A 46-year-old ASA III man is scheduled to have a total knee replacement. His past medical history is remarkable for severe rheumatoid arthritis (RA) with cervical spine involvement. He was recently diagnosed with atlanto-axial subluxation (AAS), but he has no neurological symptoms and signs. He has a history of gastroesophageal reflux disease (GERD), but it is well controlled with proton pump inhibitors. His other medications are a nonsteroidal anti-inflammatory drugs (NSAIDs) and low-dose glucocorticosteroid therapy.

On physical examination, he weighs 67 kg (148 lb) and is 167 cm (5 ft 6 in) tall (BMI of 23.9 kg·m⁻²). Examination of his airway reveals that he has a full beard, small chin, no teeth, 3.0 cm of mouth opening, and that his neck is fixed in moderate flexion. This same surgery was previously canceled, as the patient refused to complete an awake intubation using a flexible bronchoscope (FB). The patient emphatically refuses to consent to an awake intubation.

What Is Rheumatoid Arthritis? What Are the Anesthetic Implications of This Illness?

Rheumatoid arthritis (RA) is a chronic multisystem illness. It is the most common form of chronic inflammatory arthritis and affects approximately 1% of adults (range 0.3%–2.1%) in the United States and Europe. Women are typically affected two to three times more often than men and the prevalence increases with age. The etiology of RA remains unknown, but it is evident that complex interaction between environmental factors (including infectious agents) and the immune system in genetically susceptible individuals plays an essential role.¹ The class II major histocompatibility complex allele HLA-DR4 has been found to be a major genetic risk factor. The onset of RA is typically gradual between the age of 35 and 50, and may be of a nonspecific nature.^2,3 Synovial inflammation, cartilage damage, and bone erosion with subsequent destruction of joint integrity are the hallmarks of this illness. The course is characterized by symmetrical polyarthropathy and variably, considerable systemic involvement. As the disease progresses, cervical spine involvement becomes common, second only to involvement of the metatarsophalangeal joint.¹

Extraarticular manifestations of RA are widespread and can affect as many as 40% of patients, 15% of whom appear to be severely affected.^1,2 Many of these manifestations have a serious impact on anesthesia care. Cardiac manifestations most commonly present as pericarditis with effusion (in one-half of patients), but may also include cardiac conduction abnormality, granulomatous myocarditis, and valvular pathology. Rheumatoid vasculitis can affect almost any organ system and may produce coronary arteritis contributing to a coronary syndrome. Pleuropulmonary pathology, which occurs more commonly in men, includes pleural disease, effusion, pleuropulmonary nodules, interstitial fibrosis, obliterative bronchiolitis, and pneumonitis. The prevalence of airflow obstruction in rheumatoid patients is remarkably high, suggesting it might be the most common form of pulmonary involvement.⁴ Rheumatoid nodules and osteoporosis may develop in up to 30% of patients with RA. Neurologic manifestations may result from cervical spine subluxation and nerve entrapment secondary to proliferative synovitis or joint deformities, which can produce various neuropathies.

Other important extraarticular manifestations include ocular involvement, which occurs in 25% of individuals with RA, such as keratoconjunctivitis sicca, and hematologic changes—chronic anemia and thrombocytosis.^1,2

How Does RA Affect the Airway?

Airway management is one of the most critical aspects of anesthesia care for RA patients. There are several important elements implicated in how RA progression affects the airway of these patients:

1. 
   

   Cervical spine (Figure 42–1). Progression of RA of the cervical spine affects 15% to 86% of these patients, eventually leading to disintegration of cervical spine joints. Twenty-five percent of hospitalized RA patients have cervical pathology. Pain (40%–88%), neurologic deficiencies (7%–34%), and even sudden death from brain stem compression (10%)⁵ are possible manifestations of cervical spine involvement.¹ The three most commonly observed forms of cervical pathology in RA include: (1) anterior or rarely posterior AAS; (2) vertical subluxation or atlanto-axial impaction; and (3) sub-axial subluxation. Anterior AAS, the most common of these abnormalities, occurring in 43% to 86% of patients, is associated with a greater than expected mortality in this group.^1,6,7 AAS is commonly associated with spinal cord compression and neurological deficits. However, absence of preoperative neurological symptoms may not assure perioperative safety, particularly under general anesthesia when neurological symptoms may not be detectable.⁷ Thus, during airway manipulation and intraoperative positioning, specific precautions are warranted to avoid spinal cord injury. In addition, RA-related cervical spine rigidity and flexion deformity will present further complexity in airway management.^7,8

   
   
2. 
   

