Surgical Airway in Emergent and Nonemergent Contexts

Key Points

• For anatomic reasons, emergency surgical airway in the hands of advanced airway managers will usually be a cricothyrotomy.

• The critical step in cricothyrotomy is recognizing when it is required. Decision-making should not be left solely to the airway manager—those not directly involved in airway management may better recognize an emerging cannot ventilate/cannot oxygenate (CVCO) situation.

• We have chosen CVCO in this chapter to reflect two quantitative measurements that can be verbalized by team members, usually in the order they occur (e.g., “I notice the waveform capnography is flat, and the oxygen saturation is now going down to the mid 80s. I’ll get out the supraglottic device and cricothyrotomy set”). This deemphasizes the need for the airway manager to have the insight into their cognitive errors including perseveration of tracheal intubation attempts.

• Due to the infrequent need to perform cricothyrotomy, skills maintenance requires regular practice, coaching, and keeping the technique as simple as possible. Similar to Advanced Cardiac Life Support (ACLS) and Advanced Trauma Life Support (ATLS), infrequent high-acuity emergencies require a standardized predictable approach.

• Due to its unpredictable nature, cricothyrotomy supplies should be stocked in every location in which advanced airway management occurs (e.g., in every trauma room, not just on one central cart). Equipment is simple; #10 scalpel, bougie, and 6.0 tracheal tube. These should be stocked together and clearly labeled.

• The cricothyroid membrane is difficult to palpate in females, as well as in patients with a thick or short neck. There is a high failure rate of cricothyrotomy techniques that rely on accurate identification of the cricothyroid membrane (e.g., wire-guided cricothyrotomy).

• Evidence of repeated success supports simplicity of choice and technique. The use of a scalpel, bougie, and tracheal tube emphasizes simplicity. Landmarking is key to success, and when faced with challenging dissection or excessive bleeding, the index finger can be used to internally palpate and confirm airway anatomy prior to horizontally incising the cricothyroid membrane. The index finger can then serve as a guide for insertion of the bougie followed by the tracheal tube.

• Suctioning the tracheal tube immediately for blood after insertion is recommended. Waveform capnography is the gold standard of the tracheal tube being in the airway, even in the setting of cardiac arrest. Confirm intratracheal placement with waveform capnography. Bronchoscopic assessment is a helpful as a visual adjunct to tracheal tube placement and positioning. Obtain a chest x-ray to assess tracheal tube placement and possible barotrauma, including pneumothorax.

Introduction

Nonemergent and emergent surgical airway approaches differ in context, anatomic approach, equipment, and training. Nonemergent surgical airway generally takes the form of open tracheotomy or percutaneous tracheostomy in the hands of a surgeon or intensivist with expertise in these techniques. The decision to perform a nonemergent surgical airway is, by definition, scheduled with a robust multidisciplinary airway plan. Elective tracheotomy is not without its dangers; poor physiologic reserve, difficult surgical access, and the inability to easily reintubate the patient may all result in an elective tracheostomy becoming emergent. In contrast, an emergent surgical airway generally takes the form of cricothyrotomy, often in the hands of advanced airway managers whose experience of cricothyrotomy often consists of simulation only. The decision to perform an emergency cricothyrotomy must be made expeditiously in the setting of possible hypoxic brain damage or death, if not performed imminently. The power of a team approach harnessed during these emergent situations may be lifesaving.

The term surgical airway should not be misinterpreted as needing to be performed by a surgeon. Any advanced airway manager (those performing airway management beyond mask ventilation) should have the skills to perform an emergency surgical airway (cricothyrotomy) when required. The indications, methods, and complications of achieving a successful surgical airway in emergency and non-emergency contexts is the focus of this chapter.

Most nonemergent surgical airways will be in the form of either tracheotomy (open surgical technique) or tracheostomy (percutaneous technique). Most critical care patients requiring tracheostomy will undergo bedside percutaneous tracheostomy with bronchoscopic guidance by a critical care physician. Patients with difficult anatomy are usually transferred to the operating room for open tracheostomy performed by surgeons skilled in this technique. This selects for the most difficult cases being transferred to the operating room. Anesthesiologists involved in these procedures should be well versed with the steps involved, engage in open communication with the surgery team, and be prepared with alternative oxygenation techniques should any of the emergencies reviewed in this chapter occur.

