Original Contributions Initial Evaluation and Management of Upper Airway Injuries in Trauma Patients Roger S. Cicala, MD, * Kenneth A. Kudsk, MD,-/Alan Butts, MD,+ Hung Nguyen, MD& Timothy C. Fabian, MDT Departments
of Anesthesiology
Memphis,
Study Objective: findings,
and
Surgery,
University
of Tennessee,
TN.
To examine and compare the mechanism of injury, diagnostic
initial methods of airway management, and outcome of patients who had
upper airway inj~uries.
Design: A retrospective review of hospital records. Setting:
Patients:
A large metropolitan, university-affiliated
trauma center.
Forty-six cases of upper airway injuries admitted between I984
and
1988.
Interventions:
Diagnostic methods included clinical examination, cervical and
thoracic radiographs,
bronchoscopy and computerized
tomographic
(CT)
scan.
Therapeutic interventions ranged from conservative management with or without endotracheal intubation to operative reconstruction. *Associate
Professor
of Anesthesiology
tAssociate
Professor
of Surgery
$Resident
Physician,
PResident thesiology
Physician,
Department Department
and Main Results: Mechanism of injury was knife stab wound
was the larynx in 13 cases, trachea in 24 cases, cricoid cartilage in 5 cases, and multiple sites in 4 cases. Diagnostic findings varied considerably according to the of Surgery of Anes-
Address reprint requests to Dr. Cicala at the Department of Anesthesiology, University of Tennessee, 1914 Harbert Avenue, Mem-
phis, TN 38104, USA. Received for publication March 20, 1990; revised manuscript accepted for publication August 14, 1990.
6 1991 Butterworth-Heinemann
Measurements
in 9 cases, gu,nshot wound in 17 cases, and blunt trauma in 20 cases. Location
mechanism of injury, but radiographic evidence of soft tissue air and wounds opening into the airway were common findings. CT scan and bronchoscopy also were useful diagnostic tools. Overall mortality was 24Y0, suhich did not vary according to patient age or mechanism of injury. The airway injury itself was a primary or contributory cause of death in four cases, two of which were tracheal injuries and two injuries at the cricotracheal junction.
donclusions:
In any patient with possible upper airway injuy, plain ra,diographs
of the chest and neck should be obtained to aid in the diagnosis. Elective intubation should be attempted only with a surgical team present and prepared for emergency tracheotomy. Fiber-optic bronchoscopy could be a valuable aid for both intubation and evaluation in such cases.
Anesthesia; intubation, wounds; injuries.
Keywords:
trauma;
J. Clin.
intratracheal;
Anesth.,
vol.
larynx; trachea;
3, March/April
1991
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Original Contributions
Introduction
port on late complications glottic stenosis.
Traumatic injury to the upper airway is uncommon due to the protection of the airway by the mandible and sternum anteriorly, the bony spinal column posteriorly, and the mobility and elasticity of the upper airway itself. Despite these protective mechanisms, upper airway injuries do occur in association with both blunt and penetrating trauma. While the frequency of upper airway injuries has been reported to be as low as 0.03% of patients admitted to a major trauma center,’ these injuries often are lethal,’ resulting in a higher reported frequency of airway injuries in autopsy series of trauma victims.” Up to 21% of patients sustaining airway injuries die within the first 2 hours after hospital admission.,* Conversely, the diagnosis of airway damage is often delayed in patients with nonlethal injuries,4,” which increases the frequency of late complications.ti.7 Attempts to intubate the trachea in patients with unsuspected airway injuries may result in complete obstruction of the airway, resulting in death.8,” Since even major trauma centers may see only a few cases of airway injuries each year, a high degree of suspicion is necessary to recognize and manage these patients.
Materials and Methods Records of all patients admitted to the Presley Trauma Center in Memphis, Tennessee, from July 1984 to July 1988 with a diagnosis that included injury to the extrathoracic airway were reviewed. In all cases, a definitive diagnosis of airway injury was considered to be the direct visualization of the injury either operatively, by laryngoscopy or bronchoscopy, or during postmortem examination. Presenting symptoms, results of diagnostic studies, physical, examination, ability to phonate on arrival, techniques of airway management, outcome, and in-hospital complications were summarized. No attempt was made to review the patients’ follow-up care or outcome after discharge from the hospital. Therefore, the authors do not reTable 1.
such as dysphonia
or suh-
Results Demografdzics During the period examined, a total of 10, I I3 patients were admitted to the Presley Trauma Center in Memphis, Tennessee. Forty-six of these patients had diagnosed injuries to the upper airway (0.45%). Forty of the patients were male, and six were female. The average age of patients with airway injuries was 33.5 years (range 17 to 81 years). The distribution of injuries according to the type and location of trauma is shown in Table 1. Motor vehicle accidents accounted for the majority of blunt trauma victims (13), with pedestrians struck (3), beating (Z), hanging (l), and clothesline injury (1) accounting for the remainder.
Diagnosis of Injury Clinical evidence suggesting the possibility of airway damage differed according to the mechanism of injury. Of the nine patients who suffered stab wounds, an obvious opening into the airway was present in five cases, and subcutaneous emphysema as well as soft tissue air on a lateral cervical spine radiograph was apparent in three other cases. One patient had no physical or radiographic findings, and a small puncture wound in the cricotracheal membrane was diagnosed by bronchoscopy. Patients with gunshot wounds usually presented with soft tissue air on a lateral cervical spine radiograph (nine cases, only four of which also had clinically evident subcutaneous emphysema) or obvious open wounds (four cases). Two patients with gunshot wounds to the cervicothoracic trachea were diagnosed during resuscitation efforts because of a tension pneumothorax with massive air leak. Two other pa.tients had fractures of the thyroid cartilage without airway penetration, one of which was diagnosed by palpation
Location and Types of Injuries Cricoid
Larynx
Stab wound Gunshot wound Blunt trauma Total
1
2 4 7 (1) 13
i (3) 5
Trachea
6 9 (4) 9 (4) 24
Multiple Sites
Total
0 3 1 4
9 17 20 46
*Note: The location and mechanism of injury of all patients diagnosed as having suffered upper airway injuries at the Regional Medical Center at Memphis between 1984 and 1988. Numbers in parentheses indicate the number of patients in each category in which there were problems managing or controlling the airway, necessitating emergency tracheotomy.
92
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Airway injuries: Gicala et al.
and the other by CT scan. Two of the gunshot wound victims had significant hemoptysis in addition to other findings. Findings in patients who had sustained blunt trauma often were more subtle and varied according to the location of injury. Four of the seven patients with laryngeal trauma had cartilaginous fractures without disruption of the airway mucosa. Three of those patients were diagnosed by CT scan and confirmed by laryngoscopy. The fourth, who had been endotracheally intubated prior to arrival, had a normal CT scan despite a severely comminuted thyroid cartilage fracture, and the diagnosis was made by direct laryngoscopy 48 hours after admission. The three blunt trauma patients with laryngeal fractures that disrupted the mucosa all had radiographic evidence of peritracheal air, but only one had clinically apparent subcutaneous emphysema. Of the patients with blunt injury involving the trachea only or larynx and trachea (ten), one had an open wound secondary to a clothesline injury and seven had evidence of soft tissue air on lateral cervical radiographs. Five of these seven patients also had clinically apparent subcutaneous emphysema. One patient arrived without vital signs and was successfully intubated but had definitive diagnosis of tracheal injury at autopsy. Another arrived with an endotracheal tube in place, remained on mechanical ventilation, and was diagnosed by CT scan after soft tissue emphysema developed on hospital day 2. Of the three patients who sustained blunt cricoid injuries, one presented with obvious subcutaneous emphysema. The two remaining patients presented with no physical or radiographic findings and were therefore undiagnosed prior to the induction of anesthesia for laparotomy. Both cases were diagnosed when the distal portion of the trachea was dislodged, in one case during attempted awake nasotracheal intubation and in the other during rapid sequence induction of anesthesia. Complete airway obstruction requiring Table 2.
tracheotomy occurred immediately. In one of these cases, tracheotomy was unsuccessful because of retraction of the distal trachea into the thorax. Only 6 patients (12.5%) in this series presented with vocal abnormalities, but at least 21 other patients underwent definitive airway managernent (endotracheal intubation or tracheotomy) before the ability to phonate was assessed. The diagnostic abnormalities present in the patients with airway injuries are summarized in Table 2.
