1.Adequate preoxygenation with 100% oxygen

Preoxygenation is administered by face mask for 3 minutes of normal tidal volume breathing that will increase oxygen reserve in the functional reserve capacity (FRC) and provide additional safe apnea time. Passive oxygen insufflation by a nasal canula with 10 l/min during laryngoscopy can prolong the apnea time until desaturation in high risk patient of difficult intubation during airway management [28, 29].

High frequency nasal canula (HFNC) or trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) with up to 60 l/min oxygen can be used in critically ill patient that have shorter safe apneic time [30]. It was found that THRIVE will not cause gastric distension or increase the risk of regurgitation. Oxygen flow of 70 l/min will generate a nasopharyngeal pressure of 7 cm H2O, with this pressure it is unlikely to cause gastric distension. In a study 80 patient underwent RSI with the use THRIVE for preoxygenation, no patient shows any sign of regurgitation [31].


All equipment should be ready for intubation as variable size facemask, different types of laryngoscopes, different sizes of endotracheal tubes, oral and nasal airways, video laryngoscope, supraglottic airway of different sizes, and a bougie. Anxiolytic might be used to relieve anxiety; Opioid dose should be used carefully to avoid respiratory depression and loss of airway reflexes [32]. Patient head should be positioned in sniffing position to facilitate intubation, the operating table head part to put it up to make the larynx above the level of lower esophageal sphincter. Short acting Opioids Fentanyl 1–3 mcg/ kg IV 3 min before induction will reduce sympathetic response to intubation. Induction of anesthesia can be done by Propofol 1.5–2.5 mg/kg IV, Etomidate 0.2–0.6 mg/kg IV or Ketamine 1–2 mg/kg IV depending on the patient general condition. Intravenous Lidocaine 1 mg/kg can be given 2 min prior to intubation to blunt the sympathetic response of intubation. Succinylcholine 1–1.5 mg/kg provide complete relaxation in 30–60 s or Rocuronium 0.9– 1.2 mg/kg achieve maximum neuromuscular block in 55–75 s if Succinylcholine is contraindicated.

**Sellick's** maneuver or cricoid pressure of approximately 30 N or 3 kg is applied on the cricoid ring against the cervical vertebra to occlude the lumen of the esophagus to prevent regurgitation of the stomach content to the pharynx. It is routinely applied during RSII until confirmation of Endotracheal Tube (ETT) position and inflation of the tube cuff [33]. Assistant should be directed to apply cricoid pressure by the intubating physician either to shift or release the pressure if the laryngeal view is disturbed or active vomiting has happened. It is advised to leave the NG tube in place while doing RSII, connect it to suction to drain stomach contents then leave it open to air and to suction the stomach before emergence [34].

If difficult intubation is expected, or patient might desaturate with apnea e.g. obese patients, patients with high intraabdominal pressure or those with sepsis or fever, it is advised to use **modified RSII.** Modified RSII refers to cricoid pressure and gentle mask ventilation before intubation [35].

Number of studies shows that application of cricoid pressure will prevent gastric insufflation even if mask ventilation pressure is up to 60 cm H2O [36]. Some patients cannot tolerate preoxygenation such as agitated patients due to hypoxia, hypercapnia or underlying medical condition. In those patients it is advisable to intubate them using **delayed sequence intubation (DSI)**. DSI is done under procedure sedation using a dissociative dose of Ketamine (1–1.5 mg/kg) to sedate the patient sufficiently to allow mask preoxygenation with his airway reflexes being reserved. Small observational studies in ICU show some improvement in preoxygenation using DSI [37]. Another study shows that using Ketamine to facilitate preoxygenation will decrease peri-intubation hypoxia from 44 to 3.5% [38].

