Supraglottic airway devices in children with difficult airways

INTRODUCTION — 

In patients with difficult airways, supraglottic airways (eg, laryngeal mask airway or i-gel) permit oxygenation and ventilation until a definitive airway can be secured. Supraglottic airway devices may be life-saving in children with difficult airways in whom conventional endotracheal intubation has failed. They should be available for any child undergoing emergency endotracheal intubation. This topic discusses the indications, contraindications, and techniques for use of such devices in children.

The following pediatric topics on the difficult airway are presented elsewhere:

●Identification of the difficult airway (see "The difficult pediatric airway for emergency medicine")

●Devices to facilitate endotracheal intubation (see "Video laryngoscopy and other devices for difficult endotracheal intubation in children: Overview and techniques")

●Needle cricothyroidotomy (see "Needle cricothyrotomy (thyroidotomy) with percutaneous transtracheal ventilation")

●Wire-guided cricothyroidotomy (see "Emergency cricothyrotomy (cricothyroidotomy)", section on 'Seldinger technique')

The general principles of pediatric airway management and rapid sequence intubation are discussed separately. (See "Basic airway management in children" and "Technique of emergency endotracheal intubation in children" and "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

TERMINOLOGY — 

Extraglottic devices are designed to provide oxygen and ventilation without direct entry into the airway (larynx) [1].

Supraglottic airway devices are placed above the glottis without extension of any components into the esophagus. Common examples include the:

●Laryngeal mask airway (LMA) (figure 1)

●i-gel

●Air-Q masked laryngeal airway

●CobraPLA (picture 1)

Some investigators describe the original devices like the LMA Classic as "First Generation" supraglottic devices and later devices, with additional features as "Second" and "Third Generation" devices. Many second and third generation devices have decompression channels that permit the passage of a suction catheter or feeding tube to decompress the stomach as a means to decrease the risk of aspiration and to avoid overdistension of the abdomen with the potential to restrict ventilation.

By contrast, devices such as laryngotracheal airways or the Combitube that extend into the esophagus are extraglottic devices but are not supraglottic devices.

INDICATIONS — 

A supraglottic airway (SGA) may be effective in acute care situations in which tracheal intubation is difficult or impossible, and, when placed correctly, can avoid the need for continuous mask seal during bag-mask ventilation (algorithm 1). SGA placement can also be attempted in the "cannot intubate-cannot ventilate" emergency airway situation, but the clinician must ensure that the patient does not experience an excessively long period of hypoxemia (algorithm 2). (See 'Rescue airway' below.)

In addition, during difficult intubations, the SGA can serve as a bridge between bag mask ventilation and intubation as well as facilitate the use of advanced airway devices (eg, fiberoptic stylet, flexible intubating scope) [2-5]. (See 'Conduit for endotracheal intubation' below and "Video laryngoscopy and other devices for difficult endotracheal intubation in children: Overview and techniques".)

A SGA provides less protection against aspiration than endotracheal intubation, but in situations requiring the insertion of a rescue airway, the risk of aspiration is generally outweighed by the benefits [6]. However, placement of a SGA requires sedation or anesthesia sufficient to block airway reflexes as for rapid sequence intubation (RSI) and maintenance of sedation to prevent vomiting, coughing, and bucking during use.

CONTRAINDICATIONS — 

A SGA is unlikely to be effective in cases of airway obstruction (eg, croup, asthma) because the pressure in the airway is higher than the sealing pressure of the LMA mask. Thus, air leaks around the mask cuff and impairs or prevents lung ventilation.

It also should not be used in patients with distorted airway anatomy (eg, laryngeal trauma or burns, congenital anomalies of the larynx, or epiglottitis) because of likely failure due to malpositioning.

In one operating room study of 11,910 children undergoing anesthesia, the laryngeal mask airway had a failure rate of <1 percent, but failure was independently associated with congenital or acquired airway abnormality, airway obstruction, and coughing or "bucking" in an inadequately sedated patient [7].

CONTINGENCY PLAN FOR THE FAILED AIRWAY — 

A contingency plan in the event of a failed endotracheal intubation should be developed for all patients, ideally before rapid sequence intubation (RSI) is necessary. Clinicians should have rescue devices available whenever performing an emergency pediatric intubation. For patients in whom a difficult airway is predicted, the clinician should also call for additional assistance from a critical airway team, which may include a pediatric anesthesiologist, pediatric intensivist, and/or an otolaryngologist with pediatrics expertise, prior to attempting RSI. (See "The difficult pediatric airway for emergency medicine", section on 'Identification of the difficult pediatric airway'.)

Rescue devices permit oxygenation and ventilation in situations in which endotracheal intubation cannot be performed in a timely manner and can also facilitate endotracheal intubation in patients with difficult airways (algorithm 1). Based upon operating room experience in children predicted to have a difficult airway, these devices permit successful airway management in over 90 percent of such patients [8,9]. (See "The difficult pediatric airway for emergency medicine", section on 'Management'.)

A failed airway exists when the clinician cannot oxygenate or ventilate a patient. Clinically, this occurs when a patient cannot be intubated, and ventilation with a bag and/or mask or supraglottic airway device fails to maintain oxyhemoglobin saturations >90 percent. These patients require needle cricothyrotomy (children ≤10 years old (figure 2)) or surgical cricothyrotomy (>10 years old). (See "Needle cricothyrotomy (thyroidotomy) with percutaneous transtracheal ventilation" and "Emergency cricothyrotomy (cricothyroidotomy)".)