Patients requiring nonemergent surgical airway procedures often have an orally or nasally placed tracheal tube in situ. Although many airway managers will not perform a surgical airway in a nonemergent context, many will be called upon to assist or support oxygenation and ventilation during the tracheostomy. It is important to understand the anatomy, steps involved, and potential pitfalls. Communication and understanding of the sequential steps involved on both sides of the drape will prevent a nonemergency situation from devolving into an emergency. Oral/nasal tracheal tube withdrawal should only occur following confirmation of proper placement of the new surgical airway. The surgical airway should be confirmed by waveform capnography. If there is no waveform despite suctioning through the surgical airway, the creation of a false passage should be assumed. False passage occurs when surgical dissection diverges from the airway into anterior neck tissues. False passage creation is associated with hypoxia, cardiorespiratory instability, and loss of the airway if not managed correctly. Other rare immediate complications include airway fire in the presence of a combustible gas (such as a high Fio ₂ escaping from the tracheal incision, a spark from electrocautery, and ignition of drapes, towels or gauze) or uncontrolled bleeding from an overlying thyroid gland or important vessels that cross the midline, such as the innominate artery. Finally, barotrauma or pneumothorax can result due to tube migration, high pressure/high flow ventilation, or accidental trauma to the pleura from challenging surgical dissection in the mediastinum or lung apices in the lateral neck.

Establishing an emergency surgical airway is often a second- or third-line choice to secure an airway after tracheal intubation (TI) attempts have failed. It is important to consider, particularly in the setting of obstructing airway pathology, if performance of a surgical airway whilst the patient is awake should be the first choice of securing the patient’s airway. A styleted tracheal tube or flexible bronchoscope through the patient’s native narrowed airway may completely obstruct the airway. This may lead to patient panic, loss of cooperation, and the change from a semiurgent situation into a less-controlled emergency.

Advanced airway managers, regardless of specialty, will be usually involved in performing an emergency cricothyrotomy at least once in their career, usually during a cannot ventilate/cannot oxygenate (CVCO) situation.

Waveform capnography and pulse oximetry provide objective physiologic assessments of patency from the patient’s mouth to alveoli and of oxygenation of circulating blood, respectively. Both are essential parts of advanced airway management. We have used the term CVCO in this chapter to reflect the temporal sequence of these two objective findings; nonreassuring waveform capnography (due to upper airway obstruction) usually precedes the patient becoming hypoxemic. The term CVCO, unlike cannot intubate/cannot oxygenate (CICO), deemphasizes failure of TI as a criterion for diagnosing the CVCO airway emergency. In retrospective and prospective observational studies, CVCO has been associated with perseveration of TI attempts. If this life-threatening emergency situation can be recognized by any member of the healthcare team based on objective criteria, the decision to adjust the action becomes independent of the primary airway manager’s insight to a failure of airway management. Team members should be empowered to state when waveform capnography is no longer a square wave or is completely absent, as well as pulse oximetry falling. This level of engagement and situational awareness allows the entire team to mobilize and prepare for immediate surgical airway.

A failed airway is not defined as the need for a surgical airway. A failed airway is:

• 1.

  not recognizing the need for surgical airway, or

• 2.

  not performing a surgical airway in a timely manner, or

• 3.

  not being adequately practiced in the technique.

In a coordinated manner, the team should ensure the following: adequate patient paralysis, optimal two-handed, two-person with oral airway bag-valve-mask (BVM) technique, and insertion of a supraglottic device while positioning and preparing for a surgical airway, usually in the form of a cricothyrotomy.

The ideal cricothyrotomy technique should be as simple as possible with equipment that can be stocked and maintained in every airway management location. It should be practiced and refined on a regular basis. It should have a high first-pass success rate that is not dependent on fine motor skills, which often deteriorate due to the airway manager’s own physiologic stress response. For these reasons, the authors recommend a scalpel-bougie-ETT cricothyrotomy for the performance of a surgical airway in a CVCO emergency for all non-surgeon airway managers.