   Temporomandibular joints (TMJs) and mandible abnormalities. Up to 31% of RA patients report TMJ dysfunction. The severe form of this abnormality can lead to TMJ ankylosis and can significantly reduce the patient’s ability to open the mouth. It has also been associated with a high incidence of upper airway obstruction.^9,10 In a study of 218 RA patients, a positive correlation was reported between the severity of RA and the range of motion of the jaw.¹⁰

   
   
3. 
   

   Micrognathia. Hypoplastic mandible, another airway hazard, is found to be associated predominantly with a juvenile form of RA, in some cases as a congenital association and in others due to the effect of TMJ arthritis.¹¹

   
   
4. 
   

   Cricoarytenoid arthritis. This is reported in 30% to 50% of RA patients, and between 45% and 88% of postmortem studies.¹² The prevalence of this potentially life-threatening condition seems to be much higher than expected. There are numerous reports of severe and even fatal airway obstruction during the perioperative course, frequently unanticipated.^12–15

   
   
5. 
   

   Rheumatoid nodules. when present in the larynx, these RA nodules have occasionally been reported as a cause of airway complications that contribute to difficulties in airway management of RA patients.^9,15,16

In summary, RA patients frequently confront the anesthesia practitioner with multiple airway management challenges. This may be due to a severe form of a single airway-related pathology or any combination of pathologic changes, such as cervical spine problems (rigidity, AAS, low cervical subluxation), TMJ ankylosis, micrognathia, cricoarytenoid arthritis, and laryngeal tissue damage. When approaching these patients’ airways, the anesthesia practitioner should bear in mind that there are two separate facets of the problem: a high incidence of difficult direct laryngoscopy (DL) requiring an alternative technique(s) and a danger of neurological complications as a consequence of airway manipulation. Tests for the presence of RA and the duration of the disease do not show direct correlation with the incidence of difficult intubation.¹⁷ Thus meticulous preoperative airway assessment is warranted, regardless of the severity and duration of disease.

What Is Informed Consent? What Are the Elements of Informed Consent?

The legal and moral basis of informed consent is established on the ethical principle of respect for patient autonomy and self-determination. In the United States, this is also rooted in constitutional guarantees of privacy and noninterference. In 1914, the case of Schloendorff v. Society of New York Hospital established that it was the right of “every human being of adult years and sound mind to determine what shall happen to his own body.”^18,19 The term “informed consent” came into common use in 1957 as a result of the case of Salgo v. Trustees of Leland Stanford Hospital, when it was postulated that physicians have a duty to inform patients about the risks and alternatives to treatment, in addition to the procedures themselves and their consequences.¹⁹ This gave the concept of informed consent its modern interpretation, which was directed to maximize the ability of the patient to make substantially autonomous informed decisions. In other words, informed consent is the process by which a fully informed patient can participate in the decisions about his or her health in a meaningful way. It is generally accepted that in order to complete a modern informed consent properly, the following seven components and principles must be established.¹⁹

1. 
   

   Decision-making capacity. Decision-making capacity is the reasonable ability to understand discussed issues and make a particular decision at a specific time, as well as the ability to express a preference based on rational, internally consistent reasoning.

   
   
2. 
   

   Voluntariness. The voluntariness principle is based on the notion that physicians should perform procedures only on competent patients who participate willingly. Anesthesia practitioners may potentially compromise voluntariness through manipulation and coercion when they physically or pharmacologically restrain patients who have sufficient decision-making capacity.

   
   
3. 
   

