Airway Management in Head and Neck Surgery

History

The anatomy of H&N is largely noncompliant, and any significant pathologic processes and injuries tend to result in substantial patient suffering and functional impairment. Tobacco and alcohol use are associated with most cases of H&N cancer and predispose these patients to significant comorbidities, such as chronic obstructive pulmonary disease (COPD), hypertension, coronary artery disease, and alcohol withdrawal. Appropriate diagnostic tests are indicated for these patients as part of the preoperative workup and preoperative optimization. Patients with significant lung disease and ventilation/perfusion (V̇/Q̇) mismatch may not be suitable candidates for advanced intraoperative ventilation techniques, such as spontaneous ventilation, apneic intermittent ventilation, JV, transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) or SponTaneous Respiration using IntraVEnous anaesthesia and Hi-flow nasal oxygen (STRIVE Hi). It is not uncommon for H&N cancer patients to present with chronic anemia. Appropriate laboratory studies must be obtained, and electrolyte and fluid status of these patients should be optimized preoperatively. Patients with chronic alcohol consumption require preoperative evaluation of liver function and coagulation status.

Some patients may present with increased aspiration risk, complicating DA management. Lower cranial nerve involvement (cranial nerves XI, X, and XII) may lead to airway difficulty related to aspiration or obstruction. Almost one-half of the patients presenting with laryngeal and voice disorders have silent laryngopharyngeal reflux as the primary cause or as a significant etiologic factor. ^, Coexistent significant glottic insufficiency (e.g., VC paralysis) may place these patients at increased risk for aspiration of gastric contents. ^, This can usually be diagnosed during a routine preoperative flexible scope laryngoscopy or laryngostroboscopy performed by the surgeon. Those presenting for esophagoscopy for evaluation and treatment of esophageal obstructing lesions, achalasia, Zenker diverticulum, active gastrointestinal bleeding, or esophageal foreign body removal constitute another category of patients at high risk for aspiration. Even when gastroesophageal reflux disease (GERD) is not clinically significant, adequate preoperative pharmacologic control of the symptoms is warranted: The combination of acid exposure and direct trauma from the operating procedure and TI can lead to laryngeal mucosal injury.

Many patients presenting for H&N surgery are ≥60 years old and will demonstrate high incidence of undiagnosed sleep-disordered breathing and OSA. The nature of many H&N diseases, the presence of craniofacial abnormalities (e.g., retrognathia, macroglossia), male sex, and a history of excessive alcohol intake must also increase the anesthesia provider’s level of suspicion for OSA. A variety of bedside screening tools (e.g., the snoring, tiredness, observed apnea, high blood pressure, body mass index, age, neck circumference, and male gender [STOP-Bang] questionnaire) can be used to identify patients at highest risk for OSA.

Information about previous H&N surgical procedures and radiation therapy, as well as the history of anesthetic and airway management problems, must be obtained and communicated. History of previous difficult TI is one of the most important predictors of anticipated airway management difficulties, yet it is still taken lightly in anesthesia practice.

The history of prior H&N radiation therapy must be elucidated because exposure to radiation therapy frequently makes TI difficult. The radiation-induced tissue fibrosis results in loss of tissue compliance, frequently leads to long-standing glottic and epiglottic edema as a result of impaired lymphatic drainage, and may also restrict the patient’s mouth opening and neck extension.

Physical Examination

A systematic and comprehensive preoperative airway assessment is paramount, and the American Society of Anesthesiologists (ASA) 11-point bedside airway assessment tool is a good start. However, standard airway assessment tests are poorly predictive, do not account for aspiration risk and lower airway problems, and fail to assess the severity of upper airway disease and BOT pathology (e.g., epiglottic cancer, epiglottic and vallecula cysts, lingual tonsillar hypertrophy) ( Fig. 38.5 ). ^,

Postradiation changes in the neck and decreased mandibular protrusion are important factors predicting the risk of impossible mask ventilation, difficult mask ventilation, and difficult DL in patients at risk for these conditions (see Chapter 9 ). The reduced submandibular compliance attributed to cancerous involvement, masses, inflammation, or previous radiation therapy ( Fig. 38.6 ) may severely diminish pharyngeal space and restrict tongue displacement during DL, resulting in difficult or failed TI.

