteriorating airway, those who do not meet the optimal conditions for intubation, or those patients in whom tracheostomy is not possible due to patient factors or availability of physicians experienced in the surgical airway. Cricothyroidotomy is dependent on continuity of the cricoid and trachea. Cricothyroidotomy should subsequently be converted to a tracheostomy to prevent the development of subglottic stenosis. Following emergent management of the airway, these patients should undergo endoscopic evaluation of the aerodigestive tract in the operating room.
Figure- Clothesline injury followed by intubation in the field resulting in complete separation of the larynx and trachea. A, Patient was managed by low tracheostomy followed by neck exploration. The airway was separated between the cricoid and the first tracheal ring, which was crushed and fractured. B, The second tracheal ring and cricoid were anastomosed.
Discuss important aspects of the evaluation and management of a stable patient with external laryngeal trauma.
Discuss important aspects of the evaluation and management of a stable patient with external laryngeal trauma.
A. History:
- Mechanism of injury: Be suspicious in the setting of high velocity impact directed anteriorly to the neck.
- Temporal evolution: Determine if symptoms are getting worse.
B. Physical exam:
- Head and neck exam: Bony and soft tissue trauma, voice quality, respiratory effort, loss of landmarks, crepitus
- Associated injuries: Neurological, vascular, or spinal injuries
C. Flexible laryngoscopy: Damage to mucosa of supraglottis, damage to vocal folds (mucosal tears, hematoma, exposed muscle or cartilage), vocal fold mobility
D. Definitive management:
- Nonsurgical management
- Appropriate for “reversible injuries” due to blunt trauma: endolaryngeal edema, hematoma, contusion, abrasion, non-displaced fractures and small lacerations. These patients commonly have dysphonia, neck pain and tenderness to palpation.
- Observe for 12–24 hours following injury. +/- Steroids; +/- Proton Pump Inhibitor; +/- Cool mist.
- Controversy regarding plating/repairing all laryngeal framework fractures. Some authors prefer plating even non-displaced fractures due to concerns of displacement over time.
- Surgical management: Goal is preservation of airway patency and function. Earlier intervention is associated with better outcomes. Surgical approach may require some or all of the following:
- Midline thyrotomy
- Repair of mucosal lacerations, muscle disruption, cartilage repair
- Stenting may or may not be used. Surgeon experience/preference will determine this.
- Repair laryngeal skeletal fractures with wires, sutures, plating. Plating may be difficult in the more cartilaginous pediatric larynx.
What is the preferred imaging modality for the assessment of laryngeal trauma?
What is the preferred imaging modality for the assessment of laryngeal trauma?
In the patient with a stable airway, CT scan is the preferred imaging modality due to its fast acquisition and adequate imaging of the larynx and surrounding structures. It is important to note that airway management should not be delayed for imaging. Imaging is particularly helpful in patients with blunt injury in whom it is difficult to ascertain severity of injury and/or when the continuity of the endolarynx/trachea is unknown.
What associated injuries should be ruled out in laryngeal trauma patients?
What associated injuries should be ruled out in laryngeal trauma patients?
- Cervical spine injury: Based on the National Emergency X-Radiography Utilization Study (NEXUS) criteria, laryngeal trauma qualifies as a “distracting injury” and cervical radiography is indicated to evaluate for the presence of cervical spine injuries. Since a CT scan may be obtained to evaluate the larynx, a cervical spine protocol may be added.
-
Pharyngeal/Esophageal Injuries:
- Infrequent in penetrating and blunt laryngeal injuries (4% to 6%) but potentially catastrophic
- Rigid esophagoscopy recommended in all patients undergoing surgical treatment of external airway injuries
- Barium esophagram may also be useful in nonsurgical patients.
Propose an algorithm for evaluation and management of external laryngeal trauma.
Propose an algorithm for evaluation and management of external laryngeal trauma.
Algorithm for early treatment of acute external laryngeal trauma. CT = computed tomography; Ctomy = Cricothyroidotomy; EMG = electromyography of the larynx; ORIF = open reduction and internal fixation of laryngeal skeletal fractures; STENT = endolaryngeal stent or lumen keeper; TRACH = tracheotomy; VS = videostroboscopy of larynx.