   Disclosure. The goal of disclosure is to provide comprehensive information to the patient relevant for his/her decision-making. The exact nature of the procedure must be discussed. Reasonable alternatives to the proposed procedure must be discussed revealing the pros and cons of those options.

   
   
4. 
   

   Recommendation. Anesthesia practitioners should present an expert opinion regarding advantages and disadvantages of each option. Patients can then participate in decision-making to determine the best option, which suits their priorities.

   
   
5. 
   

   Understanding. Considerable efforts should be made to confirm that patients understand the risks and benefits of the proposed procedures, and why those recommendations were made. Pain and distress do not ordinarily impair comprehension to the degree that it precludes the need for a legally sufficient informed consent.

   
   
6. 
   

   Decision. Once informed as described above, the patient participates in the choice of the anesthetic technique. Patients vary in their preferences for decision-making participation. Therefore, anesthesia practitioners should thoughtfully attempt to tailor the extent of patient and physician decision-making to the individual patient and the situation.

   
   
7. 
   

   Autonomous authorization. Finally, the informed consent process concludes with the patient intentionally authorizing the anesthesia practitioner to perform a specific procedure or intervention, and this will constitute the patient’s self-determination and the basis of informed consent.

What Is Informed Refusal of Treatment or a Procedure? What Are the Options for the Anesthesia Practitioner in This Case?

Informed consent would be meaningless if the patient cannot also decline medical intervention based on his/her reasoning.^20–22 It is essential, in recognition of patient autonomy, to show recognition and respect for different individual values that may be reflected in the patient decision-making process.²³ However, if a patient rejects an anesthesia practitioner’s advice, or requests a technique that the anesthesia practitioner believes is inappropriate, the focus of discussion turns from informed consent to informed refusal. In this case, in addition to all requirements similar to informed consent, the patient should be substantially well versed about the risks and benefits of refusal and, importantly—about reasonable alternatives. Despite full disclosure and proper consent procedure, some patients may occasionally demand an intervention that is extremely unreasonable, and predictably associated with inappropriately high risk. Determination of an appropriate choice of anesthesia is difficult and should not be made lightly or out of convenience. The conscientious physician cannot be forced by anyone, including a patient, to practice negligently.¹⁹ It is important to remember that just as the patient can refuse to have an awake intubation, the anesthesia practitioner may also decline to provide care to a patient, unless it is an emergency. In this case, an anesthesia practitioner who chooses to withdraw from the patient’s care is obligated to make a reasonable effort to find a competent and willing replacement.¹⁹

In this case, in which the patient refuses an awake intubation, a complete discussion and description of the process of awake intubation should occur and an assessment should be made to determine that the patient fully understands the procedure. Additionally, efforts should be made to ensure that patient refusal is not a result of false beliefs based on misinformation, misunderstanding, or atypical and inappropriate previous experience.^20,23 Other alternatives to awake intubation must then be discussed with the patient, as well as the associated risks and benefits associated with these alternatives. Finally, the patient and the airway practitioner need to be in agreement with the proposed airway management plan, especially as the patient’s cooperation is required.

In an emergency situation in which the patient requires a life- or limb-saving procedure and no other anesthesia colleague is available, the anesthesia practitioner is obliged to proceed under emergency conditions and honor the refusal of the patient to have a particular technique. In this situation, complete documentation should be performed, including a disclosure note on the chart that all inherent risks of the treatment options were described to the patient. The anesthesia practitioner must convey to the patient what procedure(s) is/are in the patient’s best interest. If the patient denies consent, it may be helpful for the surgeon and/or family members to become involved in the decision-making. If the anesthesia practitioner ultimately fails to obtain consent for a procedure, yet proceeds with that procedure, he/she assumes the risk that a charge of physical assault may ensue.²⁴

What Are the General Principles of Decision-Making with Regard to Airway Management Options?