Outcome and Management Eleven patients died (including 4 who arrived in cardiopulmonary arrest), resulting in an overall mortality of 24% for patients with airway injuries at the Presley Trauma Center. The average age of those patients who did not survive (35.5 years) was no different from that of survivors (33 years). The mortality rate was 22% for stab wound victims (2 of 9 patients), 24% for blunt trauma victims (5 of 21 patients), and 33% for gunshot wound victims (6 of 18 patients). When patients were examined according to the location of injuries, the mortality rate was 8% for larynge,al injuries (1 of 13 patients), 25% for tracheal injurie,s (6 of 24 patients), and 44% for laryngotracheal or cricoid injuries (4 of 9 patients). Cause of death was exsanguination for both patients who died following stab wounds and for three of those patients who died following gunshot wounds involving the trachea. One patient with laryngotracheal injury secondary to blunt trauma died 3 days after admission as a direct result of a cerebral contusion, and another died 28 days after admission from complications related to sepsis and multiple organ system failure. Of the remaining four patients who did not survive, two died during resuscitation efforts when an airway could not be established. In one case, the trachea was transected by blunt injury at the level of the manu-
Diagnostic Findings in Patients with Airway Injuries
Radiographic soft tissue air Subcutaneous emphysema* Airway open into wound Computerized tomography Bronchoscopy Pneumothorax Sudden loss of airway Autopsy *All patients with subcutaneous
Stab Wound (n = 9)
Gunshot WoLmd (n = 17)
3 (33%) 3 (33%) 5 (56%) 0
9 (53%) 4 (24%)
1(11%) 0 0 0 emphysema
Blunt Trauma (n = 20) 1’0 (50%) 8 (40%) 1 (5%) 4 (20%) I (5%)
4 (24%)
1 (6%) 1 (6%)
2 (12%) 0 0
i (10%) 1 (5%)
also had soft tissue air present on radiography
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Original Contributions
brium, and the distal tracheal stump could not be reached through a tracheotomy incision. In the other (a gunshot wound victim), a cricothyroidotomy was performed, but the patient had a distal tracheal injury and was not successfully ventilated. One other patient who arrived in full arrest following a gunshot wound to the trachea had a delay of more than 7 minutes before ventilation was established (unsuccessful intubation attempts followed by tracheotomy) during resuscitation efforts. Another death occurred when an unsuspected blunt cricoid injury was disrupted by applying cricoid pressure during the induction of anesthesia. This patient suffered a complete cardiopulmonary arrest before a tracheotomy could be performed, and subsequent resuscitation efforts were unsuccessful. Inability to secure and manage the airway after arrival at the Presley Trauma Center was therefore a contributing or causative factor in four deaths (8.3% of all patients). Difficulties with airway management occurred in 7 of the surviving patients. Two patients with gunshot wounds to the trachea and 5 patients with blunt trauma (1 cornminuted fracture of thyroid cartilage, 2 tracheal injuries, and 2 cricoid injuries) required emergency tracheotomy for airway management after attempted awake endotracheal intubation was unsuccessful. All of these patients had successful outcomes. The cases in which difficulties in airway management occurred (4 nonsurvivors and 7 survivors) are identified according to the location and mechanism of injury by the figures in parenthesis in Table 1. Overall, difficulty with airway management requiring emergency tracheotomy occurred in 24% of patients with gunshot wounds (4 of 17 cases) and 35% of patients with blunt trauma (7 of 20 cases). Thirty-five cases had no apparent airway management problems. Four patients with nondisplaced laryngeal fractures were admitted for observation but not intubated. Six patients (4 stab wounds, 1 gunshot wound, and 1 blunt trauma) were intubated through an open airway defect. Awake nasotracheal intubation was successfully performed on 4 patients, and 21 patients had orotracheal intubations, 9 of which were performed with the patient awake. Elective tracheotomy after endotracheal intubation was performed as part of the surgical repair of the airway in 7 of these cases.
Discussion Mechanism of Injury The intrinsic structures by a broad submucosal
94
J, Clin. Anesth.,
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vol. 3, March/April
1991
connective tissue is especially thick in the anterior and posterolateral margins, which is termed the conus elasticus and firmly attaches the thyroid, cricoid, and arytenoid cartilages to one another. The larynx is connected to the trachea by the cricotracheal ligament, which is a thin elastic membrane. This attachment is weaker than that between the various intrinsic cartilages of the larynx and is the most likely point of airway separation. I0 The individual tracheal cartilages are connected to each other by fibrous tissue and smooth muscle, and the entire trachea is encased internally and externally by layers of elastic connective tissue.lO.ll Blunt injuries to the upper airway can be caused by direct blows, severe flexion/extension injuries, or crushing injuries to the chest.” Direct blows are most likely to injure the cartilages of the larynx,’ while flexion/extension injuries are most commonly associated with tracheal tears or laryngotracheal separation.‘” Crushing injuries to the trachea are possible if it is compressed between the manubrium and the vertebral column. Crushing injuries to the chest when the glottis is closed results in an abrupt increase in intraairway pressure, which may cause longitudinal tears of the membranous portions of the trachea or bronchi.” These tears are usually found within 2.5 cm of the carinalz.1” at the junction of the membranous and cartilaginous portions of the airway.R When the larynx is injured, the thyroid cartilage often is fractured vertically, tearing the thyroarytenoid ligaments. II The false vocal cord may therefore be separated from the true vocal cord, and the arytenoid cartilages often are edematous and displaced. l5 When fractures occur in the lateral portion of the thyroid cartilage, false passages may be created, and cartilage fragments often are visible during laryngoscopy.l() Cornminuted fractures of the thyroid cartilage often present with separation of the epiglottis from the larynx and displacement of the thyroid cartilage and soft tissue, so supraglottic structures cannot be visualized. Cricoid fracture and separation of the cricotracheal ligaments can result in complete laryngotracheal disruption and dislocation. Tracheal dislocation or disruption has been reported to occur in as many as 63% of patients with blunt airway injuriesI and in 23% of all cases of airway trauma.r7 Since the recurrent laryngeal nerve enters the glottis through the cricothyroid ligament, cricoid fractures may result in recurrent laryngeal nerve paralysis, which further compromises the airway lumen. 17,rH In the authors’ experience, blunt trauma was most likely to injure the larynx or trachea (see Table 1). Although it occurred less frequently, injury to the
Airivuy injuries: Cicala et al.