An approach to the failed airway is provided in the algorithm and discussed separately (algorithm 2). (See "The difficult pediatric airway for emergency medicine", section on 'Approach to the failed airway'.)

CHOICE OF DEVICE

Rescue airway — Common supraglottic airway (SGA) devices that are available in pediatric sizes include:

●Laryngeal mask airway (LMA (table 1)) (see 'Laryngeal mask airway (LMA)' below)

●i-gel (eg, i-gel (table 2) (see 'i-gel laryngeal airway' below)

●Air-Q (table 3) (see 'Air-Q masked laryngeal airway' below)

●CobraPLA (see 'CobraPLA (CPLA)' below)

These versatile airway rescue devices for children all share a similar functional principle: if the peripharyngeal area can be occluded with a mask or balloon and the laryngeal opening can be isolated from the esophagus, the relatively lower resistance of the distal airway will permit ventilation without direct tracheal intubation. Because emergency SGA placement in the emergency department (ED) is a rare event, emergency clinicians should receive training and regular practice using the SGA device in use at their institution.

Comparative studies for pediatric use of the newer generation SGA devices is limited. However, observational studies in children with difficult airways, trials of OR placement during elective procedures, and trials of placement in simulation settings by clinicians with varying levels of experience suggest that first-attempt success rates are high (approximately 90 percent or better) for all devices [7,10-15].

Conduit for endotracheal intubation — Blind endotracheal intubation is feasible through the airway channel of any SGA device [12]. SGA devices specifically designed to facilitate endotracheal intubation include:

●Air-Q masked laryngeal airway (table 3) (see 'Air-Q masked laryngeal airway' below)

●Intubating laryngeal mask airway (ILMA, only for children >30 kg) (see 'Intubating laryngeal mask airway (ILMA)' below)

Endotracheal intubation can proceed blindly or with guidance provided by a flexible intubating scope, optical stylet, or lighted stylet. Once tracheal intubation is achieved, the emergency clinician can leave the Air-Q or ILMA in place until removal can occur in a more controlled environment such as the operating room or intensive care unit.

Neonatal resuscitation — Evidence supports the use of a size 1 laryngeal mask airway (LMA) as a rescue airway in term and preterm infants as well as an alternative to bag-mask ventilation during initial resuscitation as discussed separately. (See "Neonatal resuscitation in the delivery room", section on 'Laryngeal mask airway (LMA)'.)

TRAINING — 

Supraglottic airway devices are likely to be used by the emergency care provider when standard airway management techniques have failed, and tensions are high. The patient's life may depend upon the clinician's ability to secure an alternative airway, and the clinician will be under considerable stress. These are not the circumstances under which to use an unfamiliar device for the first time. Thus, emergency clinicians and others who might need to use a rescue airway device should learn to use it well in advance of need. Training can be accomplished in a simulation center, a cadaver lab, or an operating room, depending upon the type of device and the availability of mentors [16]. Additionally, several organizations offer training in difficult airway management for emergency practitioners. Acquiring the skill to use these devices appears to be rapid. Most providers are able to successfully insert them in simulated difficult pediatric airway scenarios within 30 seconds, although the primary determinant of success with a particular device appears to be operator experience [17].

Studies suggest that successful placement of laryngeal mask airways in the first attempt after formal training is as high as 90 to 94 percent [18-20]. Additionally, there are data from the prehospital literature to suggest that providers using supraglottic airways are able to rapidly establish effective oxygenation and ventilation and that skill retention remains high with these devices, which is an advantage when providers are faced with a rarely-used technique in an emergency situation [10,17,21].

LARYNGEAL MASK AIRWAY (LMA)

Device features — The laryngeal mask airway (LMA) is widely used in children. It comes in sizes that permit placement in all pediatric patients (table 1). The recommended approach to selection of an appropriately-sized LMA is based upon the child's weight. When the weight is not known, use of an LMA with an outer diameter approximately the same as the child's external ear (auricle) is an alternative method that is practical and moderately correlates with the weight-based approach [22].

The LMA Supreme is a single-use device that is similar to the ProSeal. It is available in sizes appropriate for use in infants and children. In anesthesia studies in children, LMAs can be successfully inserted on the first attempt 80 to 100 percent of the time, depending upon the technique (rotational, lateral, or standard placement) and specific device used (Classic LMA or ProSeal LMA) [11].

Most sources have recommended inserting the LMA until resistance to further insertion is felt. However, the optimal depth of insertion can also be calculated using the child's height and weight in the following formula:

Depth of insertion (in centimeters) = 7 + 0.04 × patient's height (in centimeters) + 0.05 × patient's weight (in kilograms) [23]

The Classic LMA is a scaled-down version of the adult LMA, while the pediatric ProSeal LMA has specific design features that may permit a better seal and greater protection against aspiration and gastric inflation, especially in infants and young children, including a gastric channel that permits passage of a nasogastric tube and gastric decompression while the LMA is in place [11].

Choice of technique — There are three techniques available for LMA placement: standard, rotational, and lateral. The usual technique depends on the child's age:

●≥7 years old – The standard technique is appropriate during LMA placement for children of any age, although the lateral or rotational techniques may also be used. (See 'Standard technique' below.)

●<7 years old – For children <7 years old, clinicians may use the rotational technique instead of the standard technique during LMA placement. In this age range, the rotational technique results in a higher success rate on the first attempt in elective settings, and a lower risk of airway trauma or laryngospasm. However, during emergency placement as a rescue device, the standard technique is an option, especially if the clinician is inexperienced with the rotational technique.