When confronted with a difficult airway, either anticipated or unanticipated, the anesthesia practitioner should keep in mind practical recommendations made in the ASA Difficult Airway Management Guidelines.²⁵ A number of different factors must be considered when making specific decisions while following the ASA guidelines. These factors include: the mechanism (cause) of the difficult airway, preexisting comorbidity, type of surgery, urgency of the procedure, the patient’s position during surgery, the patient’s mental status and degree of cooperation, availability of equipment, as well as the technical skills and the experience of the airway practitioner. Several fundamental conclusions can be drawn from these guidelines: (1) considerable efforts should be made to predict the possibility that an airway will be difficult to manage by performing a methodical and comprehensive preoperative airway assessment; (2) a thorough airway assessment may substantially reduce the occurrence of an unanticipated difficult airway; however, it cannot completely eliminate it so the anesthesia practitioner should always be prepared, mentally and physically, to deal with an unforeseen difficult airway; (3) if a difficult airway is predicted, especially in patients with anticipated difficult ventilation, the airway should be secured while preserving uninterrupted spontaneous breathing until complete control of the airway has been achieved; and (4) always have a backup plan(s) if the initial plan to secure the airway fails.²⁵

What Would be the Best Technique for This Patient?

This patient with long-standing RA presents multiple signs of a potentially difficult airway—rigid neck, limited mouth opening, micrognathia, and a full beard. In patients with AAS, there is often complete cervical rigidity and accompanying trismus. These patients are known to present tracheal intubation difficulty. The neck deformity and the AAS complicates complicate positioning for airway management. On the other hand, appropriate positioning of patients with instability of the occipito-atlanto-axial complex is still poorly understood.^7,26,27 Minimizing movements of the cervical spine is the best way to avoid exacerbation of AAS mitigating neurological consequences. To achieve this goal, the most commonly recognized and recommended technique is awake intubation using FB, which is considered the safest technique for securing a difficult airway in patients with RA complicated by AAS.^8,26,28,29 In our case, this method serves dual purposes: protecting the spinal cord by minimizing neck movements and solving the problem of an already known difficult airway. However, this patient refuses an awake tracheal intubation, thus it is necessary to develop an alternative anesthesia plan. Bearing in mind the peripheral location of the anticipated surgery, regional anesthesia may be considered and offered as a safe and practical alternative technique.

How Does the Ability to Perform Mask Ventilation Influence Your Anesthesia Plan? How Do You Predict and Manage Difficult and Impossible Bag-Mask-Ventilation?

The ability to perform effective bag-mask-ventilation (BMV) is a quintessential element of anesthesia care. All types of anesthesia may require BMV: after induction of general anesthesia, following a respiratory arrest from a complication of regional anesthesia or as a result of excessive sedation. Failure to effectively provide BMV may have fatal consequences unless an emergency airway can be immediately established.

The incidence of difficult BMV has been reported to be 5% to 7.8% in patients presenting for general surgery.^30–32 Five independent risk factors have been identified: a history of snoring; a BMI greater than 26 kg·m⁻²; lack of teeth; age greater than 55 years; and the presence of a beard.³¹ Other authors have also included Mallampati Class 4 and male gender as independent variables.³² Impossible BMV has been found to be much less frequent—0.15%, with neck radiation changes as the most significant clinical predictor.³³ Other predictors included male gender, sleep apnea, Mallampati III–IV classification, and the presence of a beard.³³ A considerable proportion of those patients (close to 25%) were also found to be difficult to intubate.³³ The patient in this case is edentulous, and has a full beard. Thus, he has two of the five risk factors and is considered to be at risk for difficult mask-ventilation and potentially impossible BMV, with the added risk factor of being male. The importance of this determination is a deliberate reinforcement of immediately available backup plans, including performance of a surgical airway. Having pointed out the importance of preparation in the anticipated difficult BMV, it is noteworthy that there are a number of rescue techniques described to improve difficult BMV depending on the contributing factors. For example, in the presence of facial hair (beard), as presented in our case, the use of a clear intravenous site dressing (Tegaderm™), a cut defibrillator pad over the bearded area, or plastic kitchen wrap around the entire head has been proposed to reduce gas leaks from the face mask.^34–36 Use of a small mask placed between the lower lip and nostrils or an infant mask covering only the nostrils has also been suggested.³⁷ The last maneuver has also been described as beneficial in cases in which BMV difficulty was related to an edentulous status. It is also possible to keep a patient’s dentures in place while performing BMV and then remove them just prior to intubation. Other options include using an oropharyngeal airway as early as feasible and placing gauze rolls inside the cheeks to prevent the oral cavity from collapsing. Nasal airways can also be used in this circumstance.

