**3.5 Supra-glottic airway devices (SGA)**

SGA is a broad term for devices which sits above the glottic opening, examples includes laryngeal masks, Proseal LMA, Intubating LMA (ILMA, Fastrach), LMA Supreme, LMA Protector, i-gel (with non-inflatable cuff).

The ease of use for non-experienced personnel, makes those devices an appealing option for the use in the out of hospital environment or remote setup. SGA insertion does not require sophisticated skills, it provides proper means of ventilation and oxygenation in unconscious patients. Those features helped the adoption of such devices and increased their use worldwide. Moreover, SGA has become a backup tool in failed intubation in accordance with the difficult airway algorithm by the American Society of Anesthesia (ASA) [3]. Unfortunately, these devices do not protect from aspiration and may induce soft tissue trauma.

#### **3.6 Extra-glottic airway devices**

These devices have an extra advantage over the other SGA by having large pharyngeal tubes to seal the oropharynx or esophageal balloons to seal the esophagus so they can provide oxygenation and ventilation with reasonable protection from aspiration. They are easy to use and do not require advanced training.

A group of airways includes Laryngeal tube [4], Esophageal tracheal airway (Combitube) which be either inserted in the trachea or esophagus, King laryngeal tube (LT), Rusch EasyTube unlike the Combitube, Intubating Laryngeal Tube Suction Disposable (iLTS-D).

## **3.7 Endotracheal intubation (ETI)**

Endotracheal intubation is considered the gold standard method of airway management, which allows proper oxygenation, positive pressure ventilation, positive end-expiratory pressure (PEEP), and protection from gastric content aspiration.

The performance of ETI requires advanced training and highly skilled personnel, keeping in mind that out of hospital ETI is carried out in suboptimal environment and unusual positions. First attempt ETI among EMS providers in an Australian cohort study was found to be around 80%, non the less, the paramedic experience was not associated with improved patient survival [5]. But in other studies the first-pass intubation was correlated with improved return of spontaneous circulation rate and survival [6]. Those conflicting result highlights the importance of the approach to airway management, experience in performing one specific procedure like ETI does not warrant a better outcome, moreover literature suggest that out of hospital ETI is not achieving the goals it intended for and that in some cases it might even cause harm [7].

The fundamental role of performing ETI in the Field is to improve patient outcome. There are multiple studies that have looked into the morbidity and mortality of field ETI compared to other airway management maneuvers like the use of supraglottic/extra-glottic devices or bag mask ventilation, most of the studies had an inconclusive results on survival or outcome. In a recent study of the national database of Thailand registry that looked into the return of spontaneous circulation (ROSC) in out of hospital cardiac arrest patients who received ETI vs. bag mask ventilation, both groups had comparable ROSC rate although the bag mask ventilation group had less severe condition and received faster treatment [8]. In a meta-analysis by Benoit and his colleagues that investigated the outcome of out of hospital ETI vs. SGA insertion in patients with cardiac arrest among more than 75,000 patients, they concluded that patients who arrested outside of the hospital had better outcome when they received ETI rather than SGA device by EMS providers, specifically speaking ROSC, survival to hospital admission and neurological outcome were all better in the ETI group [9]. Similar conclusion was demonstrated by a study of the Korean nationwide registry that studied the survival of out of hospital cardiac arrest in approximately 100,000 patients who received bag mask ventilation vs. ETI vs. SGA, ETI group had favorable outcomes compared to both other groups [10].

Out of hospital endotracheal intubation brings a lot of challenges to the provider, other than just performing the procedure itself, other complication can occur, like misplacement of the endotracheal tube, hemodynamic changes associated with the intervention and their pathophysiological impact on the disease process itself, intervention with the resuscitation efforts, airway trauma and others.

In an observational study at level trauma center the rate of endotracheal misplacement without the use of continuous end-tidal carbon dioxide (ETCO2) monitoring was around 23%, using ETCO2 continuous monitor reduced it to around zero [11].