What anatomic factors affect laryngeal trauma in the pediatric patient?
What anatomic factors affect laryngeal trauma in the pediatric patient?
There are several differences between the pediatric larynx and adult larynx that affect laryngeal trauma in the pediatric population. Some of these factors are protective, but some also convey increased risk. First, the larynx lies at the level of C3 in young children and descends gradually until the age of three when it takes on a more adult location at the level of C6. The relatively high location of the pediatric larynx provides some additional protection afforded by the overhanging mandible. Another protective feature of the pediatric larynx is its pliability. Compared to an adult larynx, which is relatively rigid due to ossification, the pediatric larynx remains pliable. The flexibility allows for compression without fracture in the setting of external blunt trauma.
Conversely, the child’s larynx is relatively smaller than the adult airway, which translates to greater potential compromise from edema. Furthermore, the submucosal tissue in a pediatric patient is loosely adherent to the underlying perichondrium when compared to the adult, resulting in the potential for greater soft tissue injury, edema, and hematoma formation. This combination of factors translates to greater risk of airway compromise in these patients despite the protective factors discussed above.
Discuss the etiology of internal laryngeal trauma.
Discuss the etiology of internal laryngeal trauma.
The predominant cause of internal laryngeal trauma is iatrogenic injury related to endotracheal intubation. The injury can result from the act of intubation or the presence of an endotracheal tube: risk factors include prolonged intubation, excessive endotracheal tube (ET) size, intubation in the emergency setting, and intubation without neuromuscular blockade. Acute complications include mucosal lacerations, arytenoid dislocation, and tracheal rupture, among others. Trauma related to prolonged intubation is the result of long-standing excessive pressure from the ET or the cuff, leading to tissue necrosis, inflammation, and subglottic stenosis from scar formation. Longer duration correlates with greater histologic damage.
There are several locations that are at risk for injury from prolonged intubation, including the narrowest portions of both the adult and pediatric airway—the glottis and subglottis, respectively. In children, intubation injury in the subglottis can result in subglottic stenosis. In adult patients, damage at the level of the glottis generally occurs posteriorly and can result in posterior glottic stenosis and even bilateral vocal cord immobility
(Figure- Posterior subglottic stenosis. A, Interarytenoid adhesion with a mucosally lined tract posteriorly. B, Posterior commissure and interarytenoid scar without a mucosally lined tract posteriorly. C, Posterior commissure scar extending into the right cricoarytenoid joint. D, Posterior commissure scar extending into both cricoarytenoid joints.).
What is the incidence of subglottic stenosis following endotracheal intubation?
What is the incidence of subglottic stenosis following endotracheal intubation?
The incidence in pediatric patients (those most at risk) ranges from approximately 1% to 8%. More recent reports indicate an incidence between 0% and 2%. Of patients with acquired subglottic stenosis, approximately 90% of cases are due to endotracheal intubation.
What are other causes of internal laryngeal trauma?
What are other causes of internal laryngeal trauma?
Caustic injections and inhalational burns are two other causes of internal laryngeal injury. The larynx is involved in 40% of caustic ingestions. Thermal injury of the larynx occurs in 30% of burn patients. These injuries tend to produce more severe stenosis compared to postintubation trauma.
What is arytenoid dislocation?
What is arytenoid dislocation?
Arytenoid dislocation is a rare injury that can occur as the result of external laryngeal trauma with disruption of the laryngeal framework or more commonly as a result of upper aerodigestive tract instrumentation (intubation). Dislocation occurs either anteriorly or posteriorly. Anterior dislocation results from anterior displacement of the cartilage during laryngoscope or ET insertion, whereas posterior cartilage displacement can result from forces applied by the ET as it passes through the glottis. Another possibility includes extubation with an inflated cuff, which translates posteriorly directed forces on the cartilage.
How common is arytenoid dislocation?
How common is arytenoid dislocation?
Arytenoid dislocation is extremely rare with an estimate incidence of 0.1% of tracheal intubations.
