Supraglottic Airway Placement: Before Procedure

Indications

• Supraglottic airway placement (SGA) use for managing the airway:

• Bag-mask ventilation is ineffective or impossible:

• Noninvasive maneuvers such as nasal and oral airway placement, jaw thrust, chin lift, two- or three-person efforts are ineffective or fail to maintain SpO₂ >90%.

• Decision to utilize a supraglottic airway (e.g., laryngeal mask airway [LMA]) should be made rapidly to avoid desaturation or endanger the patient’s safety.

• Semi-elective use for ventilation/oxygenation support for procedures where bag-mask ventilation known or suspected to be difficult/cumbersome/patient intolerant to procedure without airway support (e.g., OSA patient for upper endoscopy with moderate sedation):

• Bronchoscopy in patients intolerant to sedation (OSA, obese, debilitated, cardiopulmonary cripple)

• Percutaneous tracheostomy

• Upper endoscopy

• Transesophageal echocardiography (TEE)

• Brief procedure requiring unconsciousness and airway control

Equipment

• Equipment for mask ventilation

• Induction medications, topical anesthesia medications, and equipment for intubation

• Disposable or reusable SGA device

• Lubricating jelly

• Syringe for cuff inflation/deflation

• Tape to secure SGA

• Bite block optional

• SGA includes many available models of the original LMA from LMA North America and the many available other brands with similar offerings.

• Choice of device is often based on cost, comfort with product.

• Evidence-based use exists for some but not all product offerings.

• Sizes range from neonatal to large adult, will vary by manufacturer.

• SGA sizes available should meet needs of patient population in your facility.

• SGA access in facility may be best on code cart, airway cart or bag, rapid-response care cart, resuscitation areas in any and all areas where airway management may take place, either elective, urgent, or emergent.

• Remote hospital locations may be covered by carrying SGA devices in a transportable airway bag or tackle box that is carried by the airway team.

Anatomy

Though there are a variety of SGAs that occupy the periglottic area and surround the glottic opening with a cuff, most models differ very little except in the manufactured materials, their flexibility or rigidity, ease of use, weight, and effectiveness. Most but not all (e.g., Igel laryngeal mask) have an inflatable cuff that lies in the hypopharynx and essentially seals the supraglottic region (from the epiglottis down the cricopharyngeal sphincter). A sealed airway allows positive pressure ventilation to be delivered but is limited by the effectiveness of the cuff seal/periglottic mucosal surface interface. Many will allow effective delivery of pressure breathing to 10 to 20 cm H₂O pressure before leaking, while other models are specifically designed to allow much higher sealing thresholds (25-35 cm). These latter models are particularly effective generating ventilatory support for the obese and morbidly obese patient and when confronted by low pulmonary compliance situations (congestive heart failure, acute respiratory distress syndrome, abdominal distention, pregnancy, ascites, and pulmonary fibrosis).

In general, placement of the SGA can be performed in the exaggerated “sniff” position to the other extreme, a neutral cervical spine. The SGA generally can be placed effectively when faced with little to no neck flexibility. The SGA is lubricated and then passed toward the roof of the mouth across the hard to soft palate, encouraging smooth advancement along the posterior throat so as to minimize getting hung up on the epiglottis. It typically comes to lie with its distal tip in the cricopharyngeal region. Unfortunately, the cuff end may buckle over on itself, come to lie over the glottic opening, or be displaced in a contorted position that impedes effective ventilation and oxygenation. The SGA may indeed be placed incorrectly but still function in near perfect form with effective ventilation; it is a peculiar airway device. It can be forgiving, yet it still requires skill and finesse to place it properly in most situations. Guidance by a skilled and frequent user is the best method to learn the details of its proper use. Ideally, it lies just over the glottic opening and allows access to the trachea. However, the SGA is frequently malpositioned or the epiglottis is folded over to a lesser or greater degree, partially or completely blocking the pathway to the glottic opening, yet ventilation and oxygenation remain unabated. This may be adequate for airflow to and fro but not for the passage of an ETT into the glottic opening. Hence, most generic SGA models do require fiberoptic-guided placement of an ETT because of the uncertain position of the SGA.

After Procedure

Postprocedure Care

• The SGA used in the semi-elective, urgent, or emergent setting is often of short duration (2-20 minutes), since the goal is typically to intubate the trachea. Hence the SGA acts as a rescue ventilation device and/or an intubation conduit.

Outcomes and Evidence

The LMA design offers a relatively short learning curve for the airway novice and affords fewer episodes of desaturation, less difficulty in maintenance of a patent airway, larger tidal volume than mask ventilation, and decreased arm and hand fatigue when compared with a conventional face mask. Its value in the ICU setting for assistance during emergency airway management is undeniable, especially during difficult intubation or when ventilation is not possible with a standard bag-mask assembly. Blind or fiberoptic-assisted tracheal intubation is an extremely attractive asset the SGA device offers the clinician and provides an entirely novel rescue approach when conventional laryngoscopy and tracheal intubation prove troublesome or impossible. It is also useful in maintaining airway support in the intensive care unit (ICU) setting for patients who require repetitive general anesthetic or heavy sedation-analgesia for brief procedures, fiberoptic bronchoscopy, or diagnostic visualization of the airway. Recent work suggests that the SGA is better tolerated and produces fewer cardiovascular side effects than tracheal intubation. Insertion in the patient with an unstable cervical spine may be far easier than direct laryngoscopy, because its insertion does not absolutely require neck manipulation.

The device may be difficult to place into the hypopharynx in the presence of a small mouth, a large tongue or tonsils, hypertrophied lingual tissue, or a posteriorly displaced pharynx. However, the SGA often proves easier to use than conventional methods of airway control such as direct laryngoscopy. The threat of gastric dilatation and regurgitation/aspiration may lead some to avoid its use in the critically ill, but its excellent track record and very low incidence of regurgitation/aspiration (0/278 emergency insertions, Hartford Hospital, TCM) supports its role as a primary airway rescue device when conventional methods fail. The role of the SGA as a rescue device in the elective and emergency setting is unparalleled, but further studies into its use in the emergency setting are needed to solidify its standing as the premier rescue airway device, regardless of which model is used.

Bougie-Assisted Intubation: Before Procedure

Indications

• Exchange of tracheostomy tube

• Exchange of ETT (Warning: most bougie models are approximately 55-65 cm in length and are shorter than the recommended airway exchange catheters. This may present a problem with maintaining control of the bougie during the exchange, owing to its length [component within the airway and the length outside the mouth available to thread new ETT].)

• Assist with passing ETT into trachea when limited by the “line of sight”:

• Full view of laryngeal inlet (unable to pass ETT because of hang up on cricoid ring)

• Partially obstructed view of laryngeal inlet:

• Grade II or III view of the larynx with laryngoscopy (conventional)

• Grade II: posterior third of glottis visible (Lehane-Cormack classification). More detailed classification (Cook-Yentis):

• Grade IIa: arytenoids and posterior cords visible

• Grade IIb: only epiglottic edge and arytenoids visible

• Grade III: no cords visible, only epiglottis visible; Cook-Yentis classification:

• Grade IIIa: only epiglottic edge visible

• Grade IIIb: downfolded or floppy epiglottis is visible

• Grade IV: no view of any airway structure; bougie use not recommended (Figures W1-1 through W1-6)

Figure W1-1 Line of sight with direct laryngoscopy.

Figure W1-2 Lehane Cormack laryngeal view grading system with the Cook-Yentis modifications, grade I→IV.

Figure W1-3 Cook-Yentis grade IIb laryngeal view with direct laryngoscopy achieves a very high success rate with bougie-assisted intubation.

Figure W1-4 Cook-Yentis grade IIIa view with direct laryngoscopy achieves a respectable success rate with bougie-assisted intubation, especially when compared to blind passing of the endotracheal tube “around the corner.”

Figure W1-5 A grade IV view, essentially no view at all of the laryngeal structures. The bougie is not indicated for a grade IV view. It is best handled with the laryngeal mask airway, fiberoptic bronchoscopy, or VL.

Figure W1-6 Two bougie models are shown (tracheal tube introducer). Note the characteristic 30-degree angle. Coude tip allows manipulation of the bougie tip underneath the epiglottis to increase its rate of passage through the laryngeal opening.

• Combined use with videolaryngoscope to assist with ETT placement:

• Channeled VL devices (Pentax AWS, AirTraq)

• Unchanneled VL devices (GlideScope, McGrath, Storz C-Mac):

• Very difficult to manipulate the bougie “around the corner” of the models with blades of excessive angulation (GlideScope, McGrath)

• Excellent adjunct with conventionally shaped “Video C-Mac”

• Useful if ETT is located just proximal to glottic opening and the bougie is passed through the existing ETT and then manipulated into the trachea

• Use of the bougie to determine the location of the ETT (esophagus versus trachea):

• Hang-up test (Cheney’s sign)

• Bougie tip will hang up on carina or mainstem bronchus, compared to simply passing unimpeded into the esophagus.

• Useful in cardiac arrest or clinical situation in which it is difficult to discern proper ETT placement

Contraindications

• Unfamiliar with its use

• Recent tracheal-bronchial reconstruction

Equipment

• A tracheal tube introducer “bougie” is an inexpensive, disposable, easily transportable airway device that requires minimal setup time, no battery or electrical power, and is noted on all the major airway-management algorithm lists of desired airway devices that should be immediately available.

