A 32-year-old man (Figure 26-1) presented to the emergency department with dysphagia, dysphonia, and dyspnea. Further inquiry revealed a 1-week history of right-sided jaw pain. This was initially treated with oral antibiotics and analgesics by his family doctor while awaiting an appointment with his dentist. He saw his dentist the previous day and had an abscessed molar tooth extracted from his right mandible. Unfortunately, his pain continued and he developed swelling and fever, prompting him to present to the emergency department. His past medical history was unremarkable, and aside from his remaining prescription of the penicillin and hydromorphone, he was on no medications. He had no known allergies.
This 32-year-old man presented with dysphagia, dysphonia, and dyspnea. There was marked swelling of the right side of the neck. Due to marked discomfort, he was unable to protrude his tongue for proper pharyngeal evaluation.
26.2.1 Discuss the Incidence and Etiology of Deep-Neck Infections in Adults
The management of the patient whose airway is compromised due to a deep-neck infection is a challenge for even the most experienced practitioner. Fortunately for all, these are relatively rare. A typical ENT referral center may see one to three adult cases per year requiring airway management. As in this case, the deep-neck infection is often odontogenic. Intravenous drug abuse is another important cause. However, many cases of deep-neck infections do not have an identifiable etiology.1 Diabetes mellitus may also be a risk factor and its presence tends to be associated with more aggressive infection.2,3
26.2.2 Do All Deep-Neck Infections Require Airway Intervention?
Most patients with deep-neck infections can be managed conservatively without surgical intervention and do not require intervention to maintain the patient's airway.4,5 This conservative approach is similar to the management of adenotonsillar hypertrophy secondary to infectious mononucleosis, which will typically respond to steroids with or without antibiotics. Even epiglottitis in the adult population only rarely will require airway manipulation in the form of intubation or tracheotomy. Early deep-neck infections present usually as a cellulitis that can be successfully treated with antibiotics alone. Small, localized abscesses, such as peritonsillar abscesses, can often be treated with needle aspiration followed by antibiotics.
26.2.3 What Is Ludwig's Angina and How Does It Differ from Retropharyngeal Abscess?
This life-threatening infection of the floor of the mouth was first described in 1836 by Wilhelm Frederick von Ludwig. The condition has also been called "morbus strangulatorius", "angina maligna", and "garotillo" (Spanish for "hangman's loop"). These older terms reflect the high mortality, typically by total airway obstruction, in the days before antibiotics.
Ludwig's angina is defined as severe bilateral cellulitis and edema of the submandibular and sublingual spaces. Woody swelling of the submandibular area in a febrile patient with a history of jaw pain is the classic presentation. The infection may cause swelling of the tongue and epiglottis that will then impair the ability to swallow and clear secretions. Total airway obstruction may result from progressive swelling or from laryngospasm secondary to aspiration of pus secretions, or both.6 Surgical intervention is usually required if abscess formation and airway compromise occur. Whereas most cases of deep-neck infections can be managed conservatively with antibiotics alone, true cases of Ludwig's angina typically require more aggressive intervention in terms of surgical drainage and definitive airway management. Treatment of Ludwig's angina is three-pronged and involves airway management, antibiotic therapy, and surgical drainage.
26.3.1 Why Might Airway Management Be Difficult in Patients with Ludwig's Angina?
Patients with Ludwig's angina or a retropharyngeal abscess frequently have features that create difficulty with all aspects of airway management: bag-mask-ventilation (BMV), ventilation using extraglottic devices (LMA), laryngoscopy and tracheal intubation, and even performing a surgical airway.
