What is the initial assessment and management of a patient presenting with stridor?

Initial Assessment and Management of Stridor

Immediate Recognition and Stabilization

Stridor indicates at least 50% airway narrowing and represents imminent complete obstruction requiring immediate systematic intervention. 1

Critical Initial Actions

• Assess severity immediately by looking for use of accessory muscles, tracheal tug, sternal/subcostal/intercostal retractions, agitation, or cyanosis—these signs indicate critical airway compromise 1
• Apply high-flow humidified oxygen to the face immediately while determining the underlying cause 1
• Position the patient upright with elevation of the chin and mandibular traction to optimize airway patency 1, 2
• Call for help early if any signs of respiratory difficulty are present—this includes personnel with advanced airway skills (anesthesiologists) and ENT surgeons 3, 1
• Apply waveform capnography immediately if available, as this is a key intervention to improve airway management safety 1
• Monitor with pulse oximetry, though recognize this monitors oxygenation, not ventilation 3

Warning Signs of Severe Obstruction

• Oxygen saturation <90% 2
• Bradycardia or heart rate changes 2
• Inability to speak or drink 2
• Agitation or restlessness (may indicate worsening obstruction) 3
• Paradoxically, signs may become absent as obstruction worsens 3

Immediate Pharmacologic Management

For Acute Inflammatory Stridor

• Administer nebulized epinephrine 1 mg immediately for symptomatic relief of laryngeal edema in severe cases, though effect is transient (1-2 hours) 1, 2
• Administer dexamethasone intravenously for anti-inflammatory effect in all cases of acute stridor 2
• For post-extubation stridor specifically, use nebulized epinephrine while steroids take effect 1

Critical Caveat: ACE Inhibitor-Induced Angioedema

• Do NOT use epinephrine, antihistamines, or corticosteroids for bradykinin-mediated angioedema (ACE inhibitor-induced)—these will not work 4
• This requires specific treatment with C1 inhibitor concentrate, icatibant, or tranexamic acid 4
• Swelling can continue for at least 6 weeks after drug discontinuation 4

Diagnostic Evaluation While Stabilizing

History (Brief and Focused)

• Time of onset and potential triggers 3
• Previous episodes or intubations 3
• Current medications, especially ACE inhibitors 4
• Trauma history (indicates progressive edema that will worsen, not resolve) 1
• Recent extubation or surgery 1

Physical Examination Priorities

• Determine if stridor is inspiratory, expiratory, or biphasic—biphasic suggests glottic or subglottic lesion 2
• Rule out upper airway obstruction from foreign body, epiglottitis, or vocal cord dysfunction (clues: dysphonia, inspiratory stridor, monophonic wheezing loudest over central airway) 3
• Look for associated findings: drooling, inability to swallow, fever, voice changes 3
• In children 6 months to 5-6 years, look for croup signs: barking cough, hoarse voice 2

Diagnostic Procedures

• Perform flexible fiberoptic laryngoscopy when stridor persists or is severe—this is the diagnostic procedure of choice for examining laryngeal structure and function 1, 2
• Inspect both upper and lower airways, as anomalies below the epiglottis occur in up to 68% of cases 1
• Do NOT order routine imaging in typical presentations, as this delays treatment 2
• Do NOT use videolaryngoscopy if there is upper airway tumor with stridor—consider alternative difficult airway techniques 1

Context-Specific Management Algorithms

Post-Extubation Stridor

1. Nebulized epinephrine 1 mg immediately 1
2. Continue steroids if already started 1
3. Prepare for reintubation with videolaryngoscopy as first line and neck access equipment ready—approximately 15% require reintubation 1, 2
4. Note: Steroids are primarily preventive with limited benefit for established post-extubation stridor 1

Post-Trauma or Progressive Edema

1. Recognize that stridor after trauma indicates progressive edema that will worsen, not resolve 1, 2
2. Administer inhaled racemic epinephrine immediately to temporarily reduce edema 1
3. Transfer to controlled environment with most experienced operator available 1
4. Note: Steroids reduce inflammatory edema from direct injury (surgical, anesthetic, thermal, chemical) but have NO effect on mechanical edema from venous obstruction (e.g., cervical hematoma) 1

Post-Thyroidectomy Hematoma

• Use SCOOP approach at bedside immediately—do not wait for operating room: Skin exposure, Cutting sutures, Opening skin, Opening muscles (strap muscles), Packing wound 1

Anaphylaxis with Laryngeal Edema

• When lingual edema, stridor, hoarseness, or oropharyngeal swelling are present, plan for advanced airway management including surgical airway 4
• Death from food-induced anaphylaxis typically occurs within 30 minutes to 2 hours from cardiorespiratory compromise 4

Preventive Protocol for High-Risk Extubations

• Perform cuff leak test before extubation in any patient with at least one risk factor for laryngeal edema 1
• If leak volume is low or nil, prescribe corticosteroids (prednisolone 1 mg/kg/day or equivalent to 100 mg hydrocortisone every 6 hours, or dexamethasone 8 mg every 8 hours) 1
• Start at least 6-12 hours before extubation with fractionated doses, continued for at least 12 hours 1
• Single dose immediately before extubation is ineffective 1

Common Pitfalls to Avoid

• Never ignore an agitated patient complaining of difficulty breathing, even if objective signs are absent 3
• Do not attempt awake intubation in an angulated patient with evolving airway obstruction—this worsens obstruction 2
• Do not perform blind digital sweeps in suspected foreign body aspiration—this can push objects deeper 2
• Do not use excessive positive pressure ventilation immediately post-intubation, as this can cause hemodynamic collapse 1
• Do not assume steroids work for mechanical obstruction (hematoma, tumor)—these require different interventions 1
• Ensure adequate steroid dosing (equivalent to 100 mg hydrocortisone every 6 hours)—underdosing reduces efficacy 1

Adjunctive Supportive Measures

• Maintain head of bed elevated to 35 degrees to reduce airway inflammation 1
• Avoid unnecessary positive fluid balances that worsen edema 1
• Consider heliox for severe obstruction, though it limits FiO2 1
• Keep patient calm—anxiety increases work of breathing 3
• Keep patient NPO as laryngeal competence may be impaired despite full consciousness 3