cricoid cartilage was most likely to be associated with serious airway management problems, particularly laryngotracheal separation. This finding is supported by other series, which have shown injuries at the level of the cricoid cartilage to be most commonly associated with complete transection of the airway.” At least 10%19 and as many as 50%lg of patients sustaining blunt airway trauma have concurrent cervical spine injuries. In fact, cervical vertebral body fracture is a reported cause of laceration of the membranous portion of the trachea.?” Esophageal injury also occurs in conjunction with blunt airway injury, especially in those cases with concurrent cervical spine injuries.” Pneumothorax may be seen in patients with lower tracheal or bronchial injuries. Penetrating trauma secondary to either missile or stab wounds may occur anywhere from the larynx to the bronchi. Stab wounds are most likely to injure the trachea, probably because of its lack of bony protection (see Table I), while gunshot wounds may involve any portion of the airway. Patients with penetrating trauma are likely to have concurrent vascular, esophageal, and thoracic injuries.“’ Esophageal injuries occur in 25% of patients with penetrating airway trauma4 and is the diagnosis most likely to be missed until late in the patient’s hospital course.4 Mortality in patients with penetrating airway trauma is more closely correlated with an associated vascular injury than with the airway injury itself.+
Diagnosis In previous reports,‘,‘“,“’ subcutaneous emphysema, mediastinal emphysema, pneumothorax, and respiratory distress were the clinical signs most commonly associated with airway injuries, followed by hoarseness, cough, hemoptysis, stridor, hematoma, and loss of palpable landmarks. All of these symptoms are relatively nonspecific, and unless a high degree of suspicion is maintained, they may be falsely attributed to other injuries. Hoarseness and hemoptysis are rare findings in some series ,4 but when hoarseness is present, there is often injury to the recurrent laryngeal nerve.“‘) Signs of airway obstruction may not be present until some time after the initial evaluation.2” Blunt airway injury often presents with minimal diagnostic findings. Only subtle physical findings such as ecchymosis, tenderness, and the loss of normally palpable landmarks may be present, requiring a high degree of suspicion to diagnose and treat these patients. Cervical immobilization collars should have been placed prior to the transportation of these patients because of the possibility of concomitant cervical spine
injuries. The anterior component of Ihe collar must be removed under controlled circumstances to examine the neck for signs of airway injury. Chest and cervical radiographs, which should be obtained in all blunt trauma patients, are i.nvaluable for detecting the presence of pneumomediastinum, pneumothorax, and air in the soft tissue planes of the neck.‘” Angood et al. I9 found that radiography alone was sufficient to diagnose 12 of 20 patients with cervical airway trauma. Radiographic evidence 0.f air in the deep cervical tissue planes may be apparent several hours prior to the clinical findings of subcutaneous emphysemalYJ4 and may be the only indication of tracheobronchial trauma in some cases.” Cervical radiographs also may demonstrate interruption of the normal air column, indicating the location of the injury.‘-l CT scans are widely used and may be the examination of choice for the diagnosis and localization of laryngeal cartilage injuries in otherwise stable patients.“‘,” Detailed appraisal of laryngeal damage and airway encroachment can be obtained by CT scan, which is helpful in determining which injuries can be managed conservatively. However, as occurred in one case in the present series, the presence of an endotracheal tube may stent a cartilaginous fracture, yielding a falsely normal CT scan. Direct laryngoscopy traditionally has been the definitive examination for the diagnosis of laryngeal damage, but flexible bronchoscopy may now be the single most important technique for the overall diagnosis of airway injury.‘,“” Flexible bronchoscopy has been 100% accurate in a few small series’O and can be used to identify airway pathology at any level, as well as to determine the presence of vocal cord1 paralysis secondary to recurrent laryngeal nerve injury.“’ Bronchoscopy may help to determine the best waly of managing the airway (intubation UStracheotomy). Flexible bronchoscopy through an in situ endotracheal tube is less accurate, particularly regarding laryngeal and cricoid injury.19 In the cases reviewed by the authors, penetrating airway trauma usually was suspected immediately because of the proximity of the injury to the airway. In 9 of 26 cases, there was obvious communication of the wound with the airway. Clinically app,arent soft tissue air was present in only 7 of the remaining patients. Cervical radiography was a much more sensitive indicator of soft tissue air, being positive in 12 cases. Pneumothorax with air leak was present in 2 patients, both of whom arrived in extremis. Specific procedures (bronchoscopy or CT scan) were required for definitive diagnosis in only 3 patients (11%). In contrast, only 12 (60%) of the patients with blunt airJ. Clin. Anesth., vol. 3, MarchlPIpril
1991
95
Original Contributions
way trauma had apparent clinical signs of airway injuries, such as soft tissue emphysema, a wound communicating with the airway, or radiographic evidence of soft tissue air. Specific diagnostic procedures such as a bronchoscopy and CT scan were required to diagnose 5 of these patients (25%), and the diagnosis was not suspected until serious adverse events occurred in 3 other cases.
Management
of the Injured
Upper Airway
Because of the small number of patients included in most of the reported series and the prolonged periods of time over which the larger series were reviewed, the methods of airway management recommended by various authors have been anything but uniform. Most authors agree that tracheal intubation through a large open wound that communicates with the airway is appropriate, and of course patients who are in severe respiratory distress require immediate attempts to control the airway by whatever means are readily available, Controversy exists over the routine use of tracheotomy versu.s intubation as the means of airway management in stable patients with airway trauma. When blunt injury causes laryngotracheal separation or transection of the cervical trachea, the airway often is held in close approximation by peritracheal connective tissue and the soft tissues of the neck and mediastinum.26 This situation often allows the airway to remain patent as long as spontaneous, negative pressure respiration is maintained.z7 The initiation of positive pressure ventilation (PPV) may cause a severe air leak and marked soft tissue emphysema, with inadequate pulmonary ventilation. In those patients who present with no discernible physical findings to suggest airway trauma, the injury may become apparent when endotracheal intubation and PPV are attempted. If subcutaneous emphysema develops after endotracheal intubation and PPV, cervical or cervicothoracic tracheal injury distal to the cuff of the endotracheal tube must be suspected. Immediate tracheotomy should be performed distal to the airway defect, and median sternotomy to regain control of the distal trachea may be necessary. Attempting to advance an endotracheal tube blindly past a tracheal injury could result in complete transection or dislocation of the distal trachea, as occurred in one of the study patients. For this reason, tracheotomy as the initial method of airway control is adis of no vocated by some authors. 16,Z8Tracheotomy benefit, however, to patients with lower tracheal or bronchial injuries. Additionally, in patients who have 96
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suffered complete disruption of the cervical trachea, the distal portion of the trachea may retract into the thorax during tracheotomy. If this situation occurs, it is sometimes possible to retrieve the distal portion of the trachea using a surgical clamp, but emergency sternotomy may be required to regain control of the airway.7 Cricothyroidotomy and percutaneous tracheotomy are relatively contraindicated unless the exact location of the airway injury is known, since they may result in complete disruption of the airway in cases of tracheal transection or laryngotracheal dissociation.‘” In one case in the authors’ experience in which cricothyroidotomy was technically successful, the initiation of PPV resulted in massive air leaks from a mid-tracheal transection. Marked soft tissue emphysema occurred immediately and interfered with subsequent tracheotomy. Some authors report that they routinely attempt orotracheal intubation, particularly in patients who have sustained penetrating injuries.17.Z9 The tracheas of 75% of the patients with airway injuries can be successfully intubated, iy~L,O but problems with airway management often occur. For this reason, it is imperative that the proper personnel and equipment for performing a tracheotomy and median sternotomy are available before any elective intubation is attempted. The use of a straight laryngoscope blade may be necessary to elevate the epiglottis, since the elevation of the vallecula with a curved blade will not pull a dislocated epiglottis forward.‘“,“” While both awake and anesthetized endotracheal intubation have been successful in patients with airway injuries, oral intubation after an inhalation induction of anesthesia is advocated by several authors.“.Z”,‘?Z Inhalation induction allows spontaneous ventilation to continue and provides an opportunity to visualize the larynx and vocal cords. The disadvantages are the possibility of causing pulmonary aspiration of gastric contents and the possible loss of airway patency. Coughing or gagging, which can accompany attempts at awake intubation, theoretically could cause disruption of an otherwise patent airway. The use of neuromuscular blocking agents theoretically could allow separation of a transected trachea by causing relaxation of the strap muscles, which contribute to maintaining the severed ends of the airway fascicuin approximation. 32 Succinylcholine-induced lations could likewise cause disruption of an otherwise patent airway, and certainly cricoid pressure is contraindicated in patients with suspected airway trauma. In stable patients, passing an endotracheal tube over a fiber-optic bronchoscope that has reached the tracheobronchial tree distal to the site of injury may be safer than blindly passing an endotracheal tube.‘j
Airwajj injuries: Cicala et al.