In one crossover and two randomized trials in children undergoing elective surgery and LMA placement by experienced anesthesiologists, the rotational technique had a 96 to 99 percent first-time insertion success that was significantly higher than the lateral technique (84 percent, one trial) or standard technique (79 to 81 percent, three trials) [24-26]. These trials also demonstrated that infants and young children with an LMA placed by the rotational technique had a lower risk of laryngospasm compared with the other two techniques (0 versus 5 to 9 percent, respectively) as well as less airway trauma compared with the standard technique (3 to 5 percent versus 13 to 17 percent, respectively). In an observational study of 158 children undergoing LMA placement by the standard technique for elective surgery, significant malposition on fiberoptic bronchoscopy was present in 72 to 80 percent of infants weighing less than 10 kg (LMA size 1 to 1.5) [27].

Standard technique — This technique is appropriate for children of any age (figure 3) [28]. For children <7 years old, the rotational technique has a higher first-attempt success rate in elective settings. However, during emergency management of a difficult airway, the clinician should use the technique with which they are most comfortable.

●If the LMA is placed due to a failed airway, summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Select an appropriately sized LMA (table 1) and remove it from its packaging.

●Completely deflate its cuff using the special deflation tool or by placing the LMA cuff down on a flat surface and then placing the first and middle finger on either side of the cuff and deflating the cuff using the syringe (figure 4). When the cuff is correctly deflated, the LMA should look like a small boat with a curved mast or smokestack (it should be noted that successful insertion of the LMA may be facilitated by partial cuff inflation. You may wish to insert the device with cuff partially inflated, as described in the rotational technique above).

●Lubricate the cuff using water-soluble lubricant.

●Stand at the patient's head as for a standard intubation.

●Open their mouth using your nondominant hand while holding the LMA in your dominant hand so that your index finger or middle finger is resting inside the mask and the remaining fingers are holding the LMA like a pencil.

●Insert the LMA with its ventilating surface facing the patient's tongue and advance it along the palate until it can be advanced no farther.

●Inflate the cuff. This step often causes the LMA to "seat itself" into the proper location while rising up out of the airway a few millimeters.

●Attempt bag ventilation. If the patient can be properly ventilated, no further action is necessary. If not or if there is a significant air leak, the LMA must be removed or repositioned using a jaw thrust or a combination of a jaw thrust and partial removal and reinsertion. If the latter method is chosen, the cuff should be partially deflated prior to repositioning the LMA.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

Rotational technique (<7 years old) — This technique is an alternative to the standard technique for infants and young children under seven years of age (figure 1) [25,29].

●If the LMA is placed due to a failed airway, summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Select an appropriately sized LMA (table 1) and remove it from its packaging.

●Partially inflate the cuff until all indentations are gone.

●Lubricate the cuff with water-soluble lubricant.

●Stand at the patient's head as for a standard intubation.

●Open the child's mouth using your nondominant hand.

●Using your dominant hand, insert the LMA with the opening facing the palate until resistance from the posterior pharyngeal wall is felt.

●Rotate the LMA 180 degrees and pass it downward into position behind the larynx.

●Attempt bag ventilation. If the patient can be properly ventilated, fully inflate the cuff; no further action is necessary. If not or if there is a significant air leak, the LMA must be removed or repositioned.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

Lateral technique (≥7 years old) — The lateral technique is an alternative to the standard technique for children seven years of age and older [25]:

●If the LMA is placed due to a failed airway, summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Select an appropriately sized LMA (table 1) and remove it from its packaging.

●Partially deflate its cuff using the special deflation tool or by placing the LMA cuff down on a flat surface and then placing the first and middle finger on either side of the cuff and deflating the cuff using the syringe until all indentations are gone (figure 4).

●Lubricate the cuff using water-soluble lubricant.

●Stand at the patient's head as for a standard intubation.

●Open their mouth using your nondominant hand while holding the LMA in your dominant hand like a pencil.

●With the partially-inflated LMA positioned so that the ventilating surface faces the patient's tongue and the mask is oriented 45 degrees laterally against the side of the tongue, advance the LMA until resistance is felt.

●Rotate the LMA back into the midline and insert until it can be advanced no farther.

●Attempt bag ventilation. If the patient can be properly ventilated, fully inflate the cuff. No further action is necessary. If not or if there is a significant air leak, the LMA must be removed or repositioned.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

Pitfalls

●The LMA can fail when there is significant airway obstruction or anatomical distortion.

●The LMA cuff can be damaged during insertion. The cuff may also become folded on itself during insertion.

●The cuff may catch on the epiglottis or in the vallecula.

●The LMA may fold the epiglottis down onto the glottic aperture and prevent ventilation.

●The LMA does not completely protect the patient from aspiration.

●Insertion in patients who are inadequately anesthetized or who awaken during ventilation can result in vomiting with aspiration, laryngospasm, or airway trauma.

i-gel LARYNGEAL AIRWAY

Device features — The i-gel is a unique supraglottic airway because it does not employ balloons to isolate the laryngeal opening. Instead, its cuff is made of a thermoplastic elastomer gel. Once inserted, the patient's own body temperature helps the mask to conform to an appropriate configuration. The i-gel appears to function in a fashion similar to the laryngeal mask airway (LMA). However, when compared with the LMA, it may cause higher positive inspiratory pressure and decreased tidal volume when the neck is flexed [30].

