Nasopharyngeal Airway

Link to article at PubMed

2020 Sep 25. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan–.

ABSTRACT

Basic airway management in both the pediatric and adult populations includes assessing and managing airway patency, oxygen delivery, and ventilation. All efforts should be taken to maintain a patient’s airway via non-invasive methodology unless indications for invasive airway management are apparent. Non-invasive airway supplementation includes passive oxygenation (nasal cannula, non-rebreather, among others), bag-valve-mask (BVM), non-invasive positive pressure ventilation (BVM with positive-pressure valve, CPAP, BIPAP), and supraglottic airways (King Tube, Laryngeal Mask Airway, among others). Invasive airway management involves establishing a secure airway and placing patients on a ventilator via intubation (nasal or endotracheal), needle jet ventilation (in pediatric patients younger than 8 years old, cricothyroidotomy in adults and in pediatric patients older than 8 years old), and tracheostomy.

Proper airway management begins by visually evaluating the patient for any evidence of trauma, obesity, cervical collar, macroglossia, and other factors in order to determine the type of airway approach best suited for each patient. The next important step is positioning via the head tilt-chin lift maneuver, which involves extending the patient’s neck by putting one hand on the forehead and the other hand on the neck to allow for the extension of the head in relation to the neck. This maneuver puts the patient into sniffing position, with the nose pointed upward and forward. The next maneuvar that can be performed is a chin lift by placing both hands underneath the mandible and the chin and lifting the mandible until the teeth barely touch. Another airway positioning method is called the jaw-thrust maneuver, which is safer in any patient with a potential cervical spinal cord injury. This method involves maintaining the spine in a neutral position and grabbing the sides of the angle of the mandible and lifting it forward to lift the jaw and open the airway.

There are some differences between the pediatric and adult populations. For example, the large occiput of the pre-pubescent pediatric patient can lead to too much flexion of the neck and can cause tracheal obstruction. This is addressed by utilizing the head tilt-chin lift maneuver, but care must be taken to avoid overextension in the pediatric population as it can cause airway obstruction due to a weak trachea. However, the head tilt-chin lift may not be adequate to maintain a patent airway, and the jaw-thrust maneuver may need to be employed to prevent the pediatric, large, floppy tongue from obstructing the airway.

Once properly positioned, the rescuer has the best shot at delivering effective breaths either via mouth to mouth or BVM.

If there is continued difficulty at delivering breaths, then airway adjuncts like an oral pharyngeal airway (OPA) device or nasopharyngeal airway (NPA) can be useful for maintaining a patent airway to allow delivery of breaths in an unresponsive patient. NPA devices can be useful at maintaining the airway in an awake patient as well, which is beneficial if intubation is not the goal, the intubation needs to be delayed, or an awake intubation is necessary.

NPA devices are plastic hollow or soft rubber tubes that a healthcare provider can utilize to help with oxygenation and ventilation of a patient that is difficult to oxygenate or ventilate via BVM. NPAs are passed through the nose and pass through to the posterior pharynx. NPAs do not cause patients to gag and therefore are the best airway adjunct route in an awake patient and the better choice in a semiconscious patient that may not tolerate an OPA due to the gag reflex. NPAs are also helpful when a patient's mouth is difficult to open, for example, if there is angioedema, trismus, or other factors.

While NPAs are airway adjuncts for patients that are difficult to ventilate and oxygenate, they only act as a bridge to either a stabilized patient that is breathing without aid or a patient that requires a secure airway via endotracheal or nasotracheal (NT) intubation.

The NT route for intubation was the preferred route among critical care and emergency physicians up until several decades ago. However, today, the majority of clinicians prefer the endotracheal route for intubation as it has shown to have better results and fewer complications. Some of the complications of NT intubation include sinusitis, nasal structure destruction due to localized pressure and decreased perfusion of nasal cartilage, and local abscesses. Furthermore, NT intubation requires narrow tubes making pulmonary toilet very difficult due to the increased airway resistance.

However, there are clear advantages to NT intubation. NT intubation can be performed in the sitting position, which is valuable, especially in the pre-hospital setting when needing to intubate a patient in acutely decompensated heart failure that cannot lay flat. Other advantages include the patient’s inability to bite or manipulate the tube, better patient tolerance, decrease salivation, and better access to patient oral care. In addition, the NT tube is much more stable as it has the entire nasal tract holding it in place versus the endotracheal tube that flops out the mouth and can easily dislodge or become inserted into the right mainstem bronchus in the lungs.

NT intubation can be performed blind or with a flexible bronchoscope. Blind NT intubation is difficult and requires expertise and skill. However, when indicated, can be a very useful skill both in the prehospital and hospital setting. Blind NT intubation decreases the need for neck movement and mouth opening, but can only be done in the awake and ventilating patient. NT intubation via a flexible bronchoscope also requires lots of expertise and skill, and it is useless if there is blood, vomitus, or fluid that will obscure the bronchoscope camera.

PMID:30020592 | Bookshelf:NBK513220

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