ENT for Kids  
Pediatric Ear, Nose & Throat Medicine and Surgery
 

Airway Problems - An Overview

Congenital airway anomalies may vary in severity but the vast majority present early in life. Stridor is usually the initial presenting symptom, but hoarseness, obstructive sleep apnea or feeding difficulties may be the nidus for otolaryngic evaluation. Lesions from the nose and mouth to the trachea may be the source of obstruction, with the larynx being the most common origin. Stridor is a common symptom, with 87% of children with stridor being diagnosed with congenital anomalies.[1] All children with symptoms of neonatal airway obstruction who are not in acute distress should undergo a thorough evaluation to elicit the source of obstruction and rule out possible anomalies. Sometimes, however, the severity of the obstructing lesion is such that an airway must be immediately secured, as in the case of congenital laryngeal atresia or obstruction that requires the EXIT (Ex utero intrapartum treatment) procedure.

Many times the etiology of obstruction can be elicited from the history alone with a focused examination. Congenital bilateral choanal atresia, for instance, typically presents as a child with cyanosis with feedings and can be confirmed by the inability to pass a small suction catheter through either nares. Obstruction related to laryngomalacia and innominate artery tracheal compression typically dissipates when the infant is put in the prone position. Other sources of obstruction, however, need to be worked up more thoroughly.

Typically, an obstruction at the nasopharynx and/or oropharynx produce stertor, a low pitched inspiratory “snore.” Supraglottic lesions present with inspiratory stridor and a muffled cry; glottic lesions with either inspiratory or biphasic stridor and a high-pitched or aphonic cry; and tracheal lesions with expiratory stridor. However, there are exceptions and stridor should be evaluated regardless of type. If possible, evaluation should begin with a comprehensive history and physical with special attention to possible peri-natal complications such as suspicious head and neck anomalies on prenatal ultrasound, birth trauma or prematurity with subsequent need for intubation. If possible, all infants with stridor should undergo a fiberoptic flexible nasopharyngolaryngoscopy evaluation to evaluate the airway above the true vocal folds. Lesions such as vallecular or glottic cysts, laryngomalacia and vocal fold paralysis can easily be diagnosed with the scope examination. Sometimes subglottic obstructions such as congenital subglottic stenosis can be visualized, although this is difficult to definitively diagnose in an awake, crying infant. A Functional Endoscopic Evaluation of Swallowing (FEES) can also be helpful in the work-up of a stable child with history of feeding difficulty and/or aspiration. In an intubated infant, important questions to answer are the reason and ease of intubation, endotracheal tube size, intubation duration and the number of times the patient has failed extubation.

Radiographic studies are also a useful adjunct in evaluation. Anterior-posterior and lateral x-rays can demonstrate subglottic obstruction. Airway fluoroscopy can demonstrate dynamic obstruction such as glossoptosis, laryngomalacia, and tracheomalacia. A barium swallow is also helpful in cases of feeding difficulties and/or a history of aspiration, and can reveal airway anomalies such as a laryngeal cleft or tracheoesophageal fistula. The swallow study can also be done at the time of airway fluoroscopy to better assess dynamic compression such as innominate artery compression. Magnetic resonance imaging is the latest diagnostic tool in airway obstruction and has been shown to be an effective method of diagnosing the level of airway obstruction in Down Syndrome children.[2]

While some cases of upper airway obstruction can be diagnosed with an H&P, any patient with stridor should have a formal airway evaluation with microlaryngoscopy and bronchoscopy with rigid optical telescopes in the operating theater. Some advocate taking every infant with noisy breathing to the operating room to rule out synchronous lesions.[3] Similarly, dyspnea, agitation and sternal/costal retractions are signs of an impending airway emergency and the management priority in these patients is prompt establishment of a safe, secure airway.

The key to securing an airway is to intervene before the situation becomes an emergency. Establishing a cordial working relationship with your anesthesia colleagues and educating operating room staff are critical. The age-appropriate laryngoscopes, optical telescopes, and ventilating bronchoscopes should be easily accessible on the operating table and a tracheostomy tray should be in the room. Each airway evaluation should be conducted in a systematic fashion with a gross oral cavity and oropharyngeal examination as well as telescopic examinations of the supraglottis, glottis, subglottis and trachea. Being prepared for the worst possible outcome at every formal airway evaluation will ensure that you have the appropriate equipment at hand.

The degree of obstruction will dictate the airway intervention. Specific options include nasal stents, nasopharyngeal airway, BiPAP, CPAP, intubation or tracheostomy. The indication and timing for tracheostomy is related to obstruction severity but other factors such as co-morbidities and intubation indication, difficulty and duration are important in planning. Unlike older children, adolescents and adults, neonates, especially when premature, can tolerate intubation for several months without airway sequelae such as subglottic stenosis. A national inpatient database review demonstrated that congenital airway anomalies is the most common indication for tracheostomy in children less than one year old in the United States.[4] Other studies have shown that prolonged ventilation, most commonly due to bronchopulmonary dysplasia, followed by airway obstruction and pulmonary toilet are the most common reason for tracheostomy.[5, 6] In all patients with congenital airway anomalies, aggressive management of gastroesophageal reflux disease is important. Gastric secretions can irritate the airway and lead to increased edema and obstruction.

References

[1]    L.D. Holinger, Etiology of stridor in the neonate, infant and child, Ann Otol Rhinol Laryngol 89 (1980) 397-400.

[2]     S.R. Shott, L.F. Donnelly, Cine magnetic resonance imaging: evaluation of persistent airway obstruction after tonsil and adenoidectomy in children with Down syndrome, Laryngoscope 114 (2004) 1724-1729.

[3]    J.R. C Gonzalez, CD Bluestone, Synchronous airway lesions in infancy, Ann Otol Rhinol Laryngol (1987) 77-80.

[4]     C.W. Lewis, J.D. Carron, J.A. Perkins, K.C. Sie, C. Feudtner, Tracheotomy in pediatric patients: a national perspective, Arch Otolaryngol Head Neck Surg 129 (2003) 523-529.

[5]    K.W. Altman, R.F. Wetmore, R.R. Marsh, Congenital airway abnormalities requiring tracheotomy: a profile of 56 patients and their diagnoses over a 9 year period, Int J Pediatr Otorhinolaryngol 41 (1997) 199-206.

[6]     C.e. al, Pediatric tracheostomies: changing indications and outcomes, Laryngoscope (2000) 1099.

 
 
 
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