Fiber-optic intubation also minimizes movement of the cervical spine, which frequently is injured in patients who have sustained airway trauma. However, bleeding from airway or facial injuries may make fiber-optic bronchoscopy extremely difficult, and in some cases it may be impossible to advance the bronchoscope past the area of airway damage. Airway management problems did not occur in any of the current study patients who had sustained stab wounds but were seen in gunshot wound victims, especially if the trachea was involved (see Table I). Airway management problems were more common in patients who had sustained blunt trauma, especially if the cricoid cartilage or trachea was involved. Only one of the patients in this series with injuries limited to the larynx had airway management difficulties, but serious complications have been reported in conjunction with injuries at this level.“O
Outcome In a IO-year (1958 to 1967) study of both autopsy and hospital patients, Ecker et al.’ found that 81 of 105 patients (77%) died before receiving medical care. Bertelson and Howitz3 reported that 27 of 33 airway trauma victims (8 1%) died almost instantaneously. Improvements in prehospital care since that time may have increased the number of patients who survive to reach tertiary care, but Kelly et al4 found that 21% of patients with airway injuries died in the first 2 hours after admission to a hospital. Reported mortality rates are highest with injuries to the bronchi or intrathoracic trachea.3,4,27 The present authors found that in patients with trauma to the cervical airway, injuries at the cricotracheal junction had the highest mortality and complication rates, followed by those with tracheal injuries. Laryngeal injury was the least likely to be associated with mortality from airway damage. Previously reported mortality rates have varied according to several factors: age of the patient, location of the injury, presence of concurrent injuries to other organs, and time until diagnosis and treatment. While the present authors did not find age or mechanism of injury to influence outcome, mortality rates in these patients did vary according to the location of injury. Associated injuries to major vessels (aorta, carotid artery, and superior or inferior vena cava) and organs (liver, spleen, and kidneys) correlated with a poor prognosis,
as did cervical
spine injury.
Unfortunately, up to one-third of all patients who survive an airway injury suffer considerable delays in treatment before the diagnosis is made.3,4 Delay in
airway repair is associated with an increased frequency of late airway stenosis,16 and it has been reported that all patients who have an undiagnosed airway injury will eventually develop strictures.33 Early diagnosis and treatment can greatly improve the chance of survival and simultaneously decrease the likelihood of complications.
Summary Airway trauma is a rare event, even ait major trauma centers, and a high degree of suspicion is needed to recognize and treat this injury. Patients who have sustained blunt injuries are more likely to reach hospital care but also have the most subtle and varied physical findings. Preventable deaths have been found to occur in up to 10% of patients with airway trauma4 and are most likely in patients whose injuries are undiagnosed.
References 1. Gussack GS, Jurkovich GJ, Luterman A: ILaryngotracheal trauma: protocol approach to a rare injury. Laryngoscope 1986;96:660-5. 2. Ecker RR, Libertini RV, Rea WJ, Sugg WL, Webb WR: Injuries of the trachea and bronchi. Ann Thorac Surg 1971;11:289-98. 3. Bertelson S, Howitz P: Injuries of the trachea and bronchi. Thorax 1972;27:188-94. 4. Kelly JP, Webb WR, Moulder PV, Everson C, Burch BH, Lindsey ES: Management of airway trauma. I. Tracheobronchial injuries. Ann Thorac Surg 1985; 40:551-5. 5. Mahaffey DE, Creech 0, Boren HG, DeBakey ME: Traumatic rupture of the left main bronchus successfully repaired eleven years after injury. J Thoruc Surg 1956;32:312-31. 6. Kirsh MM, Orringer MB, Behrendt DM, Sloan H: Management of tracheobronchial disruption secondary to nonpenetrating trauma. Ann Thorac Surg 1976;22:93100.
7. Grill0 HC: Surgery of the trachea. In: Ravitch MM, ed. Current Problems in Surgery. Chicago: Uearbook Medical Publishers, 1970:22-5. 8. Santora AH, Wroe WA: Anesthetic considerations in traumatic tracheobronchial rupture. South MedJ 1986; 79:910-l. 9. Reese CA, Jenkins J, Nelson W, Rigor BM, Collins JR, McDermott WM: Traumatic transection of ,the trachea: anesthetic management-a case report.] Am Assn Nurse Anesth 1970;41:228-32. 10. Mathisen DJ, Grill0 H: Laryngotracheal trauma. Ann Thorac Surg 1987;43:254-62.
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Original Contributions
11. Shaw RR, Paulson DL, Kee JL: Traumatic tracheal rupture. J Thorac Cardiouasc Surg 1961;42:218-97. 12. Richards V, Cohn RB: Rupture of the thoracic trachea and major bronchi following closed injury to the chest. Am J Surg 1955;90:253-5. 13. Seed RF: Traumatic injury to the larynx and trachea. Anaesthesia 1971;26:55-65. 14. Richardson MA: Laryngeal anatomy and mechanisms of trauma. Ear Nose Throat J 1981;60:346-51. 15. Trone TH, Schaefer SD, Carder HM: Blunt and penetrating laryngeal trauma: a 13 year review. Otolaryngol Head Neck Surg 1980;88:25’7-61. 16. Reece GP, Shatney CH: Blunt injuries of the cervical trachea: review of 51 patients. South Med J 1988; 81:1542-7. 17. Lambert GE, McMurry GT: Laryngotracheal trauma: recognition and management. JACEP 1976;5:883-7. 18. Jurkovitch GJ, Gussack GS, Luterman A: Laryngotracheal trauma: a protocol approach to a rare injury. Laryngoscope
1986;96:660-5.
19. Angood PB, Attia EL, Brown RA, Mulder DS: Extrinsic civilian trauma to the larynx and cervical trachea: important predictors of long term morbidity. J Trauma 1986;26:869-73. 20. Reddin A, Stuart ME, Diaconis JN: Rupture of the cervical esophagus and trachea associated with cervical spine fracture. J Trauma 1987;27:564-6. 2 1. Jones WS, Mavroudis C, Richardson JD, Gray LA, Howe WR: Management of tracheobronchial disruption resulting from blunt trauma. Surgery 1984;5:319-22.
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22. Mace SE: Blunt laryngotracheai trauma. AnnEmergMed 1986; 15:836-42. 23. Eijgelaar A, van der Heide JNH: A reliable early symptom of bronchial or tracheal rupture. Thorax 1970; 25: 120-j. 24: Mancusco AA, Hanafee WN: Computed tomography of the injured larynx. Radiology 1979;133: 139-44. 25. Schaefer SD, Brown OE: Selective application of CT in the management of laryngeal trauma. Laryngoscope 1983;93: 1473-5. 26. Urschell HC, Razzuk MA: Management of acute traumatic injuries of tracheobronchial tree. Surg Gynecol Obstet 1973; 136: 113-7. 27. Guest JL, Anderson JN: Major airway injury in closed chest trauma. Chest 1977;72:63-6. 28. Sofferman RA: Management of laryngotracheal trauma. Am J Surg 1981;141:412-6. 29. Grover FL, Ellestad C, Arom KV, Root D, Cruz AB, ‘T‘rinkle JK: Diagnosis and management of tracheobronchial injuries. Ann Thorac Surg 1979;28:384-91. 30. Flood LM, Astley B: Anaesthetic management of acute laryngeal injury. Br J Anaesth 1982;54: 1339-43. 31. Dash HH, Gode GE: Blunt trauma to the cervical portion of the trachea. Br J Anaesth 1983;55: 127 l-2. 32. Donchin Y, Vered IY: Blunt trauma to the trachea. Br ,/ Anaesth 1976;48: 1113-4. 33. Ogura JH, Heeneman H, Spector GJ: Laryngo-tracheal trauma: diagnosis and treatment. Can J Otoluryngol 1973;2:112-8.
of Anesthesiology
Memphis,
Study Objective: findings,
and
Surgery,
University
of Tennessee,
TN.