In recent years, there have been multiple reports suggesting that the laryngeal mask airway (LMA) may be an effective airway rescue device in the management of both difficult intubation and difficult BMV.^38,39 However, there are also instances in which the LMA insertion (on its own) may be difficult or even impossible.^38,40,41 In fact, there are some reports of impossible LMA insertion in patients with diseases which limit neck movement.^40,42 There are two special concerns when considering the use of an extraglottic device (EGD), including the LMA, in RA patients. First, extra caution should be taken during the insertion and inflation of an LMA to avoid movements in the head and neck and to avoid excessive soft tissue pressure, as it may produce posterior displacement of the upper cervical spine and aggravate AAS in susceptible patients.⁴³ Second, care should be taken to minimize mucosal and cricoarytenoid joint injury. There are several reports of acute upper airway obstruction caused by this disease manifestation in association with LMA use.^13,41,44

What Are Some Additional Preoperative Considerations That May Influence the Choice of Anesthetic Management?

1. 
   

   Due to the prevalence of cervical spinal abnormalities in RA, particularly AAS,⁶ with associated severe morbidity and mortality,⁵ preoperative imaging has been strongly recommended to determine the specific cervical spine pathology and possible instability (Figure 42–1).⁴⁵ It has been demonstrated that flexion and extension views, in addition to A-P views of the odontoid, are essential for complete x-ray examination of the cervical spine to detect AAS.⁴⁵ The detection of cervical spine instability can significantly affect anesthetic management, favoring techniques that avoid unprotected manipulations of the neck under anesthesia. This valuable information could help to avoid neurological consequences during positioning.^27,45,46 In addition, the lateral neck x-ray, obtained as part of a preoperative assessment to evaluate patients with cervical deformity, may help to estimate the angle between the oral and pharyngeal axes at the base of the tongue. If this angle is less than 90 degrees, LMA insertion may be difficult or impossible.^27,40

   
   
2. 
   

   Intraoperative patient positioning can play an important role in the success of many procedures; conversely it may also cause postoperative complications. Cervical spinal involvement secondary to RA can significantly complicate head and neck positioning. Therefore, it is important to determine if the patient is able to assume the position required to perform regional anesthesia and since they will be awake during surgery. Intraoperative positioning of patients with RA related joint deformities (Figure 42–2), rheumatoid nodules and potential peripheral neuropathies should be undertaken with care.⁴⁷ The optimal intraoperative head position to minimize AAS in patients with RA has been reported as the protrusion position (head positioned on a flat pillow combined with a donut-shaped pillow) with support of the upper cervical spine and some extension at the cranio-cervical junction.⁷ However, having said that one published report noted that a rheumatoid patient with AAS had marked worsening by the sniffing position,²⁷ which is similar to the above-mentioned protrusion position; the only apparent difference was the degree of extension of the head at the occipito-atlanto-axial complex.

   
   
3. 
   

   Although this patient does not report severe GERD (well controlled with proton pump inhibitors), EGD insertion may be contraindicated in those patients with untreated and symptomatic GERD.^38,42 These patients should be treated preoperatively with a histamine (H₂) receptor blocker, metoclopramide, and a nonparticulate antacid regardless of the type of proposed anesthesia.

   
   
4. 
   

   The effects of drug therapy for RA may require certain considerations in preparing for anesthesia care. In our case, long-term NSAID use may cause gastrointestinal disturbances, chronic anemia, and abnormal platelet function. As far as corticosteroid therapy is concerned, contemporary recommendations are based on the drug regimen and intensity of surgical stress. Patients receiving low therapeutic doses of corticosteroids who undergo a surgical procedure do not routinely require standard stress doses of corticosteroids if they continue to receive their usual daily dose of corticosteroids.^47,48

   
   
5. 
   

