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.)

PathoPhysiologyStridor 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 1stVocal cord dysfunction 2ndCongenital tumoursChoanal atresiaLaryngeal webs

ChronicChronicChronicChronicChronic

Chilld

Infection -epiglottitis -Laryngitis Croup : 1-2 days duration less severeFBLaryngeal dyskinesia

acuteAcuteAcutechronic

adult

Infection -epiglottitis -Laryngitis Trauma – acquired stenosisCA Larynx or Trachea or main bronchus

AcuteAcutechronic

laryngeal web a web spread between the vocal folds near the anterior commissure

Laryngeal Web

steeple sign 

A-P

Clinical

HxPEInvestigationManagement

History 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 cryingpresence 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 patientsWe 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.

Investigati

onLaboratory 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.)

Treatment

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.