To examine and compare the mechanism of injury, diagnostic
initial methods of airway management, and outcome of patients who had
upper airway inj~uries.
Design: A retrospective review of hospital records. Setting:
Patients:
A large metropolitan, university-affiliated
trauma center.
Forty-six cases of upper airway injuries admitted between I984
and
1988.
Interventions:
Diagnostic methods included clinical examination, cervical and
thoracic radiographs,
bronchoscopy and computerized
tomographic
(CT)
scan.
Therapeutic interventions ranged from conservative management with or without endotracheal intubation to operative reconstruction. *Associate
Professor
of Anesthesiology
tAssociate
Professor
of Surgery
$Resident
Physician,
PResident thesiology
Physician,
Department Department
and Main Results: Mechanism of injury was knife stab wound
was the larynx in 13 cases, trachea in 24 cases, cricoid cartilage in 5 cases, and multiple sites in 4 cases. Diagnostic findings varied considerably according to the of Surgery of Anes-
Address reprint requests to Dr. Cicala at the Department of Anesthesiology, University of Tennessee, 1914 Harbert Avenue, Mem-
phis, TN 38104, USA. Received for publication March 20, 1990; revised manuscript accepted for publication August 14, 1990.
6 1991 Butterworth-Heinemann
Measurements
in 9 cases, gu,nshot wound in 17 cases, and blunt trauma in 20 cases. Location
mechanism of injury, but radiographic evidence of soft tissue air and wounds opening into the airway were common findings. CT scan and bronchoscopy also were useful diagnostic tools. Overall mortality was 24Y0, suhich did not vary according to patient age or mechanism of injury. The airway injury itself was a primary or contributory cause of death in four cases, two of which were tracheal injuries and two injuries at the cricotracheal junction.
donclusions:
In any patient with possible upper airway injuy, plain ra,diographs
of the chest and neck should be obtained to aid in the diagnosis. Elective intubation should be attempted only with a surgical team present and prepared for emergency tracheotomy. Fiber-optic bronchoscopy could be a valuable aid for both intubation and evaluation in such cases.
Anesthesia; intubation, wounds; injuries.
Keywords:
trauma;
J. Clin.
intratracheal;
Anesth.,
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larynx; trachea;
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Original Contributions
Introduction
port on late complications glottic stenosis.
Traumatic injury to the upper airway is uncommon due to the protection of the airway by the mandible and sternum anteriorly, the bony spinal column posteriorly, and the mobility and elasticity of the upper airway itself. Despite these protective mechanisms, upper airway injuries do occur in association with both blunt and penetrating trauma. While the frequency of upper airway injuries has been reported to be as low as 0.03% of patients admitted to a major trauma center,’ these injuries often are lethal,’ resulting in a higher reported frequency of airway injuries in autopsy series of trauma victims.” Up to 21% of patients sustaining airway injuries die within the first 2 hours after hospital admission.,* Conversely, the diagnosis of airway damage is often delayed in patients with nonlethal injuries,4,” which increases the frequency of late complications.ti.7 Attempts to intubate the trachea in patients with unsuspected airway injuries may result in complete obstruction of the airway, resulting in death.8,” Since even major trauma centers may see only a few cases of airway injuries each year, a high degree of suspicion is necessary to recognize and manage these patients.
Materials and Methods Records of all patients admitted to the Presley Trauma Center in Memphis, Tennessee, from July 1984 to July 1988 with a diagnosis that included injury to the extrathoracic airway were reviewed. In all cases, a definitive diagnosis of airway injury was considered to be the direct visualization of the injury either operatively, by laryngoscopy or bronchoscopy, or during postmortem examination. Presenting symptoms, results of diagnostic studies, physical, examination, ability to phonate on arrival, techniques of airway management, outcome, and in-hospital complications were summarized. No attempt was made to review the patients’ follow-up care or outcome after discharge from the hospital. Therefore, the authors do not reTable 1.
such as dysphonia
or suh-
Results Demografdzics During the period examined, a total of 10, I I3 patients were admitted to the Presley Trauma Center in Memphis, Tennessee. Forty-six of these patients had diagnosed injuries to the upper airway (0.45%). Forty of the patients were male, and six were female. The average age of patients with airway injuries was 33.5 years (range 17 to 81 years). The distribution of injuries according to the type and location of trauma is shown in Table 1. Motor vehicle accidents accounted for the majority of blunt trauma victims (13), with pedestrians struck (3), beating (Z), hanging (l), and clothesline injury (1) accounting for the remainder.
Diagnosis of Injury Clinical evidence suggesting the possibility of airway damage differed according to the mechanism of injury. Of the nine patients who suffered stab wounds, an obvious opening into the airway was present in five cases, and subcutaneous emphysema as well as soft tissue air on a lateral cervical spine radiograph was apparent in three other cases. One patient had no physical or radiographic findings, and a small puncture wound in the cricotracheal membrane was diagnosed by bronchoscopy. Patients with gunshot wounds usually presented with soft tissue air on a lateral cervical spine radiograph (nine cases, only four of which also had clinically evident subcutaneous emphysema) or obvious open wounds (four cases). Two patients with gunshot wounds to the cervicothoracic trachea were diagnosed during resuscitation efforts because of a tension pneumothorax with massive air leak. Two other pa.tients had fractures of the thyroid cartilage without airway penetration, one of which was diagnosed by palpation
Location and Types of Injuries Cricoid
Larynx
Stab wound Gunshot wound Blunt trauma Total
1
2 4 7 (1) 13
i (3) 5
Trachea
6 9 (4) 9 (4) 24
Multiple Sites
Total
0 3 1 4
9 17 20 46
*Note: The location and mechanism of injury of all patients diagnosed as having suffered upper airway injuries at the Regional Medical Center at Memphis between 1984 and 1988. Numbers in parentheses indicate the number of patients in each category in which there were problems managing or controlling the airway, necessitating emergency tracheotomy.
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Airway injuries: Gicala et al.
and the other by CT scan. Two of the gunshot wound victims had significant hemoptysis in addition to other findings. Findings in patients who had sustained blunt trauma often were more subtle and varied according to the location of injury. Four of the seven patients with laryngeal trauma had cartilaginous fractures without disruption of the airway mucosa. Three of those patients were diagnosed by CT scan and confirmed by laryngoscopy. The fourth, who had been endotracheally intubated prior to arrival, had a normal CT scan despite a severely comminuted thyroid cartilage fracture, and the diagnosis was made by direct laryngoscopy 48 hours after admission. The three blunt trauma patients with laryngeal fractures that disrupted the mucosa all had radiographic evidence of peritracheal air, but only one had clinically apparent subcutaneous emphysema. Of the patients with blunt injury involving the trachea only or larynx and trachea (ten), one had an open wound secondary to a clothesline injury and seven had evidence of soft tissue air on lateral cervical radiographs. Five of these seven patients also had clinically apparent subcutaneous emphysema. One patient arrived without vital signs and was successfully intubated but had definitive diagnosis of tracheal injury at autopsy. Another arrived with an endotracheal tube in place, remained on mechanical ventilation, and was diagnosed by CT scan after soft tissue emphysema developed on hospital day 2. Of the three patients who sustained blunt cricoid injuries, one presented with obvious subcutaneous emphysema. The two remaining patients presented with no physical or radiographic findings and were therefore undiagnosed prior to the induction of anesthesia for laparotomy. Both cases were diagnosed when the distal portion of the trachea was dislodged, in one case during attempted awake nasotracheal intubation and in the other during rapid sequence induction of anesthesia. Complete airway obstruction requiring Table 2.
tracheotomy occurred immediately. In one of these cases, tracheotomy was unsuccessful because of retraction of the distal trachea into the thorax. Only 6 patients (12.5%) in this series presented with vocal abnormalities, but at least 21 other patients underwent definitive airway managernent (endotracheal intubation or tracheotomy) before the ability to phonate was assessed. The diagnostic abnormalities present in the patients with airway injuries are summarized in Table 2.