• A variety of manufacturers offer bougie models in 55- to 65-cm length.

• Solid and hollow bougie models are offered by some manufacturers.

• Distinct black markings along the length of the bougie assist the clinician with the depth of insertion.

Anatomy

Though the bougie is capable of assisting intubation in nearly all airway situations except when “no view” is possible, it is most commonly used as an adjunct with Grade IIb, IIIa, and IIIb laryngeal views. Even when the laryngoscopy reveals a full view (grade I), the bougie may be useful when the hypopharyngeal opening is narrow (OSA, obesity, swelling) and passing the ETT may actually obstruct the view of the glottic opening. In this case, the narrower, more colorful tracheal tube introducer can be passed into the trachea with little visual obstruction taking place. Conversely, the floppy epiglottis is a challenge that may be technically difficult with many different airway adjuncts. The bougie may either be used to elevate the floppy epiglottis or be maneuvered around by virtue of the Coude tip. Though useful, the success rate is often less than 50%, and other alternatives may be needed (intubating laryngeal mask airway [ILMA], videolaryngoscope [VL], fiberoptic bronchoscope [FOB]) (Figure W1-7).

Figure W1-7 A grade IIIb view; floppy or overhanging epiglottis is relatively uncommon but may be difficult to navigate around with a variety of airway adjuncts. The bougie may be used to elevate the epiglottis and navigate into the trachea, but the success rate is substantially lower in the grade IIIb setting (30%-50%) compared to a grade IIIa (only leading edge of epiglottis visible, 80%-90%).

Procedure

• The bougie is grasped in the intubator’s right hand at the 20- to 25-cm mark.

• It is passed alongside the laryngoscope with the 30-degree angled tip (coude) anteriorly.

• The tip is advanced anterior to the arytenoids and into the larynx (grade IIa, IIb).

• The tip is advanced underneath the epiglottis and past the vocal cords blindly (grade IIIa).

• The tip lifts the floppy epiglottis and then is advanced blindly past the vocal cords (grade IIIb).

• Following advancement into the trachea to a depth of 22 to 26 cm in average adult:

• Tip may “bounce” or “click” past the tracheal rings, suggesting tracheal placement.

• This is a helpful sign but does not guarantee intratracheal placement.

• The lack of “clicks” does not guarantee the position of the bougie, nor does it rule out location within the trachea.

• 10%-50% of bougies passed into a grade III airway may enter the esophagus:

• Grade IIIa: 5%-12% may enter the esophagus

• Grade IIIb: 30%-50% may enter the esophagus:

• Quickly deploy backup strategy (SGA, ILMA, VL)

• Some may consider bougie as poor choice in grade IIIb view

• Tip may be gently advanced further (28-36 cm) to contact carina/main stem bronchus:

• Tip hang-up provides tactile feedback during blind passage.

• Detection of carina/bronchus is reassuring to operator.

• Advancement past 35-40 cm without hang-up strongly suggests the bougie is in the esophagus.

• Using hang-up or Cheney’s sign lowers the incidence and dangers of passing the ETT into the esophagus.

• Eliminates the delay of verifying the ETT location by insufflation, capnography, auscultation

• Decision time: passing the ETT:

• If time permits, generously lubricate the ETT.

• Smaller-sized ETT pass over the bougie more easily than larger ones.

• Maintain tongue displacement with laryngoscopy/hand grasp.

• Pass the ETT, but do not force the advancement (an assistant should grasp the proximal end of the bougie to stabilize it).

• Anticipate resistance at 16-17 cm depth due to impingement on arytenoid/vocal cord (2 methods to remedy this) (Figure W1-8):

Figure W1-8 Endotracheal tube (ETT) being passed over tracheal tube introducer (TTI, bougie) and getting hung up on the epiglottis and arytenoid. Continued advancement should be discouraged. Simply withdraw 1 to 2 cm, rotate ETT counterclockwise about 90 degrees, and readvance. VC, vocal cord.

• Preemptively advance ETT while rotating in the counterclockwise (CCW) direction to allow ETT to avoid impingement on the glottis.

• If resistance is encountered, stop and withdraw ETT 2 cm, then rotate CCW and advance the ETT into the airway.

• If ETT fails to pass, the patient may be ventilated and oxygenated with bag-mask ventilation (move the bougie to the corner of the mouth).

• Change to a smaller-diameter ETT (to ease advancement over the bougie) and assume the glottic opening may be swollen, impeding entry.

After Procedure

Postprocedure Care

• Following advancement of ETT into the trachea, stabilize the ETT in position, and remove the bougie.

• Standard methods of determining the ETT position are required.

Outcomes and Evidence

The simplicity of the trachea tube introducer makes it an attraction option for assisting with trachea intubation in the situation when a restricted laryngeal view is available with laryngoscopy. A variety of uses for the bougie make it a desirable addition to the difficult airway cart or bag, made accessible at the bedside in the ICU and other remote locations in the hospital. The bougie is a suggested option in the management algorithms offered by anesthesiology societies in the United States, Canada, the United Kingdom, Germany, and many other countries.

Use of the Intubating Model of the LMA for Emergency Airway Rescue (Fastrach) ILMA: Before Procedure

Indications

• Emergency rescue of the airway when tracheal intubation is the goal:

• Failed conventional intubation attempts

• Failed bougie-assisted intubation

• Failed videolaryngoscopy intubation

• May be a substitute for conventional SGA device following its failure to secure successful ventilation/oxygenation

Contraindications

• Inexperienced operator/airway team

• Major risk for regurgitation/aspiration (relative; loss or lack of airway is worse)

• Oral cavity inaccessible/trismus

• Similar to other SGA devices

Equipment

• Equipment for mask ventilation

• Induction medications, topical anesthesia medications, and equipment for intubation

• Disposable or reusable models of the ILMA, ETT, stabilizing rod

• Lubricating jelly

• Syringe for cuff inflation/deflation

• Tape to secure SGA

• Bite block not needed

Anatomy

In general, placement of the ILMA can be performed in the exaggerated “sniff” position or the other extreme, a neutral cervical spine. The ILMA is lubricated and then passed along the roof of the mouth across the hard to soft palate, encouraging smooth advancement along the posterior throat so as to minimize getting hung up on the epiglottis or causing its downfolding. The distal tip of the ILMA typically comes to lie with its distal tip in the cricopharyngeal region. Unfortunately, the cuff end may buckle over on itself, come to lie over the glottic opening, or be displaced in a contorted position that impedes effective ventilation and oxygenation (Figures W1-9 through W1-16).

Figure W1-9 Deflate the cuff, and lubricate with a water-soluble lubricant on the posterior surface. The lubricated intubating laryngeal mask airway is passed over the hard to soft palate along the posterior pharyngeal wall to the point where gentle resistance is felt.

Figure W1-10 Swing the mask into place in a circular movement, maintaining contact against the palate and posterior wall of the pharynx. Do not use the handle as a lever.

Figure W1-11 Inflate the mask, without holding the tube or handle, with approximately 10 to 20 mL of airway to seal the airway. Apply a manual bag or anesthesia circuit to the intubating laryngeal mask airway (ILMA) and verify ventilation. If no ventilation (leak or resistance), assume misplacement of ILMA or downfolding of the epiglottis. Manipulate the ILMA in an up-and-down or in-and-out maneuver to optimize position. Recheck ventilation, and adjust location of the ILMA to optimize ventilation. Do not attempt passing the endotracheal tube until effective ventilation is ensured.

Figure W1-12 Hold the intubating laryngeal mask airway (ILMA) handle while gently inserting the lubricated endotracheal tube (ETT) into the airway shaft. The provided ILMA-ETT is best suited for this, though a well-lubricated standard ETT may be used with fiberoptic guidance or may be used (with proper training and experience) blindly by inserting it “backwards,” meaning the concave curve of the ETT faces the nose as it is advanced into the ILMA shaft.

Figure W1-13 Advance the endotracheal tube (ETT), inflate the cuff, and confirm intubation. If unable to pass, ensure adequate lubrication. If resistance is felt, the intubating laryngeal mask airway (ILMA) may be malpositioned or may have entrapped the epiglottis and thus may block the ETT advancement. Try the in-and-out maneuver to reposition the ILMA and free up the epiglottis if applicable.

Figure W1-14 Remove the endotracheal tube (ETT) connector, and place the provided stabilizing rod onto the end of the ETT. Then ease the intubating laryngeal mask airway (ILMA) over the existing ETT and rod by gently swinging the handle caudally (keeping the ETT stable in position) until the ETT can be grasped at the level of the incisors.

Figure W1-15 Remove the stabilizing rod, and gently unthread the inflation line and pilot balloon of the endotracheal tube (ETT). Replace the ETT connector, and confirm ventilation and position per standard intubation procedures. If the intubating laryngeal mask airway (ILMA) has been used on a very challenging airway or the patient is unstable, delay removal of the ILMA from the existing ETT until stabilization takes place. Extubation of the airway is possible, so this maneuver should only be performed by those skilled in its execution.

Figure W1-16 Cook Critical Care prepackaged retrograde wire intubation kit.