Pharyngeal restriction can be further accentuated by a large tongue or intraoral masses, which can be exophytic and mobile. Common symptoms of airway obstruction may include dyspnea at rest or on exertion, voice changes, dysphagia, stridor, and cough. Voice changes provide an early suggestion of the anatomic level, severity, and progression of the lesion. A muffled voice may indicate supraglottic disease, whereas glottic lesions often result in a coarse, scratchy voice. Physical findings may include hoarseness, agitation, and intercostal, suprasternal, and supraclavicular retraction.

Drooling, dysphagia, and expiratory snoring are the signs of marked pharyngeal restriction, ^, but inspiratory stridor at rest represents the most worrisome sign, suggesting a reduction in airway diameter at the supraglottic, periglottic, or glottic level of at least 50% (see “ Special Considerations ”/“ Partially Obstructed Airway ”). ^, Airway compromise in H&N patients may also involve the lower airways. Airway narrowing at the tracheal or tracheobronchial level is typically characterized by expiratory stridor, whereas biphasic inspiratory-expiratory stridor usually points to obstructive subglottic disease. In some cases, preoperative examination of the flow-volume loops may be helpful.

It is prudent to assess the laryngeal mobility, the degree of tracheal deviation, and the location of the cricothyroid membrane (CTM) preoperatively. Significant tracheal deviation, especially in combination with the fixed hemilarynx ( Fig. 38.7 ) and poor or absent visualization of VC during preoperative nasal endoscopy, can be an ominous sign ^, and may warrant a performance of an awake tracheostomy (see “ Devising Safe Airway Management Strategies for Tracheal Intubation ”/ “ Surgical Airway as a Primary Approach to Tracheal Intubation ” and “ Special Situations ”/“ Partially Obstructed Airway ”).

Endoscopy and Imaging Studies

Usually, the extent of disease in elective cases has been comprehensively evaluated preoperatively by routine chest radiography, computed tomography (CT), magnetic resonance imaging (MRI), and flexible laryngoscopy (nasal endoscopy), providing the anesthesia provider with valuable information regarding the location, size, spread, and vascularity of the obstructive lesions; the degree of obstruction; the mobility of the vocal cords; and the extent of laryngeal and tracheal deviation or compression. ^{, ,}

Patients with H&N cancer are at increased risk for CICO, and if symptoms of airway obstruction are present, airway imaging and nasal endoscopy are considered a minimum necessary level of investigation for assessing airway management options. ^, The anesthesia provider must be thoroughly familiar with the results of these studies, and they should be reviewed and discussed jointly with the surgeon.

Preoperative nasal endoscopy is usually performed by the H&N surgeon, but with sufficient practice it can be quickly and effectively executed by the anesthesia provider (preoperative endoscopic airway examination [PEAE]) as part of the preoperative assessment. The PEAE (see Chapter 9 ) is a powerful airway assessment tool that provides precise information about upper airway and laryngeal anatomy to formulate appropriate airway management strategies. ^, Even in urgent situations, PEAE may help with anticipation and planning for a DA (see “ Special Considerations ”/“ Partially Obstructed Airway ”).

Awake Versus Asleep Approach to Tracheal Intubation

The decision to proceed with an awake approach can be very straightforward when significant anatomic distortion is present or the patient’s mouth opening is severely limited. In many cases, however, only a certain degree of difficulty can be expected, and decision-making becomes more complicated. For such patients with undefined risk, an approach to an anticipated DA should follow the framework suggested in the ASA DA algorithm, with special attention directed to predictors of difficult mask ventilation, impossible mask ventilation, and their association with difficult DL and TI (see Chapter 9 ).

The likelihood of difficult supraglottic airway (SGA) ventilation (see Chapter 19 ) and difficult surgical airway access (see Chapter 29 ) must also be considered and evaluated. If the emergency cricothyroidotomy is contemplated as part of the airway strategy, success should not be assumed, and it is best to secure the patient’s airway while awake. If the patient’s airway is marginal, but an awake approach is not feasible, the “airway double setup” is warranted: The CTM should be marked, the patient’s neck should be prepped, and the surgical team must be present for induction as well as ready to perform an emergent cricothyroidotomy or tracheostomy. The placement of the tracheal catheter or cannula through the CTM before induction of anesthesia for passive oxygen insufflation and/or subsequent JV shall also be considered (see “ Devising Safe Airway Management Strategies for Tracheal Intubation ”/“ Oxygenation Strategies and Special Situations ”/“ Partially Obstructed Airway ”). Management of cases that may involve a surgical airway as a rescue technique should always be performed where the appropriate equipment is available, most commonly in the OR. ^,

The more complicated the patient’s condition is, the more elaborate airway management strategies should become. Patients with H&N cancer, especially those with supraglottic and glottic tumors or a history of radiation therapy, require the longest intubation times and represent the highest risk for adverse TI outcomes. ^{, ,} In NAP4, airway management was considered poor in nearly 30% of these cases. ^, The pertinent preoperative imaging and PEAE findings for these patients must be reviewed and discussed with the surgeon to accurately estimate the degree of pathology and facilitate decision-making.

