Laryngospasm

extremely rare, usually associated with anesthetic use and i.v. sedation. Not a smooth muscle phenomenon. Protective reflex to prevent substances from entering lower respiratory tract (bronchioles, lungs). Partial or complete adduction (closure toward midline) of vocal cords (voluntary/ skeletal muscle). Pt grasps throat; crowing sounds. With complete obstruction of airway, hypoxia, cyanosis (turns blue), cardiac death can occur.

Causes: irritation of vocal cords by blood, mucus, saliva, dental debris. Excessive parasympathetic activity (parasympathomimetics drugs). High concentrations of general anesthetics. This is one reason we use protective gauze barriers in extractions, to prevent blood and irritants from contacting the vocal cords; also we make sure the tongue is clear of the throat, and suction out the debris from the throat.

Prevention: Avoid parasympathomimetic drugs promoting excess mucus/saliva production. Avoid irritation of vocal cords by blood, mucus, tissue/dental debris.

Treatment/ Management: clear tongue, suction, aspirate blood, debris from oral cavity. Administer 100% oxygen. If spasm still persists (life threatening!) administer 10-20 mg succinylcholine (anesthesiologist! This is a neuromuscular blocker and is not within the domain of a general dentist). This “breaks” spasm by paralyzing the diaphragm and thoracic muscles. Administer oxygen (breathe for pt) tracheal intubation should not be attempted.

Category: Pharmacology Notes