ILMA use should be learned prior to its deployment in an emergency airway crisis. Training on a mannequin or humans under elective conditions by a skilled practitioner is best.

Procedure

• The intubating model of the LMA is placed into the airway in a similar fashion as other LMA products. However, the shortened length of the ILMA model and its handle may be simpler to place than the standard LMA model. Placement is augmented by passing it along the hard to soft palate posteriorly into the hypopharynx, posterior to the epiglottis. It too comes to lie with its tip atop the cricopharyngeal area posterior to the arytenoids/glottis. The tip may fold over or under and impede air exchange or be sensed by an incomplete cuff seal (leak). This can be remedied by performing the “in-and-out” or “up-and-down” maneuver (simply moving the ILMA slightly inward and outward to free up the distal tip). Cuff inflation is followed by positive pressure oxygen delivery. Successful placement allows chest rise, ETCO₂ detection, with no audible air leak to approximately 15 to 25 cm H₂O pressure applied to the ILMA. Always confirm ventilation prior to attempting ETT advancement via the ILMA.

• Two maneuvers are handy to improve success in ILMA placement and intubation:

• Following ILMA placement, Chandy maneuver #1 involves using the ILMA handle to optimize the positioning of the ILMA within the airway, with the goal of maximizing tidal volume, ETCO₂, and the feel of “bagging.” The ILMA is held in this position in preparation for passing a lubricated ETT. The included LMA brand wire-reinforced ETT is an excellent ETT for passing, but it is suboptimal for long-term use in the ICU airway (if duration of intubation is >24-48 hours, one should consider changing the ETT over an airway exchange catheter to the standard ICU ETT model).

• Once effective ventilation/oxygenation is established, passing an ETT may be the next objective. With the ILMA in the best ventilating position (Chandy #1), Chandy maneuver #2 involves using the ILMA handle to slightly elevate or “lift” the ILMA (handle toward forehead, ILMA distal tip anteriorly) to improve the success rate of passing the ETT into the trachea, based on the ILMA portal being tilted toward the glottic opening and away from the esophagus. This lift increases seal pressure and improves the alignment of the ILMA to the glottic opening and corrects any flexion the mask has undergone following its placement. Malposition or flexion of the mask while in the ventilating position may alter the pathway of the ETT as it exits the ILMA. Generous lubrication of the ETT to ease passage through the ILMA lumen is an absolute. Intubation of the trachea may be performed blindly or with fiberoptic assistance. The skill to successfully intubate the trachea is attained by practice coupled with instruction by an experienced individual. Practicing the technique before an emergency situation arises is in the best interest of patient care.

• Troubleshooting in the event of failure to intubate (typically caused by a downfolded epiglottis, ETT impaction on the periglottic tissues, too large or too small ILMA, or patient is resisting intubation because of inadequate sedation/analgesia/muscle relaxation/anesthesia):

• If resistance is felt approximately 2 cm beyond the black transverse line marked on the ILMA ETT (or 15-16 cm marking on a standard ETT), the downfolded epiglottis may be blocking ETT advancement, as may the vestibular wall. Rotation of the ETT may allow passage if impeded by the vestibular wall. A downfolded epiglottis may need to be addressed by performing the “up-and-down” maneuver. This is a partial withdrawal of the inflated ILMA to a maximum of 6 cm, followed by reinsertion. This often frees the epiglottis from its downfolded position. Otherwise, FOB assistance is needed, or a different size ILMA may be tried.

• If the ETT meets immediate resistance at 15 to 16 cm (black mark) or at 4- to 5-cm depth past the black mark, then the ILMA is too large, and downsizing may help.

• If resistance is encountered at 3 cm past the black mark, the ILMA may be too small. If an alternative-size ILMA is not available, external manipulation of the larynx either downward or caudally may assist with passing the ETT. Likewise, ETT rotation may be helpful.

• Another miscellaneous yet quite important clinical situation that may prohibit intubation is excessive periglottic/glottic edema when viewing with the FOB. Massive airway edema may preclude advancement of the FOB-ETT owing to the inability to clearly identify the glottic opening; caution must be exercised to not advance the FOB tip into unrecognizable tissue planes. Excessive force on the FOB or ETT may lead to tissue injury and thus threaten the current airway patency by inducing further bleeding, edema, or swelling. Attaching a bronchoscopic swivel adapter to the ILMA itself or via the ETT may allow active application of positive pressure to the airway and promote lateralization of the edematous glottic tissues. This is analogous to the use of continuous positive airway pressure (CPAP) in OSA patients. The bronchoscopic adapter is too narrow to allow an ETT to pass through it. To remedy this, an Aintree catheter (bougie-type catheter with a lumen that allows a proper-sized FOB to be placed within the catheter) is sized to fit through the adapter and its diaphragm. The Aintree-FOB assembly may be passed through the bronchoscopic adapter, down the ILMA, and used to visualize the glottic opening. Once advanced into the trachea, the Aintree remains within the trachea as the FOB is withdrawn. The ILMA is then removed over the Aintree, and the ETT is advanced over the Aintree catheter in similar fashion to a bougie, tube exchanger, or FOB.

After Procedure

Postprocedure Care

• Following “blind” intubation of the trachea, standard methods to confirm ETT position are pursued (chest auscultation, ETCO₂ detection, ETT misting, chest rise, etc.).

• Following fiberoptic-assisted intubation, the same clinical confirmation of ETT position should be pursued, even though visualization of the ETT within the trachea with FOB is considered failsafe. The caveat here is that FOB confirmation, though failsafe under ideal conditions, may be limited by secretions, edema, soilage, operator inexperience, faulty battery power, and the like in the ICU airway.

• With the ETT-ILMA assembly in place, the ILMA has to be carefully removed from the patient while leaving the ETT within the trachea. Accidental tracheal extubation during ILMA removal could be disastrous.

• Step-by-step removal of the ILMA is outlined later.

• If one is unfamiliar with ILMA removal, a more experienced team should be summoned to assist with this task. Conversely, if the patient’s clinical condition needs to be stabilized prior to its removal, at a minimum, the air should be removed from the ILMA cuff to reduce the pressure effect on the pharyngeal mucosa.

Outcomes and Evidence

• The use of the ILMA has revolutionized airway management, especially in the emergency setting. It is an accepted component in the American Society of Anesthesiologists (ASA) airway management algorithm, as well as all other algorithms offered by medical societies throughout the world. The presence of videolaryngoscopy has potentially altered the ILMA’s role as a logical and rational first step toward airway rescue when conventional methods fail or are inappropriate. However, the clinician must be familiar with this device and have it readily available as a backup for VL difficulties or failures.

• In the elective setting, the ILMA has an excellent track record for a high level of successful ventilation coupled with blind and FOB assisted intubation. Its successful deployment in the acute care setting in the ICU, the emergency department, or other remote locations outside of the operating room has been well received, though the success rate for both ventilation and intubation is tempered to a more realistic success rate of nearly 8 to 9 out of 10 patient encounters. Thus, a backup plan must be in place to deal with ILMA failure and establish effective ventilation/oxygenation and ultimately tracheal intubation, either blindly or with FOB assistance.

Retrograde Wire Intubation: Before Procedure

Indications

• Secure the airway in the elective setting with the patient awake, with adequate topicalization of airway with local anesthetics or local nerve blocks

• Trismus, severe temporomandibular joint (TMJ) disease, limited cervical range of motion

• Known difficult mask ventilation, intubation

• Secure the airway emergently in the setting that mask ventilation/oxygenation is effective

• Retrograde wire-guided intubation, in the best situation, may require 2 to 5 minutes to complete, hence one must be able to sustain ventilation/oxygenation.

• Secure the airway electively when difficult airway factors are known or suspected to exist and intubation by other means may be difficult or impossible.

Equipment

• Guidewire (suggested >60 cm) matched to appropriate needle size allowing advancement

• 20, 18, 16 or 14-gauge cutting needle on a syringe

• Cuffed 6.0 endotracheal tube

• Hemostat or Kelly clamp

• Alternative: manufactured retrograde wire intubation kit (Cook Critical Care) (see Figure W1-16)

• Optional: flexible fiberoptic bronchoscope

Anatomy

The cricothyroid membrane is located between the superior thyroid cartilage and the inferior cricoid ring. The cricothyroid membrane is located just 1.5 to 2 cm below the vocal cords, so care must be practiced when advancing a needle caudad, as the underside of the vocal cords could be impaled. Passing the ETT over the wire or obturator/wire may be met with resistance at the 16- to 17-cm depth, as the ETT tip may impinge on the vocal cords or arytenoids. This is the inherent danger of passing the ETT blindly over the wire or obturator/wire assembly. The location of the distal tip (having met resistance) may or may not be at the position below the vocal cords. This is the challenge of the retrograde wire method; knowing the location of the ETT tip is unknown when the decision is made to remove the wire. If the ETT tip is erroneously positioned above the glottis, then the access to the airway is denied with wire removal; hence, the advantage of using the FOB as an intubation guide (Figure W1-17).

Figure W1-17 Anatomical landmarks for access to the cricothyroid membrane.

Procedure

• Retrograde tracheal intubation:

• Needle insertion directed cephalad; operator should approach with dominant hand more caudad (e.g., right-handed operator on right side of patient)

• Puncture cricothyroid membrane with needle directed cephalad (Figure W1-18).