The i-gel is available in pediatric sizes for patients ≥2 kg (table 2).

In studies comparing various types of supraglottic airways, the i-gel appears to offer the advantage of rapid insertion that is similar to the LMA. For example, in a study of paramedics' use of several supraglottic airways in a manikin model, the i-gel was one of the three devices that was inserted most rapidly [10]. In another study, insertion of the i-gel by inexperienced clinicians was compared with two other supraglottic devices (the air-Q and the Ambu AuraGain) in a manikin model of blind tracheal intubation for both normal and difficult airways and with and without continuous chest compressions [12]. In this study, the i-gel was superior or similar to the other devices in all scenarios.

Other potential advantages of the i-gel include an internal bite block to prevent the tube from collapsing should the patient awaken and clench the teeth, and a gastric channel that, like the LMA ProSeal, permits passage of a gastric tube to decompress the stomach (not present in size 1 [neonate] devices). However, in one study of the i-gel, anesthesiologists found that the device had a tendency to be displaced upward, toward the mouth, and that attempts to reposition the tube could result in an inadequate airway. However, the device was abandoned in favor of an alternative in <5 percent of cases [31].

Standard technique

●Summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Select an appropriately sized i-gel (table 2) and have immediately available one size smaller and one size larger than anticipated.

●Remove the i-gel from its packaging, then remove the device from the protective cradle.

●Apply water-soluble lubricant to the cradle.

●Grasp the i-gel by the ventilating tube and, using the cradle as a base, apply lubricant to the i-gel without touching the mask with your hands.

●Ensure that the patient is adequately anesthetized or unconscious.

●Grasp the i-gel by the integrated bite block portion of the ventilating tube.

●Open the patient's mouth and insert the tube with the mask opening facing the patient's chin. Unless neck movement is contraindicated, the patient's head and neck should be positioned in the "sniffing" position.

●Guide the tube along the palate and advance it until resistance to further advancement is felt. Unlike other supraglottic devices, the manufacturer of the i-gel does not recommend that you use your fingers to facilitate insertion, but instead that you guide the tube into place using only the ventilation tube.

The size 3 to 5 i-gels have a line on the ventilating tube that indicates the appropriate depth of insertion. When this line is located between the patient's central incisors, the i-gel is located at approximately the appropriate depth. The smaller sized i-gels do not have an indicator line.

●The manufacturer recommends that the i-gel be secured using the strap, which is located in the package, or with adhesive tape. In the latter case, they recommend that the device be taped in place from maxilla to maxilla. Be sure not to expose the i-gel to a radiant warmer for too long because it will excessively soften the gel and make a proper glottic seal difficult.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

Rotational technique — Although evidence is limited in children, one study suggests the rotational technique may decrease the likelihood of malposition [32]. Additionally, the rotational technique has been used in adults with good success and may be an alternative in children if the standard technique fails.

●Summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Select an appropriately-sized i-gel and have immediately available one size smaller and one size larger than you anticipate needing.

●Remove the i-gel from its packaging and then remove the device from the protective cradle.

●Apply water-soluble lubricant to the cradle.

●Grasp the i-gel by the ventilating tube and, using the cradle as a base, apply lubricant to the i-gel without touching the mask with your hands.

●Ensure that the patient is adequately anesthetized or unconscious.

●Grasp the i-gel by the integrated bite-block portion of the ventilating tube.

●Open the patient's mouth and insert the tube with the mask opening facing the patient's chin. Unless neck movement is contraindicated, the patient's head and neck should be positioned in the "sniffing" position.

●Insert the i-gel into the oral cavity, then rotate the device 90 degrees counterclockwise.

●Advance the i-gel past the body of the tongue and until resistance is felt in the hypopharynx, then rotate the device 90 degrees clockwise into the standard position, ensuring that it is positioned in the mid-line. The manufacturer of the i-gel recommends that you guide the tube into place using only the ventilation tube rather than using your fingers.

The size 3 to 5 i-gels have a line on the ventilating tube that indicates the appropriate depth of insertion. When this line is located between the patient's central incisors, the i-gel is located at approximately the appropriate depth. Smaller-sized i-gels do not have an indicator line.

●The manufacturer recommends that the i-gel be secured using the strap, which is located in the package, or with adhesive tape. In the latter case, they recommend that the device be taped in place from maxilla to maxilla.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

Pitfalls — Because the i-gel lacks an inflatable mask that can compensate for size problems, appropriate size selection is especially important. As previously mentioned, one study found that it had a tendency to be displaced upward, and that attempts to reposition the i-gel could lead to an inadequate airway. It was especially noted that flexion of the proximal portion of the tube toward the patient's feet increased airway obstruction, and that this was relieved by moving the tube toward the patient's head [31]. This might have significant implications for securing the tube in place. One series suggested that adequate sealing pressures were harder to obtain with smaller-sized i-gel tubes, and this may be a problem when positive pressure ventilation is used in such children [33].

OTHER DEVICES — 

The laryngeal mask airway and the i-gel supraglottic airway are among the most commonly used rescue airways, but there are several other effective devices available. Some of these are described below.

Air-Q masked laryngeal airway

Device features — The air-Q intubating masked laryngeal airways (AirQ and AirQ SP masked laryngeal airway) come in sizes that permit tracheal intubation in neonates and children under 30 kg (table 3). This section will focus on placement of the Air-Q masked laryngeal airway.

