While working on the general pediatric inpatient service, a pediatrician had 4 patients with similar stories.
All were under 1 year of age and were admitted for respiratory distress, cough and dehydration due to respiratory syncytial virus.
Each had a prolonged illness or needed readmission because each also had an underlying airway malacia that had been diagnosed by bronchoscopy – laryngomalacia, tracheomalacia, tracheobronchomalacia and bronchomalacia.
The patient with laryngomalacia also had inspiratory stridor during this admission. Those with lower airway malacias originally were diagnosed after having a chronic cough, poor weight gain, and/or had additional underlying disease problems (i.e. genetic syndrome).
The residents all had noted that the farther down in the airway the malacia was, the more ill the patient was clinically and/or had other underlying disease problems.
This offered a good chance to review how airway malacias can present.
Stridor is a variably pitched sound caused by increased turbulence and airflow through a narrowed part of the large airway. Usually due to narrowing of the larynx or extrathoracic trachea, stridor is usually inspiratory.
Biphasic stridor usually is due to a fixed airway obstruction at the level of the glottis or subglottis but may also extend to the mid-thoracic trachea.
Stridor is different than stertor which is a heavy-snoring, inspiratory sound occurring in coma or deep sleep, sometimes due to obstruction of the larynx or upper airways. Causes of stertor include choanal stenosis, enlarged tonsils and/or adenoids, and redundant upper airway tissues above the larynx.
Causes of upper airway obstruction that can cause stridor include:
- Acute laryngotracheobronchitis (i.e. croup)
- Hereditary angioneurotic edema
- Intubation, post-endotracheal
- Laryngeal cleft
- Laryngeal cysts
- Micrognathia or retrognathia
- Mucus retention cysts
- Subglottic stenosis
- Thyroglossal duct remnant
- Vocal cord paralysis – forceps delivery, Chiari malformation
Malacia means a softening of the tissues and is named by its location.
Laryngomalacia usually presents with noisy breathing and inspiratory stridor. There can be collapse of the arytenoids, epiglottis, and aryepiglottic folds.
Symptoms usually present around 10 days, worsen for the next several months, and then resolve by 2 years of age.
It is considered a developmental process and is usually benign.
Laryngomalacia can be associated with other airway malacias. In one study, concomitant tracheomalacia (29%) bronchomalacia (10%) and tracheobronchomalacia (7%) were identified.
Recurrent wheeze, chronic cough and recurrent respiratory tract illnesses were common problems seen in patients with both laryngomalacia and another airway malacias.
Tracheomalacia is a localized or generalized “…weakness of the trachea which causes luminal obstruction at times of increased intrathoracic pressure, such as expiration or coughing.” Tracheobronchomalacia involves both the trachea and bronchi, and bronchomalacia involves the bronchus.
Patients with all 3 intrinsic airway malacia types may have minor respiratory infections but they can also cause apnea, cyanosis and life-threatening airway obstruction. Chronic coughing and wheezing are common presentations. Most have increased illness severity during acute illnesses and take longer to resolve.
The airway malacias may be part of other congenital anomalies (including cardiac anomalies) and therefore be more difficult to treat. Treatment can include surgical (e.g. aortopexy, tracheopexy, external or internal airway stenting), and mechanical (positive airway pressure). These airway malacias often do not resolve and therefore may require treatment.
Questions for Further Discussion
1. What are indications for bronchoscopy?
2. What different delivery methods are there for oxygen therapy?
- Specialty: Otolaryngology
- Age: Infant
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Vijayasekaran D, Gowrishankar NC, Kalpana S, Vivekanandan VE, Balakrishnan MS, Suresh S. Lower airway anomalies in infants with laryngomalacia. Indian J Pediatr. 2010 Apr;77(4):403-6.
Masters IB, Zimmerman PV, Pandeya N, Petsky HL, Wilson SB, Chang AB. Quantified tracheobronchomalacia disorders and their clinical profiles in children. Chest. 2008 Feb;133(2):461-7.
Calkoen EE, Gabra HO, Roebuck DJ, Kiely E, Elliott MJ. Aortopexy as treatment for tracheo-bronchomalacia in children: an 18-year single-center experience. Pediatr Crit Care Med. 2011 Sep;12(5):545-51.
Goyal V, Masters IB, Chang AB. Interventions for primary (intrinsic) tracheomalacia in children. Cochrane Database Syst Rev. 2012 Oct 17;10:CD005304.
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ACGME Competencies Highlighted by Case
3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
4. Patient management plans are developed and carried out.
7. All medical and invasive procedures considered essential for the area of practice are competently performed.
9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.
10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
16. Learning of students and other health care professionals is facilitated.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital