Chapter 22: AIRWAY

MAXIM: Endotracheal intubation is not always the best initial intervention for respiratory failure.

Clinical Summary

Some patients in respiratory distress may benefit from other interventions, short of intubation. Patients with flash pulmonary edema may have dramatic improvement with intravenous nitroglycerin, intravenous furosemide, and BiPAP (Bi-Level Positive Airway Pressure) ventilation (see Fig. 22.1). Patients with airway narrowing (edema, neoplasm, stricture, foreign body) can have significant decreased work of breathing by decreasing airway resistance to inspired gas using administration of helium-oxygen (HELIOX) mixture. HELIOX, usually as a 78%: 22% helium: oxygen mixture, is much less dense than either air or 100% oxygen by virtue of helium replacing nitrogen or oxygen, respectively. This lowers resistance to laminar flow by as much as 20% to 25% and the effects are immediate.

Pearl

1. Alternative ventilatory adjuncts include HELIOX, CPAP, BiPAP, and Vapotherm (see Fig. 22.2). These adjuncts may prevent the need for intubation in selected patients.

MAXIM: The most important initial airway intervention may be to ask for help.

Clinical Summary

Clinical scenarios where asking for help include:

1. Laryngeal injury/tracheal disruption, for whom a nonendoscopic intubation attempt can result in tracheal disruption and fatally lost airway (see Fig. 22.3).

2. Recent neck surgery, with pending loss of airway from an expanding hematoma; definitive and life-saving intervention in this case is to open up the recent incision and evacuate the hematoma.

3. Suspected epiglottitis, where an immediate operative tracheostomy or cricothyroidotomy may be required if intubation fails due to epiglottic edema.

4. Severe angioedema with tongue, oropharynx swelling where endotracheal or nasotracheal intubation may be obstructed (see Fig. 22.4).

Pearls

1. Emergency physicians are emergency airway experts, but know your limitations.

2. Do not let your ego get in the way of proper patient airway management and care.

MAXIM: Most patients with airway/respiratory problems should be positioned for their comfort, not ours.

Clinical Summary

If mentating normally and physically able, a patient with airway difficulty will assume a position which optimizes their airway patency and gas exchange, usually sitting up and leaning forward. Such patients include those with incomplete airway obstruction, flash pulmonary edema, and massive airway bleeding from oropharyngeal trauma. Unfortunately, during preparation for intubation, such patients often are placed supine prematurely, increasing the patient’s respiratory distress and anxiety, increasing the likelihood of spontaneous emesis and aspiration, and decreasing his ability to handle oropharyngeal bleeding or secretions. In these clinical situations, we should rethink the desire to immediately place a patient supine for endotracheal intubation. Intubation can be accomplished with the patient sitting up, by either of the following.

1. Altering the intubation technique (see Fig. 22.5).

2. Altering the intubator position relative to the patient (see Fig. 22.6).

Pearls

1. Keep patients in optimal position for spontaneous ventilation until they are sedated just prior to intubation; then, place them supine.

2. Consider intubating a patient sitting upright if you feel the supine position will compromise their ability to be ventilated.

3. Titrating ketamine in small doses (10 mg every 1-2 minutes) may facilitate awake intubation in a patient sitting upright.

MAXIM: Think before you paralyze.

Clinical Summary

Before committing to rapid-sequence induction (RSI) for direct laryngoscopy, consider the following:

1. Are any planned medications contraindicated?

2. Can rescue ventilation be achieved?

3. Is direct laryngoscopy possible? (See Fig. 22.7.)

4. What are my secondary and tertiary backup plans in the event of primary plan failure?

5. Are my equipment and personnel ready for RSI?

Pearls

1. A good backup plan to direct laryngoscopy should have at least one alternative intubation technique, one alternative ventilation technique, and one surgical airway technique.

2. Prepared equipment, correct patient position, proper drug dosing, having a backup plan, effective communication, and good technique will promote first-pass intubation (see Figs. 22.8 and 22.9).

MAXIM: Patients will not die if they are not intubated; they will die if their lungs are not ventilated and their blood is not oxygenated.

Clinical Summary

The goal for airway management in any patient must be to maintain adequate ventilation and oxygenation. This does not necessarily mean intubation. Correct bag-valve-mask (BVM) ventilation/oxygenation technique is an underrated skill that will buy you time in the patient with a difficult airway. Proper steps for optimal two-person BVM ventilation include:

1. Positioning—ear-to-sternal notch alignment (when clinical scenario permits). Neck slightly flexed, head slightly extended (see Fig. 22.10).

2. Jaw thrust—displace mandible anteriorly with pressure from long, ring, and small fingers on mandible, not on soft tissues.

3. Mask compression—thumb and index fingers should apply firm pressure to face and nasal bridge (see Figs. 22.11 and 22.12).

4. Oral/nasal airways—may help maintain airway patency during BVM ventilation (see Fig. 22.13).

5. Use 7 mg/kg tidal volume, over 1 to 2 seconds at 12 breaths/min.

Pearls

1. Be an expert at BMV ventilation.

2. Ear-to-sternal notch positioning is most beneficial in obese patients and those with obstructive sleep apnea.

3. Keeping dentures in place facilitates BVM, while removing them facilitates orotracheal intubation.

4. Midface and mandibular disfiguration from whatever cause will interfere with optimal BVM ventilation.

5. Consider LMA, King LT, or Air-Q if unable to intubate or obtain adequate seal for BVM ventilation.

Patient Positioning

The optimal position to maximize laryngoscopic visualization of the larynx is:

1. The head extended.

2. The neck flexed.

3. The base of the ear is aligned with the sternal notch (see Fig. 22.10).

4. The facial plane is horizontal, parallel to the ceiling (see Fig. 22.10).

5. The facial plane should be positioned between the laryngoscopist’s xiphoid process and umbilicus (see Fig. 22.14).

This position most closely replicates in a supine posture which the patient would assume sitting up. For very large individuals or those with significant morbid obesity, this may require creation of a textile ramp of blankets, sheets, or towels to raise the head and shoulders to proper elevation and alignment.

Preoxygenation and Passive Apneic Oxygenation

Preoxygenation, when possible, should be used to create an oxygen surplus in the blood and tissue which permits a period of apnea to occur without arterial oxygen desaturation. This process hopefully begins in the prehospital setting with the placement of a nonrebreather mask with high-flow oxygen on the patient. This should continue in the ED in the event intubation is required. In addition, a nasal cannula on high flow (15 L/min) should also be placed when the patient arrives in the ED if there is a high likelihood of intubation. High-flow oxygen delivered by nasal cannula provides passive apneic oxygenation during the apneic phase of endotracheal intubation.

Technique

Stylet Shape

A stylet should be used with all oral intubations in which a laryngoscope is employed. The laryngoscopist will typically fashion an inexpensive stylet, essentially a malleable wire, into a shape of their preference, to permit control of the distal endotracheal tube (ETT) tip. One should take care not to place too much bend or curvature to the stylet, because such a configuration can actually impair the glottic view and control of the ETT tip. Optimal stylet configuration has been described as “straight to the cuff” and then a gentle anterior bend of 30 degrees.

Even with a correct bend on the stylet, it may be difficult to advance the styletted ETT into the trachea. The tip of the left-sided beveled tube can impact and catch on the anterior tracheal cartilages, preventing advancement. This can often be remedied with a generous clockwise or rightward rotation of tube and stylet, which acts to rotate the bevel anteriorly and depress the ETT tip.

Optimizing Biomechanics

Holding the laryngoscope handle and blade where the proximal end of the blade is in the palm of the hand creates a natural extension of the forearm and provides fine control of the blade tip. The left thumb should run parallel to the axis of the handle. Effort mechanics are more efficient with this grip. Placing the elbow close to the body requires less effort and more mechanical control than if the elbow abducted from the body. A memory aid for these concepts are “Thumb up-Wing in.”

Mouth Opening Techniques

The scissor technique places the laryngoscopist’s right thumb on the occlusive surface of the patient’s lateral mandibular teeth or gum and long or index finger on the maxillary teeth or gum. A scissoring motion opens the mouth allowing blade insertion. The fingers should be removed once the blade is adequately inserted. An alternative technique is to place the laryngoscopist’s right thumb on the nasal bridge and long finger between the mental protuberance and alveolar margin. The thumb and long finger are moved away from each other, causing the mouth to open.

Blade Insertion

The blade is initially inserted just to the right of midline with the handle pointed toward the patient’s feet. As the tip of the blade advances downward along the tongue base and into vallecula, the tongue is swept slightly to the left to increase the amount of workspace. When fully inserted into the vallecula, the angle of the handle is now approximately 40 degrees from horizontal with lifting forces directed upward and forward.