Role of Conventional and Video-Assisted Laryngoscopy

Given a high incidence of anticipated and encountered DA in H&N patients, it is prudent to reach for video-assisted laryngoscopy (VAL) as a primary TI technique in many cases. The ASA Difficult Airway Task Force recommendation to consider VAL as an initial approach to anticipated DA capitalizes on an extensive body of evidence for both steering and channeled VAL techniques (see Chapter 23 ). ^, The 2013 survey of the Canadian anesthesia practice also has listed VAL as the top technique to use during difficult TI. For complex patients, and for patients for whom at least some degree of DL difficulty is anticipated, we therefore advocate expanding airway evaluation beyond the ASA recommendations to determine the likelihood of difficult VAL. The first-pass intubation success rate with the acute-angle VAL systems, such as the Glidescope or Storz CMac, may be expected to reach 93% to 96% in the general surgical population. For patients with H&N pathology, and particularly those presenting with intraoral airway masses, inadequate glottic exposure may be observed with increased frequency, even with the use of the hyperangulated VAL blades. Hyman and colleagues have found that VAL fails to obtain an adequate view (Cormack-Lehane grade ≥3) in roughly one-third of these patients, highlighting a significantly increased risk for failed TI and oxygenation in this patient population.

Difficult VAL also may be expected in patients with neck pathology (particularly a scar or a mass), abnormal neck anatomy, decreased cervical spine motion, decreased oral entry, and restricted oropharyngeal space. ^{, , ,} Choosing a VAL depends on the operator’s experience, but the nature and location of the lesion must be considered. For example, it may be safer to navigate around BOT tumors with a channeled VAL, such as Pentax Airway Scope, whose blade engages under the epiglottis, unlike other devices that typically require the tip of the blade to be placed in the vallecula. On the other hand, the steering technique of VAL with a styleted ETT may be more effective for maneuvering around the intraoral lesions.

Difficulties with VAL notwithstanding, management of the anticipated DA with DL alone remains persistent and alarming practice. By studying over 188,000 patients in the Danish Anesthesia Database, Nørskov and colleagues have shown that half of the patients with anticipated difficult TI and over 40% of high-risk patients with anticipated combined ventilation and TI difficulty were planned to be managed by DL as a primary approach.

A consistent NAP4 finding in patients with H&N pathology was the deterioration of the airway following a single or repeated attempts at DL. The H&N tumors can cause considerable airway distortion and can be friable, leading to bleeding, defragmentation, airway soiling, and rapid edema formation. If DL is chosen as a primary approach to TI, multiple attempts should be avoided in order to avert total airway obstruction and CICO situation. ^{, ,}

Role of Operative Laryngoscopy and Rigid Bronchoscopy

Should DL fail, the rescue with operative laryngoscopy using the anterior commissure scope or with the rigid bronchoscope by the surgeon can be successful. ^{, ,} The anterior commissure scopes, such as Holinger ( Fig. 38.8 ), are very effective in handling poor laryngeal exposure or glottic obstruction and can be used as a conduit for TI when the bougie introducer or ETT is passed directly down the lumen ( Fig. 38.9 ). Hillel and colleagues have demonstrated that the use of the anterior commissure scopes by otolaryngologists, who were part of the DA response team (DART), helped secure over 35% of DAs and to decrease the number of emergent cricothyroidotomies nearly in half.

