SAI YAN AUSAI YAN AU

StridorStridor

Harsh, high pitched, musical sound produced by Harsh, high pitched, musical sound produced by turbulent airflow through a partially obstructed turbulent airflow through a partially obstructed airway.airway.

A signA sign May be inspiratory, expiratory or biphasicMay be inspiratory, expiratory or biphasic Inspiratory stridor – extrathoracic lesion Inspiratory stridor – extrathoracic lesion

(laryngeal, nasal, pharyngeal)(laryngeal, nasal, pharyngeal) Expiratory stridor – intrathoracic lesion (tracheal Expiratory stridor – intrathoracic lesion (tracheal

or bronchial)or bronchial) Biphasic stridor - subglottic or glottic anomalyBiphasic stridor - subglottic or glottic anomaly

Stridor: MechanismStridor: Mechanism

Venturi principleVenturi principle Gases produce equal pressure in all directionGases produce equal pressure in all direction When gas move in a linear direction, it produces When gas move in a linear direction, it produces

pressure in the forward vector and decreases the pressure in the forward vector and decreases the lateral pressurelateral pressure

When air passes through a narrowed flexible When air passes through a narrowed flexible airway in child, the lateral pressure that holds the airway in child, the lateral pressure that holds the airway can drop and causes airway to close – airway can drop and causes airway to close – airflow obstruction – stridor airflow obstruction – stridor

Stridor In Infants: CausesStridor In Infants: Causes

Laryngomalacia (congenital laryngeal Laryngomalacia (congenital laryngeal stridor)stridor)

Subglottic stenosisSubglottic stenosis Laryngeal websLaryngeal webs

Laryngomalacia (congenital Laryngomalacia (congenital laryngeal stridor)laryngeal stridor)

Most common cause of persistent stridor in Most common cause of persistent stridor in infants (first 6 weeks of life)infants (first 6 weeks of life)

Congenital abnormality of the laryngeal Congenital abnormality of the laryngeal cartilagecartilage

Delay in maturation of cartilaginous support Delay in maturation of cartilaginous support for the supraglottic structuresfor the supraglottic structures

No known sex and race predilection existsNo known sex and race predilection exists Causes – congenital Causes – congenital

Laryngomalacia: Laryngomalacia: pathophysiologypathophysiology

May affect the epiglottis, May affect the epiglottis, arytenoid cartilages or botharytenoid cartilages or both

Epiglottis – elongated and Epiglottis – elongated and the walls fold in on the walls fold in on themselves ( OMEGA, themselves ( OMEGA, Ω Ω shaped)shaped)

Arythenoid cartilage – Arythenoid cartilage – enlargedenlarged

Either cases, cartilage is Either cases, cartilage is floppy; prolapsed over the floppy; prolapsed over the larynx during inspirationlarynx during inspiration

Increase risk of GOERIncrease risk of GOER Reflux laryngitisReflux laryngitis

LaryngomalaciaLaryngomalacia History:-History:- Hx of inspiratory noises; may sound like nasal congestionHx of inspiratory noises; may sound like nasal congestion Stridor worse in the supine position, increased activity, Stridor worse in the supine position, increased activity,

URTI and during feeding but improved in the prone URTI and during feeding but improved in the prone position with the head upposition with the head up

Assoc. with pectus excavatumAssoc. with pectus excavatum On Examination:-On Examination:- mild tachypnoeamild tachypnoea Normal or slight drop in ONormal or slight drop in O22 saturation saturation Nasal airflow increase in supine positionNasal airflow increase in supine position Noise is purely inspiratory Noise is purely inspiratory

LaryngomalaciaLaryngomalacia

Investigations:-Investigations:- O2 saturationO2 saturation FluoroscopyFluoroscopy Laryngoscopy and bronchoscopyLaryngoscopy and bronchoscopy Treatment:-Treatment:- > 99%, no Rx is needed> 99%, no Rx is needed Simple tracheotomy or laryngoplastySimple tracheotomy or laryngoplasty

Subglottic StenosisSubglottic Stenosis Narrowing of the subglottic which Narrowing of the subglottic which

is housed in the cricoid cartilageis housed in the cricoid cartilage no racial predilection existsno racial predilection exists equal sex distributionsequal sex distributions Causes: -Causes: - congenital (in utero malformation congenital (in utero malformation

of the cricoid cartilage)of the cricoid cartilage) Acquired ( infections e.g. TB, Acquired ( infections e.g. TB,

diphtheria, typhoid and syphilis, diphtheria, typhoid and syphilis, mechanical trauma due to mechanical trauma due to endotracheal intubation and endotracheal intubation and GOER)GOER)