Outcome and Management Eleven patients died (including 4 who arrived in cardiopulmonary arrest), resulting in an overall mortality of 24% for patients with airway injuries at the Presley Trauma Center. The average age of those patients who did not survive (35.5 years) was no different from that of survivors (33 years). The mortality rate was 22% for stab wound victims (2 of 9 patients), 24% for blunt trauma victims (5 of 21 patients), and 33% for gunshot wound victims (6 of 18 patients). When patients were examined according to the location of injuries, the mortality rate was 8% for larynge,al injuries (1 of 13 patients), 25% for tracheal injurie,s (6 of 24 patients), and 44% for laryngotracheal or cricoid injuries (4 of 9 patients). Cause of death was exsanguination for both patients who died following stab wounds and for three of those patients who died following gunshot wounds involving the trachea. One patient with laryngotracheal injury secondary to blunt trauma died 3 days after admission as a direct result of a cerebral contusion, and another died 28 days after admission from complications related to sepsis and multiple organ system failure. Of the remaining four patients who did not survive, two died during resuscitation efforts when an airway could not be established. In one case, the trachea was transected by blunt injury at the level of the manu-
Diagnostic Findings in Patients with Airway Injuries
Radiographic soft tissue air Subcutaneous emphysema* Airway open into wound Computerized tomography Bronchoscopy Pneumothorax Sudden loss of airway Autopsy *All patients with subcutaneous
Stab Wound (n = 9)
Gunshot WoLmd (n = 17)
3 (33%) 3 (33%) 5 (56%) 0
9 (53%) 4 (24%)
1(11%) 0 0 0 emphysema
Blunt Trauma (n = 20) 1’0 (50%) 8 (40%) 1 (5%) 4 (20%) I (5%)
4 (24%)
1 (6%) 1 (6%)
2 (12%) 0 0
i (10%) 1 (5%)
also had soft tissue air present on radiography
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brium, and the distal tracheal stump could not be reached through a tracheotomy incision. In the other (a gunshot wound victim), a cricothyroidotomy was performed, but the patient had a distal tracheal injury and was not successfully ventilated. One other patient who arrived in full arrest following a gunshot wound to the trachea had a delay of more than 7 minutes before ventilation was established (unsuccessful intubation attempts followed by tracheotomy) during resuscitation efforts. Another death occurred when an unsuspected blunt cricoid injury was disrupted by applying cricoid pressure during the induction of anesthesia. This patient suffered a complete cardiopulmonary arrest before a tracheotomy could be performed, and subsequent resuscitation efforts were unsuccessful. Inability to secure and manage the airway after arrival at the Presley Trauma Center was therefore a contributing or causative factor in four deaths (8.3% of all patients). Difficulties with airway management occurred in 7 of the surviving patients. Two patients with gunshot wounds to the trachea and 5 patients with blunt trauma (1 cornminuted fracture of thyroid cartilage, 2 tracheal injuries, and 2 cricoid injuries) required emergency tracheotomy for airway management after attempted awake endotracheal intubation was unsuccessful. All of these patients had successful outcomes. The cases in which difficulties in airway management occurred (4 nonsurvivors and 7 survivors) are identified according to the location and mechanism of injury by the figures in parenthesis in Table 1. Overall, difficulty with airway management requiring emergency tracheotomy occurred in 24% of patients with gunshot wounds (4 of 17 cases) and 35% of patients with blunt trauma (7 of 20 cases). Thirty-five cases had no apparent airway management problems. Four patients with nondisplaced laryngeal fractures were admitted for observation but not intubated. Six patients (4 stab wounds, 1 gunshot wound, and 1 blunt trauma) were intubated through an open airway defect. Awake nasotracheal intubation was successfully performed on 4 patients, and 21 patients had orotracheal intubations, 9 of which were performed with the patient awake. Elective tracheotomy after endotracheal intubation was performed as part of the surgical repair of the airway in 7 of these cases.
Discussion Mechanism of Injury The intrinsic structures by a broad submucosal
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connective tissue is especially thick in the anterior and posterolateral margins, which is termed the conus elasticus and firmly attaches the thyroid, cricoid, and arytenoid cartilages to one another. The larynx is connected to the trachea by the cricotracheal ligament, which is a thin elastic membrane. This attachment is weaker than that between the various intrinsic cartilages of the larynx and is the most likely point of airway separation. I0 The individual tracheal cartilages are connected to each other by fibrous tissue and smooth muscle, and the entire trachea is encased internally and externally by layers of elastic connective tissue.lO.ll Blunt injuries to the upper airway can be caused by direct blows, severe flexion/extension injuries, or crushing injuries to the chest.” Direct blows are most likely to injure the cartilages of the larynx,’ while flexion/extension injuries are most commonly associated with tracheal tears or laryngotracheal separation.‘” Crushing injuries to the trachea are possible if it is compressed between the manubrium and the vertebral column. Crushing injuries to the chest when the glottis is closed results in an abrupt increase in intraairway pressure, which may cause longitudinal tears of the membranous portions of the trachea or bronchi.” These tears are usually found within 2.5 cm of the carinalz.1” at the junction of the membranous and cartilaginous portions of the airway.R When the larynx is injured, the thyroid cartilage often is fractured vertically, tearing the thyroarytenoid ligaments. II The false vocal cord may therefore be separated from the true vocal cord, and the arytenoid cartilages often are edematous and displaced. l5 When fractures occur in the lateral portion of the thyroid cartilage, false passages may be created, and cartilage fragments often are visible during laryngoscopy.l() Cornminuted fractures of the thyroid cartilage often present with separation of the epiglottis from the larynx and displacement of the thyroid cartilage and soft tissue, so supraglottic structures cannot be visualized. Cricoid fracture and separation of the cricotracheal ligaments can result in complete laryngotracheal disruption and dislocation. Tracheal dislocation or disruption has been reported to occur in as many as 63% of patients with blunt airway injuriesI and in 23% of all cases of airway trauma.r7 Since the recurrent laryngeal nerve enters the glottis through the cricothyroid ligament, cricoid fractures may result in recurrent laryngeal nerve paralysis, which further compromises the airway lumen. 17,rH In the authors’ experience, blunt trauma was most likely to injure the larynx or trachea (see Table 1). Although it occurred less frequently, injury to the
Airivuy injuries: Cicala et al.