#### **3.8 Rapid sequence intubation versus no-medication intubation**

Rapid Sequence Intubation (RSI) is an airway management technique that aims toward controlling the airway in the emergency setting in the fastest and safest means possible, that might require the use of anesthetic induction agents and neuromuscular blocking agents in order to minimize the possibility of gastric content aspiration during endotracheal intubation. Rapid sequence induction technique is further discussed in another chapter.

The debate over whether to use RSI vs. intubation without the use of medications to facilitate the process of intubation in the prehospital setting is still ongoing. Despite that the use of medications in RSI provides optimum conditions for successful endotracheal intubation but it does not goes without risks, mainly because of the significant hemodynamic changes associated with the use of anesthetic induction agents and the possibility of development of difficult airway scenario and loss of spontaneous ventilation after the use of muscle relaxants.

**29**

*Airway Management in the Pre-Hospital Setting DOI: http://dx.doi.org/10.5772/intechopen.94999*

The use of medications to assist endotracheal intubation provides conditions that properly optimize the procedure. Factors that might be associated with failure to intubate like inability to pass the tube through the vocal cords, inability to visualize the cords, trismus and presence of gag reflex, can all be resolved with the use of medications to assist the endotracheal tube insertion [12]. Bernard et al. in a randomized clinical trial concluded that the neurological outcome of patients with severe traumatic brain injury was better when out of hospital RSI is performed by

In a study that evaluated the outcome in patients with severe traumatic brain injury who received RSI by paramedics compared to matched non intubated historical controls, concluded that RSI group had increase in mortality [14]. Moreover RSI

Therefor the decision whether to incorporate RSI vs. non medication intubation should be individualized based on the level of training of EMS providers as well as

Management of hypoxia thus management of the airway is of a paramount importance for trauma victims, trauma is one of the leading causes of death among the young adult population, and number of potentially preventable prehospital death is high, reaching up to 43% according to a recent review [15], the majority are due to the missed opportunity of performing a proper basic airway management

Airway management of trauma cases is challenging due to many factors, some are directly related to the type of trauma like trauma to the face or the respiratory tract, while others are related to the hypovolemia as a result of the trauma insult. Cervical spine injuries present a specific set of challenges that would render managing the airway in such population quite difficult and might need special equipment

Since upper airway obstruction is one of most important factors of morbidity and mortality in trauma victims, identifying the factors that would lead to airway mismanagement is very important. Factor that would contribute to airway misman-

Special attention to patients who might have potential inadequate respiration such as patient with decreased level of consciousness due to head injury or intoxication, patients with direct trauma to the airway, facial and maxillary region, neck, larynx or throat, patient with significant blood loss and patients who might develop respiratory failure due to a blast, inhalational injury or exposure to chemical agent.

Failure of maintenance of a previously established airway due to displacement of the airway device

paramedics compared with intubation in the hospital setting [13].

the level of resources provided by the health care system.

**4. Special considerations**

and techniques to maintain patient safety.

Inability to recognize an inadequate airway

Inability to recognize a misplaced airway device

Inability to recognize the need for ventilation

Aspiration of gastric content

Inability to establish a clear airway with or without airway device

**4.1 Trauma**

technique.

agement include [16]:

led to prolonged on scene time and thus delayed transfer to the hospital.

*Airway Management in the Pre-Hospital Setting DOI: http://dx.doi.org/10.5772/intechopen.94999*

The use of medications to assist endotracheal intubation provides conditions that properly optimize the procedure. Factors that might be associated with failure to intubate like inability to pass the tube through the vocal cords, inability to visualize the cords, trismus and presence of gag reflex, can all be resolved with the use of medications to assist the endotracheal tube insertion [12]. Bernard et al. in a randomized clinical trial concluded that the neurological outcome of patients with severe traumatic brain injury was better when out of hospital RSI is performed by paramedics compared with intubation in the hospital setting [13].

In a study that evaluated the outcome in patients with severe traumatic brain injury who received RSI by paramedics compared to matched non intubated historical controls, concluded that RSI group had increase in mortality [14]. Moreover RSI led to prolonged on scene time and thus delayed transfer to the hospital.

Therefor the decision whether to incorporate RSI vs. non medication intubation should be individualized based on the level of training of EMS providers as well as the level of resources provided by the health care system.