   Another prudent element of difficult airway management is planning for extubation and a post-extubation strategy ahead of time.²⁵ Special consideration should be given to RA patients in preparation for the post-extubation period due to the high prevalence of laryngeal involvement. Extra care should be taken to avoid post-extubation complications. For example, laryngospasm presents a predictably difficult scenario, in which rescue maneuvers, such as positive pressure BMV, will be predictably difficult if not impossible. Laryngeal trauma during airway instrumentation, including the use of EGDs, should be minimized to avoid postoperative acute upper airway obstruction caused by cricoarytenoid arthritis.^12–16 Extubation over an airway exchange catheter may be an option in these patients.

What Anesthetic Agents Should be Used for Induction?

If the ability to perform adequate BMV or successfully place an EGD is predicted to be problematic, then uninterrupted spontaneous ventilation (SV) should be maintained during induction until the airway is secured. An inhalational induction with sevoflurane may be performed to minimize the risk of sudden loss of airway control.^49–51 However, maintenance of a patent airway without cervical spine movement may be difficult. Intravenous drugs with minimal effect on the respiratory drive, such as low-dose midazolam, ketamine, or dexmedetomidine, can be titrated in combination with an inhalational agent. Administration of opioids should be minimized, as they depress respiratory drive. Muscle relaxants should be avoided unless BMV or EGD ventilation has been established. Although not considered as safe, there are reports of induction of anesthesia without maintaining SV, followed by successful LMA or other EGD placement in patients with limited neck mobility.^39,52,53 However, this should only be performed if there is a high level of certainty in the ability to provide adequate BMV or EGD ventilation following the induction of GA (e.g., a recent history of a similar technique being successful). Only short-acting drugs, such as propofol, should be used. Thorough denitrogenation is particularly essential in this case as it will delay oxygen desaturation in the event that there are difficulties in obtaining control of the airway. The use of high-flow oxygen, either through a non-rebreather face mask or nasal cannula, is becoming more popular as an adjunct in the denitrogenation process for patients considered to be at higher risk for desaturation, such as those who are morbidly obese or undergoing rapid sequence induction.^54,55 Positive end-expiratory pressure during induction of general anesthesia has also been successfully utilized to prevent atelectasis formation, as well as increase the duration of non-hypoxic apnea in both non-obese and obese patients.⁵⁶

Following Induction of General Anesthesia, How Should This Patient’s Airway be Secured?

Another prudent recommendation in the ASA Difficult Airway Management guidelines regarding technique choices is: “Do what you do best.”²⁵ In general, anesthesia practitioners are familiar with at least one of the EGDs currently available on the market, including a particular LMA, such as the LMA-Classic™, LMA-Unique™, or the Intubating LMA (LMA-Frastrach™). These devices can be inserted with relative ease and can provide adequate positive pressure ventilation (PPV), without tracheal intubation. Additionally, these devices can serve as conduits for tracheal intubation. A 6.0-mm inner diameter (ID) endotracheal tube (ETT) can be passed through a #4 LMA-Classic™, and a 7.0-mm ID ETT through a #5 LMA-Classic™. ETTs (up to size 8.0-mm ID) have been designed for use with the Intubating LMA (ILMA) or disposable ILMA, which have special shaped tips to allow easier and less traumatic passage through the glottis and can be passed through the #3, #4, and #5 ILMAs. Despite the reports that LMA use in RA patients may be associated with aggravation of laryngeal RA and acute upper airway obstruction, the literature has demonstrated that the LMA or ILMA are useful and effective devices in airway management in anesthetized patients with RA.^{13,41,44,49,57–59}

