What is the emergency management of stridor in an adult?

Emergency Management of Stridor in Adults

In an adult presenting with stridor, immediately assess airway patency and prepare for emergency front-of-neck airway (FONA) while simultaneously securing the airway using rapid sequence intubation (RSI) in the semi-Fowler position with preoxygenation, or proceed directly to scalpel cricothyroidotomy if a "can't intubate, can't oxygenate" (CICO) situation develops. 1

Immediate Assessment and Preparation

Critical First Steps

• Position the patient semi-upright (semi-Fowler position) to optimize oxygenation and first-pass intubation success 1
• Administer high-flow humidified oxygen immediately 1
• Call for help early - assemble the airway team including an expert operator and notify the emergency airway team in advance for possible surgical airway 2
• Get the FONA set to the bedside after recognizing stridor as a potential airway emergency 1

Recognize the Severity

Stridor indicates critical upper airway obstruction at the laryngeal or tracheal level and represents a vital emergency 3. Warning signs of impending complete obstruction include:

• Progressive respiratory distress with increased work of breathing 1
• Agitation (indicating hypoxemia) 1
• Inability to speak or worsening voice changes 1
• Desaturation despite supplemental oxygen 1

Airway Management Algorithm

Plan A: Rapid Sequence Intubation (if time permits)

Preoxygenation Strategy:

• Use high-flow nasal oxygen (HFNO) when laryngoscopy is expected to be challenging 1
• Use non-invasive positive pressure ventilation (NIPPV) if severe hypoxemia (PaO2/FiO2 < 150) is present 1
• Continue apneic oxygenation during intubation attempts 1

RSI Technique:

• Administer sedative-hypnotic agent and neuromuscular blocking agent (NMBA) in rapid succession 1
• In shock states, consider ketamine (1-2 mg/kg) as it provides vasopressor effects 1
• Limit to ONE intubation attempt by the most experienced operator available 1
• Use video laryngoscopy if available 1
• Confirm placement with waveform capnography 1

Plan B: Supraglottic Airway (SGA) if Intubation Fails

After one failed intubation attempt:

• Open the FONA set immediately 1
• Insert a second-generation SGA (e.g., ProSeal LMA, i-gel) for rescue oxygenation 1
• Ensure adequate neuromuscular blockade to optimize conditions 1
• Confirm ventilation with capnography waveform 1
• Maximum of three attempts at SGA placement with changes to size, type, and operator 1

If SGA successful:

• Consider single attempt at fiberoptic-guided intubation through the SGA using an Aintree Intubation Catheter for a 7.0 mm tube 1
• Do not delay FONA if oxygenation deteriorates 1

Plan C: Front-of-Neck Airway (FONA) - The Definitive Rescue

Indications for immediate FONA:

• Failed intubation AND failed ventilation via SGA or facemask (CICO situation) 1
• Progressive hypoxemia despite rescue oxygenation attempts 1
• Complete upper airway obstruction with inability to ventilate 1

FONA Technique (Scalpel Cricothyroidotomy):

• Declare CICO explicitly to the team: "This is a can't intubate, can't oxygenate situation. We need to perform an emergency front of neck airway" 1
• Ensure adequate neuromuscular blockade 1
• Maximum neck extension 1
• Horizontal incision with wide scalpel blade (size 10 or 20) through the cricothyroid membrane if palpable 1
• If cricothyroid membrane impalpable: large vertical midline skin incision first 1
• Insert bougie as guide for 5.0-6.0 mm cuffed tracheal tube 1
• Confirm placement with waveform capnography 1
• Transition to FONA should occur within 60 seconds of declaring CICO 1

Critical Pitfalls to Avoid

Do not delay FONA due to procedural reluctance - this is a greater cause of morbidity than complications of the procedure itself 1. The 2018 British Journal of Anaesthesia guidelines emphasize that delayed transition to FONA results in avoidable harm 1.

Avoid transtracheal jet ventilation (TTJV) as the primary FONA technique - it has high failure rates, risk of barotrauma, and is poorly suited for critically ill patients with poor lung compliance 1.

Do not perform multiple intubation attempts - each attempt causes airway trauma, worsens edema, and increases mortality risk. Cardiac arrest occurs in 1 in 8 emergency intubations when four or more attempts are required 1.

Never rely solely on pulse oximetry - it does not monitor ventilation and can give false readings 1. Use waveform capnography as the definitive monitor 1.

Specific Etiologies Requiring Modified Approach

Anaphylaxis with Laryngeal Edema

• Early recognition of difficult airway is paramount with hoarseness, lingual edema, or oropharyngeal swelling 1
• Plan for surgical airway from the outset 1
• Administer IV epinephrine 0.05-0.1 mg (NOT the cardiac arrest dose) with close hemodynamic monitoring 1
• Aggressive fluid resuscitation with 1000 mL boluses of isotonic crystalloid 1

Paradoxical Vocal Fold Motion Disorder

• Consider this diagnosis in patients with stridor who do not respond to standard airway interventions 4, 5
• Transnasal laryngoscopy shows vocal cord narrowing on inspiration 5
• Management includes reassurance, heliox, and avoiding unnecessary intubation 4, 5
• However, do not delay definitive airway management if true obstruction is present 4

Post-Intubation Management

• Continue high-flow humidified oxygen 1
• Maintain semi-upright positioning 1
• Monitor with continuous waveform capnography 1
• Have difficult airway equipment immediately available 1
• Brief the on-call team with written airway management plan 1