**9. DA extubation strategy: Recommendations for extubation**

There is not a sufficient basis to evaluate the benefits of an extubation strategy for DA. For the DA management guidelines, an extubation strategy is considered a logical extension of the intubation strategy.

The extubation strategy will depend on the surgery or situation that led to ICU hospitalization, in addition to the patient's condition and the skill of the physician.

The recommended strategy for extubation of the DA, according to the literature, includes:


This type of device can be a stylet (intubation plug) or a conduit. Intubation stylets or spark plugs are generally inserted through the lumen of the tracheal tube and into the trachea before removing the tracheal tube; they can be used to provide a temporary means of oxygenation and ventilation. The tubes are inserted through the mouth and can be used for supraglottic ventilation and intubation. The intubating laryngeal mask airway and the laryngeal mask airway are examples of conduits.

## **10. Other considerations in DA management**

#### **10.1 Human factors**

Human factors (HF) issues have been considered to have contributed to adverse outcomes in 40% of the instances reported to the National Audit Project (NAP4) [22, 23]; however, HF influences in every instance. It has been identified as latent threats (poor communication, poor training and fragile teamwork, deficiencies in equipment, and inadequate systems and protocols) predisposing to loss of situation awareness and subsequent poor decision-making that lead to final errors. Developing guidelines and a professional willingness to follow them are not enough to avoid serious complications of airway management during the procedure. During a crisis, it is common to receive more information than can be processed. An information overload impairs decision-making and can make clinicians 'lose sight of the big picture. It is of huge importance for the team to stop and think to help reduce this risk. For any plan to work well in an emergency, it must be known to all members of the team and should be rehearsed. For rare events, such as CICO, this rehearsal can be achieved with simulation training [17, 21].

#### **10.2 Rapid sequence induction (RSI)**

Intubation of the trachea with a cuffed tube offers the greatest protection against aspiration. Suxamethonium is the U.K. and other European countries the neuromuscular blocking agent of choice due to its rapid onset that allows early intubation without the need for bag-mask-ventilation (BMV). Suxamethonium has been compared with rocuronium for RSI, and both are very similar in properties [46]. The ability to antagonize the effect of rocuronium with sugammadex may be a great advantage. Sugammadex can be used as a part of the failed intubation plan, (the correct dose is 16 mg kg − 1.) Cricoid pressure can be applied to protect the airway from gastric content aspiration during the period between the loss of consciousness and placement of the tube (BURP). This is a standard maneuver of an RSI in many countries. Gentle mask ventilation after BURP and before tracheal intubation prolongs the time to desaturation. In case of initial attempts at laryngoscopy are difficult during RSI, cricoid pressure should be released. This should be done only under vision with the laryngoscope and suction available; in the event of gastric regurgitation cricoid pressure should be immediately reapplied [16, 17, 21].

#### **10.3 Position**

Adequate patient positioning maximizes the chance of successful laryngoscopy and tracheal intubation. The best position for direct laryngoscopy with a Macintosh-style blade is performed with the neck flexed and the head extended at the atlanto-occipital joint; the classic 'sniffing' position [21]. In the obese patient, the 'ramped' position must be used to ensure horizontal alignment of the external auditory meatus and the suprasternal notch because this improves the view during

**299**

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

direct laryngoscopy [47, 48]. This position improves airway patency and respiratory mechanics, facilitating passive oxygenation during apnoea [49]. All patients must be pre-oxygenated before the induction of general anesthesia. De-nitrogenation can be achieved with an appropriate flow of 100% oxygen into the breathing system while maintaining a total face-mask seal [17, 21]. Preoxygenation increases the oxygen reserve delays the onset of hypoxia and allows more time for laryngoscopy, tracheal intubation, and airway rescue in case of a failed intubation. In healthy adults, the duration of apnoea without desaturation (defined as the interval between the onset of apnoea and the time peripheral capillary oxygen saturation reaches a value of ≤90%) is limited to 1–2 min whilst breathing room air but can be extended to up 8 min when using pre-oxygenation. The duration of apnoea without desaturation can also be prolonged by passive oxygenation during the apnoeic period, delivering up to 15 liters min − 1 of oxygen through nasal cannulae. Nasal Oxygenation During Efforts Of Securing A Tube (NODESAT) has been shown to extend the apnoea time in obese patients and patients with DA. Transnasal humidified high-flow oxygen (up to 70 liters min − 1) via nasal cannulae has been shown

