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* From the Division of Pulmonary and Critical Care Medicine (Drs. Hashem and Davis), Medical College of Georgia, Augusta, GA; and Veterans Affairs Medical Center (Dr. Smith), Augusta, GA.
Correspondence to: W. Bruce Davis, MD, FCCP, Medical College of Georgia, 1120 15th St, Rm No. BBR5513, Augusta, GA 30912-3135; e-mail: bruced{at}mail.mcg.edu
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Physical Examination
In the recovery room, the patient was alert with BP of 126/68 mm Hg and a pulse rate of 101 beats/min. Oxygen saturation was 96% on 2 L O2 flow by nasal cannula. Her weight was 75 kg, and her height was 150 cm. Head and neck examination revealed a short, thick neck and periorbital swelling. Subcutaneous crepitations over the chest, neck, and face were noted. The lungs were clear to auscultation. A cardiac examination revealed mild tachycardia with regular rhythm. The abdomen was soft and nontender.
Laboratory and Radiographic Findings
Recovery room data showed a hemoglobin concentration of 11.5 g/dL, a hematocrit of 34.7%, and a WBC count 5,600 cells/µL with a normal differential cell count. The platelet count was 267,000. Cardiac enzymes showed a creatine phosphokinase concentration of 96 U/L and a creatine kinase-MB concentration of 1.2 ng/mL. The serum sodium level was 137 mEq/L, chloride level was 98 mEq/L, the bicarbonate level was 25 mEq/L, the BUN level was 18 mg/dL, and the creatinine level 0.8 mg/dL. The ECG showed T-wave inversion in the anterior leads. Chest radiography revealed subcutaneous and mediastinal emphysema (Fig 1
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What is the appropriate diagnostic and management approach?
Diagnosis: Tracheal tear diagnosed by bronchoscopy: conservative management includes close observation, antibiotic prophylaxis, and cough suppressant
The differential diagnosis of subcutaneous and mediastinal emphysema after endotracheal intubation includes hypopharyngeal perforation, tracheobronchial laceration, esophageal perforation, and barotrauma from mechanical ventilation. In order to establish the correct diagnosis, imaging studies and bronchoscopy must be performed promptly.
Tracheobronchial laceration is a rare but potentially serious complication of endotracheal intubation. It can occur following difficult as well as uneventful intubations. The laceration usually occurs longitudinally in the posterior membranous wall of the trachea or in the junction between the membranous wall and the cartilaginous ring. Most injuries occur in the lower third of the trachea.
Several mechanisms have been proposed to explain the injury, but in many cases the cause remains unclear. Overinflation of the cuff is thought to be the most common cause, resulting in either mechanical disruption or necrosis of the mucosa after prolonged intubation. Monitoring the cuff pressure (appropriate pressure, 25 mm Hg) during anesthesia is required to avoid the accidental overinflation resulting from nitrous oxide diffusion into the cuff. Other potential causes are repositioning of the tube without cuff deflation or the abrupt dislocation of the tube during patient movement. A sudden increase in the intratracheal pressure caused by vigorous coughing in the presence of the endotracheal tube can lead to a tracheal rupture. Almost all cases of postintubation tracheal laceration are reported in short female patients. Susceptibility to tracheal injury in these patients is related to a weakness of the membranous wall and the small caliber of the airways. Other factors contributing to intubation-related injury are malpositioning of the tube, inappropriate tube size, COPD, and other conditions associated with a weakness of the membranous trachea (eg, elderly patient, esophageal surgery, and steroid therapy). Mucosal erosion or perforation of the anterior cartilaginous tracheal wall from the tip of the tube or the stylets is very rare.
The clinical symptoms present either acutely or more insidiously (within 24 to 48 h) depending on the extent of the injury. In most cases, the initial presentation is cervicothoracic subcutaneous emphysema with mediastinal emphysema seen on chest radiograph. Patients with mediastinal emphysema develop substernal chest pain, dyspnea, and, in some cases, ECG findings of low voltage, nonspecific axis deviation, and ST-T-wave changes. Pneumomediastinum can lead to a unilateral or bilateral pneumothorax and rarely to retroperitoneal emphysema as air dissects along fascial planes. Other symptoms include cough and hemoptysis resulting from the tracheal tear itself.
A chest radiograph can reveal early signs raising the suspicion of tracheal rupture. These signs include a deviation of the tip of the endotracheal tube to the right, an overdistended balloon cuff, and the migration of the balloon toward the endotracheal tube tip. Mediastinal and subcutaneous emphysema eventually appear on the chest radiograph. Bronchoscopy is essential to confirm the diagnosis, and to assess the location and the extent of the injury. Bronchoscopy should be performed with adequate sedation in order to avoid coughing that could extend the tracheal tear. Chest CT scanning is required to evaluate the mediastinum for any fluid collection.
A postintubation tracheal tear can be associated with life-threatening respiratory distress and hypoxemia due to extensive mediastinal emphysema, tension pneumothorax, and major air leak from the tear. Other potential acute complications are mediastinitis or sepsis. Tracheal stenosis has been reported as a late complication. The outcome for postintubation tracheal injury is good with early recognition of the injury and appropriate management.
Surgical management has been the treatment of choice for postintubation tracheal injury. However, case reports document a successful conservative nonsurgical approach in selected individuals. The choice between the surgical and conservative approach depends on the clinical presentation, the extent of the injury, and the overall condition of the patient.
Conservative management may be appropriate for uncomplicated longitudinal lacerations of the membranous tracheal wall that are < 3 to 4 cm in size and involve less than one third of the tracheal circumference. The goal of conservative management is to prevent complications and to establish airway patency for uneventful healing of the injury. The management includes broad-spectrum antibiotic prophylaxis in an effort to prevent a paratracheal abscess or mediastinitis, and cough suppressants to avoid increasing intratracheal pressure that might extend the injury. Extubation, if feasible, is recommended. Otherwise the endotracheal tube must be placed under fiberscope control with the cuff inflated distal to the tear. In the presence of a tear involving the carina or main bronchus, bilateral bronchial intubation should be considered. A tracheotomy should be avoided. Mechanical ventilation should maintain low airway pressures. Frequent endotracheal suctioning should be avoided and, if necessary, bronchoscopy can be used for pulmonary toilet. The patient should be observed closely for any sign of instability or clinical deterioration. Repeat bronchoscopy can be performed to document proper wound healing. In all published cases of conservative management, healing was uneventful and without airway stenosis.
Prompt surgical repair is indicated with any signs of clinical deterioration, mediastinitis or increased mediastinal fluid collection, and uncontrolled air leaks. Tracheal lacerations involving the cartilaginous wall always require a surgical repair. The surgical approach is determined by the site of the injury; right thoracotomy is used for the lower third of the trachea, and cervical incision is used for the two upper thirds.
In the present patient, a chest CT scan showed extensive subcutaneous and mediastinal emphysema, and a probable tracheal laceration (Fig 2 ). There was no fluid collection seen in the mediastinum on the CT scan. Flexible bronchoscopy revealed a 3-cm linear laceration of the posterior membranous wall in the lower third of the trachea (Fig 3 , left, A). Because the patient was clinically stable, the decision was made to observe her closely. She was started on therapy with ampicillin-sulbactam, and codeine for cough suppression. During the hospital course, the patient remained stable without any signs of infection. A chest radiograph performed on hospital day 8 showed significant resolution of the subcutaneous and mediastinal emphysema. The patient was discharged home on day 10. A follow-up bronchoscopy after 7 weeks revealed complete healing without stenosis (Fig 3, right, B).
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Received for publication July 12, 2004. Accepted for publication August 5, 2004.
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