*7.2.1 Supraglottic devices*

They are laryngeal masks that seal around the glottis and remain superior to the larynx. The laryngeal mask airway (LMA) is a useful supraglottic device added to emergent airway management. Its use is extended by 3 or 4 degrees Cormack-Lehane of laryngoscopic view and Difficult Bag Ventilation Mask (DBVM). This device allows clinicians to provide adequate ventilation in severely hypoxic patients facilitating subsequent treatment. It is very important to correctly fix the LMA as its dislocation is easier compared to endotracheal intubation. However, the LMA does not increase the risk of aspiration if its fixation is ensured.

We can consider LMA as the milestone in the field of supraglottic airway approach. It was first described by Archie Brain in 1983 and has become a commonly accepted device for rescue airway management and is included in the major societal recommendations and DA management algorithms [29].


**293**

**Table 6.**

Macintosh. Adults.

*Common types of blades.*

Indirectly rising the epiglottis.

*Management of New Special Devices for Intubation in Difficult Airway Situations*

substantial advance as a rescue device in situations of CICO [29, 30].

There are multiple types of laryngeal masks, each with specific characteristics. Therefore, the placement of a laryngeal mask (**Figure 3**) is an important tool in adults with a DA, especially in the case of a high anterior larynx, which represents a

They are laryngeal tubes that end in the upper part of the esophagus, posterior to the glottis, and have two balloons, one pharyngeal and the other oesophagal, with ventilation fenestrations in the middle that line up with the glottic opening (**Table 6**).

The purpose of the laryngoscope is to move the oral anatomical structures out of the laryngoscopist's line of vision to expose the glottic opening. The blade of a laryngoscope consists of a flat element (spatula), a vertical element (flange), and a

Both the Macintosh (curve) and Miller (straight) blades are available in sizes 0 (neonatal) to 4 (large adult), although we commonly prefer to use the straight blade

*7.3.1 Fiber-optic guided intubation (FBO) and awake tracheal intubation (ATI)*

Fiber-optic intubation is a technique in which a flexible endoscope with an endotracheal tube loaded along its length is passed through the glottis. The tracheal tube is then pushed out of the endoscope and into the trachea and the endoscope is removed. The nasotracheal route is used frequently and requires the use of nasal vasoconstrictors. A nebulized local anesthetic is delivered to the airways through a mask. Sedation can be given, but ideally, the patient should breathe spontaneously

> Miller. Infants.

Improve lifting of the epiglottis.

**7.3 Rigid laryngoscopic blades of alternative design and size**

light source. Straight and curved blades are the most common.

for infant intubations and curved blades for adults.

**Curve blade Straight blade**

and respond to verbal commands [31].

*DOI: http://dx.doi.org/10.5772/intechopen.97400*

*7.2.2 Retroglottic devices*

*ILMA (FASTRACH).*

**Figure 3.**

#### **Table 5.** *Common extra-glottic devices.*

*Management of New Special Devices for Intubation in Difficult Airway Situations DOI: http://dx.doi.org/10.5772/intechopen.97400*

There are multiple types of laryngeal masks, each with specific characteristics. Therefore, the placement of a laryngeal mask (**Figure 3**) is an important tool in adults with a DA, especially in the case of a high anterior larynx, which represents a substantial advance as a rescue device in situations of CICO [29, 30].

**Figure 3.** *ILMA (FASTRACH).*

*Special Considerations in Human Airway Management*

**7.2 Extraglottic devices for ventilation**

spasms/reflexes that can impair ventilation (**Table 5**).

not increase the risk of aspiration if its fixation is ensured.

societal recommendations and DA management algorithms [29].

**Supraglottic devices Retroglottic devices**

room, and other settings [26, 29].

*7.2.1 Supraglottic devices*

LMA. (Laryngeal mask airway).

*Common extra-glottic devices.*

ILMA. (Intubating laryngeal mask airway).

*Cook airway exchange catheter.*

Airway exchange catheters are long, hollow catheters that allow clinicians to remove and replace tracheal tubes without the need for laryngoscopy (**Figure 2**). These catheters often have connectors for manual and jet ventilation or oxygen insufflation. Cook's Airway Exchange Catheter (CAEC) is one example [26].

