Nasopharyngeal Airway

Excerpt

Basic airway management in children and adults includes assessing and managing airway patency, oxygen delivery, and ventilation. All efforts should be taken to maintain airway patency noninvasively unless indications for invasive airway management are apparent.

The following methods may accomplish noninvasive airway supplementation:

1. Passive oxygenation by nasal cannula or nonrebreather mask

2. Bag-valve-mask (BVM) ventilation

3. Noninvasive positive pressure ventilation, as in BVM with a positive-pressure valve, continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP)

4. Supraglottic airways, including the King Tube and laryngeal mask airway

Meanwhile, invasive airway management involves establishing a secure airway and placing patients on a mechanical ventilator via the following methods:

1. Nasotracheal (NT) or endotracheal (ET) intubation

2. Needle jet ventilation

3. Cricothyroidotomy

4. Tracheostomy

Needle jet ventilation may be used in pediatric patients younger than 8 years. Cricothyroidotomy is appropriate for adults and children older than 8 years.

Proper airway management begins by determining the best airway approach for the patient. Factors that can influence airway choice include obesity, macroglossia, evidence of trauma, cervical collar use, presence of a gag reflex, and age.

After selecting the airway type, the patient's head is positioned for airway placement. Methods for head positioning include the following:

1. Head tilt-chin lift maneuver. One hand tilts the forehead while the other lifts the chin. Both actions extend the neck, reduce upper airway obstruction, and align the upper respiratory airways. This maneuver puts the patient in a sniffing position, with the nose pointed upward and forward.

2. Chin lift: Both hands are placed underneath the mandible and chin. The mandible is then lifted until the teeth barely touch.

3. Jaw-thrust maneuver: The spine is maintained in a neutral position. Then, the sides of the mandibular angle are lifted forward to lift the jaw and open the airway. This method is appropriate for individuals with a possible cervical spinal cord injury.

Differences exist between the pediatric and adult airways. For example, prepubescent pediatric patients have a large occiput that can hyperflex the neck and obstruct the trachea. The head tilt-chin lift maneuver can correct this problem. However, care must be taken using this maneuver in children who have a weak trachea because neck overextension can also obstruct the airway.

The head tilt-chin lift may be inadequate to keep the airway patent in children with a large, floppy tongue. The jaw-thrust maneuver is an alternative for these patients.

Once properly positioned, effective breaths must be delivered mouth-to-mouth or via BVM ventilation. If difficulties are encountered in delivering breaths, airway adjuncts like an oral pharyngeal airway (OPA) device or nasopharyngeal airway (NPA) may be used to keep the airway patent (see Image. Airway Adjuncts). OPAs are appropriate for unresponsive patients. NPA devices may be used on both unconscious and awake patients. Thus, NPAs are beneficial if intubation is not indicated or needs to be delayed. NPA use may also be a temporizing measure if awake intubation is necessary.

NPAs are hollow plastic or soft rubber tubes inserted into the nose and posterior pharynx. These devices should not cause patients to gag. Thus, NPAs are the best airway adjuncts for awake patients. These devices are also indicated for semiconscious patients with an intact gag reflex and may not tolerate an OPA. NPAs may also be useful when a patient's mouth is difficult to open, as in cases of angioedema and trismus. However, despite their many applications, NPAs only keep the airway patent in stable patients with spontaneous respirations or serve as a temporizing measure for patients needing an ET or NT airway.

NT intubation was traditionally a commonly performed airway management method among critical care and emergency physicians. However, most clinicians today prefer the ET intubation route, which has demonstrated better results and fewer complications than the NT method. Oral and maxillofacial surgery are the only disciplines where NT intubation is widely used. Studies have since found that using an NPA before NT intubation during surgery improves the ease of NT tube insertion and minimizes bleeding during NT tube placement.