cricoid cartilage was most likely to be associated with serious airway management problems, particularly laryngotracheal separation. This finding is supported by other series, which have shown injuries at the level of the cricoid cartilage to be most commonly associated with complete transection of the airway.” At least 10%19 and as many as 50%lg of patients sustaining blunt airway trauma have concurrent cervical spine injuries. In fact, cervical vertebral body fracture is a reported cause of laceration of the membranous portion of the trachea.?” Esophageal injury also occurs in conjunction with blunt airway injury, especially in those cases with concurrent cervical spine injuries.” Pneumothorax may be seen in patients with lower tracheal or bronchial injuries. Penetrating trauma secondary to either missile or stab wounds may occur anywhere from the larynx to the bronchi. Stab wounds are most likely to injure the trachea, probably because of its lack of bony protection (see Table I), while gunshot wounds may involve any portion of the airway. Patients with penetrating trauma are likely to have concurrent vascular, esophageal, and thoracic injuries.“’ Esophageal injuries occur in 25% of patients with penetrating airway trauma4 and is the diagnosis most likely to be missed until late in the patient’s hospital course.4 Mortality in patients with penetrating airway trauma is more closely correlated with an associated vascular injury than with the airway injury itself.+
Diagnosis In previous reports,‘,‘“,“’ subcutaneous emphysema, mediastinal emphysema, pneumothorax, and respiratory distress were the clinical signs most commonly associated with airway injuries, followed by hoarseness, cough, hemoptysis, stridor, hematoma, and loss of palpable landmarks. All of these symptoms are relatively nonspecific, and unless a high degree of suspicion is maintained, they may be falsely attributed to other injuries. Hoarseness and hemoptysis are rare findings in some series ,4 but when hoarseness is present, there is often injury to the recurrent laryngeal nerve.“‘) Signs of airway obstruction may not be present until some time after the initial evaluation.2” Blunt airway injury often presents with minimal diagnostic findings. Only subtle physical findings such as ecchymosis, tenderness, and the loss of normally palpable landmarks may be present, requiring a high degree of suspicion to diagnose and treat these patients. Cervical immobilization collars should have been placed prior to the transportation of these patients because of the possibility of concomitant cervical spine
injuries. The anterior component of Ihe collar must be removed under controlled circumstances to examine the neck for signs of airway injury. Chest and cervical radiographs, which should be obtained in all blunt trauma patients, are i.nvaluable for detecting the presence of pneumomediastinum, pneumothorax, and air in the soft tissue planes of the neck.‘” Angood et al. I9 found that radiography alone was sufficient to diagnose 12 of 20 patients with cervical airway trauma. Radiographic evidence 0.f air in the deep cervical tissue planes may be apparent several hours prior to the clinical findings of subcutaneous emphysemalYJ4 and may be the only indication of tracheobronchial trauma in some cases.” Cervical radiographs also may demonstrate interruption of the normal air column, indicating the location of the injury.‘-l CT scans are widely used and may be the examination of choice for the diagnosis and localization of laryngeal cartilage injuries in otherwise stable patients.“‘,” Detailed appraisal of laryngeal damage and airway encroachment can be obtained by CT scan, which is helpful in determining which injuries can be managed conservatively. However, as occurred in one case in the present series, the presence of an endotracheal tube may stent a cartilaginous fracture, yielding a falsely normal CT scan. Direct laryngoscopy traditionally has been the definitive examination for the diagnosis of laryngeal damage, but flexible bronchoscopy may now be the single most important technique for the overall diagnosis of airway injury.‘,“” Flexible bronchoscopy has been 100% accurate in a few small series’O and can be used to identify airway pathology at any level, as well as to determine the presence of vocal cord1 paralysis secondary to recurrent laryngeal nerve injury.“’ Bronchoscopy may help to determine the best waly of managing the airway (intubation UStracheotomy). Flexible bronchoscopy through an in situ endotracheal tube is less accurate, particularly regarding laryngeal and cricoid injury.19 In the cases reviewed by the authors, penetrating airway trauma usually was suspected immediately because of the proximity of the injury to the airway. In 9 of 26 cases, there was obvious communication of the wound with the airway. Clinically app,arent soft tissue air was present in only 7 of the remaining patients. Cervical radiography was a much more sensitive indicator of soft tissue air, being positive in 12 cases. Pneumothorax with air leak was present in 2 patients, both of whom arrived in extremis. Specific procedures (bronchoscopy or CT scan) were required for definitive diagnosis in only 3 patients (11%). In contrast, only 12 (60%) of the patients with blunt airJ. Clin. Anesth., vol. 3, MarchlPIpril
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Original Contributions
way trauma had apparent clinical signs of airway injuries, such as soft tissue emphysema, a wound communicating with the airway, or radiographic evidence of soft tissue air. Specific diagnostic procedures such as a bronchoscopy and CT scan were required to diagnose 5 of these patients (25%), and the diagnosis was not suspected until serious adverse events occurred in 3 other cases.
Management
of the Injured
Upper Airway
Because of the small number of patients included in most of the reported series and the prolonged periods of time over which the larger series were reviewed, the methods of airway management recommended by various authors have been anything but uniform. Most authors agree that tracheal intubation through a large open wound that communicates with the airway is appropriate, and of course patients who are in severe respiratory distress require immediate attempts to control the airway by whatever means are readily available, Controversy exists over the routine use of tracheotomy versu.s intubation as the means of airway management in stable patients with airway trauma. When blunt injury causes laryngotracheal separation or transection of the cervical trachea, the airway often is held in close approximation by peritracheal connective tissue and the soft tissues of the neck and mediastinum.26 This situation often allows the airway to remain patent as long as spontaneous, negative pressure respiration is maintained.z7 The initiation of positive pressure ventilation (PPV) may cause a severe air leak and marked soft tissue emphysema, with inadequate pulmonary ventilation. In those patients who present with no discernible physical findings to suggest airway trauma, the injury may become apparent when endotracheal intubation and PPV are attempted. If subcutaneous emphysema develops after endotracheal intubation and PPV, cervical or cervicothoracic tracheal injury distal to the cuff of the endotracheal tube must be suspected. Immediate tracheotomy should be performed distal to the airway defect, and median sternotomy to regain control of the distal trachea may be necessary. Attempting to advance an endotracheal tube blindly past a tracheal injury could result in complete transection or dislocation of the distal trachea, as occurred in one of the study patients. For this reason, tracheotomy as the initial method of airway control is adis of no vocated by some authors. 16,Z8Tracheotomy benefit, however, to patients with lower tracheal or bronchial injuries. Additionally, in patients who have 96
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suffered complete disruption of the cervical trachea, the distal portion of the trachea may retract into the thorax during tracheotomy. If this situation occurs, it is sometimes possible to retrieve the distal portion of the trachea using a surgical clamp, but emergency sternotomy may be required to regain control of the airway.7 Cricothyroidotomy and percutaneous tracheotomy are relatively contraindicated unless the exact location of the airway injury is known, since they may result in complete disruption of the airway in cases of tracheal transection or laryngotracheal dissociation.‘” In one case in the authors’ experience in which cricothyroidotomy was technically successful, the initiation of PPV resulted in massive air leaks from a mid-tracheal transection. Marked soft tissue emphysema occurred immediately and interfered with subsequent tracheotomy. Some authors report that they routinely attempt orotracheal intubation, particularly in patients who have sustained penetrating injuries.17.Z9 The tracheas of 75% of the patients with airway injuries can be successfully intubated, iy~L,O but problems with airway management often occur. For this reason, it is imperative that the proper personnel and equipment for performing a tracheotomy and median sternotomy are available before any elective intubation is attempted. The use of a straight laryngoscope blade may be necessary to elevate the epiglottis, since the elevation of the vallecula with a curved blade will not pull a dislocated epiglottis forward.‘“,“” While both awake and anesthetized endotracheal intubation have been successful in patients with airway injuries, oral intubation after an inhalation induction of anesthesia is advocated by several authors.“.Z”,‘?Z Inhalation induction allows spontaneous ventilation to continue and provides an opportunity to visualize the larynx and vocal cords. The disadvantages are the possibility of causing pulmonary aspiration of gastric contents and the possible loss of airway patency. Coughing or gagging, which can accompany attempts at awake intubation, theoretically could cause disruption of an otherwise patent airway. The use of neuromuscular blocking agents theoretically could allow separation of a transected trachea by causing relaxation of the strap muscles, which contribute to maintaining the severed ends of the airway fascicuin approximation. 32 Succinylcholine-induced lations could likewise cause disruption of an otherwise patent airway, and certainly cricoid pressure is contraindicated in patients with suspected airway trauma. In stable patients, passing an endotracheal tube over a fiber-optic bronchoscope that has reached the tracheobronchial tree distal to the site of injury may be safer than blindly passing an endotracheal tube.‘j
Airwajj injuries: Cicala et al.