In experienced hands, rigid bronchoscopy can rescue failed TI and CICO situations. It also serves as an indispensable tool for managing acute airway obstruction resulting from foreign bodies, hemoptysis, or tumors. ^, After the bronchoscope is placed into the patient’s trachea by the surgeon, manual ( Fig. 38.10 ) or JV can commence in a safe manner through the lumen of the bronchoscope. Subsequent airway exchange to ETT can be performed using an airway exchange catheter (AEC) or a gum elastic bougie (GEB) introducer ( Fig. 38.11 ). ^,

Relying on operative laryngoscopy and rigid bronchoscopy as airway rescue assumes immediate availability of the equipment and expert surgical help. Unfortunately, even in skilled hands quick deployment of these devices can be problematic, especially when unfavorable anatomy precludes full atlanto-occipital extension and establishing the straight line of sight ( Fig. 38.12 ). ^{, , ,}

Role of Inhalation Induction

Inhalation induction can be safely used in the presence of noncollapsing lesions, with anticipated failure rate of approximately 5%. Difficulty in maintaining the airway during inhalation induction in patients with large pedunculated tumors, granulomas, and cysts should be anticipated, even if preoperative symptoms of airway obstruction are mild. ^, Early application of continuous positive airway pressure (CPAP) can help to stent the airway open, but inhalation induction should be considered highly problematic if mask ventilation difficulty is anticipated. In the NAP4 study, inhalation induction failed in 12 of 16 (75%) H&N patients with the compromised airway, and in nearly all these patients (11 of 12) spontaneous ventilation became impossible.

Sevoflurane is the most commonly used inhalation induction agent in adult and pediatric patients. ^, The minimum alveolar concentration (MAC) of sevoflurane required to provide adequate TI conditions in 50% of unpremedicated adult patients (MAC _TI50 ) is 4.5% (95% confidence interval 3.9% to 5.2%), and the 95% effective dose (ED ₉₅ ) for TI is 8%. The time for achieving this ED ₉₅ target in patients with normal airways is approximately 7 minutes, but up to 20 minutes may be required when partial airway obstruction or the preexisting increase in minute ventilation and V̇/Q̇ mismatch are present. ^, The induction time can be shortened with the addition of small intravenous doses of midazolam or fentanyl ^, but at the expense of an increased risk of apnea and loss of the airway. Even in patients without severe airway compromise, inhalation induction frequently causes expiratory stridor (25%–40%) and breath holding (7.5%–15%), and the intubating conditions still remain inferior to the use of the neuromuscular blocking (NMB) agents. ^,

Overall, if inhalation induction is chosen as the primary approach to the difficult H&N airway, the possibility of failure should be anticipated, and the clear rescue strategies must be in place from the outset.

Role of Flexible Scope Intubation and Optical Stylets

Recent randomized trials have demonstrated that an awake acute-angle VAL can be as effective as an awake flexible scope intubation (FSI) ^, ; however, the latter remains the gold standard of care (see Chapter 24 ). It is frequently underused when indicated, probably because of a lack of confidence, skills, judgment, and equipment.

Patients with H&N pathology may require awake FSI more frequently due to common occurrence and/or coexistence of H&N cancer, previous surgery, history of radiation, associated OSA, obesity, and anatomic characteristics, such as reduced mouth opening, limited neck extension, and progressive airway compromise. Both awake and asleep FSI can fail frequently in H&N patients: In NAP4, such failure was observed in nearly 61% of these cases. When performed by designated H&N anesthesia providers, a much lower yet still sufficiently high failure rate of 8.8% may be expected. In the mixed surgical population with anticipated DA, the awake FSI may be expected to fail in 1% to 4% of cases, ^{, ,} usually without associated severe adverse effects.

The most common reasons for awake FSI failure appear to be the inability to either identify the glottis or to pass the flexible intubation scope (FIS) or ETT. Additional reasons for the failure of asleep FSI include repeated TI attempts, bleeding, and airway obstruction. Previous reports also documented a mere 50% success rate of FSI after repeated DL attempts, and awake FSI should be chosen over an asleep approach in H&N patients whenever possible. ^,

The awake FSI requires a high degree of skill yet can be challenging even with proper patient preparation and cooperation. Similar to the inhalation induction strategy, the failure of either awake or asleep FSI should be anticipated in patients with advanced H&N pathology, and solid backup strategies must be in place before the start of the procedure. ^,

The optical intubation stylets, such as Bonfils, Shikani, SensaScope, and Clarus Video System (see Chapter 22 ), can effectively lead within an ETT to help bypass mobile supraglottic and glottic masses. The FIS may fail in this situation, either because of the inability to displace the tumor or because the ETT simply would not pass. With optical stylets, once the glottis is entered, the ETT will follow the trajectory of the stylet into the patient’s trachea. However, most of the available adult-size optical stylets require the use of an ETT with a minimum ID of 5.5 to 6 mm.

