Written by: Sarah Harris-Gendron, MD, MSW (NUEM ‘29) Edited by: Cody Ellis, MD (NUEM ‘27)
Expert Commentary by: Gentry Wilkerson, MD
Overview
Inducible laryngeal obstruction (ILO), also known as paradoxical vocal fold motion, is a functional and reversible narrowing of the larynx triggered by various stimuli.
Normally, the vocal folds abduct during inspiration and partially adduct during expiration, speech, or coughing. In ILO, the vocal folds paradoxically adduct during inspiration, expiration, or both, causing airflow limitation without structural obstruction.
Common triggers include:
Asthma
Exercise (exercise-induced laryngeal obstruction)
Post-extubation states
Inhaled irritants
Laryngopharyngeal reflux
Neurologic injury
Psychosocial stress or anxiety
Clinical Presentation
Patients often present with acute stridor and respiratory distress, which can appear severe but is typically benign and reversible.
Key symptoms:
Dyspnea
Stridor
Dysphagia
Dysphonia
Sensation of throat tightness
Feeling of choking
Respiratory distress
Distinguishing features:
Oxygen saturation is usually normal
No wheezing (unlike asthma)
Does not respond to albuterol
Why Recognition Matters
ILO closely mimics conditions such as:
Asthma exacerbations
Anaphylaxis
Misdiagnosis can lead to:
Unnecessary epinephrine or steroids
Repeated ineffective therapies
Inappropriate intubation or surgical airway interventions
Therefore, prompt recognition in the ED can prevent avoidable morbidity.
Diagnostic Evaluation in the ED
Gold Standard
Laryngoscopy - Looking for paradoxical adduction of the vocal cords
Additional Evaluation
CT of the upper airway to exclude structural causes of dyspnea
Acute Management in the ED
Evidence for acute therapy is limited; most treatment focuses on long-term prevention.
However, several strategies can help abort or improve an acute episode:
Non-pharmacologic
Reassurance — there is no structural abnormality
Supportive care – O₂ as needed
Breathing maneuvers:
Panting
Pursed-lip breathing
Aim: activate the posterior cricoarytenoid muscle → abduct vocal folds
Pharmacologic
Benzodiazepines
Reduce anxiety
Risk: respiratory depression
Ketamine (dissociative dosing)
Maintains respiratory drive
Risk: laryngospasm at higher doses
Nebulized or topical lidocaine
Interrupts hyperactive glottic/supraglottic contraction patterns
Airway Support
Positive airway pressure (CPAP/BiPAP)
Heliox to reduce inspiratory turbulence (short-term benefit)
Intubation Considerations
Intubation should be a last resort and reserved only for unstable patients
Patients with ILO are difficult to extubate
Many who are intubated require tracheostomy and prolonged ICU care
If intubation is unavoidable:
Anticipate a difficult airway
Prepare for cricothyrotomy as backup
Disposition
Disposition can be challenging, particularly for patients with ongoing stridor.
Discharge is reasonable when:
Diagnosis of ILO is confirmed
Vital signs are stable
Symptoms have improved (or are manageable)
Follow-up is reliable
Admit for further evaluation if:
Diagnostic uncertainty exists
No continuity of care can be ensured
Vital signs are unstable
Significant anxiety or social barriers are present
Long-Term Management
Avoidance of known triggers
Multidisciplinary care
Speech-language pathology is the cornerstone:
Breathing retraining
Relaxation techniques
Prevention of recurrent episodes
Summary
ILO is a functional disorder marked by paradoxical vocal fold motion, often triggered by environmental, physiologic, or psychological factors.
It presents with sudden stridor and respiratory distress but is benign and reversible.
Correct identification is essential to prevent unnecessary interventions such as steroids, epinephrine, or intubation.
ED management emphasizes reassurance, supportive care, targeted pharmacologic therapy, and avoidance of aggressive airway procedures unless absolutely necessary.
Expert Commentary
As emergency physicians, we are professionally obligated to worry about the airway. It is practically in the job description, somewhere between “drink coffee” and “wear your bike helmet.” When a patient arrives in respiratory distress with dramatic stridulous noises, it can be hard not to reach for the laryngoscope and secure the airway.
But patients with inducible laryngeal obstruction (ILO), the preferred term for what many of us learned as vocal cord dysfunction, may be intubated unnecessarily if we do not recognize the pattern. Clues include loud inspiratory stridor over the neck, normal or near-normal oxygen saturation, preserved phonation, minimal hypercapnia, rapid episodic improvement, and a disappointing lack of response to albuterol.
Definitive diagnosis requires flexible fiberoptic laryngoscopy while the patient is symptomatic, which may show inspiratory adduction of the vocal folds, sometimes with a posterior diamond-shaped glottic opening or supraglottic collapse. In the ED, though, ILO is often a working diagnosis made after excluding the scary stuff: anaphylaxis, angioedema, epiglottitis, foreign body, and severe asthma.
Treatment is mostly the opposite of our usual airway reflexes: stay calm, reassure the patient, coach relaxed breathing, and treat any coexisting triggers. Anxiolysis or heliox may help selected patients. The laryngoscope can usually stay in its holster.
References
Denipah N, Dominguez CM, Kraai EP, Kraai TL, Leos P, Braude D. Acute Management of Paradoxical Vocal Fold Motion (Vocal Cord Dysfunction). Annals of Emergency Medicine. 2017;69(1):p18-23.
Dowdall J, Thompson C. Inducible laryngeal obstruction (paradoxical vocal fold motion). UpToDate. Updated June 26, 2024. Accessed November 18, 2025.
WikEM. Accessed November 18, 2025. https://wikem.org/wiki/Paradoxical_vocal_fold_motion
Farkas J. Vocal cord dysfunction (VCD). Internet Book of Critical Care (IBCC). Updated June 22, 2020. Accessed November 18, 2025. https://emcrit.org/ibcc/vcd/#acute_evaluation_%E2%80%93_diagnostics_&_approach
Buddiga P; Kaliner MA, editor. Vocal cord dysfunction: Treatment & management. Medscape. Updated June 24, 2024. Accessed November 18, 2025. https://emedicine.medscape.com/article/137782-treatment?lang=en&icd=login_success_email_match_fpf#d8
Dr. Gentry Wilkerson, MD
Emergency Medicine, University of Maryland
Associate Professor, University of Maryland School of Medicine, Department of Emergency Medicine
How To Cite This Post:
[Peer-Reviewed, Web Publication] Harris-Gendron, S. Ellis, C. (2026, July 19). Inducible Laryngeal Obstruction [NUEM Blog. Expert Commentary by Wilkerson, Gentry]. Retrieved from http://www.nuemblog.com/blog/.