Optimal Epiglottoscopy

The key to using the laryngoscope to optimally visualize the glottic opening is to first visualize and control the epiglottis, a relatively fixed anterior structure. Pulmonary secretions, blood, and/or vomitus that pools in the posterior pharynx may obscure the posterior laryngeal structures, dependent with gravity. The epiglottis itself may be camouflaged in this pool of muck (see Fig. 22.20). One should carefully insert the laryngoscope blade with a goal of adequately visualizing and controlling the epiglottis. Failure to do so risks inserting the laryngoscope blade too deeply, and often results in displacing the larynx anteriorly to expose the esophagus, which, as a consequence of anterior-ward tension on the laryngoscope blade, may then look like a glottic opening begging for a tube. By carefully controlling the epiglottis, the intubating clinician will be able to locate important airway landmarks. Be careful to displace the tongue to the left side as you insert the blade. If the bulk of the tongue wraps around the blade, it can both impair your view and impede insertion of the ETT.

Progressive visualization of laryngeal structures is predictable:

1. Uvula and posterior pharynx (see Fig. 22.21A)

2. Epiglottis (see Fig. 22.21B)

3. Posterior arytenoids cartilages and interarytenoid notch (see Fig. 22.21C)

4. Glottic opening (see Fig. 22.21D)

5. Vocal cords (see Fig. 22.21E)

6. Esophagus (see Fig. 22.21F)

Bimanual Laryngoscopy

Even with well-performed laryngoscopy, adequate visualization of the laryngeal structures may be difficult. Bimanual laryngoscopy (external laryngeal manipulation by the operator), where the laryngoscopist performs laryngoscopy while simultaneously manipulating the external larynx, facilitates optimal visualization. This eliminates any delay or miscommunication between an assistant and laryngoscopist. Once optimal position is found, an assistant can maintain that position. Alternatively, an assistant’s hand, placed on the laryngeal structures, guided by the laryngoscopist’s hand can maintain optimal position after the laryngoscopist removes his hand from the assistant’s hand.

Lip Commissure Retraction

The lip commissure is the junction of the upper and lower lips. Lateral retraction of the patient’s right lip commissure by an assistant facilitates visualization of oral structures and insertion of the ETT into the oral cavity. This creates an optimal workspace for tube delivery. After glottis visualization is achieved, an assistant places their right index finger in the patient’s right commissure and thumb against the maxilla. The index finger retracts the commissure laterally while applying an opposing force with the thumb to avoid excessive movement of the head. A memory aid of this concept is “pull out commissure, push on maxilla,” or “POC-POM.” Retraction of the lip commissure aids in keeping the ETT from blocking the view of the glottic opening during advancement of the ETT. Using the retracted lip commissure as a fulcrum or “toggle” gives optimal control of the ETT tip, especially when the stylet is in the “straight to cuff” shape. Retraction may also facilitate intubation by allowing clockwise rotation of the tube if the ETT tip becomes hung up on the proximal tracheal cartilages. A memory aid of this concept is “right on rings” or rotate the tube to the right or clockwise if it hangs up on the tracheal rings.

Endotracheal Tube Handling

The thumb, index, and long fingers provide the fine dexterity for the hand, and should be used to control the tube during endotracheal intubation. The ETT should be held like a “throwing dart” between the thumb, index, and long fingers midway along the tube for precise control during the procedure. A trained assistant should hand the tube to the laryngoscopist in this manner.

Endotracheal Tube Delivery

Obtain the best glottic view and have an assistant provide right lip commissure retraction. Introduce the ETT at the 3-o’clock position of the mouth. Advance the tube posteriorly in a manner that will not obstruct the direct view of the “target.” Advance the tube through the glottis. The last thing you should see is the tube going through cords. If resistance is met, it is most likely due to the bevel being caught on a tracheal ring. Turn the tube to the right or clockwise and attempt to advance the tube. Advance the tube to 22 cm at the lip, inflate the cuff, and confirm placement. Secure the tube in place (see Table 22.1).

Pearls

1. The key to first-pass intubation success is identification and control of the epiglottis during direct laryngoscopy.

2. The glottic opening lies between the epiglottis and interarytenoid notch. Identification and passing the tube between these structures will improve first-pass success.

3. While most intubations are performed without difficulty, if a difficult airway is anticipated and there is time to prepare, optimize the patient’s ear-to sternal notch position.

