Upper Airway Disease in Kids

Anatomy

1) nasal and oral cavities -> pharynx (naso, oro, laryngo)
trachea -> mainstem bronchi -> bronchi -> terminal bronchioles/alveoli

2) epiglottis, arytenoids, aryepiglottic folds, cricoid cartilage


CROUP

- abrupt onset of a barky cough, along with various combinations of inspiratory or biphasic stridor, hoarseness, and/or respiratory distress.
- caused by progressive edema of the airway
- onset of a mild, brassy, barky cough - often described as "barking like a seal" - is preceded by rhinorrhea and sniffles for 1-2 days
- with serious progression we get, hypoventilation, hypercapnea, and hypoxia

Respiratory distress is quite notable

- dyspnea, intercostal retractions, nasal flaring, and tracheal tugging
- agitated with increased crying, which worsens the existing symptoms
- lethargic


Rx = humidification & night-time air,
    = racemic epinephrine should be monitored for at least 6-10 hours
        = +/- steroids (dexamethasone)

- Complications are generally secondary to extension of the process including otitis media, pneumonia, and adenitis. Rarely, meningitis, mediastinal emphysema, or pneumothorax is seen

4 classes
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1) Acute laryngotracheobronchitis, ie, viral croup
-ages 3 months to 5 years
- causes parainfluenza type 1 & 3, influenza A, adenovirus, rsv, echovirus, and mycoplasma
-worse at night and continuing only for a few days. Mild rhinitis and conjunctivitis are followed a few days later by a harsh, barky cough; stridor; and other symptoms of respiratory distress. Hoarseness and aphonia are common as well as a low-grade fever
- stridor (rhonchi) and crackles (rales)
- Xray = steeple sign

2) Acute spasmotic laryngitis, ie, spasmotic croup

- Unlike viral croup, however, it is characterized by acute attacks of inspiratory stridor that occur at night and subside in a short time, only to recur in subsequent nights. The children are usually between 1 and 3 years of age.

. Acute spasm of the vocal cord adductors may be the cause, possibly triggered by allergy, viral infection, or gastroesophageal reflux.


3) Acute infectious laryngitis

- influenza A, rhinovirus, and adenovirus
- if diptheria = watch for pseudomembrane

Treatment = resting the voice and inhalation of humidified air. Antibiotics if diphtheria



REVIEW Questions

- 3 indications for hospitalization
- Xray finding
- cough is described as
- what rare but deadly disease is in the differential
- what 3 drugs should not be given (bronchodilators, expectorants = irritate/ sed&opiates decr. respiratory drive)


4) Acute epiglottitis, ie, acute supraglottitis

- infection of the epiglottis and supraglottic structures
- ages 2-7 years old and is caused by Haemophilus influenzae, pneumococcus
- abrupt onset of high fever, sore throat and dysphagia, moderate to severe respiratory distress, stridor, and lethargy
- toxic, quiet, drooling, sit forward in sniffing position, hot potato voice
- so tired from work of breathing lethargy, fatigue, or even frank respiratory failure, you can bag if you can't intubate
- careful exam so as not to trigger reflex laryngospasm, acute airway obstruction, and respiratory arrest
- lateral Xray shows "thumb" sign as it resembles the size and shape of the human thumb
- cherry-red supraglottic structures on direct visualization

Rx - ampicillin and chloramphenicol combined or single agents such as ceftriaxone or cefotaxime
- intubate with an uncuffed tube
- Racemic epinephrine and corticosteroids are not helpful in the treatment of epiglottitis
- consider lumbar puncture, latex agglut, bloodwork
- Chemoprophylaxis with rifampin

- Complications associated with epiglottitis include otitis media, adenitis, meningitis, pericarditis, and pneumonia. Mortality may be as high as 5-10%


Conclusion
Epiglottitis produces a unique and dramatic constellation of signs and symptoms . The key points to remember are:

1. Prepare in advance for the management of the disease.
2. Have a high suspicion for the diagnosis.
3. Do not disturb the child until personnel and equipment are available and ready, as reflex laryngospasm and obstruction may occur rapidly.
4. Treat aggressively with supportive measures, antibiotics, and vaccination.
5. Most children have full recovery if treated promptly and aggressively.



DDx in Croup

Other Croup Syndromes, especially Spasmotic Croup
Diphtheria
Measles
Retropharyngeal Abscess
Foreign Body
Intrinsic or Extrinsic Airway Compression
Congenital Subglottic Stenosis , webs or cysts
Angioedema
Tetany
Asthma


DDx in Acute Epiglottitis

Viral croup
Spasmotic croup
Acute infectious laryngitis

DDx in Subglottic Stenosis

Vascular Malformations
Asthma
Croup
Bronchiolitis

DDx in Tracheomalacia

Laryngomalacia
( may be caused by vascular anomalies such as an anomalous innominate artery or vascular ring , esophageal atresia and tracheoesophageal fistula)
Subglottic Stenosis
Congenital Cysts
Vocal Cord Paralysis
Tetany

References:

A Series of Case Studies Online around Pediatric Airway Ds.
University of Iowa - Virtual Children's Hospital

http://www.vh.org/Providers/Textbooks/ElectricAirway/Text