Bag-mask-ventilation may be challenging in these patients for a number of reasons. Patients with stridor will have significantly decreased airway caliber, necessitating high airway pressures to produce adequate gas flow. It may not be possible to generate these pressures with BMV. Because of pain and anxiety, both the awake or obtunded patients may not tolerate application of the facemask and airway opening maneuvers due to pain and anxiety. It may prove difficult or impossible to open the airway of the sedated or unconscious patient due to loss of muscle tone and the resultant further narrowing of the airway. Copious secretions may increase the risk of laryngospasm, and tongue swelling may preclude use of an oral airway. A nasal airway is an option but bleeding could possibly trigger laryngospasm.
Upward displacement of the tongue by the infection can make insertion of any of the extraglottic rescue devices difficult or impossible. Although Brimacombe et al reported the successful use of a small Laryngeal Mask Airway (#2) as a rescue device for a hypoxic adult patient with quinsy,7 extraglottic rescue devices for failed BMV, even if they can be inserted, may be ineffective due to glottic edema.
Secretions and edema, particularly tongue swelling, will make direct laryngoscopy more difficult regardless of the type of blade chosen. Nuchal rigidity, trismus, or both may be improved with sedation or muscle relaxants but there is no guarantee that these agents will be effective. Blind intubation techniques, such as the intubating Laryngeal Mask Airway (LMA-Fastrach™, LMA North America Inc., San Diego, California) and light-guided intubation (Trachlight™, Laerdal Medical Corp., Wappingers Falls, New York) would not generally be considered for first-line use in these patients as these techniques run the risk of disrupting infected tissue and potentially soiling the airway. Furthermore, these nonvisual intubating techniques could result in laryngospasm during the intubation attempt. Typically these patients have heavy secretions and occasionally some bleeding, limiting the use of indirect visual techniques such as the flexible and rigid fiberscopes and video laryngoscopes. In true cases of Ludwig's angina, oral intubation with any instrument is frequently not an option due to limited oral access. Most experts would advocate either a nasal intubation or a surgical airway.
Unfortunately, performing a surgical airway in this patient population is difficult. The anatomy is often distorted due to swelling, and hyperemic tissues may increase the likelihood of bleeding. In some patients, the abscess may involve the area surrounding the trachea. Supine positioning of the patient to perform a surgical airway may worsen dyspnea and reduce the patient's cooperation.
To add to the difficulty of airway management in these patients, all possible options of ventilation and oxygenation involve some danger. The ultimate decision will be made based on the urgency of the clinical circumstance, the available resources, the careful setting of priorities, and the skill and experience of the airway team (anesthesia practitioner and surgeon).
26.3.2 Discuss the Role of CT Scan in Assessing These Patients
The advent of the CT scan has revolutionized the ability to accurately assess the swollen, inflamed neck. In addition to determining the severity of the infection involving different tissue planes and neck spaces, the resolution of the CT scan can help to differentiate between a cellulitis and an abscess. The CT scan can also determine the presence or absence of jugular vein thrombosis. Unfortunately, in the presence of a rapidly deteriorating airway, it is necessary to proceed with emergency airway management before a CT examination of the neck becomes available. Even in patients with stable airways, a CT scan may not be possible prior to definitive airway management because the patient may be unable to lie flat. In these cases, the CT scan is done to better determine the extent of the infection only after securing an airway.
26.3.3 Discuss the Technique of Nasopharyngoscopy and Its Role in the Management of Patients with Deep-Neck Infections
Nasopharyngoscopy is a safe and simple technique which should become familiar to anesthesia practitioners, otolaryngologists, and emergency specialists. Following the application of topical vasoconstrictor and topical anesthetic (10% Xylocaine), the flexible nasopharyngoscope is passed into the nasopharynx. The glottis should not be anesthetized as this could trigger laryngospasm. With the flexible nasopharyngoscope, the glottis can be viewed from above without the risk of provoking laryngospasm. The technique is usually first done in the emergency department as part of the initial evaluation, and repeated at the bedside or in the operating room as required to provide an ongoing evaluation of the airway.