The main advantage of the air-Q is that it permits ventilation in a fashion much like the standard LMA but is also designed to facilitate intubation using standard endotracheal tubes (ETT) in young children. Specifically, the ventilation tube of these devices is wide enough to allow the passage of the cuffs and pilot balloons of cuffed endotracheal tubes, thus overcoming a problem that limits intubation using some other devices. The Air-Q airway also has a tracheal tube ramp that guides the endotracheal tube towards the glottic inlet; intubation can be either be accomplished blindly or using a flexible intubating scope, optical stylet, or lighted stylet.

Additionally, this device has a bite-block built into the tube to prevent tube occlusion if the patient awakens and clenches their teeth. In a retrospective study of 34 children with difficult airways in whom the air-Q was used along with other advanced intubation techniques (flexible scope or an optical stylet), all patients were successfully intubated; 33 were intubated on the first attempt [34]. In two trials of children with normal airways who were undergoing elective surgery, success rates for intubation with a flexible scope through an air-Q were 77 and 97 percent [35,36]. The lower success rate occurred when intubation was performed by inexperienced anesthesiology trainees [36].

Technique: Insertion of the air-Q

●Standard (midline) technique:

•Select an appropriately sized air-Q (table 3) and remove it from its packaging.

•Ensure that the mask inflation valve is open either by leaving the red tag in place or by inserting an empty syringe barrel into the inflation valve.

•Thoroughly lubricate the mask.

•Open the patient's mouth and, if possible, perform a mandibular lift. This elevates the tongue and facilitates placement of the air-Q. If this is not possible, consider using a tongue blade to depress the base of the tongue.

•Place the front portion of the air-Q mask into the oral cavity and advance it until it sits between the soft palate and the base of the tongue. Angling the tube portion of the device slightly forward might facilitate proper placement.

•Gently advance the air-Q into the pharynx using a downward and inward pressure. If necessary, the back of the left (or nondominant) index finger can be placed behind the mask, and then finger flexion can be used to guide the tube into position. Once the mask has been directed into the pharynx, the nondominant hand should be used to again perform a mandibular lift.

•When resistance to further advancement is felt, inflate the cuff per the manufacturer's recommendations and secure the air-Q with tape or a tube clamp.

•Indications of proper placement include all of the following:

-Adequate chest rise

-Auscultation of breath sounds bilaterally

-Lack of gastric distention

-Detection of expired carbon dioxide

●Rotational technique: Similar to the LMA and i-gel Laryngeal Airway, use of the rotational technique rather than the midline technique for placement of the air-Q in children has been associated with better device positioning and shorter time to placement. For air-Q placement, complications were similar for the rotational versus standard technique [37]. The rotational technique is as for LMA placement.

Technique: Intubation using the air-Q

●For best results, the patient should be sedated and paralyzed prior to the intubation attempt. If the patient cannot be safely paralyzed, then local anesthetic should be administered to the vocal cords using a nebulizer, atomizer, or a similar device. Preoxygenation is also recommended.

●The clinician should limit the time of intubation attempts via the air-Q because the patient is not oxygenated or ventilated during this procedure.

●Select an appropriately sized cuffed endotracheal tube (calculator 1). (See "Technique of emergency endotracheal intubation in children", section on 'Endotracheal tube size'.)

●Inspect the endotracheal tube cuff to ensure that it is intact, then deflate the cuff as much as possible to facilitate passage through the air-Q. Liberally apply sterile, water-soluble lubricant to the endotracheal tube.

●Remove the adapter from the air-Q tube and insert the endotracheal tube into the air-Q and advance the endotracheal tube until the tip of the endotracheal tube should be just proximal to the distal opening of the air-Q tube (the opening inside of the mask).

From this position, several intubation techniques are possible:

●Intubating introducer (gum elastic bougie)

•Lubricate an intubating introducer and pass it into the endotracheal tube. Once the introducer enters the trachea, feel for the washboard sensation of the introducer running along the tracheal rings (older children). This sensation can be enhanced by placing the fingers of your nondominant hand over the larynx. In infants and younger children, this sensation may be subtle or absent. In this situation, gently advance the introducer until it wedges into a smaller airway. (See "Video laryngoscopy and other devices for difficult endotracheal intubation in children: Overview and techniques", section on 'Intubating introducers (gum elastic bougie)'.)

•Advance the endotracheal tube over the stylet or bougie. If you cannot advance the ETT, try rotating it counter-clockwise and then repeat the attempt. If this fails, consider using a smaller tube.

●Lighted stylet

•Lubricate a lighted stylet and advance it through the ETT. An intense glow (sometimes called a "jack-o-lantern" glow) coming from the thyroid cartilage and cricoid area indicates that the stylet is within the trachea.

•Withdraw the malleable stylet inside of the lighted stylet and advance the lighted stylet so that you see the glow in the suprasternal notch or, if the stylet is not long enough, advance the lighted stylet as far as possible.

•Pass the endotracheal tube over the lighted stylet and into the trachea. As described above, manipulation of the tube or selection of a smaller tube might be necessary.

●Optical technique – This technique offers the greatest assurance of tracheal intubation.

•Lubricate a flexible intubating scope (FIS) or an optical stylet and advance it into the ETT tube under direct vision.

•Advance the FIS or stylet directly into the trachea. Note that some optical stylets are designed to be advanced only until the glottic opening is visualized. When using such a stylet, advance the stylet until you have a good view of the glottic opening and then advance the ETT under direct vision.

