How to Correctly Insert a Nasopharyngeal Airway (NPA)

A nasopharyngeal airway is a soft, flexible tube inserted through the nostril to hold open the passage between the nose and the back of the throat, keeping a partially or fully obstructed airway patent. Unlike its oral counterpart, it can be placed in patients who still have a gag reflex or whose jaw is clenched, which makes it one of the most practical basic airway tools in emergency and prehospital care. Getting it in safely, though, depends on choosing the right size, preparing the nostril, and understanding the anatomy the tube passes through.

The Anatomy You Are Working With

The nasal cavity is not a wide-open tunnel. It contains three shelf-like structures called turbinates that project inward from the lateral wall. Between the lowest of these shelves and the floor of the nasal cavity runs the inferior meatus, a relatively spacious channel that serves as the preferred pathway for nasal airway devices.¹ This is the route you are aiming for when you slide an NPA in. The floor of the nose is roughly horizontal, running straight back toward the nasopharynx. A common mistake is to angle the tube upward, as though pointing toward the bridge of the nose or the forehead. In reality, the insertion path tracks parallel to the hard palate, essentially along the floor of the nasal cavity, heading posteriorly toward the back of the throat.

At the far end, the tube tip sits in the nasopharynx, just above the epiglottis. That placement lifts the soft palate and tongue base away from the posterior pharyngeal wall, which is what restores airflow in someone whose airway has collapsed due to decreased consciousness, sedation, or obstructive anatomy.

Choosing the Right Size

An NPA that is too long can contact the epiglottis or vocal cords, triggering laryngospasm or gagging. One that is too short will not reach past the base of the tongue and will be useless. Two dimensions matter: length and diameter.

For length, the traditional bedside method is to measure from the tip of the nose to the earlobe on the same side. Research supports a closely related landmark: the distance from the naris to the tragus of the ear. In adults, a study comparing external facial measurements with fiberoptic confirmation of tip position found that the naris-to-tragus distance was the best predictor of optimal insertion depth.² In children under twelve, the naris-to-tragus distance minus about one centimeter correlated best with the actual distance to the epiglottis and vocal cords, performing better than the naris-to-mandible angle method sometimes taught in pediatric courses.³

For diameter, adult NPAs are typically sized in French units. Common adult sizes are 26 Fr (about 8.7 mm outer diameter), 30 Fr (about 10 mm), and 34 Fr (about 11.3 mm). A quick visual check is to hold the NPA up against the patient’s nostril: the outer diameter of the tube should be slightly smaller than the visible opening of the naris. If you have to force it in, it is too wide. Most average-sized adult women will take a 26 or 28 Fr, and most average-sized adult men a 28 or 30 Fr, but individual variation is wide enough that the nostril comparison is more reliable than a gender-based guess.

Preparing the Nostril and the Device

The nasal mucosa is richly vascular, which means even a well-placed NPA can cause bleeding if the tissue is not prepared. Two steps reduce that risk substantially: vasoconstriction and lubrication.

A topical vasoconstrictor narrows the blood vessels lining the nasal passages. In clinical settings, drops like 0.1% xylometazoline are applied to the chosen nostril before insertion.⁴ Oxymetazoline nasal spray works the same way and is more readily available in many emergency departments and first-aid kits. In the field, where these agents may not be on hand, generous lubrication alone becomes even more important.

Water-soluble lubricant should be applied liberally along the entire length of the NPA tube. Some protocols use 2% lidocaine jelly, which provides both lubrication and topical anesthesia, dulling the discomfort and reflex tearing that insertion can trigger.⁵ In an unconscious casualty in a prehospital setting, standard water-based lubricant (or even saline if nothing else is available) is acceptable; the priority is reducing friction against the mucosa.

Before applying lubricant, inspect the NPA itself. The device has three parts: a beveled tip at the distal end, the hollow cannula (the tube body), and a flange at the proximal end that rests against the nostril to prevent the device from migrating inward. Make sure the flange is secure and the bevel is intact and smooth with no rough edges.