4. Approximately 250 mL/min of oxygen will move from the alveoli into the blood during apnea, which may extend the period of adequate arterial oxygenation during intubation.

Technique

The Eschmann stylet, also known as a “gum elastic bougie” or simply “bougie,” is a 60-cm long, flexible introducer, which is designed to assist intubation of the anterior larynx, especially those with an “epiglottis-only” view. The tip of the bougie has an anterior fixed flexion with an angle of 40 degrees to facilitate entering an anterior glottic opening. Using a laryngoscope, one obtains the best view possible of the glottic opening. In the case of limited glottic view, the bougie is inserted such that the tip is introduced just under the epiglottis and probes for the glottic opening. The intubator should feel a tactile “pop” as the bougie enters the trachea and he or she may also have a tactile sensation of “speed bumps” as the bougie is advanced and tracks across the tracheal cartilaginous rings. However, the more sensitive indicator of tracheal bougie position is the resistance encountered as the tip abuts against the carina, at approximately 27 to 30 cm. Should the bougie be inserted into the esophagus, no such endpoint is encountered.

While continuing to hold anterior traction with the laryngoscope, the laryngoscopist should direct an assistant to thread the ETT over the bougie again while maintaining anterior traction; the intubator should then advance the ETT over the bougie to the appropriate insertion depth. Resistance to tube advancement may indicate “arytenoid arrest” and can be remedied by rotating the tube counterclockwise 90 degrees followed by attempts to advance the ETT tip past the arytenoid cartilages.

A one-handed technique can be employed in which the ETT is preloaded onto the bougie, which is then curled in the right hand with approximately 20 cm of bougie protruding through the distal end. The laryngoscopist performs laryngoscopy as before, maintains anterior traction on the mandible, and inserts the bougie through the glottic opening as above. He or she then uncoils the ETT/bougie and advances the pair until resistance of the carina is met, confirming intratracheal position. The ETT is then advanced to the proper depth and the bougie is removed.

Use of the bougie does not have to be limited to the anticipated difficult airway. In fact, to gain proficiency, we recommend that practitioners use it as their routine stylet, as it has come to be used in the UK. The practitioner will then be better prepared for the unanticipated anterior larynx/limited view airway.

Pearls

1. The bougie is an excellent adjunct in the limited view or “epiglottis view” airway.

2. Bougie-assisted intubations is best deployed as a two-person technique.

3. Stall of ETT advancement when using the bougie is most frequently due to catching the bevel on the right arytenoid cartilage and can be relieved by rotating the tube counterclockwise.

Equipment

The Glidescope is a video laryngoscope composed of an integrated blade/handle which houses a blade tip–mounted camera and light source, connected by cable to a video LCD display. The Glidescope affords an excellent view of the laryngeal structures with little anteriorly directed force. Use of proprietary stylet, conformed to angle of Glidescope blade, is recommended. A more portable version, suitable for out-of-hospital use, is marketed as the Glidescope Ranger.

Technique

The blade is inserted into the mouth, along the center of the tongue, and advanced to visualize the epiglottis and laryngeal structures. Little-to-no anterior force is required, and in contrast to standard laryngoscope, levering the blade is recommended to enhance the view. Once the tube is passed through the cords, the proprietary stylet is withdrawn 5 cm to allow further passage of the tube. The steep angle of Glidescope blade and stylet causes the tube to abut the anterior tracheal rings and arrest tube delivery in most patients. Withdrawing the stylet 5 cm and rotating the tube clockwise will allow complete tube delivery to an appropriate depth.

Equipment

The Storz C-MAC video laryngoscope system consists of stainless steel, reusable blades, which house a CMOS camera chip and high-output LED light, an interchangeable powered coupling, video screen, and mobile tower. Available blades are similar in size and shape to the Mac 2, Mac 3, Mac 4, Miller 0, Miller 1, and a D-blade designed for patients with difficult airway anatomy. The near-standard shape of the blade allows direct laryngoscopy for glottic visualization as well as video laryngoscopy.

Technique

The blade connected to the power coupling should be handled like a standard laryngoscope blade. It should be inserted just to the right of midline of the tongue with the handle pointing toward the feet. As the tip of the blade advances downward along the tongue base and into vallecula, the tongue is swept slightly to the left to increase the amount of workspace. When fully inserted into the vallecula, the angle of the handle is now approximately 40 degrees from horizontal with lifting forces directed upward and forward. At anytime, the laryngoscopist can switch from a standard direct laryngoscopy to a video laryngoscopy; however, once changed to video laryngoscopy, it is best not to switch back and forth from video laryngoscopy to direct laryngoscopy.