•Advance the ETT into the trachea over the FIS or stylet.

●Blind intubation – Blind intubation through the air-Q is possible, but one of the above techniques is preferred.

•Once the lubricated ETT is in position, attempt to advance it directly into the trachea. As mentioned, it may be necessary to manipulate the tube or select a smaller size to successfully intubate the patient.

•Once you are reasonably certain that the endotracheal tube is within the trachea, partially inflate the cuff and confirm tracheal position using end-tidal CO2 detection.

•When you have determined that the ETT is within the trachea, advance it into the proper position and inflate the cuff.

Removal of the air-Q — Once tracheal intubation is achieved, the clinician must decide what to do with the air-Q device. Options are either to safely leave it in place and remove it in a more controlled environment (eg, the intensive care unit or operating room) at a later time or remove it as soon as tracheal intubation is accomplished. In most cases, the safest course of action is to leave the laryngeal airway in place with its cuff deflated until it can be removed electively. The removal technique is as follows:

●Preoxygenate the patient.

●Deflate the cuffs of both the ETT and the air-Q.

●Remove the adapter from the ETT and insert the tapered end of the air-Q removal stylet into the proximal end of the endotracheal tube and ensure that it fits snugly within the ETT.

●Maintain distal pressure on the ETT and stylet and remove the air-Q over the stylet.

●Reposition the ETT if necessary, replace the adapter, inflate the balloon, and ventilate normally.

Pitfalls — Some experts have suggested that blind intubation using the air-Q and similar devices is inadvisable in children because the epiglottis might actually lie within the mask, and blind passage of an endotracheal tube could actually damage the epiglottis or other structures. These authors advocate the use of an intubation technique that employs direct visualization such as flexible bronchoscopy whenever possible [38,39]. The air-Q and other intubating laryngeal devices might be difficult or impossible to insert when the patient has limited mouth opening [34].

Intubating laryngeal mask airway (ILMA)

Device features — The intubating laryngeal mask airway (ILMA) is a modified laryngeal mask airway (LMA) designed as a conduit for tracheal intubation. It may be used in children weighing 30 kg or greater. Rather than a flexible ventilating tube, the ILMA has a U-shaped metal tube designed to accommodate a specially adapted, flexible, endotracheal tube. Within the mask is a lever intended to lift the epiglottis as the tip of the endotracheal tube passes through the mask. A special handle is attached to the side of the tube to facilitate placement. Finally, the kit contains a rubber stabilizing bar that is used during tracheal intubation through the ILMA [40,41]. A similar device (the air-Q masked laryngeal airway) permits intubation using standard endotracheal tubes through a supraglottic device in smaller children.

The ILMA permits successful fiberoptic endotracheal intubation in children under 30 kg by experienced airway specialists [42]. However, poor glottic views are common in children under 17 kg. Thus, blind intubation through the ILMA should be avoided.

The ILMA may be used to facilitate endotracheal intubation in children weighing 30 kg or greater. The ILMA may be used with several devices as follows:

●A small flexible fiberoptic laryngoscope or bronchoscope may be inserted by an experienced clinician to ensure that the ILMA is properly positioned for intubation. (See "Video laryngoscopy and other devices for difficult endotracheal intubation in children: Overview and techniques", section on 'Optical stylets' and "Video laryngoscopy and other devices for difficult endotracheal intubation in children: Overview and techniques", section on 'Flexible scope intubation'.)

●A small bougie may be directed through the ILMA and inserted into the trachea. This can then be used to guide the endotracheal tube into position. However, because the distal holes of the special endotracheal tube are smaller than the distal hole of a standard tube before using a bougie, first be certain that the bougie will pass easily through the tube. (See "Video laryngoscopy and other devices for difficult endotracheal intubation in children: Overview and techniques", section on 'Intubating introducers (gum elastic bougie)'.)

●Some operators have used the ILMA to insert standard endotracheal tubes. This is somewhat more difficult than insertion of the specially designed tube. If a standard endotracheal tube is used with the ILMA, the tube should be thoroughly lubricated and inserted into the LMA with the curved portion of the tube facing the operator.

The ILMA should only be used in children under 30 kg with the assistance of a flexible intubating scope.

Technique — The following steps describe endotracheal intubation using the ILMA (figure 5):

●If the ILMA is placed due to a failed airway, summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Prepare the ILMA just as you would a standard LMA by deflating and lubricating the cuff (figure 4). Also, prepare the endotracheal tube by checking its cuff and lubricating its external surface.

●Taking care to follow the midline of the patient's mouth, insert the ILMA and direct it along the palate until it cannot be advanced farther.

●Inflate the cuff, attach a ventilating bag, and attempt ventilation.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

●If ventilation is successful, then you may proceed with tracheal intubation. However, since the intubation attempt might leave the patient briefly apneic, the patient should be oxygenated before intubation is attempted. Furthermore, sedation and paralysis as for rapid sequence intubation may be necessary (table 4). (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

●Remove the ventilating bag and insert and advance the endotracheal tube while gently lifting the ILMA. Passage of the endotracheal tube into the trachea may be facilitated by having an assistant apply slight pressure over the patient's thyroid cartilage. The endotracheal tube should advance easily. Significant resistance to passage suggests that the endotracheal tube is not entering the trachea and it should be removed and another attempt made after the patient has been ventilated and oxygenated.

●If the tube advances easily, then its position can be confirmed with an end-tidal CO2 detector.