Role of the Supraglottic Airways and the Supraglottic Airway-Endotracheal Tube Exchange

The SGAs are vitally important in ventilation-centered airway management for H&N patients, who have a higher incidence of difficult and failed TI. A wide variety of SGAs are available, but their comparative performance in DA situations in general, and for H&N patients in particular, has not been vigorously investigated.

By prospectively studying over 20,000 general surgical patients, Parmet and colleagues documented a 94% success rate for rescue ventilation with the classic laryngeal mask airway (cLMA) in unanticipated DA. The successful placement of cLMA and other types of LMA devices in patients with an abnormal airway and/or DA is probably independent of factors used to predict or score difficult TI. ^, However, reliable SGA ventilation in many H&N patients can be problematic because of difficulties associated with SGA insertion (e.g., restricted mouth opening), with achieving its proper positioning (e.g., space-occupying lesions, previous radiation therapy), and/or with maintaining an adequate airway seal pressure (ASP) and SGA ventilatory capability (e.g., obstructing pathology either at or below VC).

The NAP4 study has demonstrated a high failure rate of the first-generation SGAs and numerous cases of aspiration of gastric contents. Should the use of SGA be required in an H&N patient, it is prudent to reach for the second-generation SGAs with greater ventilation capability and gastric access, such as the LMA Proseal or LMA Supreme. These devices will provide superior ASP and better airway protection and will allow for a quick and reliable detection of device malposition.

It may be reasonable to anticipate a 3.8% to 5.2% failure rate with the second-generation SGAs. To minimize failures in H&N patients, we recommend the GEB-assisted insertion technique, to maximize the first-pass success (FPS) rate, and to ensure optimal esophageal and laryngeal seals. The PEAE can be highly informative in determining the feasibility of SGA placement in H&N patients after the induction of general anesthesia (see Fig. 38.13 and the illustrative case report in Box 38.2 ).

The LMA Fastrach (intubating laryngeal mask airway [iLMA]) represents another excellent SGA choice. It has an outstanding ventilatory capability and provides a 92% to 94% success rate of blind TI in patients with anticipated DAs. ^, In patients with glottic or infraglottic pathology, blind TI intubation should be superseded by FSI-guided iLMA-ETT exchange, which can be performed with or without the use of the Aintree intubation catheter (AIC) (see Chapter 19 ).

The FIS-guided SGA-ETT exchange can be considered one of the core techniques in DA management. It offers the advantage of direct visualization of the laryngeal structures, carries minimal risk of intubation trauma and esophageal intubation, and allows the practitioner to ventilate the patient’s lungs while performing TI. Such an exchange should be considered when DA is encountered, when SGA can easily be displaced, or when airway edema is present or anticipated. ^, Proceeding with the suboptimally functioning SGA as a stand-alone airway is not acceptable.

The FIS-guided cLMA-AIC exchange technique may be 96% to 100% effective in patients with anticipated DA. ^, It worked very well in NAP4 for H&N patients with different pathology, including vertebral body fracture, hematoma, pharyngeal edema, and pharyngeal bleeding. The AIC technical characteristics (4.7-mm ID, 6.5-mm OD) should be kept in mind for selecting the appropriately small FIS and ETT of 7-mm or more ID.

Despite a simple concept, the SGA-ETT exchange can fail either as a result of inability to establish the endoscopic view or the dislodgment of the AIC from the patient’s trachea. It can also cause serious complications, such as perforation of the distal tracheobronchial tree because of accidental subcarinal advancement of the AIC during the exchange. The important prerequisite for success is the anesthesia provider’s knowledge of the “anatomy” of the chosen SGA device and the ability to establish the landmark endoscopic view as illustrated for the LMA family of devices ( Fig. 38.14 ). Once such a view is established, the exchange can usually proceed unhampered.

We recommend first practicing on a manikin the details of the SGA-ETT exchange for the LMAs and other mainstream SGA devices, such as i-gel, air-Q (Cookgas intubating laryngeal airway [ILA]), and laryngeal tubes (LT-D, LTS-D), in order to develop the necessary dexterity and appreciation for the important details.

The tubular SGAs, such as the Combitube and the laryngeal tubes (LT), are especially beneficial in patients with limited access to the airway and massive upper airway bleeding or regurgitation, when rapid control of the airway is necessary. Ventilation through the Combitube can be effective when other SGAs (e.g., LMA) have failed. Winterhalter and colleagues have documented successful LT ventilation in 95% of patients with oropharyngeal cancer. Nevertheless, the tubular SGAs cannot be considered fail-safe devices, particularly when an infraglottic obstruction is present.

