laryngospasm

Laryngospasm is a sudden, involuntary spasm of the laryngeal muscles that causes narrowing or closure of the vocal cords, resulting in partial or complete upper airway obstruction. It most often occurs in the perioperative period, especially during induction or emergence from anesthesia or after extubation, but can also arise from laryngeal irritation in awake individuals with airway disease. It is more common in children, who have a reactive airway and smaller airways, but can occur in adults as well.

Causes and risk factors include airway irritation from secretions, blood, or gastric reflux; inadequate depth of anesthesia; airway manipulation; recent upper respiratory infection; reactive airway disease or laryngomalacia in infants; and postoperative swelling or trauma. Distinguishing laryngospasm from other causes of airway obstruction such as epiglottitis or bronchospasm is important but can be challenging in acute settings.

Clinical features range from audible stridor and increased work of breathing to silent chest with little or no air entry during inspiration. Hypoxemia can develop quickly, leading to cyanosis, agitation or lethargy, and in children, bradycardia or cardiac arrest if not promptly relieved.

Management requires immediate intervention. Primary steps include removing triggering stimuli, ensuring a patent airway, providing 100% oxygen, and applying a jaw thrust with ongoing mask ventilation and continuous positive airway pressure. Deepen anesthesia with inhalational agents or intravenous propofol if feasible. Consider suctioning secretions and administering a local anesthetic such as lidocaine to suppress reflexes. If laryngospasm persists despite these measures, administer a muscle relaxant (for example, suxamethonium 0.5 mg/kg IV, or 2 mg/kg IM if IV access is unavailable) to achieve rapid relaxation of the laryngeal muscles. Reassess ventilation and be prepared to reintubate if necessary.

Prevention focuses on careful airway management around extubation, adequate anesthesia depth, and techniques to minimize airway irritation. With prompt recognition and treatment, prognosis is typically favorable, though prolonged obstruction can cause serious hypoxemia and complications.