stridor
 Done by Alaa Alyounis
* Overview
* Clinical
approach
* How to deal
with patients
having stridor
Introduction
* Stridor is an abnormal, high-pitched sound produced by turbulent airflow through a
partially obstructed airway at the level of the supraglottis, glottis, subglottis, and/or trachea.
* it should be differentiated from stertor, which is a lower-pitched, snoring-type sound
generated at the level of the nasopharynx, oropharynx, and, occasionally, supraglottis.
* Stridor is a symptom, not a diagnosis or disease, and the underlying cause must be
determined.
Stridor may be inspiratory, expiratory, or biphasic depending on its timing in
the respiratory cycle.
 Inspiratory stridor suggests a
laryngeal obstruction
 while expiratory stridor implies
bronchial obstruction
 Biphasic stridor suggests a
tracheal (subglottic or
glottic anomaly.)
PathoPhysiology
 Stridor results from partial obstruction of an airway with turbulent
flow characteristics. Such respiratory tract areas are the upper
airway, glottis, and trachea.
 The obstruction can be fixed or variable. Variable extrathoracic
obstructions are primarily associated with inspiratory stridor. This is
because, during inspiration, extrathoracic intraluminal airway
pressure is negative relative to atmospheric pressure, leading to
collapse of supraglottic structures.
 During expiration, intrathoracic pressure is positive and tends to
collapse the airway. Thus, stridor caused by intrathoracic
obstructions tends to be more prominent upon expiration. Stridor
heard during both phases of respiration is usually due to either a
fixed airway obstruction or to 2 areas of obstruction (ie,
intrathoracic and extrathoracic).
Causes


Stridor may result from lesions involving the CNS, the cardiovascular system, the GI system, and the respiratory
tract.
I prefers to classify the causes according to the age and the onset
neonate
Laryngomalacia
Vocal cord dysfunction
Congenital tumours
Choanal atresia
Laryngeal webs
1st
2nd
Chronic
Chronic
Chronic
Chronic
Chronic
Chilld
Infection -epiglottitis -Laryngitis
Croup : 1-2 days duration less severe
FB
Laryngeal dyskinesia
acute
Acute
Acute
chronic
adult
Infection -epiglottitis -Laryngitis
Trauma – acquired stenosis
CA Larynx or Trachea or main bronchus
Acute
Acute
chronic
Laryngeal Web
laryngeal web a web spread between the vocal folds near the anterior commissure
A-P
steeple sign
Clinical
Hx
PE
Investigation
Management

A thorough history may provide helpful clues to the underlying etiology of stridor.
Patient profile
Name age address …etc
Main complain
Stridor (duration )
HPI
Place particular emphasis on the age of onset, duration, severity, and progression
of the stridor; precipitating events (eg, crying, feeding); positioning (eg, prone,
supine, sitting); quality and nature of crying
presence of aphonia; and other associated symptoms (eg, paroxysms of
cough, aspiration, difficulty feeding, drooling, sleep disordered breathing). elicit
history of color change, cyanosis, respiratory effort, and apnea to determine the
severity of stridor.
ROS
ENT , the respiratory tract, the cardiovascular system, the GI system, and CNS.and all
( PeriNatal )
*maternal endotracheal intubation use and duration, and presence of congenital
anomalies.
*developmental history.
*A feeding and growth history should be evaluated because significant airway
obstruction can lead to caloric waste, resulting in lack of or slow weight gain and
growth. Additionally, regurgitation and spitting up could be a sign of
gastroesophageal reflux (GER) that can cause irritation of the mucosa of the larynx
and trachea that could lead to edema and stridor.
other
Past Medical / Drugs / social / family history
Physical
Ex
 Do not try to examine the throat
in patient with stridor as this may
induce laryngospasm and total
airway obstruction.
* We start by General look at patient and we look if he in
distress or cyanosed , use of accessory muscles of respiration, nasal
flaring, level of consciousness, and responsiveness.
* Vital signs
* We must do rotine full examination like other patients
We start by HEENT RS CVS …. etc
Important notes in PE
 If distress is moderate to severe, further physical examination should be deferred until the
patient reaches a facility equipped for emergent management of the pediatric airway.
 Physical examination of a patient with suspected acute epiglottitis is contraindicated.
 The patient may prefer certain positions that alleviate the stridor.
 Note the presence of infection in the oral cavity; crepitations or masses in the soft tissues of
the face, neck, or chest; and deviation of the trachea.
 Use care when examining (especially palpating) the oral cavity or pharynx because sudden
dislodgement of a foreign body or rupture of an abscess can cause further airway compromise.
 Drooling from the mouth suggests poor handling of secretions.
 Observe the character of the cough, cry, and voice.
 The presence of fever and toxicity generally implies serious bacterial infections.
 Careful auscultation of the nose, oropharynx, neck, and chest helps to discern the location of the
stridor.
 In infants, give special attention to craniofacial morphology, patency of the nares.
 Growth parameters are very helpful, especially in evaluation of chronic stridor.
Laboratory Studies
Generally, no investigations are required for mild stridor
On initial evaluation, pulse oximetry may be useful to determine the extent and
severity of the stridor and respiratory compromise.
For moderate-to-severe cases, arterial blood gas may be needed.
Other laboratory evaluations may be performed as dictated by the clinical situation.
Imaging Studies
Anteroposterior (AP) and lateral radiographs of the neck and chest are useful to
evaluate the airway and lungs.
High-kilovoltage, short-exposure, endolateral airway radiographs (useful to
demonstrate upper airway structures) or inspiratory and expiratory or lateral
decubitus radiographs to demonstrate air trapping may be used to supplement AP
and lateral radiographs.
Barium esophagram may be performed if vascular compression, tracheoesophageal
fistula, GER, or neurological dysfunction is suspected.
Contrast-enhanced CT scanning can demonstrate mediastinal masses or aberrant
vessels.
An MRI may be helpful in delineating lesions of the upper airway and vascular
anomalies.
If GER is suspected, a pH probe or barium swallow may be performed to support the
diagnosis.
Other Tests
Pulmonary function testing (OPD –RPD)
Polysomnography (osbstructive leep apnea.)
 Medical Care
 The treatment of stridor must be tailored according to the underlying or




predisposing condition. Emergent management consists of ensuring
that the airway is adequate. If not, appropriate resuscitative measures
must be initiated. Some conditions (eg, epiglottitis, bacterial tracheitis)
may require antibiotics, while steroids may be useful in other
situations.
Surgical Care
Certain conditions, such as severe laryngomalacia, laryngeal stenosis,
critical tracheal stenosis, laryngeal and tracheal tumors and lesions (eg,
laryngeal papillomas, hemangiomas, others), and foreign body aspiration,
require surgical correction. Occasionally, tracheotomy is used to
protect the airway to bypass laryngeal abnormalities and stent or bypass
tracheal abnormalities. Other conditions, such as retropharyngeal and
peritonsillar abscess, may have to be dealt with on an emergent basis.
Please see articles on the specific conditions.
Diet
Patients with moderate to severe stridor should be given nothing by
mouth (NPO) in preparation for possible intubation, laryngoscopy,
bronchoscopy, and tracheotomy.