For which of the patient is the insertion of a nasopharyngeal airway contraindicated?

Objective Methods for the Measurement of the Nasal Airway Before and After Nasal Surgery: Brief Considerations

Many authors have noted that objective measurements of nasal airway strengthen and clarify surgical indications, promoting a better selection of patients for surgery and permitting a better evaluation of the effect of surgery on the airway.59

Objective methods for the measurement of nasal airway have been used to evaluate patients before and after nasal surgery, showing that, generally, postoperative improvement in the severity of symptoms is associated with improvement in the nasal airway.174,185,240,272,273,283,324,325 After nasal surgery, a significant decrease in NAR in the more obstructed side of the nose has been obtained in many studies.185,270,324,326-328 AR showed an improvement in airway dimension after turbinate surgery.329 Furthermore, both nasal flow and cross-sectional area increase unilaterally after septoplasty on the side of obstruction, whereas these values seem to decrease for the opposite side.325 Significant increases in AR parameters together with decrease in the sensation of congestion have been reported after nasal surgery.330,331 Interestingly, while AR could not show significant increases in nasal volume after septorhinoplasty,332 PNIF detected clinically significant objective postoperative improvement of nasal airflow, enabling the authors to conclude that PNIF should be incorporated into clinical practice as the best currently available objective outcomes assessment.174 PNIF values have been studied before and after different nasal surgical procedures. Ozkul et al. found a significant PNIF increase after septoplasty, concluding that PNIF is a very effective method in the evaluation of nasal obstruction and in deciding on operation.170 PNIF has also been proposed as a valuable instrument for the evaluation of nasal surgery outcome122,136,171,171a in turbinoplasty,172 septorhinoplasty,173,174,174a or endoscopic sinus surgery, reflecting improvements in quality of life in chronic rhinosinusitis (CRS).101 The minimal clinically important difference (MCID) for PNIF after nasal surgery has been reported to be 20 L/min.112 A PNIF improvement of 40% after septoturbinoplasty has been demonstrated in patients who rated being “satisfied” or “very satisfied” after surgery, although some patients rated themselves as either “not satisfied” or “neutral” despite a PNIF improvement three times higher than the MCID.283

Nasopharyngeal Airway

An NPA is a tube that is designed to provide an airway passage from the nose to the posterior pharynx. NPAs can create a patent pathway and help avoid airway obstruction due to hypertrophic tissue. The NPA creates a patent airway throughout the distance of the tube. NPAs can be compromised if the nasal passage is narrow and collapses the inner diameter of the NPA and can also be occluded on the distal end. Patency is the primary goal of an NPA. Oxygenation can be improved by utilizing a nasal hood over an NPA. Oxygen can also be delivered by running a nasal cannula inside the NPA.

Nasal and Oral Airways

Nasal and oral airways can sometimes be useful in pediatric patients to relieve airway obstruction, especially during face mask ventilation at the beginning or end of anesthesia. The nasal airway should be carefully placed through one of the nares after lubricating its exterior. The nasal airway must be long enough to pass through the nasopharynx, but short enough that it still remains above the glottis.

Oral airways relieve airway obstruction by displacing the tongue anteriorly. Too large an oral airway will either obstruct the glottis or may cause coughing, gagging, or laryngospasm in a patient who is not deeply anesthetized. Too small an oral airway will push the tongue posteriorly and make the airway obstruction worse. Oral airways should be placed with care to prevent trauma to the teeth and oropharynx.

Nasopharyngeal Airways

Nasopharyngeal airways (also known as Robertazzi nasopharyngeal airways [SunMed, Grand Rapids, MI]) are occasionally used in children to relieve upper airway obstruction; the distance from the naris to the angle of the mandible approximates the proper length. Commercial airways are available in sizes 12F to 36F (Rüsch Inc., Duluth, GA). Some have an adjustable flange that enables manipulation of the airway to the appropriate length. Alternatively, for infants and small children, a shortened ETT may be used, although this is not as soft and pliable as a commercially available non-latex nasopharyngeal airway and may be more likely to cause trauma with insertion. Softening the tip of the ETT by immersion in hot water before insertion has not been shown to reduce the incidence of bleeding during nasotracheal intubation in children.136 The nasopharyngeal airway may be better tolerated in the lightly anesthetized child than an oropharyngeal airway. Nasopharyngeal airways are usually avoided to prevent trauma to, and bleeding from, hypertrophied adenoids, and they are more commonly used to relieve residual airway obstruction on emergence from anesthesia.