●If the endotracheal tube is located within the trachea, then you may proceed with the next step: removal of the ILMA.

●Once again, before starting, ventilate and oxygenate the patient. You may need to inflate the cuff on the endotracheal tube to ventilate them effectively.

●Deflate the cuff on the ILMA, but leave the endotracheal tube cuff inflated.

●Next, carefully remove the adapter from the endotracheal tube and insert the rubber stabilizing bar in its place.

●Gently remove the ILMA over the endotracheal tube and stabilizer bar while maintaining slight downward pressure on the stabilizer bar. Once the mask has been removed from the mouth, remove the stabilizer bar so that the pilot balloon on the endotracheal tube can pass through the bore of the ILMA.

●Once the ILMA is completely removed, attach the adapter to the endotracheal tube, confirm its position with capnography, and ventilate the patient.

●Secure the endotracheal tube in the usual fashion; however, consider using a bite block to protect the flexible, wire-reinforced endotracheal tube from damage. (See "Technique of emergency endotracheal intubation in children", section on 'Securing the tube'.)

●Confirm proper positioning of the endotracheal tube with an end-tidal CO2 detection device. (See "Technique of emergency endotracheal intubation in children", section on 'Confirming tube position'.)

Pitfalls

●Use of the ILMA has all of the potential complications associated with use of the standard LMA. (See 'Pitfalls' above.)

●Inability to perform tracheal intubation using the ILMA.

●Inadvertent deflation of a cuffed endotracheal tube balloon during LMA removal can cause dislodgement.

●Failure to deflate the ILMA cuff during attempted removal may cause laryngeal injury.

CobraPLA (CPLA)

Device features — The CobraPLA (CPLA) differs slightly from other laryngeal or extraglottic airways. This device consists of a ventilation tube with a flexible "cobra-shaped" head at its distal end and a ventilation port at its proximal end (picture 1). The head is soft and flexible with a ventilation grill on one side. Immediately proximal to the head is a single ring-like balloon intended to occlude the hypopharynx. The CPLA is available in sizes appropriate for patients as small as 2.5 kg [43].

Randomized trials comparing the CPLA with the laryngeal mask airway for airway management in children during brief surgical procedures indicate that the CPLA is as effective for establishing an airway and is also easy to insert and maintain [13-15].

Technique — An instruction manual and training video are available from the manufacturer [44,45].

●Summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

●Remove the CPLA from its package and check the balloon.

●Deflate the balloon and fold it back against the ventilation tube.

●Lubricate the distal portion the device, paying special attention to the back of the "cobra" head.

●Pull the cuff down around the proximal portion of the tube.

●Perform a jaw thrust maneuver and insert the device with ventilation grill facing the patient's tongue.

●Advance the CPLA distally until you feel resistance. The device should be positioned such that the ventilation grill is facing the glottis.

●Inflate the balloon with air as recommended by the manufacturer (maximum pressure in adults is 60 cm of water). Air can be added to the cuff if there is an air leak around the balloon during attempted ventilation.

●Indications of proper placement include all of the following:

•Adequate chest rise

•Auscultation of breath sounds bilaterally

•Lack of gastric distention

•Detection of expired carbon dioxide

Pitfalls — The CPLA is usually easily inserted, although difficulties have been encountered in some patients with obesity. However, the primary difficulties associated with the CPLA are either not inserting the device far enough such that the ventilating surface does not cover the glottis, or advancing it too far. In the former case, the tongue might be pushed out of the mouth, indicating the need to advance the CPLA farther. In the latter case, ventilation will not be possible, and as in all such cases, the device should be removed and replaced. Additionally, the CPLA does not prevent aspiration [46] and like all such devices, is likely to be ineffective in patients who have significant distal airway resistance.

Laryngotracheal airways — Supraglottic airways (SGAs) are preferable to laryngeal tracheal airways (LTAs) in children because most pediatric providers are more familiar with their use, and they do not require esophageal occlusion. In one trial of 135 children undergoing anesthesia for elective surgery, first-pass and overall success rate were much higher in children assigned to LMA placement compared with LTA placement [47]. Prehospital experience in children and adults also suggests that SGAs are associated with better clinical outcomes compared with LTAs [48].

Several manufacturers make LTAs (eg, King LAD Airway, King LTD Supraglottic Airway, Portex Soft Seal Laryngeal Mask). Many function (and look) similar to the LMA, while others are designed to be placed directly into the esophagus, thus occluding it with a sealed distal balloon and facilitating air flow into the trachea. While these devices function in a fashion similar to an older device, the Combitube, they have two advantages over the Combitube: they are softer and therefore less likely to damage the esophagus, and they are available in multiple sizes so that they can be used in smaller children. For example, the King LTD Supraglottic Airway size 2 can be used in patients as small as 12 kg or 35 inches in height.

The Combitube is rarely used in children, is primarily a prehospital device, and contains latex, which makes it unsuitable for airway management in the emergency department.

Indications and contraindications — LTAs have the same indications and contraindications/cautions as the other supraglottic rescue airways described. Also, most do not contain latex. (See 'Indications' above and 'Contraindications' above.)

Technique — In children, LTAs are used only if supraglottic airways are not available. Devices that function like the LMA are inserted in a fashion similar to the LMA (see 'Choice of technique' above). Two insertion techniques have been described for the devices that are intended to be placed into the esophagus:

●Blind technique:

•Summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

•Remove the device from its packaging, inspect and test the balloons, and lubricate its external surface with water-soluble lubricant.