Step-by-Step Insertion

With the device sized, lubricated, and the nostril prepared where possible, the actual insertion follows a straightforward sequence:

• Select the nostril: Use the right nostril when possible. Standard NPAs have a bevel that faces the left side when the tube is inserted in the right naris, which orients the opening of the tip toward the nasal septum and reduces the chance of snagging a turbinate. If you must use the left nostril, you can rotate the NPA 180 degrees so the bevel still faces the septum, then gently counter-rotate it into position once past the initial resistance. Either nostril is acceptable, but if one side is visibly deviated, swollen, or has a history of injury, choose the other.
• Position the patient: If there is no concern about spinal injury, a slight head-tilt and chin-lift helps open the airway during insertion. In trauma patients where cervical spine motion must be minimized, keep the head in a neutral position and use a jaw thrust instead.
• Insert along the floor: Hold the NPA like a pencil with the bevel facing the septum. Advance the tube directly posteriorly, perpendicular to the face, along the floor of the nasal cavity. The direction is straight back, not upward. Think of sliding the tube toward the back of the patient’s ear, not toward their forehead. Use gentle, steady pressure.
• Navigate past resistance: You will often feel a slight catch as the tube passes the posterior end of the inferior turbinate. A gentle rotation of the tube between your fingers, about a quarter turn back and forth, usually lets it glide past. If you meet firm resistance that does not yield to gentle rotation, stop. Withdraw the tube and try the other nostril. Forcing the tube risks tearing the mucosa or creating a false passage into the submucosa.
• Seat the flange: Continue advancing until the flange rests snugly against the nostril. At this point the distal tip should be sitting in the nasopharynx behind the tongue base. You should feel or hear air movement through the tube with each breath.

After placement, reassess the patient. Listen for air movement through the tube. Watch for chest rise. If the patient is being bag-valve-mask ventilated, the NPA often dramatically improves the seal and tidal volume by preventing the tongue from falling back. In tactical combat casualty care guidelines, a properly sized NPA is specifically recommended as an adjunct during bag-valve-mask ventilation when oxygen saturation drops below 90% and ventilation is impaired.⁶

The Basal Skull Fracture Question

One of the most persistent teachings in emergency medicine is that an NPA should never be placed in a patient with a suspected basal skull fracture, because the tube might pass through a fracture line and enter the cranial cavity. This concern has been repeated in textbooks and training courses for decades. The actual evidence behind it, however, is thin. The fear traces back to just two individual case reports, and a review in the Emergency Medicine Journal concluded that the relative risk needs to be weighed in clinical context rather than treated as an absolute contraindication.⁷

In practice, most emergency and prehospital guidelines still advise caution in patients with clear signs of basal skull fracture (raccoon eyes, Battle’s sign, cerebrospinal fluid leaking from the nose or ears). If the patient has obvious midface trauma with significant disruption of the nasal anatomy, an NPA is a poor choice regardless of the intracranial concern, simply because the passage may be physically blocked or unstable. But in an unconscious trauma patient who needs an airway and has no obvious facial disruption, withholding an NPA solely because of a theoretical intracranial risk is increasingly seen as overly conservative and potentially dangerous if it delays airway management.

Complications Worth Knowing About

The most common complication is epistaxis, or nosebleed. Even with proper lubrication and a correctly sized device, the nasal mucosa can bleed. This is usually minor and self-limiting, but in a patient who is supine and unconscious, blood trickling posteriorly can cause aspiration. Suctioning the oropharynx periodically after placement helps manage this.

A less obvious but potentially serious issue is device displacement. Because NPAs are small, smooth tubes placed in urgent situations, they can migrate deeper into the nasal cavity or pharynx, especially during patient transport. A case report described an NPA that was displaced and retained in the nasal cavity, highlighting that handoffs between prehospital and emergency department teams do not always include documentation that an NPA was placed.⁸ Using NPAs with a large, well-designed flange reduces the chance of inward migration. Beyond that, good handoff communication matters: if you placed an NPA in the field, make sure the receiving team knows it is there.

Other complications include gagging or vomiting if the tube is too long and contacts the glottis, and pressure necrosis of the nasal mucosa if the device is left in place for extended periods without reassessment. If the patient regains consciousness and can protect their own airway, the NPA should be removed promptly.

NPA Versus OPA and When Each Fits

An oropharyngeal airway (OPA) goes through the mouth and sits over the tongue. It works well in deeply unconscious patients but will trigger gagging or vomiting in anyone with an intact gag reflex, which makes it dangerous in semi-conscious people. The NPA’s primary advantage is tolerance: it can be placed in patients with some degree of consciousness, trismus (clenched jaw), or oral trauma that prevents an OPA.

