Establishing a surgical airway by front-of-neck access is an indicated intervention in patients who cannot be intubated via the oral or nasal routes and also when faced with a cannot intubate–cannot oxygenate scenario. With the many devices available to improve laryngoscopy, offer oxygenation, or allow a supraglottic path for respiration, emergent surgical airways are rarely performed. When needed, absence of knowledge or preparation can lead to delays in performing this lifesaving procedure. The key is preparation and repetition through use or training in a laboratory setting.1,2
Surgical cricothyrotomy uses the cricothyroid membrane (CTM) as an insertion route, inserting a tracheal tube either directly through an incision or by using the Seldinger technique after puncture. Percutaneous transtracheal jet ventilation/oxygenation is an alternative to surgical airway establishment whereby a 12- to 16-gauge catheter is inserted into the trachea through the CTM and connected to a high-pressure (35 to 50 psi) oxygen source for both oxygenation and ventilation.
The primary indication for surgical airway placement is a cannot intubate–cannot oxygenate scenario, often following failed attempts to establish an oral/nasal endotracheal airway. Cricothyrotomy and jet ventilation can be used before laryngoscopy and direct glottic intubation if the latter is likely to fail because of anatomic distortion or any other cause that impedes visualization, notably blood, secretions, vomitus, swelling, or foreign matter. Attempting tracheal intubation prior to cricothyrotomy may increase the risk of harm to the patient by delaying oxygenation or increasing the risk of failure of a surgical airway. If standard intubation seems unlikely to succeed, it is not always necessary to attempt it prior to establishing a surgical airway.
Many things, often combined, add to difficulty of establishing a traditional endotracheal airway; the LEMON acronym helps organize those factors (Table 30-1). In addition, trauma can distort the neck anatomy by hematoma (e.g., cervical fracture, major vessel injury), create aspiration of blood or active oropharyngeal bleeding (facial trauma), or lessen the integrity of supporting structures (e.g., mandible fracture, LeForte fractures). Look for these features and have a preplanned difficult airway algorithm to include surgical airway to mitigate impending or actual respiratory failure. Often, predicting difficult laryngoscopy in the emergency setting is unreliable.3,4 Clinical signs and symptoms of airway obstruction—one common reason to perform a surgical airway—are listed in Table 30-2.
TABLE 30-1LEMON Airway Assessment Method ||Download (.pdf) TABLE 30-1 LEMON Airway Assessment Method
|Look externally (facial trauma, large incisors, beard, large tongue)
Evaluate the 3-3-2 rule
Incisor opening distance: 3 fingerbreadths
Hyoid-mental distance: 3 fingerbreadths
Thyroid-to-mouth distance: 2 fingerbreadths
|Mallampati score ≥3
|Obstruction: Presence of condition such as epiglottitis, peritonsillar abscess, or trauma
|Neck mobility (limited neck mobility)
TABLE 30-2Clinical Manifestations Associated With Acute Airway Obstruction