II. Definitions
- Vocal Cord Dysfunction
- Inappropriate vocal cord motion transiently obstructs airway
- Vocal Cords remain in adduction despite inspiration
III. Epidemiology
- Peak age 30-40 years
- Gender: Female predominance (2-3 fold more than males)
IV. Pathophysiology
- Inducible Laryngeal Obstruction
- Paradoxical vocal cord closure (e.g. during inspiration) resulting in impaired respiration and altered voice
V. Symptoms
VI. Signs
- View patient obtained video if available as exam is typically normal outside of episodes
- Sudden onset of severe Dyspnea without associated Hypoxia, Tachypnea or increased work of breathing
- Inspiratory Stridor
VII. Causes: Precipitating factors of Vocal Cord Dysfunction
- Exercise
- Psychiatric conditions
- Common in adolescents, but anxiety may also be triggered related to the unsettling nature of this condition
- Anxiety Disorder (e.g. Panic Attack, Generalized Anxiety Disorder, PTSD, Performance Anxiety)
- Major Depression
- Obsessive Compulsive Disorder
- Environmental Irritants (airborne)
- Ammonia and other cleaning chemicals
- Dust
- Smoke
- Fumes
-
Sinusitis or recent Upper Respiratory Infection
- Consider nasal steroid trial (e.g. Flonase)
- Consider Antibiotic course
-
Gastroesophageal Reflux disease
- Proton Pump Inhibitors are variably effective in improving Vocal Cord Dysfunction even when GERD is primary trigger
-
Extrapyramidal Side Effects
- Focal Dystonic Reaction to Neuroleptic drugs (Antipsychotics)
VIII. Associated Conditions
- Asthma (25-30% of cases)
- Gastroesophageal Reflux
- Anxiety Disorder
IX. Imaging
-
Chest XRay
- Evaluate differential diagnosis (upper chest mass resulting in compression)
- Lateral Neck XRay
- Consider for evaluation of the epiglottis in the acute setting
X. Diagnostics
-
Pulmonary Function Test (PFT)
- Flow volume loop shows flattened inspiratory portion of the curve
- FEF50/FIF50 >1
- Where FEF50 is Expiratory Flow at 50% of Forced Vital Capacity (FVC)
- Where FIF50 is Inspiratory Flow at 50% of Forced Vital Capacity (FVC)
- Consider Methacholine Challenge
- Evaluate for Asthma in differential diagnoses
-
Nasolaryngoscopy (flexible Laryngoscopy)
- Diagnostic with direct visualization of the cords
- Directly observe abnormal vocal cord movement to the midline on inspiration or expiration
- Provocative maneuvers performed under direct visualization improve Test Sensitivity
- Panting
- Exercise
- Deep breathing
- Phonating
XI. Differential Diagnosis
- See Stridor
- Asthma (most common)
- Hypothyroidism
- Acute upper airway conditions
- Chronic airway structural conditions
- Laryngomalacia (adults)
- Subglottic Stenosis or Tracheal stenosis
- Tracheal Mass
- Vocal cord specific disorders
- Vocal Cord Paralysis
- Vocal Cord Polyp and other vocal cord neoplasm
- Other neurologic conditions
- Amyotrophic Lateral Sclerosis
- Vagus Nerve Injury
- Recurrent Laryngeal Nerve Injury
XII. Management: Emergency Department evaluation of undifferentiated Stridor
- See Awake Nasotracheal Intubation
- Maintain airway and consider differential diagnosis
- Ready all airway management equipment (RSI, intubation, failed airway)
- Evaluate and manage acute Asthma
XIII. Management: Short-Term symptomatic relief
- Remember that patients do not have volitional control over airway obstruction
- Be prepared for Advanced Airway and failed airway measures if case Stridor cause is not functional
- Maneuvers that help relieve acute symptoms
- Panting
- Diaphragmatic breathing
- Nasal breathing
- Breathing through a short straw
- Pursed-lip breathing
- Make hissing sound during expiration
- "Rescue Breaths" Technique
- Other measures: Severe or persistent symptoms
- Epinephrine neb (5 ml of 1 mg/ml, 1:000 Epinephrine)
- Ipratropium Bromide (Atrovent) Inhaler
- Heliox
- Anxiolysis with Benzodiazepine (e.g. 1 mg Ativan)
- Ketamine
- Not studied, but has been used anecdotally with good success in acute severe Stridor
- Paradoxical Vocal Cord Dysfunction episodes often resolves (anecdotally) with Ketamine
- Ketamine may uncommonly cause laryngospasm (be ready with paralytics and Advanced Airway)
- Braude et al in Herbert (2015) EM Rap 15(2): 3-4
XIV. Management: Long-Term elimination of underlying causes
- Treat causes above
- Consider Sinusitis Management (e.g. nasal steroid, Antibiotic)
- Consider GERD management (e.g. Proton Pump Inhibitor)
- Eliminate airborne irritants
- Review possible medication triggers (e.g. Antipsychotic Medications)
- Manage Asthma
- Speech therapy
- Therapeutic breathing Exercises including relaxed throat breathing
- Vocal cord Relaxation Techniques
- Otolaryngology Consultation
- Consider Botox Injection for Spasmodic Dysphonia