Combined Intubation Techniques

A combined use of VAL with FIS or optical stylet is gaining increased attention and popularity in complex airway management (see Chapter 25 ). The VAL facilitates FIS/optical stylet maneuvering when the anatomy is severely distorted or supraglottic/glottic tumors are present and allows for continuous observation of the intubation procedure and ETT advancement both from above and below the vocal cords, with diminished risk of tumor disturbance (see Fig. 38.15 and illustrated case report in Box 38.3 .).

In the large prospective study of 140 patients with anticipated DA, Lenhardt and colleagues have shown that a combined VAL-FSI technique increases the success rate of TI in patients with cervical spine pathology who could not be intubated with VAL alone. Cook and colleagues have demonstrated a 100% success rate of TI in patients with anticipated DA when a combination of a channeled VAL (Airtraq) and a flexible dynamic stylet (an introducer or FIS) was used; TI was accomplished in less than 30 seconds in 73% of these patients. Mazzinari and colleagues prospectively studied a combined VAL (Glidescope)-FIS technique in 80 patients with multiple predictors of difficult TI and demonstrated 90% reduction in TI injury, 35% increase in TI FPS, and shorter intubation time.

The combined techniques will likely continue to play a bigger role in complex airway management of H&N patients. They demand excellent dexterity that can be achieved with prior manikin practice in the simulation lab. It should be kept in mind that the VAL-FIS technique requires the presence of two operators, with at least one of them being proficient with FIS.

Oxygenation Strategies

Oxygenation-centered airway management is critical for H&N patients, who present with the higher incidence of failed TI and a CICO situation. The active oxygenation strategies should be in place throughout the process of DA management and are described in detail in Chapter 15 .

THRIVE improves the patient’s oxygenation during awake FSI. Its use during asleep TI should be strongly considered in H&N patients, as THRIVE prolongs the apneic period, increases peri-intubation Spo ₂ , and improves FPS, even in patients with a severely compromised airway. ^, It is likely that THRIVE will continue to play an even bigger role in DA management and laryngologic surgery in the future, pending adequate validation studies. Placement before induction of anesthesia of a transtracheal jet ventilation (TTJV) catheter for providing tracheal oxygen insufflation or high-frequency TTJV also can be considered in complex cases; proper placement of the catheter should be confirmed by aspirating the tracheal air with the syringe and by capnography. Substituting a TTJV catheter for an Arndt cricothyroidotomy cannula offers the advantage of using its 3-mm-ID lumen with the low-pressure gas source, thus allowing for manual ventilation using the anesthesia circuit or an Ambu bag.

Surgical Airway as a Primary Approach to Tracheal Intubation and Airway Rescue

An awake tracheostomy is usually undertaken in patients with significant airway compromise, where postoperatively the caliber of the airway is not expected to improve. The procedure should be performed under local anesthesia, and without sedation in advanced cases. In selected cases, judicious IV sedation may be appropriate, but it should be administered with extreme caution. The decision to proceed with the awake tracheostomy by the surgeon may also be contingent upon the lack of advanced airway skills on the part of the anesthesia provider. Data indicate that when the patient’s airway is managed by dedicated H&N anesthesia providers, the awake tracheostomy can be largely avoided: In a prospective series by Iseli and coworkers, it was required in only 2 of 153 (1.3%) patients.

In advanced cases, awake tracheostomy can prove technically challenging or impossible and will require general anesthesia. There is a clear preference on the part of H&N surgeons to perform a tracheostomy under controlled conditions, after induction of anesthesia, to avoid airway trauma, tumor disturbance, and tracheostomy tube displacement or obstruction. An elective tracheostomy should also be considered if significant postoperative airway compromise is anticipated, if the patient may return to the OR, or after major H&N reconstructive procedures.

An awake dilator cricothyroidotomy also can be safely performed and may serve as a viable alternative to tracheostomy for many H&N patients with a DA. ^,

For emergency airway management, surgical cricothyroidotomy is strongly preferred over transcutaneous CTM access; in the NAP4 study, the emergency transcutaneous cannula cricothyroidotomy failed in 60% of H&N patients. ^, The observed failure was attributed to the inability to place the cannula or to its misplacement, fracture, kinking, blockage, dislodgment, and barotrauma. ^, These findings highlight the need for training anesthesia providers to perform the surgical airway and for the immediate availability of all the necessary equipment for surgical airway access.