Tracheal obstruction can be caused by a variety of mechanical, infectious, and congenital abnormalities Clinicians must rapidly assess the cause of obstruction while working toward stabilization of the airway Surgical causes of obstruction require prompt consultation and coordination of care Clinical Considerations Clinical Recognition Tracheal compromise produces symptoms that vary from mild to severe, depending on the degree of obstruction present When symptoms are mild, an underlying cause may not be evident Occasional episodes of respiratory infection that are believed to result from croup or bronchiolitis may be the only symptom Stridor, wheezing, or harsh barky cough occurs in patients with more significant obstruction, and a history of frequent hospitalizations for respiratory compromise may be obtained Severe tracheal compromise is usually manifested by a history of stridor at rest Progressive cyanosis and apneic episodes may occur On examination, a child with obstruction caused by extrinsic compression often has wheezing or stridor throughout the respiratory cycle In contrast, a patient with the floppy trachea of tracheomalacia often wheezes only during expiration Radiographic evaluation of the stable patient should begin with PA and lateral chest radiographs, ideally obtained at full inspiration and again at full expiration Lateral radiographs of the neck may be useful in showing an edematous epiglottis in patients with suspected epiglottitis Mass lesions will require cross-section imaging (e.g., computed tomography [CT]) for evaluation Bronchoscopy is often indicated to evaluate obstructive lesions, whether in the lumen, the wall, or extrinsic to the wall of the trachea Management If the patient has a life-threatening airway obstruction, he or she should receive airway management as outlined in Chapters A General Approach to the Ill or Injured Child and Airway A coordinated effort between the emergency department (ED) care team, the surgeon, and the anesthesiologist or critical care physician may be necessary to establish an airway by endotracheal intubation, bronchoscopy, or tracheotomy Intubation of the airway to within a short distance of the carina supports most patients with critical obstruction secondary to lesions extrinsic to the trachea or within the tracheal wall Such patients require admission to an intensive care unit with ventilator capability Lesions within the lumen will likely require endoscopic management in an operating room, and early involvement of an experienced surgeon is recommended Many inflammatory processes within the trachea are controlled with antibiotics and respiratory care without airway manipulation or surgical intervention Treatment in these cases includes the administration of humidified oxygen and inhaled racemic epinephrine, combined in some cases with the administration of oral, intramuscular, or intravascular dexamethasone Although laryngoscopy and tube delivery may be difficult in patients with epiglottitis, an appropriately placed endotracheal tube fully stabilizes most patients since the inflammation is supraglottic with no tracheal or lower respiratory tract involvement Rarely is intubation necessary for more than 24 to 48 hours in these patients, after which antibiotics have begun to reduce the swelling associated with infection In a patient with viral or bacterial tracheitis, however, intubation for more than 24 to 48 hours may produce tracheal injury and ulceration Tracheomalacia Tracheomalacia, sometimes complicating lung disease of prematurity, is a relatively common cause of airway obstruction It is characterized by a floppy trachea that collapses during expiration when the intrathoracic trachea is compressed by the positive intrathoracic pressure It can be caused by intrinsic tracheal defects, extrinsic compression by surrounding structures, or from prolonged positive pressure ventilation It commonly occurs in association with TEF repair (see TEF below) Clinical Recognition The clinical presentation of tracheomalacia depends on the severity and location of obstruction with more severe lesions presenting earlier in infancy When the intrathoracic trachea is involved, patients often have expiratory wheeze that may be hard to distinguish from asthma Intrathoracic involvement is more likely to cause stridor, which can progress to occur at rest Patients often have cough and evidence of respiratory distress They may present with recurrent respiratory infections and episodes of severe obstruction and respiratory failure Tracheomalacia is typically diagnosed using bronchoscopy during spontaneous respiration, which demonstrates the characteristic tracheal collapse with expiration Although dynamic imaging studies may be useful, standard imaging modalities are typically not helpful in making this diagnosis Management In general, children