Successful airway management of traumatic complete tracheal transection

Abstract

A man in his 20s sustained complete tracheal transection after being injured by a sandbag pile falling on his neck. An oral endotracheal tube (ETT) was inserted by rapid sequence induction in view of respiratory distress. CT revealed that the ETT did not traverse the distal tracheal segment; however, there were rebreathing bag movements, and normal capnograph and oxygen saturation, which were misleading clinical findings. We describe the successful airway management in this challenging case.

Background

Rebreathing bag movements in a spontaneously breathing patient and normal capnography and oxygen saturation are considered the confirmatory clinical signs for endotracheal intubation. However, in a trauma setting where a patient has sustained blunt neck trauma, these findings can be misleading. We present the airway management of a patient with complete tracheal transection and a misplaced endotracheal tube (ETT) with misleading clinical findings.

Case presentation

A male construction worker presented to the emergency department with an alleged history of injury by fall of sand piles on his neck. He was conscious, oriented and haemodynamically stable. Because of worsening respiratory distress at presentation, rapid sequence induction was done, and the trachea was intubated with a cuffed 7.0 mm ETT under direct laryngoscopy, following which mechanical ventilation was initiated.

Investigations

CT imaging was done to evaluate further injuries, which revealed a complete tracheal transection and C6 lamina fracture (figure 1). The ETT had traversed the proximal transected segment of the trachea but had not entered the distal tracheal segment, with the tip lying superoanterior to the distal transected segment of the trachea.

Figure 1.

The endotracheal tube (ETT) traversing the proximal transected segment of the trachea, with the tip lying superoanterior to the distal transected segment of the trachea.

Management

The patient was immediately shifted to the operating room (OR) for airway management and tracheal repair. On arrival in the OR, the patient was spontaneously breathing, generating around 300 mL of tidal volume, with subcutaneous emphysema over the neck. The capnography tracing was normal with an ETCO₂ of 39 mm Hg and oxygen saturation of 96%, although there was indrawing of neck muscles at the site of tracheal rent (video 1).

Video 1. Indrawing of neck muscles observed at the site of tracheal rent.

bcr-2022-251688supp001.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2022-251688.video01

The primary challenge was to negotiate the ETT into the distal end of the trachea. This was complicated by the non-alignment of the proximal and distal ends of the transected trachea due to retraction of the distal segment of the trachea. In addition, positive pressure ventilation was to be avoided to prevent insufflation of the neck tissue, which could have potentially worsened the distorted neck anatomy and further complicated the intubation. Thus, airway management strategy was planned to ensure safe airway management. The primary plan was fibreoptic bronchoscopy (FOB) evaluation, followed by FOB-aided ETT negotiation with the maintenance of spontaneous respiration, while surgical tracheostomy was the back-up plan if intubation failed or in case of loss of airway control. On FOB evaluation, we observed that the ETT had passed through the proximal cut end of the trachea, but the tip of the ETT opened into the soft tissue between the two ends of the trachea (figure 2). The ETT was gradually withdrawn into the proximal tracheal end under FOB vision, and the FOB was advanced. The distal tracheal end was found posterolateral to the ETT tip. With gentle external manipulation of the neck, the FOB was successfully negotiated into the distal end, following which the ETT was railroaded over it and the tip secured above the carina. A neuromuscular relaxant was then administered, and mechanical ventilation was initiated. Neck exploration and primary repair of tracheal transection were done. The remaining intraoperative course was uneventful.

Figure 2.

The lumen of the transected distal segment as visualised by fibreoptic scope inserted through the endotracheal tube.

Outcome and follow-up

Post-procedure, the patient was tracheostomised and shifted to the intensive care unit, where he was weaned off mechanical ventilation over the next 12 hours and thereafter discharged in a stable condition. The patient has been in follow-up in the outpatient department for more than 2 months and is scheduled for tracheostomy decannulation.

Discussion

Tracheobronchial injuries are rare but life-threatening and may be caused by either blunt or penetrating trauma.^{1 2} Tracheobronchial injury affects approximately 0.5%–2% of people who have sustained blunt trauma.³ This mostly includes motor vehicle accidents (59%), followed by crush injuries (27%).⁴ In our patient, direct compression over the neck by a pile of sandbags resulted in complete tracheal transection and a C6 lamina fracture (figure 3). Over 80% of the patients with tracheal injuries usually die on the spot due to the loss of their airway and other associated injuries.² Late diagnosis or misdiagnosis can lead to a fatal outcome. For patients who survive and reach the hospital, safe and effective airway management poses a great challenge.

Figure 3.

