Revisiting the Nasopharyngeal Airway (NPA): The Next-Level NPA

The purpose of this research and development project is to respond to the Defense Health Agency’s (DHAs) call to enhance the effectiveness of the nasopharyngeal airway (NPA). The NPA is an airway adjunct that is designed to be inserted into the pharynx via the nasal passageway to open a patient’s airway that has collapsed due to deep sedation or coma. The NPA, which has remained largely unchanged since its inception in 1881, has been considered an essential part of hospital and prehospital emergency care kits since at least the 1970s. However, despite the NPA’s history and wide distribution, it is not universally effective in relieving airway upper obstruction. Currently, the NPA is a top-tier device within Tactical Combat Casualty Care (TCCC) guidelines as a means for medics to open an obstructed airway. However, data from the Department of Defense Trauma Registry (DODTR) suggests that NPA’s are underutilized in the field. Since the rate of NPA usage is very close to that of cricothyroidotomy rates, the data suggests that some cricothyroidotomies may have been performed unnecessarily due to a lack of confidence in the NPA or simply overt NPA failure.  Upper airway patency depends on an appropriate balance between structural components, the dilating force of the pharyngeal muscles, and the collapsing force of negative intraluminal pressure in the airway caused by inspiratory airflow. The neuromuscular activity of upper airway stabilizing muscles are greatly diminished during sleep, sedation, and altered states of consciousness such as the lethargy and coma that can be associated with shock, brain injury, and severe metabolic disturbances. Airflow during inhalation further contributes to airway narrowing by dropping the pressure within the collapsible segment of the upper airway. A properly sized standard NPA will pass below the soft palate with the tip residing approximately 1 cm above the epiglottis. This position will provide relief of obstruction at the soft palate level if the distal tip or the lumen of the NPA does not become obstructed with tissue or secretions. However, the effectiveness of the NPA in reliably relieving obstruction at the level of tongue base and epiglottis (lower levels of the upper airway) is not fully understood.  Although the simplicity and ease of use of the NPA is ideally suited for the relief of airway obstruction in austere settings, this 140-year-old technology does not fully address the complexity of upper airway obstruction and is in desperate need of an innovative overhaul.   Olifant medical proposes to develop a novel and more effective NPA founded upon the contemporary understanding of dynamic upper airway collapse and by utilizing modern manufacturing and engineering methods.