Extraglottic airway devices are used to establish an airway for oxygenation and ventilation without entering the trachea. They are important tools that are frequently used in the pre-hospital setting, the emergency department, the operating

These devices are useful in cases of DA management in patients who cannot be intubated or ventilated. Contraindications to the use of extra-glottic airway devices include obstructive airway diseases, traumatized airways, gag reflex, etc. These types of devices should be used under sedation to reduce pharyngeal

They are laryngeal masks that seal around the glottis and remain superior to the larynx. The laryngeal mask airway (LMA) is a useful supraglottic device added to emergent airway management. Its use is extended by 3 or 4 degrees Cormack-Lehane of laryngoscopic view and Difficult Bag Ventilation Mask (DBVM). This device allows clinicians to provide adequate ventilation in severely hypoxic patients facilitating subsequent treatment. It is very important to correctly fix the LMA as its dislocation is easier compared to endotracheal intubation. However, the LMA does

We can consider LMA as the milestone in the field of supraglottic airway approach. It was first described by Archie Brain in 1983 and has become a commonly accepted device for rescue airway management and is included in the major

Combitube.

King LT (King laryngeal tube).

*7.1.2 Tube exchangers*

**Figure 2.**

**292**

**Table 5.**

Air-Q. i-Gel.

## *7.2.2 Retroglottic devices*

They are laryngeal tubes that end in the upper part of the esophagus, posterior to the glottis, and have two balloons, one pharyngeal and the other oesophagal, with ventilation fenestrations in the middle that line up with the glottic opening (**Table 6**).

#### **7.3 Rigid laryngoscopic blades of alternative design and size**

The purpose of the laryngoscope is to move the oral anatomical structures out of the laryngoscopist's line of vision to expose the glottic opening. The blade of a laryngoscope consists of a flat element (spatula), a vertical element (flange), and a light source. Straight and curved blades are the most common.

Both the Macintosh (curve) and Miller (straight) blades are available in sizes 0 (neonatal) to 4 (large adult), although we commonly prefer to use the straight blade for infant intubations and curved blades for adults.

#### *7.3.1 Fiber-optic guided intubation (FBO) and awake tracheal intubation (ATI)*

Fiber-optic intubation is a technique in which a flexible endoscope with an endotracheal tube loaded along its length is passed through the glottis. The tracheal tube is then pushed out of the endoscope and into the trachea and the endoscope is removed. The nasotracheal route is used frequently and requires the use of nasal vasoconstrictors. A nebulized local anesthetic is delivered to the airways through a mask. Sedation can be given, but ideally, the patient should breathe spontaneously and respond to verbal commands [31].


**Table 6.** *Common types of blades.*

#### *7.3.1.1 Advantages of FBO-guided intubation*


Due to all these advantages, intubation with FBO is the cornerstone of DA management as well as its ultimate goal: suspect and identify a DA, perform intubation with the patient awake to avoid unnecessary risks.

Intubation with an awake patient while maintaining spontaneous breathing is the "gold standard" in the treatment of "predicted difficult airway."

Awake fiber-optic intubation is reported to be successful in 88–100% of DA patients. Case reports using other techniques for awake intubation (blind tracheal intubation, intubation through supraglottic devices, optically guided intubation) report not so high odds of success with DA patients [21].

Awake intubation has the following advantages [28, 34]: the patient retains the ability to keep the ventilation and airway patent and the muscle tone that keeps the pharynx clean and preserved; the collaboration of the patient and helps us pass the ET with deep breathing; with good local anesthesia, it facilitates a poor haemodynamic response.

FBOs also have disadvantages [33]: necessary training, skill, patient cooperation, longer execution time, optical fibers are fragile and require rigorous precautions.

The route for tracheal intubation should take into account the patient's anatomy, surgical access, and the tracheal extubation plan. In patients with limited mouth opening, the nasal approach is the only option, while in patients who had nasal surgical interventions, the oral approach should be preferred. No evidence or consensus is found among experts on the superiority of a route if both are feasible. Awake tracheal intubation (ATI) by using video-laryngoscopy has the same success rate and safety as ATI: FBO (98.3% each) [35]. Careful selection of the tracheal tube is critical to the success of any ATI technique. It is advisable to use the tracheal tube with a smaller external diameter, as it can reduce the incidence of injury [36]. A checklist of all the supplies needed should be disposable.

