One of the more frightening events in anesthesia is laryngospasm – the protective, reflex, spasmodic closure of the vocal cords that occurs when the vocal cords are stimulated. When laryngospasm occurs, vocal cord closure can be so forceful that it can prevent all ventilation or even the passage of the endotracheal tube. Life-threatening hypoxia can quickly follow. Other potential complications include post obstructive pulmonary edema, and possibly even cardiac arrest. This post discusses the different muscle actions that combine to make laryngospasm create dangerous airway obstruction.