When both devices can be used safely, which performs better? A comparative study during fiberoptic bronchoscopy found that the OPA group had a lower rate of oxygen desaturation events than the NPA group.⁹ But that study involved awake, sedated patients undergoing a procedure in which the bronchoscope itself partially occupies the airway, so it does not generalize neatly to the typical field scenario of an unconscious patient who just needs a basic airway adjunct. A separate trial comparing the two devices in obese patients under total intravenous anesthesia found that both devices achieved similarly high rates of successful insertion and comparable oxygenation.¹⁰

The real-world choice usually comes down to the patient’s level of consciousness and the condition of their mouth and face. In many prehospital settings, particularly in combat or remote environments, the NPA is the default because it can be placed in a wider range of patients without risking aspiration from a triggered gag reflex.

Materials and Why They Matter for Extended Use

Most disposable NPAs are made from PVC (polyvinyl chloride) or thermoplastic elastomers. These materials are chosen because they soften slightly at body temperature, conforming to the contours of the nasal passage and reducing pressure on the mucosa. But not all materials behave the same way over time. A study that submerged various airway devices in saline at body temperature for up to fifteen days found that standard PVC NPAs maintained their length and wall thickness throughout, while NPAs made from a different polymer (Mediprene) showed a statistically significant increase in both length and wall thickness starting within the first one to two days.¹¹

For a device placed in an emergency that is removed within hours, this swelling is irrelevant. But in intensive care or prolonged field care scenarios where an NPA might remain in place for a day or longer, material expansion could increase pressure on the nasal mucosa and contribute to tissue damage. Clinicians managing patients with an NPA left in situ should be aware of what material the device is made from and should reassess the nostril regularly for blanching, swelling, or signs of pressure injury. Rotating to the opposite nostril periodically, if feasible, can distribute the mechanical load.

Common Mistakes and How to Avoid Them

Certain errors come up repeatedly in training and clinical practice:

• Aiming upward: New practitioners often angle the tube toward the bridge of the nose. The correct trajectory follows the floor of the nasal cavity straight back. Imagining a line from the nostril to the ear canal on the same side helps orient the angle.
• Forcing past resistance: If the tube does not advance with gentle pressure and slight rotation, forcing it risks creating a submucosal tunnel, causing significant bleeding, or breaking off a turbinate. Withdraw and try the other side.
• Skipping lubrication: Even in a time-critical scenario, taking two seconds to coat the tube with lubricant dramatically reduces mucosal trauma. Some NPAs ship pre-lubricated or with a lubricant packet in the packaging for exactly this reason.
• Forgetting the flange check: If the flange is loose or missing, the entire tube can disappear into the nose. Verify the flange is firmly attached before insertion.
• Not documenting placement: In chaotic multi-casualty or transport situations, an NPA can be forgotten during handoff. Document it, or at minimum verbally report it to the next provider. A retained, unrecognized NPA can obstruct further airway management or become a foreign body.

Pediatric Considerations

Children are not just smaller adults when it comes to airway anatomy. Their nasal passages are narrower, their turbinates proportionally larger, and their mucosa more vascular and fragile, all of which increase the risk of bleeding and make proper sizing even more critical. The naris-to-tragus minus one centimeter measurement mentioned earlier provides a more reliable estimate of insertion depth in children under twelve than the naris-to-mandible angle sometimes taught in older protocols.³

Diameter selection in children often relies on matching the NPA to the diameter of the child’s little finger or the opening of the nostril, whichever is smaller. Lubrication is nonnegotiable. Insertion should be even gentler and slower than in adults, with an extremely low threshold for abandoning one nostril in favor of the other if any resistance is met. Because children have a higher baseline heart rate and are more prone to vagal responses from nasopharyngeal stimulation, monitoring should be close and continuous after placement.

When to Remove or Reassess the NPA

An NPA is a temporizing tool, not a definitive airway. It buys time while you address the underlying cause of airway compromise or prepare for a more secure airway like endotracheal intubation or a supraglottic device. Reassess frequently. If the patient wakes up and begins coughing or gagging on the tube, remove it gently by pulling it straight out along the floor of the nose, reversing the insertion path. If the patient’s airway obstruction worsens despite the NPA, the device may have kinked, become plugged with secretions or blood, or may simply be insufficient for the degree of obstruction. Suction through the tube, reposition it, or escalate to a different airway strategy.

In prolonged transport or austere settings where an NPA may need to stay in place for hours, periodic suctioning of both the NPA lumen and the oropharynx keeps the passage clear. Watch for progressive nasal swelling that tightens around the tube, and be prepared to replace the device with a smaller diameter or switch nostrils if signs of mucosal compromise appear.