Figure W1-18 Puncture of cricothyroid membrane, with air aspiration reflected in bubbling in saline-filled syringe.

• Aspirate air with syringe to locate air column (1-2 mL of saline in syringe; allow bubbles to percolate to verify the air column).

• Pass guidewire through needle aimed superiorly so that distal end of wire may be retrieved from mouth (or if desired, nose) of patient. Withdraw needle off wire:

• Pull majority of wire out of the mouth (or naris)

• Secure distal end of wire by clamping hemostat at level of the cricothyroid membrane (Figures W1-19 and W1-20)

Figure W1-19 Locating and retrieving the retrograde wire within the oral cavity.

Figure W1-20 Advancing the wire from the neck to the oral cavity.

• Three choices to pass ETT down the wire into the airway (nasal or oral): (1) wire assisted, (2) wire with obturator to reinforce wire, (3) flexible bronchoscope (loaded with ETT) passed over wire into airway

• Wire assisted:

• Load lubricated ETT over oral (or nasal) end of wire, passing wire into tube through Murphy’s eye.

• Pull wire relatively taught and straight.

• Advance ETT over wire into trachea to cricoid area, then gradually relaxing cricothyroid end of wire, advance ETT to appropriate intratracheal location.

• Release cricothyroid end of wire, and withdraw wire out of ETT.

• Confirm ETT position (auscultation/capnography).

• Flexible FOB (loaded with smaller-sized ETT [6-7 mm]) (Figure W1-22)

Figure W1-22 A better choice than the obturator is the FOB passed over the wire via the suction port of the fiberoptic bronchoscope.

• Advance wire through the suction portal of the FOB.

• Grasp wire end from top of FOB.

• Advance FOB down wire, observing the airway structures as you advance (Figure W1-23).

Figure W1-23 Retrograde wire seen emerging from glottis.

• Advancing the FOB to distal end of wire will occlude view and appear “pink” (backside of cricothyroid membrane). Correct position may be verified by darkening the room to transilluminate the cricothyroid membrane puncture site (Figure W1-24).

Figure W1-24 Fiberoptic bronchoscope (FOB) passed over retrograde wire, with tip of FOB at wire insertion site at the cricothyroid membrane, with transillumination of light from the FOB.

• Once the FOB is below the vocal cords, the cricothyroid end of wire may be released as fiberscope is advanced to carina and wire, then pulled out of fiberscope.

• Or the wire may be pulled out inferiorly through cricothyroid puncture and fiberscope then advanced into the trachea.

• Advance the FOB tip into distal trachea, and advance ETT into position and confirm.

After Procedure

Postprocedure Care

• Following advancement of ETT into the trachea, stabilize the ETT in position.

• Standard methods of determining the ETT position are required.

Outcomes and Evidence

Retrograde intubation, once a prominent adjunct prior to today’s many varied airway devices, retains an important position in managing the difficult airway, but it has been relegated to a much less prominent role. It is important for clinicians to maintain the ability, knowledge, and equipment to perform this specialized method of securing the airway. Even in the best of clinical situations and manned by an experienced team, this method remains a relatively time-consuming technique that limits it to the nonemergency pathway, where ventilation/oxygenation is possible with either bag-mask ventilation or SGA.

Needle Cricothyrotomy with Transtracheal Jet Ventilation: Before Procedure

Indications

(Similar to cricothyrotomy)

• Impossible or failed oral or nasal endotracheal intubation owing to any of the following:

• Difficult or impossible intubation (CVCI)

• Massive oral, nasal, or pharyngeal hemorrhage

• Massive regurgitation or emesis

• Masseter spasm, clenched teeth, TMJ limitations

• Structural deformities of oropharynx, congenital or acquired

• Stenosis/narrowing of upper airway

• Mass (cancer, tumor, polyp, or other) with partial obstruction

• Airway obstruction (partial but not complete) above cricothyroid membrane

• Nontraumatic versus traumatic:

• Oropharyngeal edema

• Mass (cancer, tumor, polyp, or other) (Figure W1-25)

Figure W1-25 Classic example of when not to incorporate transtracheal jet ventilation (TTJV). This intratracheal tumor mass occludes more than 85% of the tracheal lumen. Providing high-pressure TTJV supports oxygen transfer into the pulmonary tree, but overpressurization of the thorax will likely occur, because egress of the transmitted pressure may be blocked by the mass and its potential ball-valve effect. Likewise, a glottic or subglottic mass (above the site of needle insertion) may equally disallow egress or relief of the pressure buildup with high-pressure TTJV, thus leading to barotrauma.

• Traumatic:

• Foreign body obstruction

• Stenosis

• Traumatic injuries making oral or nasal endotracheal intubation difficult or potentially hazardous:

• Maxillofacial injuries

• Cervical spine instability

Equipment

• Sanders handheld high-pressure ventilator

• 12/14-gauge Jelco on a syringe

• Optional: wire-reinforced needle-catheter (e.g., Cook Critical Care)

• Alternatively: ENK oxygen modulator system by Cook Critical Care (low-pressure choice). Requires 15 L/min oxygen supply. Oxygen delivery is derived by finger occlusion of the portals on the plastic assembly. Delivered in similar ratio as high-pressure transtracheal jet ventilation (TTJV).

Anatomy

The thyroid cartilage consists of two approximately quadrilateral-shaped laminae of hyaline cartilage that fuse anteriorly to form the laryngeal prominence. The anterior superior edge of the thyroid cartilage, the laryngeal prominence, is known as the Adam’s apple and is usually easily seen in men. It is probably the most important landmark in the neck when performing a cricothyrotomy. The cricoid cartilage is shaped like a signet ring with the shield located posteriorly and forms the inferior border of the cricothyroid membrane. The thyroid cartilage forms the superior border of the cricothyroid membrane.

The cricothyroid membrane is a dense fibroelastic membrane located between the thyroid cartilage superiorly and the cricoid cartilage inferiorly; the cricothyroideus muscles bound it laterally. The cricothyroid membrane covers an area that is trapezoidal in shape. The average size of the cricothyroid membrane in the adult is approximately 22 to 30 mm wide and 9 to 10 mm high. Palpating a notch, a slight indentation or dip in the skin inferior to the laryngeal prominence, can identify the cricothyroid membrane. The cricothyroid membrane is located approximately 2 to 3 cm below the laryngeal prominence in an adult.

Procedure

• Place the patient in supine position (shoulder roll to extend cervical spine forward if possible).

• Prep neck area if time permits.

• Locate cricothyroid membrane.

• Using a 12- or 14-gauge needle on a syringe, puncture the skin midline and directly over the cricothyroid membrane. (2-3 mL saline in 5- or 10-mL syringe will assist visualizing bubbles).

• Direct the needle at a 45-degree angle caudally, and carefully insert it through the upper half of the cricothyroid membrane, aspirating as the needle is advanced. Aspiration of air signifies entry into the tracheal lumen.

• Secure the needle (assign one person to maintain catheter position), and attach Luer-Lok end of high-pressure ventilator.

• Administer low-pressure airflow (5-10 psi initially) bursts of positive-pressure ventilation.

• 6-10 breaths per minute to maximize exhalation time (I/E ratio > 1 : 5)

• Adjust pressure upward with the goal of visible chest wall excursions and life-sustaining saturation.

• Continue efforts to maintain airway patency to ensure egress of pressurized air (exhalation):

• Jaw thrust, chin lift, neck extension

• Oral airway, nasal airway, tongue retraction

• SGA device, laryngoscopy

• TTJV is short-term oxygen delivery strategy during airway management difficulties

• Alternative airway management methods should be pursued.

• Continue efforts to secure the airway from above if feasible.

• Pressurization of airway may allow previously failed rescue methods to succeed.

• NOTE: placing catheter via cricothyroid membrane prior to airway intervention (anticipating difficulty) is acceptable, since placement during a crisis is often hindered by lack of landmarks, suboptimal positioning, and inexperience. If placed but not used, it can be simply removed with little consequence.

After Procedure

Postprocedure Care

• TTJV is considered a short-term “fix” to supplement oxygenation in a life-saving fashion; ventilation (CO₂ exchange) may be limited.

• Continued efforts to secure the airway with advanced techniques (FOB, VL, SGA) should be pursued.

• Creation of a surgical airway (tracheostomy) is possible with active TTJV taking place.

• Removal of the catheter is quick and with little consequence.

Outcomes and Evidence

• Patient outcomes after TTJV are related to their coexisting condition:

• Recognized as life-saving maneuver in many airway management algorithms

• Lack of training, lack of practice, low frequency of performing procedure make it high risk

• Successful catheter placement may be fraught with incorrect I : E ratio, excessive delivery of breaths (>12/min), lack of pressure egress

• Owing to the emergency nature of the procedure, randomized controlled studies in humans are not possible in the emergency setting.

