Anesthesia in Tracheal Injury - Considerations and Challenges

Introduction

Tracheobronchial lacerations from trauma have the potential to be life-threatening. The condition will present significant challenges for safer anesthetic management to the patient as well as the healthcare provider. Early recognition of tracheal injuries, along with prompt airway control, can be lifesaving in the case performed properly.

Traumatic injury and lacerations in the trachea are very uncommon. The incidence of the same is anywhere between 0.5 percent to 2 percent and is mostly observed among those patients suffering from numerous injuries. Around 19 percent of tracheal injuries and lacerations take place inside the trachea itself. Approximately 32 percent of the injuries occur in the left main stem of the bronchus. Roughly 47 percent of injuries occurred in the right main stem of the bronchus. Tracheobronchial injuries and lacerations are some of the most common reasons for death. It should be noted that more than 75 percent of the patients do not survive before they arrive at the emergency branch. Tracheobronchial injuries and lacerations present with unique difficulties to the anesthesiologist. Thus early recognition with prompt anesthesia management is the vital key to survival.

What Are the Causes of Tracheal Injury?

Tracheobronchial injuries and lacerations can be caused by several reasons. Mentioned below are a few of them.

• Blunt trauma.

• Penetrating trauma.

• Iatrogenic injuries.

• Emergency intubations.

• Multiple intubation attempts.

• Over-inflation of the tracheal cuff.

Acute traumatic tracheal injury is very rare to be seen by anesthesiologists because tracheobronchial lacerations and injuries usually lead to an acute airway obstruction along with death at the site of an accident or even at the crime scene. In recent studies, many more patients suffering from tracheobronchial lacerations and injuries presented to the emergency department because of a better pre-hospital evacuation method and procedure as well as heightened pieces of training.

Tracheobronchial lacerations and injuries from traumatic dislocation of the first rib are exceedingly rare. The anatomical location of the first rib is the key to the significant dislocation that could potentially result in injuries of the subclavian vessels as well as the trunks of the brachial plexus along with the cervicothoracic area and trachea. The first rib is not commonly dislocated in trauma because strong ligaments stabilize its articulations at the first thoracic vertebra and the manubrium. In rare cases, traumatic first rib dislocations can cause a potential injury to the subclavian artery and the trachea.

How to Diagnose Tracheal Injury?

The diagnosis of tracheobronchial lacerations and injuries is based on a very high clinical suspicion as well as the signs and symptoms of subcutaneous emphysema (lung condition causing shortness of breath) and pneumothorax (presence of air in between the lungs and chest wall). CT (computed tomography) scans of the chest must be the initial screening and the diagnostic tool in hemodynamically stable patients who are suffering from multiple chest trauma. A persistent pneumothorax with large air leaking from a well-placed chest tube must be raised to the suspicion of potential airway injury. A few of the essential radiographic findings that are linked with tracheobronchial tears include incorrect placement or an overdistention of the endotracheal tube cuff. Mentioned below are a few of the diagnostic tools with regard to anesthesia in tracheal injury.

• The gold standard for diagnosis of anesthesia in tracheal injury is bronchoscopy, which may identify the details of the injury and the laceration as well as guide the accurate positioning of the endotracheal tube.

• The tracheobronchial tears may not be very visible in case the tracheal mucosa remains in a single piece or is sealed with the help of fibrin.

• In addition to this, expertise, as well as the availability of bronchoscopy, may further delay the diagnosis of the tracheal injury.

• On a supine computerized tomography examination, a classic sign is visible, which is called the “fallen-lung sign.”

• This sign is reported as being quite specific for a bronchial injury, which may refer to the peripheral, central, and lung collapse that occurs when the normal bronchial anchoring attachments to the lung are disrupted.

• The lung that is collapsed falls toward the dependent portion of the chest and is observed posteriorly when the patient is supine during the computed tomography examination.

How to Manage Anesthesia in Tracheal Injury?

The accurate management of small injuries and lacerations that are smaller than one centimeter without surgical intervention may possibly occur if the endotracheal tube can stent the laceration or wound, and thus this may allow for wound healing. Lacerations that are larger than one centimeter or two centimeters or with extensive, progressive subcutaneous emphysema and deteriorative ventilation should be managed with primary rehabilitation. Patients with a high suspicion of a tracheal laceration and injury or those who are clinically unstable with a rapid drop in oxygenation must be intubated as soon as possible, under involuntary ventilation, with the guidance of flexible bronchoscopy. Mentioned below are a few of the additional anesthesia management strategies for a patient suffering from tracheal injury.

• Other ventilatory management options.

• Awake intubation with local anesthetic infiltration.

• Cricothyrotomy (an emergency procedure involving making an incision through the skin and cricothyroid membrane to establish an airway in the neck).

• Tracheostomy (a surgical procedure involving creating an opening in the front of the neck and into the trachea to provide an alternate airway for breathing).

• ECMO or extracorporeal membrane oxygenation.

• CPM or cardiopulmonary bypass.

• Cross-field ventilation.

• Awake intubation with local anesthetic infiltration has the potential to be a much safer option in several difficult airway management plans.

• In order to prevent a large tear or a massive injury that may be caused by an unintended movement during intubation, general anesthesia with spontaneous ventilation is to be performed.

• Patients for cricothyrotomy or tracheostomy, due to the presence of the first rib as well as the position of the laceration, may not be the ideal candidate for extensive management strategies.

Conclusion

Early diagnosis and multidisciplinary collaborations are keys to the successful management of those patients suffering from tracheal injury with respect to anesthesia. Flexible bronchoscopy is one of the most useful in airway management for urgent and emergency tracheal laceration and injury that requires repair.