who are otherwise healthy will have resolution of symptoms by about year of age as the cartilaginous tracheal structures mature During episodes of acute illness, however, these children can present with severe work of breathing, cyanosis, and respiratory failure In addition to medical management, they may benefit from noninvasive or invasive ventilatory strategies The subset of children with severe disease resulting in recurrent bouts of respiratory failure may require tracheal surgery or placement of a tracheal stent Vascular Rings Vascular rings represent a rare and varied group of developmental anomalies of the aorta and great vessels They may produce obstruction of the esophagus, trachea, or both These rings are a result of failure of the normal involution of the appropriate segments of the six embryologic aortic arches Vascular rings are characterized as complete when both the esophagus and trachea are fully encircled and incomplete when they are only partially encircled Complete rings are typically caused by a double aortic arch or a right-sided aortic arch with an aberrant left subclavian artery and left ductus arteriosus or ligamentum Incomplete rings are often caused by a pulmonary artery sling, innominate artery compression, or an aberrant right subclavian artery The level of respiratory obstruction is usually the trachea, but compression of a bronchus by the ductus arteriosus or by a pulmonary artery sling, may produce compression more distally Clinical Recognition Vascular rings may be asymptomatic in infancy but lead to significant airway obstruction in childhood The wide variety of anomalies produces varying degrees of symptoms Presentations range from incidental findings on imaging studies to neonates with critical airways Vascular rings should be suspected in infants with stridor, dysphagia, failure to thrive associated with difficult feeding, or recurrent pneumonia Esophageal obstruction can produce difficulty swallowing A patient with esophageal compression may also have respiratory symptoms from compression on the trachea from a distended esophageal pouch This may lead to reflex apnea during feeding, and eventually tracheomalacia in a more chronic setting Often, diagnosis is delayed by failure to consider these anatomic obstructions since their presentation can be quite varied and subtle In a patient presenting with an acute airway obstruction or other medical problems requiring intubation and nasogastric tube placement, detection of a vascular ring can be even more difficult because of the presence of these tubes Chest radiographs are the initial test of choice and suggestive findings include an abnormal-appearing aortic knob or deviation of the trachea or esophagus Chest radiographs may be supplemented by various diagnostic tests: contrast esophagography (e.g., barium swallow), angiography, echocardiography, magnetic resonance imaging (MRI), and digital subtraction angiography are needed in some combination to define the anatomy Management Although some patients with constricting anomalies improve as they grow, most will require surgical correction Surgical treatment is usually indicated to relieve the obstruction, with predictable and immediate resolution of symptoms and excellent outcomes Surgical repair is accomplished by dividing the vascular ring and preserving the blood supply to the aortic branches This is usually accomplished by a left thoracotomy but more recently, video-assisted thoracoscopic surgery (VATS) and endoscopic robotic-assisted techniques have been adopted in some centers for select patients BRONCHIAL LESIONS Bronchial Atresia Congenital bronchial atresia is a rare anomaly characterized by a bronchocele caused by a mucus-filled, blindly terminating segmental or lobar bronchus, with resulting hyperinflation of the distal obstructed segment of lung Hyperaeration is believed to result from communication with the normally aerated lung via the pores of Kohn and the channels of Lambert Clinical Recognition Neonates and infants with this lesion are usually seen for respiratory distress In older patients, a history of episodic upper respiratory infection and wheezing may be elicited Some older patients may complain of dyspnea on exertion or unilateral chest pain Physical examination findings seldom suggest the diagnosis, but unilaterally decreased breath sounds may be evident Management Often, the diagnosis is suggested by chest radiograph, but high-resolution chest CT scan may be necessary to more closely define the anatomy Bronchoscopy is the most efficient way to identify the atretic opening to the involved bronchus Complete atresia of a main stem or lobar bronchus may lead to infectious complications or compression symptoms from overdistention of the affected lobe This may require surgical management, such as lobectomy Primary Tracheobronchial Tumors