Chapter 36: Laryngeal Trauma

INTRODUCTION

General Considerations

The larynx has 3 significant functions: respiration, phonation, and airway protection during swallow. Given the importance of these actions, injury to the larynx can be disastrous. Though laryngeal trauma is relatively infrequent (an incidence of approximately 1/137,000), it is an important entity for physicians to understand because incorrect management can quickly lead to considerable morbidity and potential mortality (1). Protocols for evaluation and management of these traumas have been standardized in order to improve patient outcomes. Early diagnosis and proper treatment are essential to preserve a functional larynx.

A. External Laryngeal Trauma

There are many potential mechanisms for external laryngeal trauma. Motor vehicle accidents and direct impact from an object (sports injuries or interpersonal assaults) are the most common causes. A less common cause of blunt laryngotracheal trauma is strangulation. Clothesline injuries may also occur; though this is rare, it is significant as bilateral true vocal fold (VF) paralysis or even laryngotracheal separation may result.

Despite the dangers listed above, laryngeal trauma is rather infrequent due to inherent anatomic protections. Both the low position of the mandible and the high location of the sternum allow only a small portion of the airway to be exposed and therefore susceptible to trauma. Laterally, thick musculature protects the larynx and trachea. If a traumatic blow is directed posteriorly, the spinal column will bear the brunt of the injury before the airway is affected.

Pediatric laryngotracheal injuries deserve special mention, as the anatomy differs from that of adults and therefore carries different risks. Pediatric laryngeal cartilage is more pliable and less likely to fracture than that of adults because adults often have cartilaginous calcification. Also, the larynx has a particularly high position in the neck in children when compared to adults, increasing the shielding of the airway by the mandible. Despite these advantageous features, it is important to keep in mind that the decreased size of the pediatric airway can make these injuries more dangerous. Minor edema can create proportionally greater obstruction given the smaller circumference of the pediatric larynx and trachea. Additionally, laryngeal injuries may mimic more common and less dangerous pediatric respiratory issues (such as croup) and this may delay appropriate management. Birth trauma can also be a cause of pediatric laryngeal injury but this may have subtle differences from congenital VF paralysis.