The mechanism of injury and the forces causing damage of neck structures. (A) A pile of sandbags falling on the patient’s neck. (B) Sandbags compressing the trachea and transmitting force on cervical vertebra. (C) Complete tracheal tear and C6 laminar fracture due to forceful impact by heavy sandbags. The figure has been drawn by Dr Abhishek Nagarajappa.

Since most patients with complete tracheal transection die before reaching the hospital, there is sparse literature describing the anaesthetic and airway management. A few anecdotal cases with similar airway injuries have been reported. In a case with complete cervical tracheal transection due to blunt trauma, the patient had respiratory distress, and the CT scan suggested the diagnosis. The ETT was advanced distal to the transection site under FOB guidance. The peritracheal tissue barely maintained oxygenation, like our case; however, the authors do not describe the details of anaesthetic management. In another case of blunt neck trauma, the patient presented with significant surgical emphysema and respiratory and haemodynamic instability. Endotracheal intubation was attempted after administering ketamine, which was unsuccessful, and the subcutaneous emphysema increased with positive pressure ventilation. However, the endotracheal tube could not be negotiated beyond the vocal cords, and hence a surgical cricothyroidotomy was performed. After dissection, the authors observed complete tracheal transection at cricotracheal level and the tip of the ETT lying out of the trachea. A new ETT was inserted in the distal tracheal segment. However, the patient immediately developed cardiorespiratory arrest due to prolonged hypoxia and could not be resuscitated. Due to multiple attempts and positive pressure ventilation, the authors concluded that there was most likely a partial tracheal rent that was converted to a complete tracheal tear. Securing an airway is the priority in trauma patients presenting with respiratory distress. Blind attempts to secure an airway in patients with laryngotracheal injury can be fatal, as a partial tracheal injury can lead to complete transection or complete airway obstruction. Thus, airway management in patients with neck trauma should be based on a high index of clinical suspicion. The most frequent symptoms include respiratory distress, which occurs in 76%–100% of patients. Other symptoms include hoarseness or dysphonia in 46% of patients. The most common signs of airway injuries reported are subcutaneous emphysema (35%–85%), pneumothorax (20%–50%) and haemoptysis (14%–25%).³ However, subcutaneous or mediastinal emphysema may be the only finding, making the airway appear normal.⁵

CT scan is the most sensitive and specific non-invasive diagnostic investigation for tracheobronchial injury. CT scan may show mediastinal air, disruption of the tracheobronchial air column, deviation of the airway and the specific site of airway disruption, which may help in diagnosing the tracheal injury.⁶ However, its role in diagnosing more distal tracheobronchial injuries is not well established. The most important tool in diagnosing and performing endotracheal intubation in these patients is FOB.⁷ It has several advantages for stable patients. Neck extension is not required for fibreoptic intubation; hence, cervical spine stabilisation with a semirigid cervical collar can be achieved. There is no need for sedation, and patients can be awake and spontaneously breathing during intubation. A FOB can also help in diagnosing the site of injury and placing the ETT into the distal end of the trachea. However, in an emergent situation, orotracheal intubation with manual in-line stabilisation still remains the method of choice, as with our patient. He was in respiratory distress, so rapid sequence induction with orotracheal intubation was performed with manual in-line stabilisation. Since the patient was haemodynamically stable and getting ventilated, he was immediately shifted to radiology suite for a CT scan for the diagnostic evaluation of other injuries. The patient was still getting ventilated and oxygenated, probably because of the presence of peritracheal connective tissue, which may have provided a conduit for airway continuity and made ventilation possible even if tracheal continuity was disrupted. The Murphy eye of the ETT may also be partially allowing the passage of oxygen. Hence, rebreathing bag movements were present, and capnography and oxygen saturation were also normal.

Learning points.

• Tracheal injuries are potentially fatal. Airway management in a patient with complete tracheal transection is extremely difficult and necessitates a carefully planned strategy.

• The presence of rebreathing bag movements, and a normal capnograph and oxygen saturation can be misleading in a trauma setting.

• Patients with complete tracheal transection may still be getting ventilated and oxygenated because of the presence of peritracheal connective tissue, which may be providing a conduit for airway continuity. The Murphy eye of the endotracheal tube may also partly allow the passage of oxygen.

• A high degree of suspicion, clinical findings, and liberal use of fibreoptic bronchoscopy aid the diagnosis and airway management. Maintenance of spontaneous ventilation is advocated until the airway is secured. Endotracheal tube insertion under direct vision, with the cuff positioned beyond the injury site, is recommended.

Ethics statements

Patient consent for publication

Obtained.