Laryngospasm

Learning objectives

Laryngospasm is the sustained closure of the vocal cords resulting in partial or complete loss of the airway
Primitive protective airway reflex to prevent tracheobronchial aspiration after an offending stimulus
Problematic prolongation of this initial reflex can occur under general anesthesia, often during intubation or extubation
Can rapidly result in hypoxemia and bradycardia
Overall incidence ~1%
Incidence up to 25% in patients undergoing tonsillectomy and adenoidectomy

Respiratory stridor
Paradoxical respiratory movements
Suprasternal and supraclavicular retractions
Rapidly decreasing oxygen saturation
Excessive chest movements but no movement of the reservoir bag and no capnogram reading
Bradycardia
Negative pressure pulmonary edema
Cardiac arrest
Pulmonary aspiration
Arrhythmias

Patient-related	Surgery-related	Anesthesia-related
Obesity	Nasal, oral or pharyngeal surgeries (adenoidectomy and tonsillectomy)	Laryngeal mask/Guedel airway device
Young age	Gastrointestinal endoscopy	Extubation
Active and passive smoking	Bronchoscopy	Suction catheter
ASA IV	Appendectomy	Light anesthesia plan
Gastroesophageal reflux	Anal or cervical dilatation	Blood/secretions in the airway
Obstructive sleep apnea	Mediastinoscopy	Regurgitation
Upper airway infection	Inferior urologic surgery	Desflurane
Hypocalcemia	Skin transplant	Ketamine and thiopental induction
Asthma	Nociception	Nasogastric tube
Difficult airway	Surgical stimulus	Inexperience of anesthesiologist
	Movement	Failed intubation
	Recurrent laryngeal nerve damage	Laryngoscopy
	Esophageal stimulation
	Iatrogrnic removal of parathyroid glands

Anesthetic technique
- Ensure adequate depth
- Inhalation induction with non-irritant agent (e.g., sevoflurane)
- IV induction with propofol is less problematic
- Extubate either in a deep plane of anesthesia or fully awake, but not in-between
  - “Deep” extubation: Suction the airway and place the patient in a lateral position
  - Awake extubation: Once facial grimacing, adequate tidal volume, a regular respiratory pattern, coughing, and preferably eye opening have returned, use “no touch” technique: Pharyngeal suctioning and lateral positioning while anesthetized, followed by avoidance of any stimulation until eye opening when extubation is performed
  - Extubation during forced positive pressure inflation decreases laryngeal adductor excitability, decreasing the risk of laryngospasm
Pharmacological prevention
- Magnesium 15 mg/kg IV intraoperatively
- Lidocaine topically 4 mg/kg or IV 1.5-2 mg/kg (further research needed)