• Technique used successfully in elective setting with proper equipment, trained and knowledgeable personnel performing TTJV

Needle and Surgical Cricothyrotomy: Before Procedure

Indications

• Airway obstruction (partial or complete) that cannot be cleared

• Nontraumatic:

• Oropharyngeal edema

• Laryngospasm

• Mass (cancer, tumor, polyp, or other away from insertion site)

• Traumatic:

• Foreign body obstruction (above level of insertion)

• Supraglottic, glottic or subglottic stenosis/narrowing (above insertion site)

• Traumatic injuries making oral or nasal endotracheal intubation difficult or potentially hazardous:

• Maxillofacial injuries

• Cervical spine instability

• Elective versus urgent versus emergent:

• Elective: critical airway situation noted prior to induction, patient hemodynamically stable, oxygenation/ventilation adequate

• Urgent: critical airway situation noted prior to or during induction, patient’s hemodynamics and/or oxygenation/ventilation compromised

• Emergent: critical airway situation during induction, patient hemodynamically unstable and/or oxygenation/ventilation deterioration

Anatomy

The thyroid cartilage consists of two approximately quadrilateral-shaped laminae of hyaline cartilage that fuse anteriorly to form the laryngeal prominence. The anterior superior edge of the thyroid cartilage, the laryngeal prominence, is known as the Adam’s apple and is usually easily seen in men. It is probably the most important landmark in the neck when performing a cricothyrotomy. The cricoid cartilage is shaped like a signet ring with the shield located posteriorly and forms the inferior border of the cricothyroid membrane. The thyroid cartilage forms the superior border of the cricothyroid membrane (Figure W1-27).

Figure W1-27 Anatomical outline shows the sternal notch (lower “V”), the straight line (cricoid ring), and the two curved arrows that overlay the cricothyroid membrane, with the outline of the thyroid cartilage above the cricothyroid membrane.

The cricothyroid membrane is a dense fibroelastic membrane located between the thyroid cartilage superiorly and the cricoid cartilage inferiorly; the cricothyroideus muscles bound it laterally. The cricothyroid membrane covers an area that is trapezoidal in shape. The average size of the cricothyroid membrane in the adult is approximately 22 to 30 mm wide and 9 to 10 mm high. Palpating a notch, a slight indentation or dip in the skin inferior to the laryngeal prominence, can identify the cricothyroid membrane. The cricothyroid membrane is located approximately 2 to 3 cm below the laryngeal prominence in an adult.

Procedure: Conventional Approach

• Place the patient in a supine position, hyperextended neck with shoulder roll if possible.

• Surgically prep the area using antiseptic solution (if applicable, time permitting).

• Palpate the cricothyroid membrane anteriorly, between the thyroid cartilage and cricoid cartilage.

• Immobilize the larynx—in the right-handed operator, the thumb and long fingers of the left hand are used to grasp the thyroid cartilage.

• Incise the skin—vertical and midline, approximately 2 to 3cm in length from the depth of the thyroid cartilage, membrane, and cricoid cartilage.

• Prepare subcutaneous tissue—dissect down to the cricothyroid membrane.

• Incise the membrane—transverse, midline, and at least 1.5 cm long to facilitate ETT placement.

• Place tracheal hook on lower edge of thyroid cartilage, lift upward and cephalad.

• Alternatively, place tracheal hook on upper edge of cricoid ring, lift upward and caudad.

• Place ETT or tracheostomy tube—smaller diameter preferred (5.0 to 6.5 mm)

• Inflate cuff, confirm placement using auscultation and/or capnography.

• Secure the tube.

• Optional: FOB evaluation

Procedure: Stylet-Dilator Method

• Place the patient in a supine position, hyperextended neck with shoulder roll if possible.

• Surgically prep the area using antiseptic solution (if applicable, time permitting).

• Palpate the cricothyroid membrane anteriorly, between the thyroid cartilage and cricoid cartilage.

• Using a 14-gauge needle on a syringe, puncture the skin midline and directly over the cricothyroid membrane.

• Direct the needle at a 45-degree angle caudally, and carefully insert it through the upper half of the cricothyroid membrane, aspirating as the needle is advanced. Aspiration of air signifies entry into the tracheal lumen.

• Secure the needle, and advance the flexible end of the wire first.

• Once a sufficient amount of the wire is introduced into the trachea, remove the needle.

• Using a 20-blade scalpel, make a deep horizontal puncture.

• Insert the dilator and endotracheal tube assembly onto the wire, and gently advance through the cricothyroid membrane with a continuous downward twisting motion.

• Remove the dilator, inflate the endotracheal cuff, and connect the breathing circuit.

• Secure ETT, auscultate breath sounds, and confirm the return of CO₂.

• Optional: FOB evaluation of airway

Procedure: Seldinger Technique–Melker Cook Critical Care

• Supine position, hyperextended neck with shoulder roll if possible

• Surgically prep the area using antiseptic solution (if applicable, time permitting).

• Palpate the cricothyroid membrane anteriorly, between the thyroid cartilage and cricoid cartilage.

• Immobilize larynx as described earlier.

• Puncture the skin and the cricothyroid membrane with the puncture cannula with connected syringe.

• Aspiration of air confirms entry into trachea with needle directed caudad.

• Disconnect syringe from needle, pass the wire caudad into airway, remove needle.

• Incise skin 0.5 to 1 cm on each side of the wire guide.

• Insert the dilator together with deflated airway catheter over the wire, through the skin, into the trachea,

• Remove dilator, inflate cuff, and confirm correct tube placement.

• Secure ETT, auscultate breath sounds, and confirm the return of CO₂.

• Optional: FOB evaluation of airway

Procedure: Surgical Approach–Rapid Four-Step or Modified Three-Step

• Supine position, hyperextended neck with shoulder roll if possible

• Surgically prep the area using antiseptic solution (if applicable, time permitting).

• Palpate the cricothyroid membrane anteriorly, between the thyroid cartilage and cricoid cartilage.

• Immobilize larynx as described earlier.

• Incise skin and cricothyroid membrane transversely with scalpel blade.

• Insert a tracheal hook through the incision, take the cricoid cartilage with the hook.

• Move to a more ventral and caudal position (outward and downward direction with hook).

• Insert smaller-diameter ETT into opening of trachea.

• Three-step technique:

• Midline incision into the skin followed by horizontal division of cricothyroid membrane

• Advancement of elastic bougie through tracheal space into right mainstem bronchus

• Advancement of ETT over bougie, removal of bougie

• Secure ETT, auscultate breath sounds, and confirm the return of CO₂.

After Procedure

Postprocedure Care

• Postprocedure care should include the insertion of an orogastric or nasogastric tube in cases of full stomach.

• Revision of the cricothyrotomy may be needed as soon as the patient is stable.

• Most cases have previous laryngeal damage or postobstruction pulmonary edema and will require ventilation in the ICU.

Outcomes and Evidence

• Patient outcomes after needle cricothyrotomy are related to coexisting conditions.

• Lowest survival rates are associated with cricothyrotomy undertaken during cardiac arrest (only 6%), compared to 76% for any other reason.

• Most common causes of death are patient comorbidities, followed by failure to achieve an airway, and lastly by the procedure itself.

• Owing to the emergency nature of the procedure, randomized controlled studies in humans are not likely to be performed.

• Because cricothyroidotomy is a rarely performed but potentially life-saving procedure of last resort in the patient with a failed airway, clinicians responsible for airway management must retain familiarity with the necessary equipment and relevant anatomy.

• Clinicians responsible for advanced airway management should review the anatomy and practice with the equipment needed for cricothyroidotomy several times per year.

• At the very least, clinicians should know who to call for assistance with gaining surgical access to the airway.

• Immediate access to needed equipment is imperative to optimize patient safety.

• Delay in starting surgical access, lack of equipment, and inexperience with the technique are the most common underlying reasons for poor outcome.

Esophageal-Tracheal Combitube: Before Procedure

Indications

• Emergency airway device in the cannot intubate/cannot ventilate pathway

• Provides rapid control of airway when intubation is impossible and other techniques of securing the airway fail

• Airway management when the patient situation disallows laryngoscopy or bag-mask ventilation due to positioning, confinement:

• Example: trapped in a car after motor vehicle crash and inability to perform laryngoscopy

Contraindications

Equipment

• The Esophageal-Tracheal Combitube (Kendall-Sheridan, Argyle, New York) is available in two sizes, 41F (large adult) and 37F. It is a double-lumen soft plastic tube that is inserted into the mouth with or without laryngoscopy and advanced blindly into either the trachea or esophagus (>90% pass into the esophagus). The Combitube has two inflatable cuffs: a smaller distal cuff similar to that of a conventional endotracheal tube and a larger proximal cuff designed to seal the pharynx. Once placed, the practitioner must ventilate the proper conduit to deliver oxygen into the trachea. Understanding the Combitube’s design is imperative to its successful use and fosters the ability to troubleshoot difficulties. The Combitube is joined by its recently introduced cousins, the Rusch EasyTube and King laryngeal tube (LT). The Rusch EasyTube is a latex-free alternative that is offered in a large model (similar to the Combitube 41F) and a smaller adult version (35F). The Combitube enters the esophagus in over 95% of cases; ventilation is through lumen #1 (blue connector). End-tidal CO₂ detection, pulse oximetry, and other confirmatory measures must be confirmed for all placements. The occasional placement in the trachea requires ventilation of the lungs through lumen #2 (Figure W1-28).

Figure W1-28 King laryngeal tube (LT) (upper) and Combitube (lower) are both dual-balloon airway devices. Combitube has a long track record of excellent performance but is being challenged by the smaller-sized King LT, with its single pilot valve/dual cuff design and single ventilation portal.