The induction agent should be selected according to the clinical condition of the patient. Propofol, the most commonly used induction agent in the UK, suppresses laryngeal reflexes and provides better conditions for airway management than other agents. The National Audit Project of the Royal College of Anesthetists highlighted the relationship between DA management and awareness [22, 23]. Several other agents are used depending on the clinical status, these are Midazolam, Ketamine, Etomidate, etc. It is important to ensure that the patient is anesthetized during repeated attempts at intubation. Neuromuscular block (NMB) if intubation is difficult, further attempts should not proceed without full neuromuscular block. NMB abolishes laryngeal reflexes, improves chest compliance, and facilitates face-mask ventilation. A complete NMB should be used if any difficulty is encountered with airway management. Rocuronium has a rapid onset and can be antagonized immediately with sugammadex, but the incidence of anaphylaxis may be higher than with other types of non-depolarizing NMB agents. Mask ventilation with 100% oxygen should begin as soon as possible after the induction of anesthesia. If some difficulty is encountered, the airway position should be optimized and airway maneuvers such as a chin lift or jaw thrust should be ensured.

The choice of laryngoscope greatly influences the reaching a successful tracheal intubation. Video-laryngoscopes (VAL) offer an improved view when compared with traditional direct laryngoscopy and are currently the first choice or default device for many anesthetists, intensivists and emergency practitioners. Metaanalyses of RCTs comparing both types of laringoscopes in patients with predicted DA report better results with VAL but no differences in time to intubation, airway

trauma, gum/lip trauma, dental trauma, or sore throat has been reported. **Airtraq** is employed regularly daily in our environment even by our colleagues' Anesthesia on many patients with excellent results. We have a very good experience with this device in cases of DA. Airtraq has a lot of endorsing literature showing better results than the traditional Macintosh and Miller laryngoscopy, as well as with other VAL, reporting excellent intubation rates, less cardiac and haemodynamic alterations, better results in obese patients, a better curve of learning for novice personnel, and very good results when combined

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

to extend the apnoea time.

**10.4 Choice of induction agent**

**10.5 Choice of laryngoscope**

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

direct laryngoscopy [47, 48]. This position improves airway patency and respiratory mechanics, facilitating passive oxygenation during apnoea [49]. All patients must be pre-oxygenated before the induction of general anesthesia. De-nitrogenation can be achieved with an appropriate flow of 100% oxygen into the breathing system while maintaining a total face-mask seal [17, 21]. Preoxygenation increases the oxygen reserve delays the onset of hypoxia and allows more time for laryngoscopy, tracheal intubation, and airway rescue in case of a failed intubation. In healthy adults, the duration of apnoea without desaturation (defined as the interval between the onset of apnoea and the time peripheral capillary oxygen saturation reaches a value of ≤90%) is limited to 1–2 min whilst breathing room air but can be extended to up 8 min when using pre-oxygenation. The duration of apnoea without desaturation can also be prolonged by passive oxygenation during the apnoeic period, delivering up to 15 liters min − 1 of oxygen through nasal cannulae. Nasal Oxygenation During Efforts Of Securing A Tube (NODESAT) has been shown to extend the apnoea time in obese patients and patients with DA. Transnasal humidified high-flow oxygen (up to 70 liters min − 1) via nasal cannulae has been shown to extend the apnoea time.

## **10.4 Choice of induction agent**

*Special Considerations in Human Airway Management*

**10. Other considerations in DA management**

rehearsal can be achieved with simulation training [17, 21].

**10.2 Rapid sequence induction (RSI)**

**10.1 Human factors**

This type of device can be a stylet (intubation plug) or a conduit. Intubation stylets or spark plugs are generally inserted through the lumen of the tracheal tube and into the trachea before removing the tracheal tube; they can be used to provide a temporary means of oxygenation and ventilation. The tubes are inserted through the mouth and can be used for supraglottic ventilation and intubation. The intubating laryngeal mask airway and the laryngeal mask airway are examples of conduits.

Human factors (HF) issues have been considered to have contributed to adverse outcomes in 40% of the instances reported to the National Audit Project (NAP4) [22, 23]; however, HF influences in every instance. It has been identified as latent threats (poor communication, poor training and fragile teamwork, deficiencies in equipment, and inadequate systems and protocols) predisposing to loss of situation awareness and subsequent poor decision-making that lead to final errors. Developing guidelines and a professional willingness to follow them are not enough to avoid serious complications of airway management during the procedure.

