1. Morning Report Tuesday, November 8th, 2011
Good Morning!!!
Morning Report Tuesday, November 8th, 2011

2. What is Stridor?
Monophonic, high-pitched sound usually caused by upper airway narrowing and partial obstruction
Can be:
Inspiratory
Expiratory
Biphasic

3. The Anatomy of Stridor
Inspiratory stridor is caused by extrathoracic obstruction
Extrathoracic region
Supraglottic area
Nasopharynx, epiglottis, larynx, aryepiglottic folds, false vocal cords
Glottic and subglottic area
Vocal cords to the extrathoracic segment of the trachea
Subglottis is the narrowest part of the trachea

4. The Anatomy of Stridor

5. The Anatomy of Stridor
Expiratory stridor (wheezing) is caused by intrathoracic obstruction
Includes portion of the trachea that lies within the thoracic cavity and the mainstem bronchi
Biphasic stridor is caused by critical and fixed airwary obstruction at any level

6. Pathophysiology Extrathoracic Intrathoracic
Extrathoracic: Left, during forced expiration, intratracheal pressure (Ptr) exceeds the pressure around the airway (Patm), lessening the obstruction. Right, during forced inspiration, when intratracheal pressure falls below the atmospheric pressure, the obstruction worsens resulting in flow limitation.
Intrathoracic: Left panel, during forced expiration, the intrathoracic intratracheal pressure (Ptr) is less than the pressure in the pleural pressure (Ppl), worsening the obstruction. Right, during forced inspiration, intratracheal pressure exceeds the pleural pressure, lessening the degree of obstruction.

7. Anatomic Differential Diagnosis
Inspiratory Stridor
Immobile cords
Noid (adenoid) and tonsil enlargement
Soft cartilage (laryngomalacia)
Pharyngeal and hypopharyngeal masses
Expiratory Stridor
Tracheomalacia
Bronchomalacia
Vascular ring/ sling
I/S: Laryngomalacia is most common cause of stridor in infants, followed by vocal cord paralysis (usually due to CNS lesions or traction on the recurrent laryngeal n. (birth complication), complication of PDA ligation/cardiac/ neck surgery)
When comparing stridor from laryngomalacia with that of vocal cord paralysis, stridor wth laryngomalacia “wet with variable pitch;” vocal cord paralysis more high-pitched
N: Stertor (low pitch)
P: Peritonsillar, retropharyngeal abscess; epiglottitis, bacterial tracheitis, croup

8. Anatomic Differential Diagnosis
Biphasic Stridor
Subglottic stenosis
Critical fixed airway obstruction
Vocal cord lesions*
Croup*
With subglottic stenosis, inspiratory component is louder
**Don’t forget foreign body; type of stridor will depend on where the object is lodged**

9. Historical Pearls Age:
Laryngomalacia, subglottic stenosis, tracheomalacia: congenital disorders
Foreign body aspiration: >6mos
Croup: 6-36mos
Retropharyngeal abscess: <4 yo
Peritonsillar abscess: >10 yo

10. Historical Pearls Acuity of onset: Abrupt Insidious Recurrent
FB aspiration
Allergic reactions
Infectious processes (epiglottitis, tracheitis, etc…)
Insidious
Viral croup
Delayed airway burns
Recurrent FB
Subglottic stenosis
Vascular ring
Tumor

11. Historical Pearls PMHx/ Birth Hx Prenatal/ perinatal complications?
Intubations? Length?
Surgical history?
Exposure to allergens?

12. Physical Exam
Gen: **Quickly identify any patients with impending airway obstruction**
HEENT: Size of tongue and mandible, ?craniofacial malformations
Neck: scars, edema
Lungs: WOB, location of stridor*
Ext: clubbing
Lymphatics: peripheral LAD
Skin: hemangiomas, café-au-lait spots
*place the bell over the child’s mouth and neck to determine to location of the stridor

13. Imaging Plain neck films Non-specific
May reveal changes associated with
Retropharyngeal abscess
Epiglottitis
Croup
Foreign body

14. Plain Neck Films Croup Retropharyngeal abscess
Croup: (lateral view): hypopharynx is distended and there is subglottic haziness, normal epiglottis; diagnostic value of steeple sign is limited

15. Imaging CXR Airway fluoroscopy CT/MRI
Important when an intrathoracic problem is suspected
Mediastinal LAD or mass
R aortic arch (vascular ring)
Foreign body
Airway fluoroscopy
Tracheomalacia
CT/MRI
Retropharyngeal cellulitis/ abscess
Tumors/ LAD
Abnormal vasculature
**Biggest disadvantage of CT is not being able to image across the long axis of the trachea MRI better; gives a good evaluation of the mediastinum and estimates the length and degree of tracheal obstruction/ stenosis**

16. Other Diagnostic Modalities
Spirometry
Difficult to perform in small children

17. Other Diagnostic Modalities
Airway visualization
Emergent, flexible or rigid laryngoscopy:
Epiglottitis
Tracheitis
Non-urgent, nasopharyngoscopy:
Laryngomalacia
Anatomic defects b/t nose and pharynx
Non-urgent, flexible or rigid laryngoscopy:
Thorough evaluation needed for diagnosis
Foreign body

18. Case #1
4 yo M with a 2 day history of fever to Today, Mom noticed that his breathing was noisy and he was refusing to eat and drink. In the office, he is leaning forward, drooling with stridor…
Epiglottitis: edematous epiglottis with the thumb sign, enlarged aryepiglottic folds, ballooned hypopharyngeal airway (BUT 70% of patients have normal neck films!)

19. Questions…Case #1 Diagnosis? Inspiratory or expiratory stridor?
Epiglottitis
Inspiratory or expiratory stridor?
Inspiratory
Associated symptoms?
Drooling
Dysphagia
Distress
Leans forward (refuses to lie down)

20. Case #2
A mother brings in her 2 week old ex 37 wga F with c/o noisy breathing. She describes it as an inspiratory noise that seems to worsen when she cries and when she is lying down. The infant is growing and gaining weight appropriately.

21. Questions…Case #2 Diagnosis? Inspiratory or expiratory stridor?
Laryngomalacia
Inspiratory or expiratory stridor?
Inspiratory
Associated symptoms
Can have retractions
Stridor worse with agitation and supine position
Stridor improves with expiration
Symptoms improve with time

22. Case #3
When you walk into an exam room to see your 2 month old WCC, you appreciate a loud wheeze. You notice the infant is feeding and ask Mom if this noise is a common occurrence with feeds. She says that it is and that the infant also seems to have difficulty “getting down” the formula…

23. Questions…Case#3 Diagnosis? Inspiratory or expiratory stridor?
Vascular ring
Inspiratory or expiratory stridor?
Expiratory
Associated symptoms
Stridor worse with feeds
Feeding difficulty

24. Case #4
3 mo M with Trisomy 21 presents to the ED with noisy/ difficult breathing. Per Mom, she saw her PCP yesterday for the noisy breathing. He said it was “wheezing from a cold” and gave her Albuterol nebs to give q4. Since the meds, the infant’s respiratory distress has worsened…

25. Questions…Case #4 Diagnosis? Inspiratory or expiratory stridor?
Tracheomalacia
Inspiratory or expiratory stridor?
Expiratory
Associations
Confused with asthma
Asthma: wheeze high-pitched, diffuse and musical; improves with beta-agonists
Tracheomalacia: wheeze low-pitched, central and homophonous; worsens with beta-agonists
Associated with Trisomy 21, TEF s/p repair, mechanical ventilation, and BPD

26. Thanks for your attention!
Noon Conference: VLBW Infant, Dr. Rivera