**4. Special considerations**

#### **4.1 Trauma**

*Special Considerations in Human Airway Management*

even cause harm [7].

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

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.

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

spontaneous ventilation after the use of muscle relaxants.

further discussed in another chapter.

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].

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

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

**28**

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 technique.

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 and techniques to maintain patient safety.

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 mismanagement include [16]:


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.

In most of the cases of trauma victims, simple maneuvers are usually sufficient to overcome upper airway obstruction, but in cases were simple techniques were ineffective the aim should be toward establishing a definitive airway technique. In an prospective observation study Lockery and his colleagues investigated the effectiveness prehospital advanced airway management in trauma patient, among the patient whom had received advanced airway management technique around 57% of them had airway compromise upon there arrival to the trauma centers, the success rate of ETI for non-physician paramedic was 64% and 11% reached a health care facility with unrecognized esophageal intubation. While physician-paramedic teams achieved definitive airway management for all patients [17]. Therefore, level of training, and availability of expertise are important in situations when advanced airway technique is warranted in trauma patient population group.

Advanced airway management techniques include ETI or a surgical airway. Below is a list of the most common indications for advanced airway technique in trauma victims.


It is recommended to assume that patients with major trauma, head and facial injuries, decreased level of consciousness or with neck pain as having cervical spine injury thus warranting cervical immobilization techniques to prevent further damage. Cervical immobilization has been known to attribute to difficulties with laryngoscopic view and hence difficult airway management. In a prospective study by Heath, that investigated the effect of different cervical spine immobilization techniques on the ease of laryngoscopy, poor view on laryngoscopy (grade 3 or 4) was more encountered when the cervical spine immobilized using rigid collar, tapes and sandbags compared to in-line manual immobilization. Therefore, manual in-line stabilization of cervical spine is the method of choice during tracheal intubation [18].
