How to manage laryngospasm preventing mask ventilation after induction?

Management of Laryngospasm Preventing Mask Ventilation After Induction

Immediately call for help, apply continuous positive airway pressure with 100% oxygen while performing jaw thrust, then proceed with Larson's manoeuvre, followed by propofol 1-2 mg/kg IV if laryngospasm persists, and ultimately suxamethonium 1 mg/kg IV if hypoxia worsens despite these measures. 1

Immediate Initial Steps

• Call for help immediately upon recognizing laryngospasm to ensure additional experienced personnel are available 1
• Apply continuous positive airway pressure (CPAP) with 100% oxygen using a reservoir bag and facemask while ensuring optimal head positioning (neck flexion with head extension) 1
• Avoid any unnecessary upper airway stimulation that could worsen the spasm 1
• Ensure adequate jaw thrust to maintain upper airway patency during CPAP application 1

Larson's Manoeuvre

If CPAP alone fails to break the laryngospasm:

• Place the middle finger of each hand in the "laryngospasm notch" located between the posterior border of the mandible and the mastoid process 1
• Apply deep pressure at this point while simultaneously displacing the mandible forward in a jaw thrust maneuver 1
• This technique has been confirmed effective through real-time imaging studies showing immediate vocal cord opening 2

Pharmacological Management - Escalating Approach

If Laryngospasm Persists and/or Oxygen Saturation is Falling:

Propofol Administration:

• Administer propofol 1-2 mg/kg intravenously 1
• Low doses may be effective in early laryngospasm, but larger doses are needed for severe laryngospasm or total cord closure 1
• Propofol deepens anesthesia and helps relax the vocal cords 1

If Severe Laryngospasm Continues with Worsening Hypoxia:

Suxamethonium (Succinylcholine) Administration:

• Administer suxamethonium 1 mg/kg intravenously immediately for continuing severe laryngospasm with total cord closure 1
• This dose provides cord relaxation, permitting ventilation, re-oxygenation, and intubation if necessary 1
• In the absence of IV access, suxamethonium can be administered via alternative routes 1:
  • Intramuscular: 2-4 mg/kg 1, 3
  • Intralingual: 2-4 mg/kg 1, 3
  • Intraosseous: 1 mg/kg 1

Additional Considerations

Ensure Full Neuromuscular Blockade:

• If suxamethonium was used at induction and laryngospasm persists despite optimal airway maneuvers, consider that inadequate muscle relaxation may be contributing 1
• The rocuronium/sugammadex combination is preferred if available for re-establishing neuromuscular blockade 1

Monitor for Bradycardia:

• Atropine may be required to treat bradycardia that can occur with suxamethonium administration 1

Prepare for Escalation:

• In extremis, consider a surgical airway if all other measures fail 1
• When a "can't intubate, can't oxygenate" situation is declared, call for specialist help including ENT surgeon and/or intensivist 1

Critical Pitfalls to Avoid

Do Not Delay Pharmacological Intervention:

• Complete laryngospasm presents with silent inspiration (no crowing sound), indicating total cord closure 1
• If unrelieved, laryngospasm can progress to post-obstructive pulmonary oedema, hypoxic cardiac arrest, and death 1
• The younger the patient, the shorter the time to critical desaturation 1

Recognize That Laryngospasm is Always Complete:

• Recent endoscopic studies confirm that laryngospasm, when it occurs, is always complete closure requiring active airway management and IV therapy 3

Consider Supraglottic Airway Device if Intubation Becomes Necessary:

• If mask ventilation remains impossible despite breaking the laryngospasm and intubation is required, a second-generation supraglottic airway device (SAD) with gastric drain tube is recommended 1
• Temporarily release cricoid pressure during SAD insertion as it impedes placement 1
• Limit SAD insertion attempts to a maximum of 2-3 to avoid trauma 1

Post-Event Monitoring:

• Monitor for post-obstructive pulmonary oedema which occurs in >50% of laryngospasm cases and presents with dyspnea, pink frothy sputum, and bilateral alveolar opacities on chest X-ray 1
• This complication occurs after 0.1% of all general anesthetics and typically resolves within hours with prompt management 1