Equipment

The McGrath MAC enhanced direct laryngoscope is a combination of direct and video laryngoscope in a compact, battery-powered, device that uses disposable standard curved Macintosh blades and has an adjustable LED screen. It can be used in direct laryngoscopy and video laryngoscopic situations.

Technique

The disposable plastic Macintosh blade is placed onto the McGrath MAC EDL and the device is powered on. The blade is inserted just to the right of midline of the tongue with the handle pointing toward the feet. As the tip of the blade advances downward along the tongue base and into vallecula, the tongue is swept slightly to the left to increase the amount of workspace. When fully inserted into the vallecula, the angle of the handle is now approximately 40 degrees from horizontal with lifting forces directed upward and forward. At anytime, the laryngoscopist can switch from a standard direct laryngoscopy to a video laryngoscopy; however, once changed to video laryngoscopy, it is best not to switch back and forth from video laryngoscopy to direct laryngoscopy.

The laryngeal mask airway (LMA) was originally designed to facilitate ventilation during anesthesia for short operating room procedures. It has been shown to provide improved ventilation in cardiac arrest and failed airway cases and has a shallow learning curve, promoting its use by relative novices.

Equipment

The LMA consists of a short curved tube connected to a small mask with inflatable cuff. The shape promotes blind insertion with an endpoint detected as resistance as the leading edge of the cuff just enters and obstructs and the esophageal inlet. The inflated cuff then seals around the laryngeal inlet. The distal “mask” incorporates a small grate to prevent prolapse of the epiglottis within the mask. The LMA has several configurations including a disposable model, the LMA “Unique” (Figs. 22.44 and 22.45). LMAs are available in three adult sizes, #3 (30-50 kg), #4 (50-70 kg), and #5 (>70 kg). They are also available in pediatric sizes from size 0 to 2.5 for infants through toddlers.

Technique

The LMA is inserted into the mouth and held against the hard palate while being advanced into the hypopharynx. The LMA is advanced until resistance is met, and the cuff is then inflated with 20 to 40 mL of air to effect a seal. The mask should be lubricated prior to insertion.

Because the LMA aligns with the glottic opening, it is possible to intubate the trachea through the LMA with minimal interruption of ventilation. The distal grate prevents anything larger than a 6.0 ID ETT through a #3 and #4, and a 7.0 ID ETT through a #5. In addition to passing a small ETT directly, it is also possible to pass a flexible fiberoptic scope or a rigid fiberoptic scope (Levitan or Shikani) through the LMA under direct visualization. One must be sure to have an ETT, sized to pass through the LMA, loaded onto the stylet prior to passage. It is recommended to rotate the ETT counterclockwise 90 degrees to orient the bevel posteriorly, rotating clockwise as the tube is passed into the glottis.

Equipment

The tracheal lightwand is a device which consists of a bright light bulb on the end of a wire. The best current embodiment is the TrachLight (Laerdal), which incorporates (1) a very bright distal light encased in a tube-like flaccid stylet, (2) a removable stiffening wire to provide rigidity and allow the stylet to conform to the required bending angle, (3) a handle which comprises a water-proof battery housing, on-off magnetic reed switch, and a track which provides for easy length adjustment of the stylet for different size ETTs. There is cam-like locking device to firmly secure the tube to the stylet. The stylet is marked in centimeter markings to align with those on the ETT, ensuring that the distal bulb is always at the proper position at the tip of the ETT.

Technique

The intubation technique relies on the unique appearance and location of the transilluminated glow of the skin overlying the anterior neck to provide feedback to the intubator about the ETT tip position and the subsequent stylet movements needed for tracheal placement and advancement. For intubation, the stylet is bent at the distal 5 cm, conveniently labeled with “BEND HERE.” The bend angle is critical and depends upon the head and neck position of the patient. For a patient who is in a neutral head/neck position, such as a patient in a halo device, the stylet should be configured to about an 80 degree acute angle. If the patient is hyperflexed, a more acute angle is required, approximately 60 degrees. Finally, for patients who are hyperextended, an obtuse angle of 110 or 120 degrees would be appropriate.