Fiber-optic intubation also minimizes movement of the cervical spine, which frequently is injured in patients who have sustained airway trauma. However, bleeding from airway or facial injuries may make fiber-optic bronchoscopy extremely difficult, and in some cases it may be impossible to advance the bronchoscope past the area of airway damage. Airway management problems did not occur in any of the current study patients who had sustained stab wounds but were seen in gunshot wound victims, especially if the trachea was involved (see Table I). Airway management problems were more common in patients who had sustained blunt trauma, especially if the cricoid cartilage or trachea was involved. Only one of the patients in this series with injuries limited to the larynx had airway management difficulties, but serious complications have been reported in conjunction with injuries at this level.“O
Outcome In a IO-year (1958 to 1967) study of both autopsy and hospital patients, Ecker et al.’ found that 81 of 105 patients (77%) died before receiving medical care. Bertelson and Howitz3 reported that 27 of 33 airway trauma victims (8 1%) died almost instantaneously. Improvements in prehospital care since that time may have increased the number of patients who survive to reach tertiary care, but Kelly et al4 found that 21% of patients with airway injuries died in the first 2 hours after admission to a hospital. Reported mortality rates are highest with injuries to the bronchi or intrathoracic trachea.3,4,27 The present authors found that in patients with trauma to the cervical airway, injuries at the cricotracheal junction had the highest mortality and complication rates, followed by those with tracheal injuries. Laryngeal injury was the least likely to be associated with mortality from airway damage. Previously reported mortality rates have varied according to several factors: age of the patient, location of the injury, presence of concurrent injuries to other organs, and time until diagnosis and treatment. While the present authors did not find age or mechanism of injury to influence outcome, mortality rates in these patients did vary according to the location of injury. Associated injuries to major vessels (aorta, carotid artery, and superior or inferior vena cava) and organs (liver, spleen, and kidneys) correlated with a poor prognosis,
as did cervical
spine injury.
Unfortunately, up to one-third of all patients who survive an airway injury suffer considerable delays in treatment before the diagnosis is made.3,4 Delay in
airway repair is associated with an increased frequency of late airway stenosis,16 and it has been reported that all patients who have an undiagnosed airway injury will eventually develop strictures.33 Early diagnosis and treatment can greatly improve the chance of survival and simultaneously decrease the likelihood of complications.
Summary Airway trauma is a rare event, even ait major trauma centers, and a high degree of suspicion is needed to recognize and treat this injury. Patients who have sustained blunt injuries are more likely to reach hospital care but also have the most subtle and varied physical findings. Preventable deaths have been found to occur in up to 10% of patients with airway trauma4 and are most likely in patients whose injuries are undiagnosed.
References 1. Gussack GS, Jurkovich GJ, Luterman A: ILaryngotracheal trauma: protocol approach to a rare injury. Laryngoscope 1986;96:660-5. 2. Ecker RR, Libertini RV, Rea WJ, Sugg WL, Webb WR: Injuries of the trachea and bronchi. Ann Thorac Surg 1971;11:289-98. 3. Bertelson S, Howitz P: Injuries of the trachea and bronchi. Thorax 1972;27:188-94. 4. Kelly JP, Webb WR, Moulder PV, Everson C, Burch BH, Lindsey ES: Management of airway trauma. I. Tracheobronchial injuries. Ann Thorac Surg 1985; 40:551-5. 5. Mahaffey DE, Creech 0, Boren HG, DeBakey ME: Traumatic rupture of the left main bronchus successfully repaired eleven years after injury. J Thoruc Surg 1956;32:312-31. 6. Kirsh MM, Orringer MB, Behrendt DM, Sloan H: Management of tracheobronchial disruption secondary to nonpenetrating trauma. Ann Thorac Surg 1976;22:93100.
7. Grill0 HC: Surgery of the trachea. In: Ravitch MM, ed. Current Problems in Surgery. Chicago: Uearbook Medical Publishers, 1970:22-5. 8. Santora AH, Wroe WA: Anesthetic considerations in traumatic tracheobronchial rupture. South MedJ 1986; 79:910-l. 9. Reese CA, Jenkins J, Nelson W, Rigor BM, Collins JR, McDermott WM: Traumatic transection of ,the trachea: anesthetic management-a case report.] Am Assn Nurse Anesth 1970;41:228-32. 10. Mathisen DJ, Grill0 H: Laryngotracheal trauma. Ann Thorac Surg 1987;43:254-62.
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11. Shaw RR, Paulson DL, Kee JL: Traumatic tracheal rupture. J Thorac Cardiouasc Surg 1961;42:218-97. 12. Richards V, Cohn RB: Rupture of the thoracic trachea and major bronchi following closed injury to the chest. Am J Surg 1955;90:253-5. 13. Seed RF: Traumatic injury to the larynx and trachea. Anaesthesia 1971;26:55-65. 14. Richardson MA: Laryngeal anatomy and mechanisms of trauma. Ear Nose Throat J 1981;60:346-51. 15. Trone TH, Schaefer SD, Carder HM: Blunt and penetrating laryngeal trauma: a 13 year review. Otolaryngol Head Neck Surg 1980;88:25’7-61. 16. Reece GP, Shatney CH: Blunt injuries of the cervical trachea: review of 51 patients. South Med J 1988; 81:1542-7. 17. Lambert GE, McMurry GT: Laryngotracheal trauma: recognition and management. JACEP 1976;5:883-7. 18. Jurkovitch GJ, Gussack GS, Luterman A: Laryngotracheal trauma: a protocol approach to a rare injury. Laryngoscope
1986;96:660-5.
19. Angood PB, Attia EL, Brown RA, Mulder DS: Extrinsic civilian trauma to the larynx and cervical trachea: important predictors of long term morbidity. J Trauma 1986;26:869-73. 20. Reddin A, Stuart ME, Diaconis JN: Rupture of the cervical esophagus and trachea associated with cervical spine fracture. J Trauma 1987;27:564-6. 2 1. Jones WS, Mavroudis C, Richardson JD, Gray LA, Howe WR: Management of tracheobronchial disruption resulting from blunt trauma. Surgery 1984;5:319-22.
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22. Mace SE: Blunt laryngotracheai trauma. AnnEmergMed 1986; 15:836-42. 23. Eijgelaar A, van der Heide JNH: A reliable early symptom of bronchial or tracheal rupture. Thorax 1970; 25: 120-j. 24: Mancusco AA, Hanafee WN: Computed tomography of the injured larynx. Radiology 1979;133: 139-44. 25. Schaefer SD, Brown OE: Selective application of CT in the management of laryngeal trauma. Laryngoscope 1983;93: 1473-5. 26. Urschell HC, Razzuk MA: Management of acute traumatic injuries of tracheobronchial tree. Surg Gynecol Obstet 1973; 136: 113-7. 27. Guest JL, Anderson JN: Major airway injury in closed chest trauma. Chest 1977;72:63-6. 28. Sofferman RA: Management of laryngotracheal trauma. Am J Surg 1981;141:412-6. 29. Grover FL, Ellestad C, Arom KV, Root D, Cruz AB, ‘T‘rinkle JK: Diagnosis and management of tracheobronchial injuries. Ann Thorac Surg 1979;28:384-91. 30. Flood LM, Astley B: Anaesthetic management of acute laryngeal injury. Br J Anaesth 1982;54: 1339-43. 31. Dash HH, Gode GE: Blunt trauma to the cervical portion of the trachea. Br J Anaesth 1983;55: 127 l-2. 32. Donchin Y, Vered IY: Blunt trauma to the trachea. Br ,/ Anaesth 1976;48: 1113-4. 33. Ogura JH, Heeneman H, Spector GJ: Laryngo-tracheal trauma: diagnosis and treatment. Can J Otoluryngol 1973;2:112-8.