History of Surgical Airways

Emergency surgical airway as a lifesaving procedure has been performed for thousands of years. The first depictions of surgical tracheostomy were found on Egyptian tablets dating from 3600 bce. In the second century ad , Galen suggested tracheostomy, using a vertical incision, as an emergency treatment for airway obstruction. Vesalius published the first detailed descriptions of tracheostomy in the 16th century, using a reed to ventilate the lungs. Ironically, his alleged resuscitation through tracheostomy and ventilation of a Spanish nobleman led to condemnation by the Spanish Inquisition and his ultimate death. Such condemnation may be reenacted to a degree in contemporary practice, whereby the performance of a surgical airway may be met with a retrospective and harsh critique!

Dr. Chevalier Jackson published a landmark article on tracheostomy in 1921, enumerating the surgical principles still relevant today. Cricothyrotomy, which Jackson called high tracheostomy, was condemned as the cause of subglottic stenosis. It is now clear that subglottic stenosis developed due to underlying inflammation of the respiratory mucosa, usually from an infectious cause (often diphtheria), rather than the site of incision. However, knowledge translation of this evidence has taken decades and is only now leading to a paradigm shift supporting the safety of cricothyrotomy.

The dangers of cricothyrotomy were not widely reconsidered until 1976, when Brantigan and Grow published a retrospective study of cricothyrotomy for long-term airway management in 655 patients. Only 5 patients (0.76%) developed subglottic stenosis. More recently, a 2019 systematic review analyzed the short- and long-term complications of cricothyrotomy (n = 1219) and tracheotomy (n = 342) procedures performed during emergency situations, the most common reason being trauma. All studies included were retrospective. Early complications occurred in 4.8% of cricothyrotomies, the most common being failure of the technique (1.6%) and damage to cartilaginous structures (1.6%). By comparison, early complications occurred in 9.1% of emergency tracheotomies, the most common being hemorrhage (5.6%) and pneumothorax/subcutaneous emphysema (2.9%). Subglottic stenosis occurred in 1.1% of patients who underwent cricothyrotomy regardless of whether early conversion to tracheotomy was performed versus 7.0% of patients undergoing tracheostomy.

In conclusion, not every cricothyrotomy performed requires immediate conversion to tracheotomy to prevent subglottic stenosis. The exception to this remains what Chevalier Jackson observed 100 years ago: in the face of inflammatory or infectious airway pathology, conversion as soon as possible to performing tracheostomy is advised, ideally within 24 hours.

Incidence of Surgical Airway

The incidence of surgical airway varies depending on the clinical context. For example, in critical care where prolonged ventilatory support is anticipated, the incidence of tracheostomy can range from 7% to 24% depending on available resources and patient population. In emergencies, such as on the battlefield and in the prehospital setting, frequencies range between 0.5% and 18.5%. In the emergency department, a rate of 0.9% to 2.8% has been observed. In the operating suite, the incidence is much lower at 0.002% to 0.39%.

Types of Surgical Airway

Surgical airway encompasses both cricothyrotomy and tracheotomy. Principles of the ideal surgical airway procedure can be found in Table 29.1 . An anatomic comparison of cricothyrotomy versus tracheotomy can be found in Table 29.2 . Surgical cricothyrotomy and surgical tracheotomy refer to the use of a scalpel and other surgical instruments to create an opening through the anterior neck and into the airway, through the CTM or through/between tracheal rings, respectively. In adults, these techniques allow the insertion of a cuffed tube. The 2019 American Society of Anesthesiologists (ASA) airway-related closed claims review reported protracted delays in performing a surgical airway due to, among other reasons, the belief that a surgeon was required. Therefore, the authors support the use of the term surgical airway to encompass both cricothyrotomy and tracheotomy, with one or both being in the skill set of any advanced airway manager. Surgical airway may be further subclassified according to the technique used: (1) surgical, (2) percutaneous, (3) dilatational, and (4) cannula based.