The technique can be performed with the intubator facing the patient, or with the intubator at the head of the bed behind the patient. The lightwand should be held in the dominant hand with a pencil grip at the ETT hub/handle junction. With his nondominant hand, the intubator should grasp the tongue with gauze, gently distracting forward. This acts to bring the epiglottis anteriorly. The lightwand/ETT is introduced into the center of the mouth and advanced to the hypopharynx while maintaining anterior pressure, holding the elbow high and the arm abducted, to keep the stylet bulb anterior. Advancement stops when the intubator recognizes an orange glow on the anterior neck tissues or when tube advancement meets resistance. The appearance and position of this glow determines the next maneuver.

If transillumination positional feedback indicates that the tube tip is in one of the pyriform fossae, the stylet/ETT is withdrawn slightly and rotated toward the midline and reinserted. This process is continued repeatedly in an iterative manner until the correct midline glow indicating tracheal position is encountered. At that point, the stiffening wire is withdrawn several centimeters, resulting in a caudad displacement of the glow as the intratracheal stylet “relaxes.” The tube and stylet is then advanced until the glow just disappears below the sternal notch. The tube is now confirmed to be intratracheal and the tube tip is confirmed to be reliably in the mid-trachea, with no need for confirmatory chest radiograph.

Failure to modify the position of the transilluminated glow usually indicates that the stiffening wire has displaced from the locking notch that keeps the wire from rotating in place.

Digital intubation relies on tactile definition of intubation landmarks, primarily the epiglottis but often the posterior cartilages and interarytenoid notch.

Technique

Digital intubation technique is performed with the intubator facing the patient from the side. With the gloved nondominant hand, the intubator should insert the index and third fingers into the patient’s mouth. He should next “walk” the fingers down the tongue to progressively displace the tongue anteriorly as the fingers are advanced to the epiglottis. The epiglottis will have a feel similar to the earlobe. As the third finger encounters the epiglottis, the finger traps and holds the epiglottis anteriorly. The ETT, with stylet configured to an open “C,” is introduced by the dominant hand into the corner of the mouth and advanced to the palmer side of the intraoral index finger. The intraoral index finger is then used to guide the ETT tip to the third finger, where the ETT is slipped between the epiglottis and third finger. The third finger is used to keep the ETT anterior against the laryngeal surface of the epiglottis while the ETT is advanced by the dominant hand and assisted by the intraoral index finger. It is often possible to palpate the arytenoid cartilages/interarytenoid notch, in which case one need only ensure that the ETT tip remains anterior to those cartilages and is prevented from drifting posteriorly to the esophageal inlet. The posterior cartilages project cephalad, feeling like snake fangs. Correct ETT position can be confirmed by palpating the arytenoid cartilages posterior to the ETT.

Pearls

1. Digital intubation may be the best airway delivery option in austere conditions or in patient with copious airway secretions or blood.

2. Can only be used in a paralyzed, comatose, or dead patient.

Equipment

The reusable ILA is similar in concept to the classic LMA but has a structural features that provide an easier and more stable insertion with less likelihood of tube kink. In addition, it has a unique “keyhole” like airway outlet which helps to direct an ETT to the midline at the proper glottic entry angle. Because it has a larger lumen, the ILA can accommodate standard ETT up to 8.5 mm ID. The ILA comes in five sizes—1.0 (<5 kg), 1.5 (10-20kg), 2.4 (20-50kg), 3.5 (50-70kg), and 4.5 (70-100kg), accommodating maximum ETT sizes of 4.5, 5.5, 6.5, 7.5, and 8.5, respectively.

Technique

The mandible is displaced anteriorly with a jaw lift maneuver, bringing the tongue and epiglottis forward. The ILA is then inserted into the mouth, advancing with a downward and inward force to follow the curve of the oropharynx/hypopharynx. The insertion endpoint is firm resistance to further insertion. The cuff is then inflated with approximately 20 mL of air or until the pilot balloon is firm. Ventilation can proceed by attaching a ventilating bag to the proximal port.

Intubation can be accomplished through the ILA in a well-sedated/chemically paralyzed patient after first removing the proximal 15-mm adaptor port. A well-lubricated standard ETT can then be inserted through the ILA. This procedure can also be aided by using a lightwand, opitcal sytlet, or fiberoptic intubating bronchoscope, or bougie, through the ETT to facilitate optimal alignment for intubation.

Once the ETT is inserted, the ILA can be easily removed by inserting the disposable tube stabilizer/stylet.

