Laryngeal inspiratory wheezing

Specialty: Respiratory.

• high inspiratory wheeze
• high-pitched laryngeal stridor
• cervical wheeze

Why it occurs

• Vocal fold dysfunction or paradoxical movement of the vocal folds during inspiration (the vocal folds adduct abnormally during inspiration, generating an imprecise wheezing noise that is frequently confused with bronchial asthma)
• Acquired or congenital subglottic stenosis (narrowing of the airway immediately below the vocal cords due to trauma from previous prolonged intubation)
• Acute inflammatory or infectious laryngitis with marked glottic edema
• Obstructive vocal cord or laryngeal neoplasia (squamous cell carcinoma of the larynx with exophytic growth)
• Bilateral vocal cord paralysis in the adducted position (due to surgical injury to both recurrent laryngeal nerves).

Initial workup

Real-time flexible nasofibrolaryngoscopy (essential to observe the movement of the vocal cords during inspiration and phonation); Computed tomography (CT) of the larynx and trachea with three-dimensional reconstruction; Flow-volume curve obtained by spirometry (shows a characteristic flattening of the inspiratory branch, suggestive of fixed or variable extrathoracic obstruction).

Standard management

• Heliox inhalation — 70/30 or 80/20 mixture of helium and oxygen, which reduces airflow turbulence through the narrow airway
• Dexamethasone — 4-8 mg intravenously or intramuscularly every 8 hours to reduce inflammatory or post-traumatic laryngeal edema
• L-adrenaline (nebulized, 2.5-5 mL of 1:1000 solution for induction of rapid mucosal vasoconstriction).