## 4.Wide bore suction (Yankeur) must be immediately available

The importance of suction cannot be overemphasized in airway decontamination. It has been incorporated with the laryngoscopy steps in the **Suction Assisted Laryngoscopy Airway Decontamination procedure (SALAD)** which was developed by Dr. James DuCanto. SALAD is performed using a rigid suction catheter to decontaminate the oral cavity and to depress or lift the tongue for better laryngoscope position then further decontamination of the hypopharynx followed by further insertion of the catheter into the proximal esophagus for continuous drain of emesis. The suction catheter is placed to the left corner of the mouth so that it will be easier to be pinned in place by the laryngoscope. Intubation and inflation of the tracheal tube will be performed while the suction catheter in upper part of esophagus so that any pharyngeal soiling or regurgitated contents could be removed instantaneously (**Figure 3**).

**115**

*Airway Management in Full Stomach Conditions DOI: http://dx.doi.org/10.5772/intechopen.93591*

thus could decrease the severity [39].

*with his permission, Hamad medical corporation, Doha, Qatar.*

difficult airway

**Figure 3.**

*5.4.3 Postoperative*

reflux or in lateral position.

**6. Management of aspiration**

ive therapy and broad-spectrum antibiotics.

Suction of pharyngeal contents decrease the volume of aspirates to the lung,

*A videoscope picture showing the SALAD technique. On the left, suction catheter advanced in upper esophagus. On the right, ETT in place while the suction catheter in upper esophagus. Picture courtesy of Dr. Nabil Shallik* 

5.Use of airway adjuvant as optical stylet, or a video laryngoscopy in expected

Optical Stylets (OS) are rigid or semirigid tubular devices that fit inside

tracheal tube. OS composed of a fiberoptic bundles or a video chip at distal end to convey the image. Different types of Optical stylets are available for instance Shikani Optical Stylets and Bonfils Retromolar Intubation Fiberscope. Optical stylets are useful mainly in patients with suspected difficult intubation. Airway trauma and technical difficulties due to fogging and secretion limit OS use.

Different kinds of laryngoscopes can be used to assist intubation, many studies recommend the use of video laryngoscope use for higher first attempted intubation

On extubation, emptying of the stomach using NG tube is recommended before emergence of the patient from anesthesia and it is advised to extubate the patient in a fully awake state, and a full recovery of the airway reflexes. Patient should be transferred to recovery with the head of the bed elevated to reduce the chance of

The first step in aspiration management is to be vigilant for any signs and symptoms of aspiration in patients especially in those who are known to have full stomach. Any witnessed gastric or oropharyngeal contents into the trachea during induction, maintenance or emergence from anesthesia, witnessed vomitus through the nose or mouth or sudden elevation of peak airway pressures during ventilation or cough, persistent hypoxia, bronchospasm or abnormal breath sounds following intubation, sore throat, dyspnea at recovery may suggest that a patient has aspirated (**Table 4**). Management in the intensive care unit includes monitoring and support-

rate especially for Mallampati 3 and 4, and better glottic view [40].

#### **Figure 3.**

*Special Considerations in Human Airway Management*

is contraindicated.

before emergence [34].

a bougie. Anxiolytic might be used to relieve anxiety; Opioid dose should be used carefully to avoid respiratory depression and loss of airway reflexes [32]. Patient head should be positioned in sniffing position to facilitate intubation, the operating table head part to put it up to make the larynx above the level of lower esophageal sphincter. Short acting Opioids Fentanyl 1–3 mcg/ kg IV 3 min before induction will reduce sympathetic response to intubation. Induction of anesthesia can be done by Propofol 1.5–2.5 mg/kg IV, Etomidate 0.2–0.6 mg/kg IV or Ketamine 1–2 mg/kg IV depending on the patient general condition. Intravenous Lidocaine 1 mg/kg can be given 2 min prior to intubation to blunt the sympathetic response of intubation. Succinylcholine 1–1.5 mg/kg provide complete relaxation in 30–60 s or Rocuronium 0.9– 1.2 mg/kg achieve maximum neuromuscular block in 55–75 s if Succinylcholine

