Stridor

Dr Haribalan

Assistant professor

Department of ENT

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Stridor is a hallmark of laryngeal obstruction. It is an abnormal (stridulent or harsh) noise that is caused by a turbulent airflow in the impaired airway.

• Types,
• Inspiratory stridor
• Expiratory stridor
• Biphasic stridor

• Inspiratory stridor: It is because of obstruction from larynx and pharynx.
• Expiratory stridor: Expiratory stridor and prolonged expiratory phase are because of bronchial and low tracheal obstruction.
• Biphasic stridor: It is because of obstruction at the level of cervical trachea.

Causes

Stridor may arise from lesions of,

• Nose
• Tongue
• Mandible
• Pharynx
• larynx
• trachea and bronchi

ASSESSMENT OF PATIENT with stridor

History and Physical Examination of Upper Airway

• The clinical manifestations of impaired airway may include dyspnea and stridor, voice change (hoarseness), cough, local pain, restlessness, indrawing of intercostals, suprasternal, and supraclavicular spaces, and drooling.
• Bleeding and subcutaneous emphysema occur in cases of trauma.

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Severity: Severity of subcostal, intercostals and suprasternal recession is an indicator of the severity of airway impairment.

• Cyanosis: It is a late feature.
• Nasal patency: It can be assessed with a mirror, cotton wisp or bell of stethoscope.
• Jaw and tongue: Assess the jaw and tongue size.

Characteristic Features

Impairment in airway affects the feeding particularly in infants.

Airway impaired babies typically “come up for air” during the breastfeeding.

Bottle-fed babies need small hole bottle and thickened feeds. Poor feeding may result in failure to thrive and poor weight gain.

The following characteristic features indicate the cause of airway obstruction.

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Effect of position:

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Prone position: Stridor of laryngomalacia, micrognathia, macroglossia and innominate artery compression disappears when baby lies in prone position.

• Supine position: Stridor in supine position occurs with a pedunculated laryngeal mass and micrognathia (results in tongue base occlusion).

Effect of crying: Dynamic stridor evident in first few weeks of life indicates laryngomalacia.

Improvement: Airway improvement during crying occurs in gross nasal obstruction, such as bilateral choanal atresia.

Worsening: In laryngomalacia, stridor is less at rest and during sleep and becomes worse by crying and feeding.

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Progress:

Gradual: A gradual increase in severity of stridor implies subglottic hemangioma, mediastinal mass and cancer of upper airway.

Rapid: Rapid progression of airway impairment with drooling is hallmark of acute epiglottitis, whereas bacterial tracheitis and laryngotracheobronchitis have relatively prolonged course.

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Fever: Associated fever indicates infective condition such as laryngitis, epiglottitis, laryngotracheobronchitis or diphtheria.

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• Cough: It is present in cases of tracheoesophageal fistula and tracheomalacia.

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• Hoarseness: It suggests laryngeal papillomatosis and vocal cord palsy.

Sound of stridor:

Musical quality: Laryngomalacia

Breathy quality: Vocal cord palsy

Barking cough: Tracheomalacia.

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Investigations:

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• � Oxygen saturation monitoring in cases of acute airway obstruction.
• Arterial blood gases estimation.
• � Endoscopy and intubation in operation theater in cases of
• suspected epiglottitis.
• � X-ray chest PA view: Ground glass appearance in bronchopulmonary dysplasia and mediastinal shift in cases of obstructive emphysema due to foreign body.

� X-ray neck lateral view: Demonstrate subglottis, oropharynx and nasopharynx.

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Expiratory and inspiratory films (in older children): Diaphragmatic immobility is seen on the side of foreign body obstruction.

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� Videofluoroscopy (in young children) for diaphragmatic screening and tracheomalacia.

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� Bronchography with safer nonionic contrast media: Demonstrates tracheobronchial stenosis and malacia.

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MRI and helical CT: For tracheal lesions, extrinsic compression and abnormal vasculature.

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� pH probe study: For pH in upper esophagus and pharynx in cases of gastroesophageal reflux disease.

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� Ultrasound of vocal cords for vocal cord palsy.

TREATMENT:

� Active resuscitation: Such as setting up humidified oxygen and preparation for intubation/tracheostomy. In cases of inadequate ventilation, airway must be secured through either medical or surgical means.

Acute Airway Obstruction:

� Steroids: Dexamethasone 0.15–0.6 mg/kg IM (may be given intravenous and oral) with inhaled steroids in cases of LTB.

Nebulized budesonide (2 mg) for home use in cases of recurrent LTB.

� Continuous positive airway pressure via nasal cannula: Continuous positive airway pressure (CPAP) takes care of tracheobronchial malacia.

� Ventilating bronchoscope: If the secretions are very thick, viscid and tenacious and airway impairment persists after intubation, a ventilating bronchoscope is passed to examine and see for foreign body.

� Intubation: Endotracheal intubation is a quick method of establishing airway. A very gentle intubation with a small soft tube just large enough for adequate ventilation and suction of secretions is preferred over pediatric tracheostomy, which brings with it numerous problems.

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Though oral intubation tends to be easy, nasal intubation is more secured. Severe subglottic stenosis, impacted foreign body, advanced epiglottitis and laryngeal aplasia make intubation impossible.

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� Endoscopy for foreign bodies: Topical adrenaline use before foreign body removal, decongest mucosa and reduces bleeding.

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� Puncturing trachea or cricothyroid membrane: The airway can be achieved by puncturing trachea or cricothyroid membrane with a 16-gauge plastic-sheathed needle. The needle is withdrawn and cannula is connected to an oxygen supply.

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� Cricoid split: Cricoid split, which decompress the cricoid ring in cases of subglottic edema or soft immature stenosis, is indicated in neonates who fail extubation and weighs more than 1.5 kg.

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� Single-stage laryngeal reconstruction: It is indicated in premature neonates who fail extubation and have mature subglottic stenosis.

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• � Emergency cricothyrotomy/tracheostomy: Emergency tracheostomy set with correct size tube should be kept ready. If medical techniques fail, an urgent tracheotomy or cricothyrotomy must be performed, though it is rarely required.

Chronic Airway Obstruction:

� Antireflux treatment

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� Systemic steroids to treat subglottic hemangioma

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• � Prophylactic antibiotics in cases of recurrent LTB

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• � Specific treatment: Interferon, cidofovir and mitomycin C.