• Another airway device that is gaining popularity for in-hospital and prehospital use is the King LT, which is blindly inserted into the hypopharynx with the distal tip inserted past the cricopharyngeal opening of the esophagus (not in the trachea). The ventilation portal comes to rest posterior and inferior to the epiglottis in proximity to the open glottis. It has two high-volume low-pressure inflatable balloons similar to the Combitube (one that occludes the esophagus and one that inflates in the posterior oropharynx) yet requires fewer steps, because it is reliant on only a single site of inflation. The distal cuff is designed to seal the esophagus. The proximal cuff is intended to seal the oropharynx. Ventilation is achieved via a 15-mm connector (single portal as opposed to the Combitube’s two) for attachment to a standard breathing circuit or resuscitation bag. The patient may breathe spontaneously via the King LT. CO₂ detection is adaptable to all three devices (Figure W1-29).

Figure W1-29 Combitube in the esophageal position with both balloons inflated. Proper positioning of the eight side ventilation portals allow oxygen delivery into the glottis. If resistance is met when bagging, it is typically caused by two factors: (1) Combitube is positioned too deep, so some or all of the ventilation portals are occluded by esophageal mucosa (solution: withdraw Combitube to a more proximal position); (2) upper inflated cuff has forced the epiglottis downward and is partially or completely obstructing the glottic opening (solution: withdraw Combitube to a more proximal position).

Anatomy

An understanding of basic airway, tracheal, and esophageal anatomy is required to interpret which lumen should be used to ventilate the patient. Also, if ventilation is unsuccessful, it is important to understand that the positioning of the Combitube may not be ideal, and it may have to be advanced or withdrawn slightly.

Procedure: Combitube

• The Combitube is an emergency airway management device for patients requiring rapid control of the airway, particularly when poor laryngoscopic visualization of the larynx makes tracheal intubation impossible.

• Insert appropriate-sized Combitube into patient’s mouth, with or without laryngoscopy (the smaller-sized Combitube [37F] may be used in all adults <6 feet, 5 inches tall)

• Advance the Combitube blindly into either the trachea or esophagus.

• Stop advancing once the proximal depth indicator (two black rings) is at the level of the teeth.

• Inflate the smaller distal cuff and the larger proximal cuff which seals the pharynx.

• Ventilate through the proximal (blue, #1) lumen first, because 95% of Combitube placements result in an esophageal position, and auscultate the lungs and stomach.

• If breath sounds are not heard but gastric sounds are, the Combitube has likely been placed in the trachea.

• Simply change ventilation to the distal (clear, #2) lumen, and recheck for breath sounds.

• If breath sounds are still not detectable by auscultation, the Combitube has likely been advanced too deeply into the esophagus, and the pharyngeal cuff is obstructing the glottis.

• If this occurs, deflate the pharyngeal cuff, withdraw the Combitube a few centimeters, and recheck for breath sounds.

• Once the appropriate lumen has been selected and ventilation appears adequate, confirm with capnography.

Procedure: King Laryngeal Tube

The King LT is a supraglottic airway that uses two cuffs to create a supraglottic ventilation seal similar to the Combitube (hypopharynx and esophageal level). The King LT has a single ventilation port (15-mm connector) and a single valve and pilot balloon that simultaneously inflates both the pharyngeal and the esophageal balloons.

• Assuming the operator is familiar with the King LT, lubrication is applied and preoxygenation is completed.

• Sniffing position if possible but not required

• Hold the King LT at the connector with dominant hand. With nondominant hand, hold mouth open and apply chin lift.

• With the King LT rotated laterally 45 to 90 degrees such that the blue orientation line is touching the corner of the mouth, introduce tip into mouth and advance behind base of tongue.

• As tube tip passes under tongue, rotate tube back to midline (blue orientation line faces chin).

• Without exerting excessive force, advance tube until base of connector is aligned with teeth or gums.

• Inflate via the single pilot valve until sealed (40-80 mL, depending on King LT size).

• Gently ventilate to assess position (free flowing I/E, large VT).

• Depth markings give an indication of the distance from the vocal cords to the teeth.

• Confirm proper position by auscultation, chest movement, and verification of CO₂.

• If ventilation is met with high resistance, slowly withdraw device until ventilation improves.

• Intubation may be accomplished with the FOB-Aintree combination (Figures W1-30 and W1-31).

Figure W1-30 Close-up view of King laryngeal tube and the ventilation holes that come to lie posterior to the glottic opening. The upper opening will emit a fiberoptic bronchoscope (FOB) or FOB-Aintree combo to visualize/intubate the trachea.

Figure W1-31 A, The Cook brand Aintree catheter acts as a “jacket” around the fiberoptic bronchoscope (FOB), which is then passed (in this case) via the laryngeal mask airway to assist in visualizing the glottic opening. The Aintree-FOB combo can be passed via the ventilation portal of the King laryngeal tube (LT) to allow passage into the trachea. Following removal of the FOB from the Aintree (which remains in the trachea), the King LT is removed over the Aintree. A lubricated endotracheal tube (ETT) is then passed over the Aintree, as it acts as a bougie. B, The Aintree catheter, a 56-cm-long, hollow catheter.

After Procedure

Postprocedure Care

• Once patient is stabilized and adequately ventilated and oxygenated, a more definitive airway should be secured.

• It is an acute emergency airway device.

• Combitube and King LT are not intended for extended use in the emergency patient.

• Intubation of the trachea is favored in most patients, so a plan should be developed to change to an ETT.

• Changing to an ETT may be performed by direct laryngoscopy (DL) alone, DL with bougie assistance, VL, or FOB (around the Combitube, not through it).

• If exchange is considered to be dangerous and risky (desaturation, massive edema, poor pulmonary compliance) or it proves to be impossible to identify the glottic opening, securing the airway surgically may be the best (or only) alternative.

• When the Combitube/King LT is in the esophageal position, surgical entrance into the trachea is not impeded by the airway device.

Outcomes and Evidence

Anesthesiologists and paramedic students have found the device to be simple and timely to place and useful for the known or suspected difficult airway patient. It has also been found to be a useful rescue airway device in cases of an unexpectedly difficult airway. Anecdotally, clinicians may prefer the King LT over the Combitube, based on its smaller size and simplicity with one inflation portal.

Evaluation of a Cuff Leak in the ICU: Before Procedure

Indications

• Audible cuff leak in an intubated patient may represent a variety of problems:

• Tear/microperforation or macroperforation of ETT cuff

• Remedy: exchange ETT

• Broken pilot balloon line

• Remedy: occlude line perforation, inflate cuff, clamp line with Kelly/hemostat (temporary, low risk)

• Remedy: cut line, attach new pilot balloon/valve/line assembly, reinflate balloon (less temporary, may perform well long term, low risk)

• Change ETT (high risk) (Figure W1-32).

Figure W1-32 Commercially available pilot balloon repair kit. Blunt needle is inserted into the cut end of the pilot valve line.

• Incompetent valve/pilot balloon perforation/dysfunction

• Remedy: cut line, attach new pilot balloon/valve/line assembly, reinflate balloon (less temporary, may perform well long term, low risk)

• Remedy: inflate cuff, clamp line with Kelly/hemostat (temporary)

• Remedy: change ETT (high risk)

• ETT cuff/tracheal wall incongruity (tracheomalacia, tracheal softening, tracheitis, overstretched poorly compliant cuff)

• Remedy: advance ETT-cuff to alternative level in trachea (temporary, low risk)

• Remedy: change ETT (high risk) or change tracheostomy to larger size, length, or cuff shape/design (moderate or high risk if trach >10 days old)

• Dislocation of ETT (partial or complete extubation of the trachea) is typified by three potential locations within the airway:

• Cuff between vocal cords (partial extubation)

• ETT tip at level of vocal cords (complete extubation)

• ETT tip-cuff in hypopharynx (complete extubation) (Figures W1-33 through W1-35)

Figure W1-33 This patient had a continuous “cuff leak” while supported on mechanical ventilation. The endotracheal tube (ETT) depth was 25 cm at the dentition, yet the ETT tip is just below the vocal cords when viewed with the fiberoptic bronchoscope (FOB). The barely visible white vocal cords are “stretched” by the ETT and are located laterally in the picture. In the upper right corner is the bluish edge of the lower portion of the ETT cuff. Distally at the ETT, one can see with the FOB that the posterior wall of the thyroid cartilage is visible (not seen in this picture).

Figure W1-34 The ICU physician was called to evaluate an intermittent “cuff leak,” difficulty passing the suction catheter, and waxing/waning oxygen saturation. The pilot balloon was intact and inflated. Fiberoptic bronchoscopic (FOB) exam found the endotracheal tube (ETT) tip was impaled on the vocal cord, with a view of the subglottic area via the Murphy eye of the ETT. The FOB was passed into the trachea via the Murphy eye, and the ETT was gently advanced into the trachea.

Figure W1-35 The intensive care unit team was called to investigate a continuous “cuff leak” in this patient. The pilot balloon was intact; the fiberoptic bronchoscopic (FOB) view of the vocal cords from the tip of the endotracheal tube (ETT) reveals that the ETT tip is well above the glottic opening. The FOB was advanced into the trachea, and the ETT was then returned to the tracheal position.

