How should laryngospasm be treated in an anesthetized, intubated patient?

Treatment of Laryngospasm in the Anesthetized, Intubated Patient

Critical Clarification

If the patient is truly intubated with a cuffed endotracheal tube in proper position, laryngospasm should not occur because the vocal cords are physically separated by the tube. This question likely refers to laryngospasm occurring during emergence/extubation or with a supraglottic airway device in place 1.

Immediate Management Algorithm

Step 1: Call for Help and Initial Assessment

• Immediately call for help as laryngospasm can progress to hypoxic cardiac arrest and death if not promptly managed 2.
• Recognize that laryngospasm presents with characteristic inspiratory 'crowing' sound, marked suprasternal recession ('tracheal tug'), use of accessory respiratory muscles, and paradoxical thoracoabdominal movements 2.
• Complete obstruction presents with silent inspiration 1.

Step 2: Apply Continuous Positive Airway Pressure

• Apply CPAP with 100% oxygen using a reservoir bag and facemask while ensuring the upper airway is patent 1, 2.
• Avoid unnecessary upper airway stimulation, as this can worsen or prolong the laryngospasm 2.
• This initial intervention resolves approximately 38% of pediatric laryngospasm cases 3.

Step 3: Larson's Manoeuvre

• Place the middle finger of each hand in the 'laryngospasm notch' between the posterior border of the mandible and the mastoid process 1.
• Simultaneously displace the mandible forward in a jaw thrust 1.
• Apply deep pressure at this point to help relieve laryngospasm 1.

Step 4: Pharmacological Intervention - Propofol

If laryngospasm persists and/or oxygen saturation is falling:

• Administer propofol 1-2 mg/kg intravenously 1, 2.
• Low doses may be effective in early laryngospasm, but larger doses are needed in severe laryngospasm or total cord closure 1.
• This represents deepening of anesthesia to break the reflex 3.

Step 5: Muscle Relaxation - Succinylcholine

If hypoxia worsens despite propofol:

• Administer succinylcholine 1 mg/kg intravenously 1, 2.
• This provides complete vocal cord relaxation, permitting ventilation, re-oxygenation, and intubation if necessary 1, 2.
• Approximately 48% of pediatric laryngospasm cases require muscle relaxants 3.

Step 6: Alternative Routes if No IV Access

• Intramuscular: 2-4 mg/kg 1, 2, 4
• Intralingual: 2-4 mg/kg 1, 2
• Intraosseous: 1 mg/kg 1, 2

Step 7: Adjunctive Management

• Administer atropine if bradycardia develops (particularly common in children <1 year, occurring in 23% of cases) 1, 5.
• In extremis, consider a surgical airway 1.

Critical Complications to Monitor

Post-Obstructive Pulmonary Edema

• Develops in approximately 4% of laryngospasm cases 2, 5.
• Results from negative intrathoracic pressure created by forceful inspiratory efforts against an obstructed airway 1.
• Presents with dyspnoea, agitation, cough, pink frothy sputum, and low oxygen saturations 2.
• Most commonly caused by laryngospasm (>50% of cases) 1.

Key Clinical Pitfalls

• Do not delay escalation of treatment if initial measures fail, as laryngospasm can progress rapidly to complete airway obstruction and hypoxic cardiac arrest 2.
• Do not assume vocal cords will spontaneously open before death occurs—this is a dangerous myth 1.
• Laryngospasm may present atypically: 14% present as simple airway obstruction, 5% as regurgitation/vomiting, and 4% as desaturation alone 5.
• Desaturation occurs in over 60% of cases, making prompt recognition and treatment essential 5.
• Approximately 24% of pediatric cases require reintubation 3.

Risk Factors for Recurrence

• Light plane of anesthesia during airway manipulation 1
• Secretions, blood, or surgical debris around the glottic area 1
• Upper respiratory infections 4
• Pediatric patients (incidence 17.4/1000 vs 8.7/1000 in general population) 3, 4
• Smokers 1