Equipment

The King laryngeal tube (King LT) consists of an airway tube with two cuffs. The distal cuff seals the esophagus and the proximal seals the oropharynx and nasopharynx when inflated. Between the cuffs are multiple ventilation channels. Inflation of the cuffs occurs through one inflation line. A separate gastric drainage channel is present in the disposable model (King LTS-D).

Technique

A lubricated King LTS-D is inserted behind the tongue while preforming a jaw lift, placing the patient in a sniffing position. The tube is advanced until resistance is met or until the connector base is aligned with the teeth or gums. The cuffs are inflated with 60 to 90 mL of air, depending on the size of the King LTS-D. Some “giggling” may be required to properly seat the tube.

Pearls

1. Most unsuccessful King LT placement attempts are due to failure to keep the tube in midline during insertion.

2. Anticipate vomiting when the King LT is removed.

Patient Preparation

The nares should be inspected for patency and the side deemed most hospitable to tube passage should be anesthetized and vasoconstricted, Additionally, it is helpful to confirm nasal patency by inserting a well-lubricated nasal trumpet. Lidocaine jelly can be used as the lubricant to provide additional topical anesthesia. We favor the use of disposable atomizers to instill 2 mL of a mixture of tetracaine 1%/phenylephrine 0.5%, which yields excellent mucosal anesthesia and vasoconstriction. Favorable intubation conditions can be achieved in about 5 minutes.

In preparation for nasal intubation, the ETT can be conformed into a circle by inserting the tip into the 15-mm proximal adaptor, and soaked in warm water to soften the tube for nasal passage. Success can also be enhanced by the use of a special ETT, called an Endotrol control tip ETT. This tube incorporates a length of nylon fishing line within a channel in the anterior wall of the ETT. Pulling on the proximal loop “trigger” causes anterior deflection of the tube tip.

Technique

Once the selected naris is suitably anesthetized, the intubator faces the patient, who can be sitting up or supine, and inserts the tube into the naris, parallel to the nasal floor/perpendicular to the facial plane (not along the nasal axis). To minimize trauma to the nasal turbinates, the bevel of the tube should face the turbinates. This implies that if the left naris is being intubated, the tube can be inserted along the normal curve of the nose-nasopharynx; however, if the right naris is being intubated, the tube should be inserted with the curve of the tube in a cephalad direction until the tube is advanced to the nasopharynx, at which point the tube is rotated to the correct anatomic configuration. As the tube is slowly advanced to the hypopharynx, the intubator listens closely for transmitted breath sounds, rotating the tube right or left to maintain maximal transmission. It takes a more-severe-than-expected rotation externally to generate a small rotation of the supraglottic tube tip. The tube is then rapidly advanced unless resistance is encountered, as would be expected with pyriform sinus tube tip position. Correct intratracheal placement should elicit cough, a reflex deep inspiration, and a loss of phonation. The intubator may also be sprayed with coughed secretions. If breath sound transmission decreases with advancement, the tube is withdrawn and re-advanced, preferably with more anterior displacement of the tip if the Endotrol tube is used. If such a tube is not available, anterior displacement can be produced by partially inflating the ETT cuff.

The audible feedback to determine tube tip position can be enhanced by the attachment of the Beck Airway Airflow Monitor (BAAM), which creates an amplified sound with air movement, much like the sound of a tea kettle. Alternatively, one can remove the diaphragm/bell from a stethoscope and insert the distal end of the stethoscope tubing into the proximal end of the ETT. In addition to amplifying transmitted sounds, this trick also can spare the intubator from a sputum ear wash. Positional feedback can also be enhanced by use of a quantitative waveform capnometer/capnograph.

Pearls

1. Blind nasotracheal intubation offers a viable option in the event that oral intubation is rendered impossible in the short term, such as a patient who has a wired jaw or large subglossal hematoma.

2. The blind nasotracheal intubation technique requires maintenance of spontaneous respirations because the intubator relies on audible variation in transmitted breath sounds via the ETT.

3. The TrachLight lightwand can be used for blind nasal tracheal (NT) intubation, with the stiffening wire removed. Tube tip position is determined identically to that with orotracheal transillumination, with identical repositioning maneuvers, except that rotational maneuvers are likely to be more extreme as noted above.

There are two methods of nasal flexible fiberoptic technique: (1) scope-first and (2) tube-first.