• Partial/complete extubation of the airway, masquerading as an ETT with a cuff leak, must be identified:

• It is imperative to check the status of the pilot balloon.

• If the pilot balloon appears to be intact (holds insufflated air), the ETT tip/cuff location is likely not intratracheal.

• If the “cuff” leak is erroneously identified as a malfunctioning ETT cuff, and the airway team passes an airway exchange catheter (AEC), the misplaced distal tip of the ETT may allow passage of the AEC to areas external to the trachea (e.g., esophagus, pyriform sinus)

• Two methods are strongly recommended to diagnostically and therapeutically manage the possible ETT tip/cuff dislocation:

• First choice: flexible FOB to diagnose the tip location and therapeutically allow reintubation of the trachea if possible (85% likely at authors’ institution)

• Second choice: laryngoscopy, preferably VL versus DL, so as to allow improved visualization of the airway and possibly improve the margin of safety in this potentially life-threatening consequence of the intubated ICU patient

• Caveat: How reliable is the level of the ETT at the dentition line in determining where the tip is located? (based on a database of 245 cases of partial extubation at the authors’ institution)

• ETT at <20 cm at the dentition line: 55% were above the glottis

• ETT at >20 cm: 73% at level of glottis or above glottis (hypopharynx)

• Conclusion: There appears to be little correlation of ETT markings at the dentition line and the location of the ETT tip.

• Overall, 51% ETT tips were above the vocal cords, 32% were at the level of the vocal cords, and in 17%, the cuff was located between the vocal cords on examination.

• Caveat: Is there any difference in the incidence of complications when using FOB versus DL to diagnose and manage a dislocated ETT?

• Managing this clinical situation with DL alone was fraught with complications such as severe hypoxemia, esophageal intubation, loss of the airway, bradycardia, and cardiac arrest.

• Diagnostic and therapeutic management with FOB was an overall excellent choice, but it was not without its own problems. The ETT tip that was above the vocal cords was often centralized and easily advanced into the trachea, but approximately 15% to 20% of these cases had the ETT tip abutting the vocal cords, pharyngeal wall, or other tissues that made it very difficult to advance the FOB into the trachea. Several of these ETTs had to be moved more proximal to allow FOB advancement, but this was not always successful.

• Alternative airway management schema beyond the FOB must be available to rescue the airway in the event difficulty is encountered.

Contraindications

• Absolute:

• Difficult intubation and ETT can be salvaged by some other means than replacing it (e.g., repair of pilot balloon or clearing of obstructive luminal secretions via the CAM Resqu-Cath) (Figures W1-36 through W1-38).

Figure W1-36 This patient immediately failed a continuous positive airway pressure (CPAP) trial. Investigation with fiberoptic bronchoscopy (FOB) found significant biofilm accumulation at several levels of the endotracheal tube (ETT) lumen. A choice of exchanging to a new ETT was contemplated, but the patient was a known difficult airway. A catheter with an inflatable cuff (similar to a Fogarty catheter) that had a mesh covering for “traction” was passed and was able to remove 90% of biofilm blockage in less than 90 seconds on two passes.

Figure W1-37 The same endotracheal tube (ETT) as in Figure W1-36, following a single pass of the biofilm removal catheter.

Figure W1-38 A, A large biofilm plug removed following a single pass of the biofilm removal system. B, Close-up of the mesh-covered catheter cuff used to remove the tracheal lumen obstruction of biofilm.

• Relative:

• Unprepared:

• Unless the situation is truly emergent, ETT exchange should not be attempted without properly preparing the patient and without having immediate access to difficult airway supplies.

• ETT is not damaged:

• If the reason for exchange is for “cuff leak,” for example, but the leak is due to supraglottic positioning, not a damaged cuff, then adjustment of the ETT and not ETT exchange is appropriate.

Equipment

• Conventional intubation equipment

• Advanced airway rescue devices including FOB, VL

• Miscellaneous equipment:

• Kelly clamp/hemostat

• Replacement pilot balloon kit

Procedure

• Place patient on 100% oxygen.

• Review patient history, problem list, medications, level of ventilatory support.

• Assemble conventional and rescue airway equipment including capnography.

• Initiate sedation/analgesia if not already present, with or without muscle paralysis

• Optimize positioning, perform FOB to determine level of the ETT tip if appropriate, then advance the ETT over the FOB into the trachea.

• Alternative rescue methods, personnel should be immediately available

• Second choice: examination of the airway (laryngoscopy, video-based preferable)

• Extra caution when advancing laryngoscope blade into oropharynx, as the tip may puncture the overinflated ETT cuff in the “back of the throat”

• Consideration should be given to replacing the ETT when its cuff has undergone overinflation and may have altered compliance.

After Procedure

Postprocedure Care

• Reconfirm endotracheal placement with capnography.

• Assess depth of ETT with breath-sound auscultation, bronchoscopy, chest radiograph (delayed).

Outcomes and Evidence

Partial extubation of the airway can be a life-threatening consequence of tracheal intubation in the ICU patient. Misdiagnosis or lack of understanding of this situation may lead to patient morbidity and mortality. Being prepared, as is the case for any ICU airway situation, is in the best interest of patient safety. Running through the differential diagnosis of a “cuff leak” is imperative. The simplest task to complete is to inquire about the characteristics of the cuff leak (duration, amount of air placed in cuff, etc.) and to check its integrity. If the pilot balloon appears intact, it is reasonable to assume the ETT tip cuff is displaced at or above the vocal cords and one should consider FOB for diagnostic and therapeutic management.

Extubation of the Difficult Airway: Before Procedure

Indications

• To optimize the safety of the ICU patient being readied for extubation, with special emphasis on the difficult airway patient

• Known difficult airway

• Known difficult mask ventilation

• Known difficult laryngoscopy

• Known difficult intubation

• Suspected difficult airway

• Obesity

• Cervical spine precautions, hard collar, halo vest, limited range of motion

• Edema, swelling, airway trauma, systemic reaction (sepsis, blood transfusion reaction, anaphylaxis)

• Massive volume resuscitation

• Evolving head/neck trauma, pathology, injury

• Any limitation to the mouth/oral cavity/oropharynx

• Excessive secretions, bleeding, bandages, alterations to anatomy

• Difficult extubation is defined as the clinical situation when a patient presents with known or presumed risk factors that may contribute to difficulty reestablishing access to the airway.

• The subsequent intolerance of the extubated state poses an increased risk to patient safety.

• An extubation strategy should be developed which allows the airway manager to (1) replace the ETT in a timely manner and (2) ventilate and oxygenate the patient while the patient is being prepared for reintubation, as well as during the reintubation itself.

• The practitioner should assess the patient’s risk on two levels: the patient’s predicted ability to tolerate the extubated state and ability (or inability) to reestablish the airway if reintubation becomes necessary. Weaning criteria and extubation parameters will not be discussed because they vary by locale, practitioner, and the patient’s clinical situation.

Contraindications

• Absolute contraindications:

• When the clinical assessment of the patient is suggestive of a high risk for difficulty establishing an airway, and airway management personnel with an expertise of handling such a patient are not present or they are not properly equipped to handle such a patient

• Patient fails routine accepted extubation parameters for your facility

• When the full complement of ICU personnel are unavailable for the extubation trial (e.g., nursing staff, respiratory therapy staff, airway team members)

• When a backup plan/strategy has not been developed or the equipment/personnel to execute such a strategy are not available

• Relative contraindications *:

• Establishing a surgical airway (tracheostomy) would be a better choice.

• Delaying the extubation trial would be in the patient’s best interest.

Anatomy

• Patient assessment must be completed prior to decision whether or not to extubate.

• Review of the patient’s stay in the ICU, medications, problem list, surgeries, procedures, previous airway interventions, and current clinical condition would be standard to provide needed information to develop an understanding of the patient’s current predicament.

• This evaluation would be supported by a clinical assessment of the patient’s airway to evaluate inability to tolerate extubation from such causes as:

• Airway obstruction (partial or complete)

• Hypoventilation syndromes

• Hypoxemic respiratory failure

• Failure of pulmonary toilet

• Inability to protect airway

• Evaluate for potential difficulty reestablishing the airway:

• Difficult airway

• Limited access to the airway

• Inexperienced personnel pertaining to airway skills

• Airway injury, edema formation

• ASA Practice Guidelines have suggested that a preformulated extubation strategy should include:

• A consideration of the relative merits of awake extubation versus extubation before the return of consciousness (more applicable to the operating room setting)

• An evaluation for general clinical factors that may produce an adverse impact on ventilation after the patient has been extubated

• The formulation of an airway management plan that can be implemented if the patient is not able to maintain adequate ventilation after extubation

• A consideration of the short-term use of a device that can serve as a guide to facilitate intubation and/or to facilitate ventilation/oxygenation

Procedure

1 Review history, current conditions, medications, mental status as previously stated.

2 Assess airway; external evaluation supplemented with internal evaluation:

• Conventional laryngoscopy has limited clinical utility in the ICU patient.

• Videolaryngoscopy allows (in most patients) the ability to “see around the corner,” thus providing a view of the periglottic airway to determine if the airway is suitable for extubation; also provides valuable information regarding the ease or difficulty of viewing the airway anatomy in the event reintubation needed following extubation.