**Sellick's** maneuver or cricoid pressure of approximately 30 N or 3 kg is applied on the cricoid ring against the cervical vertebra to occlude the lumen of the esophagus to prevent regurgitation of the stomach content to the pharynx. It is routinely applied during RSII until confirmation of Endotracheal Tube (ETT) position and inflation of the tube cuff [33]. Assistant should be directed to apply cricoid pressure by the intubating physician either to shift or release the pressure if the laryngeal view is disturbed or active vomiting has happened. It is advised to leave the NG tube in place while doing RSII, connect it to suction to drain stomach contents then leave it open to air and to suction the stomach

If difficult intubation is expected, or patient might desaturate with apnea e.g. obese patients, patients with high intraabdominal pressure or those with sepsis or fever, it is advised to use **modified RSII.** Modified RSII refers to cricoid

Number of studies shows that application of cricoid pressure will prevent gastric insufflation even if mask ventilation pressure is up to 60 cm H2O [36]. Some patients cannot tolerate preoxygenation such as agitated patients due to hypoxia, hypercapnia or underlying medical condition. In those patients it is advisable to intubate them using **delayed sequence intubation (DSI)**. DSI is done under procedure sedation using a dissociative dose of Ketamine (1–1.5 mg/kg) to sedate the patient sufficiently to allow mask preoxygenation with his airway reflexes being reserved. Small observational studies in ICU show some improvement in preoxygenation using DSI [37]. Another study shows that using Ketamine to facilitate preoxygenation will

The importance of suction cannot be overemphasized in airway decontamination. It has been incorporated with the laryngoscopy steps in the **Suction Assisted Laryngoscopy Airway Decontamination procedure (SALAD)** which was developed by Dr. James DuCanto. SALAD is performed using a rigid suction catheter to decontaminate the oral cavity and to depress or lift the tongue for better laryngoscope position then further decontamination of the hypopharynx followed by further insertion of the catheter into the proximal esophagus for continuous drain of emesis. The suction catheter is placed to the left corner of the mouth so that it will be easier to be pinned in place by the laryngoscope. Intubation and inflation of the tracheal tube will be performed while the suction catheter in upper part of esophagus so that any pharyngeal soiling or regurgitated contents could be removed instantaneously (**Figure 3**).

pressure and gentle mask ventilation before intubation [35].

decrease peri-intubation hypoxia from 44 to 3.5% [38].

4.Wide bore suction (Yankeur) must be immediately available

**114**

*A videoscope picture showing the SALAD technique. On the left, suction catheter advanced in upper esophagus. On the right, ETT in place while the suction catheter in upper esophagus. Picture courtesy of Dr. Nabil Shallik with his permission, Hamad medical corporation, Doha, Qatar.*

Suction of pharyngeal contents decrease the volume of aspirates to the lung, thus could decrease the severity [39].

5.Use of airway adjuvant as optical stylet, or a video laryngoscopy in expected difficult airway

Optical Stylets (OS) are rigid or semirigid tubular devices that fit inside tracheal tube. OS composed of a fiberoptic bundles or a video chip at distal end to convey the image. Different types of Optical stylets are available for instance Shikani Optical Stylets and Bonfils Retromolar Intubation Fiberscope. Optical stylets are useful mainly in patients with suspected difficult intubation. Airway trauma and technical difficulties due to fogging and secretion limit OS use.

Different kinds of laryngoscopes can be used to assist intubation, many studies recommend the use of video laryngoscope use for higher first attempted intubation rate especially for Mallampati 3 and 4, and better glottic view [40].

## *5.4.3 Postoperative*

On extubation, emptying of the stomach using NG tube is recommended before emergence of the patient from anesthesia and it is advised to extubate the patient in a fully awake state, and a full recovery of the airway reflexes. Patient should be transferred to recovery with the head of the bed elevated to reduce the chance of reflux or in lateral position.