*Oxygenation*: Desaturation (SpO2 ≤ 90%) with low-flow (< 30 l/min-1) oxygen techniques during ATI ranges between 12% and 16% [37, 38]. When using warmed and humidified high-flow nasal oxygen, desaturation plummets to 0–1.5% [39]. Administration of supplemental oxygen during ATI is highly recommended. It should

**295**

*Management of New Special Devices for Intubation in Difficult Airway Situations*

and may be associated with undesirable clinical consequences [41].

ATI may be safe and effective even performed in the absence of sedation [42, 43]. Its use during ATI can reduce patient anxiety and discomfort and increase procedural tolerance. In certain patient populations, the risk of over-sedation is particularly hazardous, thus an independent practitioner delivering sedation is strongly recommended. Based on our experience, we can recommend the use of minimal sedation. Two drugs, remifentanil and dexmedetomidine have been associated with high levels of patient satisfaction and low risk of over-sedation and

airway obstruction. Complications are reduced when using capnography.

○ Patients with recent voice disorders, stridor, goiter, tracheal stenosis, flexed and fixed neck, use of accessory muscles to breathe, need to sit up to breathe.

○ Improve the safety of airway procedures, such as endotracheal tube changes

*7.3.1.2 Indications and contraindications for FBO-guided intubation*

○ Teaching, learning or consolidation of experiences.

○ Unstable cervical spine injury or I. vertebrobasilar.

○ Contraindication to anesthesia or muscle relaxants.

and percutaneous tracheostomy [33, 34, 44].

*7.3.1.3 Contraindications to FBO-guided intubation*

○ Non-collaboration of the patient.

○ Lack of experience or insufficient time.

○ Allergy to local anesthetics.

○ Rejection of the technique.

○ Suspicion of difficult airway management.

○ Knowledge of the difficult airway.

○ High risk of dental damage.

○ Risk of aspiration.

○ Morbid obesity.

○ Children.

be commenced on patient arrival before the procedure and continued throughout. High-flow nasal oxygen should be the technique of choice for pre-oxygenation.

*Airway topical anesthesia*: An effective topicalization with local anesthetics the key point for a successful ATI. The use of topical endonasal vasoconstrictors before nasotracheal intubation is highly recommended. Lidocaine has benefits when compared to other local anesthetic agents due to a safety cardiovascular and systemic reduced toxicity risk profile [16, 17, 21]; perhaps this is the most used local anesthetic drug for ATI. The dose of topical lidocaine should not exceed 9 mg/kg−1 lean body weight [40]. Nebulised lidocaine can be used but the absorption is variable. The adequacy of topicalisation should be tested before airway instrumentation, for example, with a soft suction catheter. The use of an antisialogogue is not mandatory

*DOI: http://dx.doi.org/10.5772/intechopen.97400*

*Sedation:*

#### *Management of New Special Devices for Intubation in Difficult Airway Situations DOI: http://dx.doi.org/10.5772/intechopen.97400*

be commenced on patient arrival before the procedure and continued throughout. High-flow nasal oxygen should be the technique of choice for pre-oxygenation.

*Airway topical anesthesia*: An effective topicalization with local anesthetics the key point for a successful ATI. The use of topical endonasal vasoconstrictors before nasotracheal intubation is highly recommended. Lidocaine has benefits when compared to other local anesthetic agents due to a safety cardiovascular and systemic reduced toxicity risk profile [16, 17, 21]; perhaps this is the most used local anesthetic drug for ATI. The dose of topical lidocaine should not exceed 9 mg/kg−1 lean body weight [40]. Nebulised lidocaine can be used but the absorption is variable. The adequacy of topicalisation should be tested before airway instrumentation, for example, with a soft suction catheter. The use of an antisialogogue is not mandatory and may be associated with undesirable clinical consequences [41].