During a crisis, it is common to receive more information than can be processed. An information overload impairs decision-making and can make clinicians 'lose sight of the big picture. It is of huge importance for the team to stop and think to help reduce this risk. For any plan to work well in an emergency, it must be known to all members of the team and should be rehearsed. For rare events, such as CICO, this

Intubation of the trachea with a cuffed tube offers the greatest protection against

aspiration. Suxamethonium is the U.K. and other European countries the neuromuscular blocking agent of choice due to its rapid onset that allows early intubation without the need for bag-mask-ventilation (BMV). Suxamethonium has been compared with rocuronium for RSI, and both are very similar in properties [46]. The ability to antagonize the effect of rocuronium with sugammadex may be a great advantage. Sugammadex can be used as a part of the failed intubation plan, (the correct dose is 16 mg kg − 1.) Cricoid pressure can be applied to protect the airway from gastric content aspiration during the period between the loss of consciousness and placement of the tube (BURP). This is a standard maneuver of an RSI in many countries. Gentle mask ventilation after BURP and before tracheal intubation prolongs the time to desaturation. In case of initial attempts at laryngoscopy are difficult during RSI, cricoid pressure should be released. This should be done only under vision with the laryngoscope and suction available; in the event of gastric regurgitation cricoid pressure should be immediately reapplied [16, 17, 21].

Adequate patient positioning maximizes the chance of successful laryngoscopy and tracheal intubation. The best position for direct laryngoscopy with a Macintosh-style blade is performed with the neck flexed and the head extended at the atlanto-occipital joint; the classic 'sniffing' position [21]. In the obese patient, the 'ramped' position must be used to ensure horizontal alignment of the external auditory meatus and the suprasternal notch because this improves the view during

**298**

**10.3 Position**

The induction agent should be selected according to the clinical condition of the patient. Propofol, the most commonly used induction agent in the UK, suppresses laryngeal reflexes and provides better conditions for airway management than other agents. The National Audit Project of the Royal College of Anesthetists highlighted the relationship between DA management and awareness [22, 23]. Several other agents are used depending on the clinical status, these are Midazolam, Ketamine, Etomidate, etc. It is important to ensure that the patient is anesthetized during repeated attempts at intubation. Neuromuscular block (NMB) if intubation is difficult, further attempts should not proceed without full neuromuscular block. NMB abolishes laryngeal reflexes, improves chest compliance, and facilitates face-mask ventilation. A complete NMB should be used if any difficulty is encountered with airway management. Rocuronium has a rapid onset and can be antagonized immediately with sugammadex, but the incidence of anaphylaxis may be higher than with other types of non-depolarizing NMB agents. Mask ventilation with 100% oxygen should begin as soon as possible after the induction of anesthesia. If some difficulty is encountered, the airway position should be optimized and airway maneuvers such as a chin lift or jaw thrust should be ensured.

#### **10.5 Choice of laryngoscope**

The choice of laryngoscope greatly influences the reaching a successful tracheal intubation. Video-laryngoscopes (VAL) offer an improved view when compared with traditional direct laryngoscopy and are currently the first choice or default device for many anesthetists, intensivists and emergency practitioners. Metaanalyses of RCTs comparing both types of laringoscopes in patients with predicted DA report better results with VAL but no differences in time to intubation, airway trauma, gum/lip trauma, dental trauma, or sore throat has been reported.

**Airtraq** is employed regularly daily in our environment even by our colleagues' Anesthesia on many patients with excellent results. We have a very good experience with this device in cases of DA. Airtraq has a lot of endorsing literature showing better results than the traditional Macintosh and Miller laryngoscopy, as well as with other VAL, reporting excellent intubation rates, less cardiac and haemodynamic alterations, better results in obese patients, a better curve of learning for novice personnel, and very good results when combined

with fiber-optic bronchoscope intubation [50–52]. Regular practice is required to ensure that the improved view translates reliably into successful tracheal intubation. All intensivists, anesthetists and emergency practitioners should be trained to use VAL, and have immediate access to, a video-laryngoscope [16–21]. There are available several other interesting models of VAL as **GlideScope Video Laryngoscope, C-Mac Video Laryngoscope, Pentax Airway Scope, McGrath Video Laryngoscope, AirTraq Optical Laryngoscope, King Vision Laryngoscope**, etc. (**Figure 4**).