The ILMA may offer potential advantages over a nonintubating LMA in patients with RA, as it may be easier to insert in patients with a rigid neck and is a better conduit for intubation, although the LMA-Classic™ and LMA-Unique™ may be more advantageous in patients with limited mouth opening.^39,60 This patient’s airway may be secured with an ILMA following an inhalational induction with sevoflurane or an intravenous agent while maintaining SV. If the ETT designed for use with the ILMA is unavailable, an FB can be used to guide a regular ETT into the trachea. Tracheal placement of the ETT can be confirmed by FB, as well as by auscultation and capnography. The ILMA can then be removed using a special stabilizing device. If an FB is not available, a prewarmed, softened ETT can be inserted blindly through the ILMA by feeling for a loss of resistance, with good success (88%–98%).^61,62 In fact, inhalational induction followed by ILMA insertion and blind intubation is a reasonable option in patients with severe AAS undergoing elective surgery who prefer airway management under general anesthesia.⁶³ However, given the airway pathology in this patient, it would not be prudent to proceed without an FB. Compared to blind insertion of an ETT, FB assistance may provide less traumatic tracheal intubation, which is beneficial to RA patients to avoid exacerbation of laryngeal arthritis. Additionally, a Cook Airway Exchange Catheter (using the Rapi-fit connector, attached to the capnograph monitor to detect EtCO₂) or an Eschmann Introducer can be used to guide an ETT through the LMA. Retrograde intubation has also been used in combination with an LMA in patients with severe AAS.⁶⁴ If all these methods fail, the ILMA (or LMA) can be used alone for PPV throughout the case.

Once good positioning of an EGD that allows effective PPV without an excessive leak has been ascertained, a muscle relaxant can be administered which may provide improved conditions for further airway manipulations. The choice of a muscle relaxant may be determined by the speed of return to SV and the side effects profile of an individual agent. Succinylcholine, a depolarizing blocking agent, enables rapid onset and a short duration of action (see also Chapter 4). In addition to a number of side effects, succinylcholine provides only a short window of effective relaxation. It may limit the ability to gain definitive control of the airway, particularly when complex instrumentation and multiple airway devices are involved. Alternatively, a non-depolarizing agent can be used to ensure sufficient time to complete necessary airway instrumentation for endotracheal intubation in a controlled manner. In this case, should the situation change and rapid return to SV be required, a new reversal agent, sugammadex, is now available for emergency reversal. Sugammadex, which selectively binds rocuronium or vecuronium, enables prompt reversal of neuromuscular blockade, restoration of muscle function, and return to SV.⁶⁵ However, due to individual patient variability and concomitant drug use, the exact time of return of SV may vary. Thus, in some cases, considerable arterial desaturation can occur prior to return of effective respiratory activity. Therefore, the provision of patency of the upper airway and oxygenation should always be emphasized over excessive reliance on muscle relaxant reversal or the short duration of action for succinylcholine.⁶⁶

What Is the Role of Manual In-Line Stabilization of the Cervical Spine if DL Is Necessary? Are There Additional Methods to Improve Stability of the Cervical Spine During Airway Instrumentation in RA Patients?

The traditional standard recommendation that manual in-line stabilization (MILS) be applied during airway instrumentation in patients with cervical spine instability has been challenged. Some studies have indicated that DL and intubation with MILS in the presence of cervical instability may worsen glottic visualization, contribute to an increased rate of intubation failure, and potentially increase pathologic cranio-cervical motion.^67–69

In addition to awake intubation using FB, a proven technique of securing the airway in patients with cervical spine instability, there are a number of alternative methods that may be used with success in this patient population. Takenaka et al.²⁶ recently reported that use of the Airway Scope (Pentax) and the Eschmann Introducer in combination resulted in significantly reduced movements in cervical spine during endotracheal intubation. Ueshima et al.⁷⁰ have also reported the successful use of the Eschmann Introducer with the Pentax Airway Scope in patients with difficult airways. Other studies have used fluoroscopy to demonstrate a reduction of upper cervical spine movements during intubation using a variety of contemporary videoscopic devices.^58,71 Takenaka et al.²⁶ employed fluoroscopic monitoring during airway manipulation to avoid excessive AAS subluxation in a patient with severe RA.