Nasal airway

Paralysis of the nasalis and levator alaeque nasi combined with drooping and medial deviation of the paralyzed cheek leads to support loss of the nostril, collapse of the ala, and reduction of airflow. Nasal septal deviation, which occurs in patients with congenital facial paralysis, may further accentuate any breathing difficulties. In the patient who complains of significant symptoms, correction of airway collapse is best accomplished by elevation and lateral support of the alar base with the sling of tendon and by upper lip and cheek elevation procedures. Septoplasty may be indicated to provide an improvement in airway patency.

Nasopharyngeal Airways

Nasopharyngeal airways are occasionally of value in children to relieve upper airway obstruction; the distance from the nares to the angle of the mandible approximates the proper length. Commercial airways are available in size 12 to 36 Fr (Rüsch Inc., 2450 Meadowbrook Parkway, Duluth, GA). Some have an adjustable flange that enables manipulation of the airway to the appropriate length. Alternatively, for infants and small children, a shortened ETT may be used. The nasopharyngeal airway may be better tolerated in the lightly anesthetized patient than is the oropharyngeal airway. Under most circumstances, however, nasopharyngeal airways are avoided to prevent trauma to, and bleeding from, hypertrophied adenoids.

Nasal Airway

Nasopharyngeal airways are generally constructed from red rubber or polyvinyl chloride and are available in various sizes. They may be softened in warm water, lubricated with water-soluble or lidocaine jelly, and gently inserted transnasally. However, nasal airways may traumatize the turbinates or adenoids of young children. Also, care must be exercised when using nasopharyngeal airways in children with a bleeding diathesis or congenital abnormalities of the midface such as choanal atresia or frontonasal dysplasia. The appropriate length for the nasopharyngeal airway may be estimated from the distance between the auditory meatus to the tip of the nose and the size of the airway may be estimated from the calculated endotracheal tube size converted to French size (approximately the internal diameter in millimeters multiplied by four, or the external diameter in millimeters multiplied by three).

Nasopharyngeal Airways

Nasopharyngeal airways are not as frequently used in children because the internal diameter is often small, resulting in increased work of breathing and increased chance of blockage by secretions or blood. In addition, adenoid hypertrophy makes a child susceptible to bleeding after nasopharyngeal airway insertion. Despite its limitations it can help provide a patent airway in spontaneously breathing infants and children (particularly after pharyngoplasty or cleft palate repair) and is better tolerated in nonanesthetized children. Nasopharyngeal airways range in sizes to accommodate neonates through to adults and may have a movable ring to set the length and/or a flange on the end to prevent loss in the nasal cavity. If a stiffer airway is necessary, a well-lubricated endotracheal tube, cut to the appropriate length (to reach the nasopharynx only), may be used; however, it must be safely secured because it may accidentally pass into the nasopharynx.

2 Nasopharyngeal Airways

The nasopharyngeal airway (NPA) is an alternative airway device for treating soft tissue upper airway obstruction. When in place, an NPA is less stimulating than an OPA and therefore better tolerated in the awake, semicomatose, or lightly anesthetized patient. In cases of oropharyngeal trauma, a nasal airway is often preferable to an oral airway. NPAs are pliable, bent cylinders made of soft plastic or rubber in variable lengths and widths (Fig. 15-9). A flange (or moveable disk) prevents the outside end from passing beyond the nares, thereby controlling the depth of insertion. The concavity is meant to follow the superior side of the hard palate and posterior wall of the nasopharynx. The tip of the airway is beveled to aid in following the airway and minimizing mucosal trauma as it is advanced through the nasopharynx. A narrow NPA is often desirable to minimize nasal trauma but may be too short to reach behind the tongue. As an alternative, an ETT of the same diameter may be cut to the appropriate length to provide a longer airway. A 15-mm adapter should be inserted in the cut end of the ETT to prevent migration of the proximal end beyond the naris (see Fig. 15-9).