•If the patient's neck can be safely moved, slightly extend the chin so that it is in "sniffing position." Note that the device can still be used effectively in patients whose necks cannot be manipulated (eg, cervical spinal motion restrictions), neck extension merely facilitates placement.

•With your dominant hand, hold the device near its connector and place it in the right corner of the mouth with the ventilation port turned approximately 90 degrees to the right of the patient's midline.

•With the nondominant hand, open the mouth, and if it is safe to do so, gently lift the mandible using your nondominant thumb and forefinger.

•Advance the device along the right side of the mouth until it is past the tongue; then, rotate it 90 degrees to the patient's left so that the ventilation port is roughly aligned with the patient's midline.

•Continue advancing the device as far as recommended by the manufacturer. In many cases, this will be the point at which the base of the connector is aligned with the patient's incisors.

•Inflate the balloons, distal first and then proximal (King LTA only has a single port which permits simultaneous inflation of both cuffs). In general, the balloons should be inflated with the minimal volume of air necessary to seal the airway.

•Attempt ventilation. Indications of proper placement include all of the following:

-Adequate chest rise

-Auscultation of breath sounds bilaterally

-Lack of gastric distention

-Detection of expired carbon dioxide

•Secure the laryngotracheal airway to prevent dislodgement.

●Alternative technique:

•Summon additional airway experts (eg, anesthesiologist, otolaryngologist, emergency medicine or critical care subspecialist) if needed and if available while establishing a rescue airway.

•Remove the device from its packaging, inspect and test the balloons, and lubricate its external surface with water-soluble lubricant.

•Using a laryngoscope, direct the device into the esophagus.

•Inflate the balloons.

•Check for ventilation. If the patient cannot be ventilated, the device must be removed immediately because it may have been inadvertently placed into the trachea.

•These devices are generally not used in combination with other tools but sometimes can be used with airway guides or flexible fiberoptic laryngoscopes.

Pitfalls — Inadvertent placement into the trachea is the major pitfall associated with these tools. Other pitfalls include over-inflation of the balloons, which can distend the esophagus and cause potential injury to the esophagus itself, or compression of the trachea, and placement of the ventilating port too distally or too proximally to permit effective ventilation.

SUMMARY AND RECOMMENDATIONS

●Definition – Supraglottic airway devices are airway devices that are placed above the glottis without extension of any components into the esophagus. They permit oxygenation and ventilation until a definitive airway is secured and can facilitate endotracheal intubation. Clinicians should have supraglottic airway devices available whenever performing an emergency pediatric intubation. (See 'Terminology' above and 'Contingency plan for the failed airway' above.)

●Choice of device – Common supraglottic airway devices that are available in pediatric sizes include (see 'Rescue airway' above):

•Laryngeal mask airway (LMA; (table 1)) (see 'Laryngeal mask airway (LMA)' above)

•i-gel (eg, i-gel (table 2) (see 'i-gel laryngeal airway' above)

•Air-Q (table 3) (see 'Air-Q masked laryngeal airway' above)

•CobraPLA (see 'CobraPLA (CPLA)' above)

The advantages of supraglottic airways include:

•They are effective rescue airways in situations in which endotracheal intubation is difficult or impossible, including the "cannot intubate-cannot bag-mask ventilate" situation (algorithm 1 and algorithm 2). (See "The difficult pediatric airway for emergency medicine", section on 'Management'.)

•They can serve as a bridge between manual ventilation and intubation and facilitate the use of other devices for difficult endotracheal intubation (eg, flexible intubating scope, intubating introducer (gum elastic bougie), or fiberoptic stylet) (figure 5). (See 'Conduit for endotracheal intubation' above.)

•They are an alternative to bag-mask ventilation during initial neonatal resuscitation. (See "Neonatal resuscitation in the delivery room", section on 'Laryngeal mask airway (LMA)'.)

The LMA and similar devices are less likely to be effective in patients with distorted airway anatomy (eg, laryngeal trauma, congenital abnormalities, burns, or epiglottitis) and patients with conditions associated with airway obstruction (eg, croup, asthma). (See 'Contraindications' above.)

●LMA – The technique of LMA placement by patient age is provided above. During emergency management of a difficult airway, the standard technique is appropriate for children of any age (figure 3). For children <7 years old, the rotation technique has a higher first-attempt success rate and lower risk of airway trauma or laryngospasm during elective placement in the operating (figure 1). However, the standard technique is a reasonable option, especially for clinicians inexperienced with the rotational technique. (See 'Standard technique' above and 'Choice of technique' above.)

●i-gel – The i-gel is a unique airway device that employs a thermoelastic polymer rather than an inflatable cuff to achieve an effective airway seal. This device is available in sizes appropriate for very small children (table 2) and appears to offer the advantage of easy insertion and no cuff to inflate after placement. (See 'i-gel laryngeal airway' above.)

●Other devices – Other devices that may be used in children include the air-Q, and the CobraPLA (picture 1). The intubating LMA is appropriate for children ≥30 kg. (See 'Intubating laryngeal mask airway (ILMA)' above and 'Air-Q masked laryngeal airway' above and 'CobraPLA (CPLA)' above and 'Laryngotracheal airways' above.)

Supraglottic airways are preferable to laryngeal tracheal airways (LTAs) in children because they are easier to place, do not require esophageal occlusion, and may be associated with better clinical outcomes. (See 'Laryngotracheal airways' above.)