Patient Preparation

For both methods, the nose is prepared as described above under blind nasotracheal intubation.

Technique: Scope-First

The largest possible ETT, preferably 7.0 mm ID, is inserted over the endoscope to the most proximal position of the endoscope. The fiberoptic endoscope is then inserted through the selected naris. Under direct visual guidance, the endoscope is advanced along the floor of the nose, navigating under the inferior turbinate. The endoscope tip is manipulated by a combination of trigger deflection (up/down) and scope rotation (left/right) to keep the lumen in the center of the optical field. As the tube is advanced to the posterior nasopharynx, the scope tip is deflected downward to reveal the epiglottis and laryngeal inlet. The scope is advanced further, with the operator maneuvering the scope tip to keep the glottic opening in the center of the optical field. With the endoscope tip just above the cords, 2 mL of 1% lidocaine should be injected through the injection port of the fiberscope to provide vocal cord anesthesia prior to tube passage. The endoscope advancement continues until the endoscope tip is approximately 3 to 5 cm above the carina. The tube is then gently advanced over the fiberoptic sheath into the naris and to the trachea. If resistance is encountered at 14 to 16 cm, the tube may be impacting upon the right arytenoid. As discussed previously, this can be corrected by a severe counterclockwise rotation. The tube tip should be verified to be the correct distance from the carina.

If, during endoscope navigation through the nose, the view becomes blurry because of adherent secretions, the tip can be cleared by gently deflecting the tip into “pink” mucosa. If one becomes lost or disoriented during scope advancement or if there is no obvious lumen through which to advance, the endoscope should be withdrawn slightly and the tip maneuvered to provide a recognizable view. The endoscope should not be advanced if a lumen is not readily apparent.

Technique: Tube-First

To avoid some of the technique difficulty inherent with nasal navigation, the ETT can be passed through the naris and advanced into the hypopharynx first, before scope insertion. The endoscopist then inserts the intubating fiberscope through the ETT, and advances it to and through the glottic opening to the appropriate distance above the carina. Tube advancement proceeds as described above. The tube-first method may also facilitate endoscopic intubation in the event of epistaxis.

Equipment

The Melker kit manufactured by Cook Medical includes all the equipment necessary: catheter, thin-walled needle, Seldinger wire, cuffed tracheostomy tube 5.0 mm ID, and tapered introducer.

Technique

1. Identify the thyroid cartilage and the cricothyroid membrane directly caudally.

2. Prep the neck with suitable antiseptic; anesthetize the skin overlying the cricothyroid membrane with 1% lidocaine.

3. Isolate the trachea between the thumb and third finger of the sterilely gloved nondominant hand, using the index finger to palpate the cricothyroid membrane landmark. With a syringe attached, preferably containing sterile water or remaining lidocaine, insert the catheter through the cricothyroid membrane at a 30-degree angle to the horizontal, aiming toward the feet. Once through the skin, begin aspirating as the catheter is advanced. Air and bubbles entering the syringe confirm entry into the trachea.

4. Carefully slide the catheter off of the needle and into the trachea.

5. Reattach syringe and reconfirm tracheal position.

6. Thread Seldinger wire through catheter into trachea; lack of resistance to wire passage confirms correct position.

7. Remove catheter and, with the included scalpel, make a small incision at the wire-skin entry site.

8. Insert tracheostomy tube with dilator/introducer over wire into trachea. Expect significant resistance. Inability to pass dilator may indicate an inadequate skin incision

9. Withdraw dilator/introducer and wire as one unit, inflate cuff and initiate ventilation.

10. Secure tracheostomy tube with tracheostomy ties

Technique

1. Identify the thyroid cartilage and the cricothyroid membrane directly caudally.

2. Cleanse skin surface with appropriate antibacterial medication.

3. Anesthetize skin surface with 1% lidocaine.

4. While stabilizing the trachea with the gloved nondominant hand, make a vertical incision through the skin overlying the cricothyroid membrane.

5. Dissect the tissues over the cricothyroid membrane in a horizontal direction, until the cricothyroid membrane is exposed.

6. Incise the cricothyroid membrane horizontally and insert a tracheal hook to stabilize and control the trachea.

7. If a tracheal dilator is available, insert it into the trachea to dilate and control the trachea to facilitate tube insertion.

8. Insert a cuffed tracheostomy tube, or a 6.0 ID ETT.

9. Inflate cuff and initiate ventilation.