Nasopharyngeal Airways for Airway Management

With proper airway management we can ensure that the airway is open and clear for air to enter the lunges. This is important for a person’s respiration. Airway management also allows adequate ventilation and oxygenation. Without airway management, a compromised airway (for example the tongue restricts or blocks air passageway) can quickly lead to hypoxia and life-threatening conditions.

One of the most common medical devices used in airway management is a nasopharyngeal airway (NPA). It is a soft, flexible tube inserted through the nose into the posterior pharynx to maintain an open airway. For instance, if the tongue or soft palate collapse and block the airway in the oropharynx, the nasopharyngeal airway acts as a "stent" to keep the airway open, preventing this collapse. The NPA physically holds the airway open by ensuring soft tissue doesn't block the passage of air through the pharynx.

How to Insert a Nasopharyngeal Airway

1) Determine the Size of Nasopharyngeal Airway Used

If asked how do you size a nasopharyngeal airway, you can provide the steps below as your answer.

A. Determine the Diameter

Sizing by patient’s nostril size: The external diameter of the NPA should match the diameter of the patient’s nostril. A good starting point is to compare the NPA's external diameter to the size of the patient’s little finger or nostril.

Typical sizes: NPAs are measured in millimeters (mm) of internal diameter or in French (Fr) units. Common sizes are:

I. Adults: 6-9 mm internal diameter (approximately 28-34 Fr)

II. Pediatrics: 12-24 Fr (smaller internal diameter for younger children)

B. Determine the Length

The correct length of the NPA should ensure that it reaches from the patient’s nostril to just above the epiglottis without causing trauma.

Measure the length of the NPA from the tip of the patient’s nostril to the earlobe or the angle of the jaw.

Alternatively, some clinicians measure from the tip of the nostril to the tragus of the ear.

2) Position the Patient

Conscious patient: Position the patient in a supine or semi-upright position with the head in a neutral or slightly extended position.

Unconscious patient: If no spinal injury is suspected, the head can be tilted back using the head tilt-chin lift maneuver. If there is concern for cervical spine injury, perform a jaw thrust without moving the neck.

3) Inserting the Nasopharyngeal Airway

I. Use a water-based lubricant to reduce friction and make insertion easier. Avoid oil-based lubricants as they can damage tissues and the NPA.

II. Hold the NPA: Grasp the tube near the flange with the bevel (the angled tip) facing toward the nasal septum.

III. Insert the NPA into the nostril

A. Gently insert the lubricated NPA into one of the patient’s nostrils.

B. Angle the tube toward the floor of the nose (parallel to the hard palate), avoiding pushing it upward, which could cause trauma to the nasal mucosa.

C. Advance the NPA slowly: Gently guide it through the nasal passage. If resistance is met, try to reposition slightly or switch to the other nostril.

D. Continue to insert until the flange (the wider part at the top) rests against the nostril.

4) Assess Placement

Check for proper ventilation: You should be able to feel or hear air movement through the NPA and see chest rise if the patient is breathing.

Monitor for distress: Ensure the patient is not gagging, coughing excessively, or showing signs of discomfort.

We have explained airway management and how a nasopharyngeal airway is used for airway management. Let’s go back to history of airway management so that we have some background information about airway management to become more knowledgeable.

History of Airway Management

Ancient Times

Early Intubation Attempts (1500 BCE): The earliest known attempts at airway management were likely during ancient Egyptian times, when healers performed tracheostomies. Evidence exists from ancient Egyptian and Greek texts describing techniques to open the airway surgically.

18th Century

Scientific Inquiry (1543-1628): Renaissance physicians such as Andreas Vesalius, known as the father of modern anatomy, first described performing a tracheotomy on a pig and suggested its application to human airways.

Chevalier Jackson (Late 18th Century): Known for advancing the tracheotomy technique, Chevalier Jackson published work on airway management in the 18th century, leading to more widespread use.

19th Century

Introduction of Anesthesia (1846): The development of anesthesia marked a major turning point in airway management. During surgeries, physicians realized the need to maintain open airways, as anesthesia could suppress spontaneous breathing.

Invention of Endotracheal Tube (1878): Friedrich Trendelenburg performed one of the first successful endotracheal intubations using a rubber tube to protect the lungs from blood during surgery.

Early 20th Century

Introduction of Laryngoscope (1913): Sir Robert Macintosh and Sir Ivan Magill pioneered the development of modern laryngoscopy. This device helped physicians visualize the vocal cords for accurate tube placement.

World War I Advances: The widespread use of general anesthesia during surgery accelerated developments in airway management, including improvements in equipment and techniques for securing airways.

Mid-20th Century

Standardization of Techniques and Equipment (1940s-1960s): After World War II, endotracheal intubation became more standardized. Reusable and disposable equipment, such as improved laryngoscopes, endotracheal tubes, and ventilators, became more common.

Mechanical Ventilation (1950s): The polio epidemic led to the development of mechanical ventilation systems, such as the "iron lung," which paved the way for modern ventilators. This, in turn, increased the importance of airway management.

Late 20th Century to Present

Fiberoptic Intubation (1967): The invention of the flexible fiberoptic bronchoscope allowed physicians to perform more difficult intubations, particularly in cases where the anatomy is challenging or distorted.

Video Laryngoscopy (2000s): Video laryngoscopes, which project the airway onto a screen, have become widely used, especially in difficult airway management scenarios.

Supraglottic Airway Devices (1980s-present): Devices like the laryngeal mask airway (LMA) introduced non-invasive ways to secure airways without requiring endotracheal intubation, reducing complications in certain settings.

Modern Day

Airway Management Algorithms: Today, standardized protocols and algorithms (such as the American Society of Anesthesiologists’ difficult airway algorithm) are in place to guide clinicians in managing airways in a variety of settings.

Simulation and Training: High-fidelity simulation technology has improved the training of clinicians in airway management, allowing them to practice rare and difficult scenarios in controlled environments.