Subglottic Stenosis: Subglottic Stenosis: PathophysiologyPathophysiology

Congenital – incomplete Congenital – incomplete canalization of the canalization of the subglottis and cricoid subglottis and cricoid rings, assoc. with trisomy rings, assoc. with trisomy 2121

Acquired: - Acquired: - Trauma causes mucosal Trauma causes mucosal

oedema and hyperemia; oedema and hyperemia; leads to pressure necrosisleads to pressure necrosis

GOER – subglottis bathed GOER – subglottis bathed in acid, irritates and in acid, irritates and inflames the area and inflames the area and prevent from healing prevent from healing

Subglottic StenosisSubglottic Stenosis

History: -History: - Presence of biphasic and obstructive breathing Presence of biphasic and obstructive breathing Hoarseness or vocal weaknessHoarseness or vocal weakness Clinical examination:-Clinical examination:- Complete head and neck examinationComplete head and neck examination Evaluate the child’s appearance, voice and Evaluate the child’s appearance, voice and

neurological status neurological status Auscultate lung and neckAuscultate lung and neck Identify any associated featuresIdentify any associated features

Subglottic stenosisSubglottic stenosis

Investigations:- Investigations:- Direct laryngoscopy and bronchoscopyDirect laryngoscopy and bronchoscopy AP and lateral neck x rayAP and lateral neck x ray FluoroscopyFluoroscopy Dual channel pH probe testingDual channel pH probe testing MRI and CT ScanMRI and CT Scan Treatment:-Treatment:- Medical (steroids)Medical (steroids) Surgical (tracheostomy, cricoid split and Surgical (tracheostomy, cricoid split and

laryngoplasty)laryngoplasty)

Laryngeal WebLaryngeal Web

Uncommon (5% of Uncommon (5% of congenital laryngeal congenital laryngeal abnormalities)abnormalities)

Incomplete canalization of Incomplete canalization of the larynxthe larynx

Sporadic and equal sex Sporadic and equal sex distributiondistribution

Causes – congenitalCauses – congenital 4 types – based on the 4 types – based on the

degree of occlusion degree of occlusion Type I, II, III, IVType I, II, III, IV

Laryngeal WebLaryngeal Web Type I – 35% covering the anterior glottisType I – 35% covering the anterior glottis Type II – 35 to 50% occlusion of the lumen with vocal cord Type II – 35 to 50% occlusion of the lumen with vocal cord

visiblevisible Type IIIType III – 50 to 70% occlusion of the lumen with the vocal – 50 to 70% occlusion of the lumen with the vocal

cord possibly visualized; cord possibly visualized; most commonmost common Type IV – 75 to 90% occlusion with vocal cords not visualizedType IV – 75 to 90% occlusion with vocal cords not visualized

Pathophysiology: -Pathophysiology: - Developmental abnormality occurring between the 4Developmental abnormality occurring between the 4thth to 10 to 10thth

weeks of gestationweeks of gestation Epithelial fusion between 2 sides of larynx fails to dissolve Epithelial fusion between 2 sides of larynx fails to dissolve

resulting in incomplete recanalization of the primitive larynx.resulting in incomplete recanalization of the primitive larynx.

Laryngeal webs: Clinical Laryngeal webs: Clinical FeaturesFeatures

Inspiratory and expiratory stridor +/- upper Inspiratory and expiratory stridor +/- upper airway obstruction with respiratory distressairway obstruction with respiratory distress

Paroxysmal dyspnoea +/- cyanosisParoxysmal dyspnoea +/- cyanosis Aphonia, weak cryAphonia, weak cry Poor feedingPoor feeding Assoc with respiratory and CVS problems Assoc with respiratory and CVS problems

(10% - 15%)(10% - 15%)

Laryngeal WebsLaryngeal Webs

Investigations:-Investigations:- Direct laryngoscopy or bronchoscopyDirect laryngoscopy or bronchoscopy Treatment:-Treatment:- Supportive (emergency)Supportive (emergency) Surgery (thinner, thicker webs)Surgery (thinner, thicker webs)

SUMMARYSUMMARY

Laryngomalacia – delay in maturation of Laryngomalacia – delay in maturation of the cartilaginous support of supraglottic the cartilaginous support of supraglottic structuresstructures

Subglottic stenosis – incomplete Subglottic stenosis – incomplete canalization of subglottis and cricoid canalization of subglottis and cricoid cartilagecartilage

Laryngeal web – fusion of the anterior Laryngeal web – fusion of the anterior portion of true vocal cordsportion of true vocal cords