3 Develop strategy for extubation, delay extubation or secure via surgical means; extubation choices include:

• Conventional extubation (directly to oxygen source)

• Extubation over an airway exchange catheter to maintain airway access

• FOB-assisted airway evaluation/extubation

• Transition to LMA until patient is “safe” to lose “airway access” (Figure W1-39)

Figure W1-39 Laryngoscopic view (GlideScope) of a patient with a known difficult airway who is ready for an extubation trial. The airway was assessed to determine two factors: (1) the ease or difficulty of reintubating the trachea if extubation is poorly tolerated and (2) the status of the periglottic tissues (edema, swelling, trauma) and whether they are compatible with tolerance of the extubated state. This airway view demonstrated residual edema and swelling, as well as secretion build-up.

• Clinical decision plan for the difficult extubation:

• A variety of methods are available to assist the practitioner to maintain continuous access to the airway following extubation, each with their limitations and restrictions.

• Though no method guarantees control and the ability to resecure the airway at all times, the LMA offers the ability for fiberoptic-assisted visualization of the supraglottic structures while serving as a ventilating and reintubating conduit, but is hampered by a limited time frame.

• FOB is useful for periglottic assessment following extubation but requires advanced skills and minimal secretions. Moreover, it offers only a brief moment for airway assessment and continuous access to the airway following extubation.

• Conversely, the AEC allows continuous control of the airway after extubation but without visualization, is well tolerated in the vast majority of patients, and serves as an adjunct for reintubation and oxygen administration. Patient intolerance, accidental dislodgment, and mucosal and tracheobronchial wall injury have been reported but are rare.

• Carinal irritation may be treated with proximal repositioning, instillation of topical agents to anesthetize the airway, plus explanation and reassurance. Dislodgment may occur because of an uncooperative patient or a poorly secured catheter.

• Observation in a monitored environment with experienced personnel should be given top priority, as should the immediate availability of difficult airway equipment in the event of extubation intolerance.

• Acquire advanced airway rescue equipment.

• Assemble personnel (respiratory therapist, nursing staff, surgical staff).

• Prepare circumferential tape to secure the airway catheter after extubation.

• Discussion with patient/family/airway care team

• Position patient upright, suction internal and external to ETT

• If obese, ramped position recommended

• Pass lubricated AEC to 23- to 26-cm depth

• Remove the ETT while maintaining the AEC in its original position.

• Wipe excess lubrication/secretions from the AEC prior to taping.

• Secure the AEC with tape (circumferential), mark AEC “airway only.”

• Oxygen: nasal, mask, or humidified O₂ via AEC (1-2 L/min, short term only)

• Maintain NPO, provide pulmonary toilet.

• Ensure availability of smaller-caliber ETT (6.0) for reintubation if needed.

• Maintain patient in monitored setting with skilled personnel available (Figure W1-40).

Figure W1-40 Patient on postoperative day 2 following an anterior-posterior 4-level cervical fusion, laminectomy, and discectomy at two levels. She required an awake fiberoptic bronchoscopy (FOB) intubation to allow induction of anesthesia. Being a known difficult airway to start, her airway status only worsened with postoperative swelling and the addition of the halo vest that further restricted cervical movement. She was extubated over an airway catheter but developed rapid deterioration due to stridor, requiring emergency passage of a new endotracheal tube (ETT) over the airway catheter, which was accomplished in less than 20 seconds. A smaller-bore ETT was used (6.0) based on the assumption that airway swelling was the cause of the stridor and a smaller ETT would most likely pass more easily into a swollen airway.

• Clinical judgment and the patient’s cardiopulmonary and other systemic conditions, combined with the airway status, should guide the clinician in establishing a reasonable time period for maintaining a state of “reversible extubation” with the indwelling AEC. Table W1-1 shows a suggested time frame for maintaining the well-tolerated AEC.

TABLE W1-1 Time Frame * for Maintaining the Well-Tolerated Airway Exchange Catheter

Difficult airway only, no respiratory issues or airway swelling	1-4 hours
Difficult airway, no direct respiratory issues, potential for airway swelling	2-6 hours
Difficult airway, cardiopulmonary issues, multiple extubation failures	2-24 hours

^* Time frame will vary according to patient condition, airway assessment, and tolerance of the presence of the airway exchange catheter.

• If significant head/neck and/or laryngeal/periglottic edema precludes extubation, several maneuvers may be implemented to assist in decreasing swelling and edema:

• Raise head of bed as much as tolerated

• Maintain even to negative in/out fluid balance

• Diurese if volume overloaded (common in ICU)

• Pretreatment (12-24 hours prior to extubation) with corticosteroids if appropriate (controversial but may reduce postextubation stridor, breathing difficulties, reintubation, and laryngeal edema overall)

After Procedure

Postprocedure Care

• Optimize patient positioning, pulmonary toilet, minimize sedation.

• Continuous close observation by trained personnel and immediate access to an experienced airway management team

• Failure to tolerate the extubated state may vary from 2% to 25% of all patients over a variable time line such as 12 to 48 hours.

• The ICU setting is unpredictable. Patients may fail extubation because numerous alterations in the patient’s condition can take place unexpectedly (e.g., new-onset dysrhythmia, flash pulmonary edema, acute neurological changes, systemic reactions).

Outcomes and Evidence

The difficult airway patient being readied for extubation warrants a strategy that allows a predictable reintubation in a timely manner, thus a “reversible extubation.” Though regional or national guidelines that outline specific management schema for dealing with this clinical situation are not readily available, this outline offers “safety first” for the patient. Much emphasis is focused on placing the ETT into the trachea, yet the more difficult issue is replacing the ETT in a recently extubated airway, typically under adverse clinical conditions. Patient morbidity and even mortality (i.e., brain injury from anoxia) is a real consequence of extubation of the patient with a difficult airway and should be respected and approached cautiously.

Videolaryngoscope-Assisted Intubation: Before Procedure

Indications

Videolaryngoscopy (VL)

• Routine tracheal intubation

• Emergency tracheal intubation

• Rescue of other failed intubation methods

• Viewing airway structures for educational/training purposes

• Exchange of tracheostomy tube

• Evaluation of airway structures for foreign body, trauma, edema, cuff leak

• Extubation evaluation of airway

• Assistance with advancement of TEE probe, feeding tube, nasogastric tube (NGT), esophageal dilator

• Evaluate ETT position in situ

• Advantages of VL versus conventional DL (Figures W1-41 and W1-42)

Figure W1-41 Line of sight with direct laryngoscopy.

Figure W1-42 Lines demonstrating the line of sight for direct laryngoscopy (DL) versus videolaryngoscopy (VL). There is approximately 30 degrees between the two methods that accounts for the ability to “see around the corner” when the laryngeal view is restricted with DL.

• Full view of laryngeal inlet in majority of cases

• Typically transforms laryngeal view 1 to 2 grades lower (better view)

• Grade III view of the larynx with DL (grade III: no cords visible, only epiglottis visible) improves to grade I or II with VL

• Grade IV (no view of any airway structure) often improves to grade II (enough to allow ETT advancement)

• Improved line of sight of naked eye with DL, as operator must peer via the mouth opening around dentition, tongue, and the like; view is often restricted, even more so when the ETT is passed into the airway

Contraindications

• Unfamiliar with its use

• Recent tracheal-bronchial reconstruction?

Equipment

(Figures W1-43 through W1-50)

Figure W1-43 The Airtraq, a portable yet disposable channeled videolaryngoscopy (VL) device that offers excellent laryngeal viewing, given its relatively inexpensive cost and simple external design.

Figure W1-44 The Pentax AWS, a portable, reusable channeled videolaryngoscope (VL) with a disposable (clear) blade that has an adjustable video screen (black portion in photo) that adapts to various patient positions. An endotracheal tube (ETT) is preloaded into the channel of the blade to ease advancement into the larynx.

Figure W1-45 GlideScope AVL shown with video screen and two of several sizes of disposable video baton blades designed for neonatal to large adult. The optional specially shaped stylet that conforms to the blade’s extreme 60 degres allows the operator improved access to advance the endotracheal tube to the laryngeal opening.

Figure W1-46 The McGrath portable videolaryngoscope is easily transported and offers excellent video-quality images but on a smaller screen. To ease placement in patients with restricted oral access (e.g., halo vest, large chest/breasts, short neck), the device features a disposable clear blade and an adjustable video arm that can be disarticulated to allow the blade to be placed into the mouth, then reattached to the handle.

Figure W1-47 The Levitan FPS Scope is an optical stylet that assists the operator with visualization of the airway structures via the eyepiece. Elevation of the mandible-tongue complex with a manual jaw thrust or combining the optical stylet with direct laryngoscopy allows the stylet–endotracheal tube to be passed underneath the epiglottis and into the trachea.

Figure W1-48 Combining direct laryngoscopy with the optical stylet to achieve laryngeal visualization.

Figure W1-49 The view offered by a conventional laryngoscope; limited view of glottis structure owing to dependency of operator’s line of sight.

Figure W1-50 Same patient as Figure W1-49 but with video-laryngoscope-assisted view, allowing operator full view of epiglottis, arytenoids, and glottic opening.