Before insertion of an NPA, the nares should be inspected to determine their size and patency and to evaluate for the presence of nasal polyps or marked septal deviation. Vasoconstriction of the mucous membranes can be accomplished with cocaine (which has the added benefit of providing topical anesthesia) or phenylephrine drops or spray. This can also be accomplished by soaking cotton swabs in either of these solutions and then inserting them into the naris (with careful attention to removing the swabs before insertion of the NPA). The NPA is typically lubricated with a water-based lubricant (with or without a water-soluble local anesthetic) and then gently but firmly passed with the concave side parallel to the hard palate through the nasal passage until resistance is felt in the posterior nasopharynx (Fig. 15-10).

When there is resistance to passage, it is sometimes helpful to rotate the NPA 90 degrees counterclockwise, bringing the open part of the bevel against the posterior nasopharyngeal mucosa. As the tube makes the bend (indicated by a relative loss of resistance to advancement), it should be rotated back to its original orientation. If the NPA does not advance with moderate pressure, there are three management options: attempt placement of a narrower tube, redilate the naris, and attempt placement in the other naris. If the tube does not pass into the oropharynx, the clinician may withdraw the tube 2 cm and then pass a suction catheter through the nasal airway as a guide for advancement of the NPA. If the patient coughs or reacts as the NPA is inserted to its full extent, it should be withdrawn 1 to 2 cm to prevent the tip from touching the epiglottis or vocal cords. If the patient's upper airway is still obstructed after insertion, the NPA should be checked for obstruction or kinking by passing a small suction catheter. If patency of the NPA is confirmed, it is possible that the NPA is too short and the base of the tongue is occluding its tip. In this case, a 6.0 ETT can be cut at 18 cm to provide a longer airway.

Indications for an NPA include relief of upper airway obstruction in awake, semicomatose, or lightly anesthetized patients; in patients who are not adequately treated with OPAs; in patients undergoing dental procedures or with oropharyngeal trauma; and in patients requiring oropharyngeal or laryngopharyngeal suctioning. The contraindications (absolute or relative) include known nasal airway occlusion, nasal fractures, marked septal deviation, coagulopathy (risk of epistaxis), prior transsphenoidal hypophysectomy or Caldwell-Luc procedures, cerebrospinal fluid rhinorrhea, known or suspected basilar skull fractures, and adenoid hypertrophy.

The complications of NPAs consist of failure of successful placement, epistaxis due to mucosal tears or avulsion of the turbinates, submucosal tunneling, and pressure sores. Epistaxis often becomes evident when the NPA is removed, thereby removing the tamponade. It is usually self-limited. Bleeding from the nares usually is attributable to anterior plexus bleeding, and it is treated by applying pressure to the nares. If the posterior plexus is bleeding (with blood pooling into the pharynx), the physician should leave the NPA in place, suction the pharynx, and consider intubating the trachea if the bleeding does not stop promptly. The patient may be positioned on his or her side to minimize the aspiration of blood. An otolaryngology consultation may be necessary to further treat posterior plexus bleeding. The management of submucosal tunneling into the retropharyngeal space is to withdraw the airway and obtain otolaryngology consultation.

Nasopharyngeal Airways

The nasopharyngeal airway (NPA) is a (now) disposable soft tubular device designed to support the nasal route of breathing, controlling airway obstruction at the nasal cavities, nasopharynx, soft palate, and the base of the tongue. They are sized based on their outer diameter (OD) in French scale and come in sizes from 12-36 Fr (Fr [French size] is the circumference in millimeters). The larger OD is also reflected in a longer length. A proximal flange stabilizes the NPA at the naris while the distal end is beveled and ideally comes to rest approximately 10 mm above the epiglottis when fully inserted. Awake patients tolerate NPAs better than OPAs (Fig. 14.2). As with the OPAs, the NPAs have a caudad, albeit more gentle, concavity. Appropriate nasal airway sizing is determined by measuring the distance from the patient’s bony mandible or nostril to the external auditory meatus. The NPA is typically lubricated with a water-based lubricant (with or without a water-soluble local anesthetic) and then gently but firmly inserted through the caudad part of the nasal passage, following the posterior wall of the nasopharynx and oropharynx, coming to lie with the tip in the hypopharynx. The tip of the NPA is beveled in order to minimize trauma when advancing through the nasal cavities and the nasopharynx. The most common complication of NPA use is epistaxis. Contraindications to the use of NPAs include nasal fractures, marked septal deviation, coagulopathy, basilar skull fractures, cerebrospinal fluid (CSF) leak, pregnancy, transsphenoidal surgical procedures, and Caldwell-Luc procedures.7