26.3.4 How Was This Patient Assessed?
On examination, he appeared anxious and in severe discomfort. He was febrile with a temperature of 38.7°C (101.66°F). His respiratory rate was 26 breaths per minute. His heart rate was 104 beats per minute (bpm) and his blood pressure was 132/76 mm Hg. His oxygen saturation was 91% on 40% oxygen delivered through the facemask. He had a marked decrease in the range of motion of his neck. Significant swelling and erythema was observed extending from the right submandibular region, crossing the midline and down the neck to include his left upper chest.
In a lateral x-ray of the neck, marked submandibular and retropharyngeal swelling was seen, as well as a diminished airway caliber (Figure 26-2). Although potentially helpful, a CT scan was not done as it was felt that the patient could not tolerate lying flat, even for a short period of time.
Although this lateral x-ray view of the head and neck did not show any obvious sign of airway obstruction, it showed an increase prevertebral soft tissue (swelling of the posterior pharyngeal wall) (arrow), an important diagnostic sign of retropharyngeal abscess.18 There was also a loss of normal lordotic curvature of the spine.
Nasopharyngoscopy was performed in the emergency department (ED) by the ENT resident and revealed right lateral pharyngeal swelling and posterior displacement of the epiglottis obscuring the vocal cords.
26.3.5 How Do You Assess the Severity of Airway Obstruction?
Airway obstruction is assessed clinically by history and physical examination, noting symptoms and looking specifically at signs, such as oxygen saturation, respiratory rate, stridor, tracheal tug, intercostal indrawing, and accessory muscle use. Lateral x-ray (Figure 26-2) and CT scan of the head and neck can quantify the degree of obstruction. It is also possible to examine the dynamic aspect of the obstruction through nasopharyngoscopy.
26.4.1 What Are the Indications for Establishing a Definitive Airway in Patients with Deep-Neck Infections?
Indications for definitive airway management in these patients are impending airway obstruction or sepsis. The decision to secure the airway is generally made by the ENT surgeon based on impending airway obstruction. There is some evidence that it may be prudent to intervene at an earlier stage in the diabetic patient.3 In some instances, the ED physician may be forced into airway intervention if the patient is acutely decompensating (see Chapter 2, Crash Algorithm). Once the decision to intervene is made, anesthesia and ENT consultants, if not already involved, should be immediately consulted. These patients are ideally managed in the operating room, provided that the transfer is quick and complete airway obstruction is not imminent.
26.4.2 What Was the Plan in This Case?
Given the severity of the obstruction and the patient's worsening symptoms, the decision was made to establish a definitive airway. Anesthesia was immediately consulted and the plan was made to proceed to the operating room for either endotracheal intubation or tracheotomy, followed by surgical drainage of the abscess.
26.4.3 Do These Patients Require a Primary Surgical Airway or Can an Attempt Be Made to Intubate from above?
Once the need to secure the airway has been established, the next decision is whether to attempt intubation from above (either oral or nasal) or to go directly to a surgical airway. In the stable patient, this generally refers to an awake tracheotomy done by an experienced surgeon. Local anesthesia with minimal sedation (eg, remifentanil 0.05-0.1 ug·kg−1·min−1) is usually all that is needed to ensure patient acceptance when the procedure is performed by a competent surgeon. In rare circumstances, an awake cricothyrotomy may be indicated if surgical expertise or time is not available. The choice of airway should be a joint decision of the anesthesia practitioner and surgeon based on the predicted difficulties of each of the following: bag-mask-ventilation, EGD ventilation, direct laryngoscopy, alternative intubation, and surgical access. The skill and experience of the airway team will also affect this decision. Potter et al8 reviewed the literature in 2002 and found that the background of the involved surgeon had a significant influence on preferred management. They found primary surgical airways appeared to be favored by otolaryngologists, while oral and maxillofacial surgeons favored oral or nasal intubation.
26.4.4 Discuss the Double Set Up and Plan C
In many cases, it will be reasonable to make a nonsurgical attempt to secure the airway. The specific route (awake, asleep, oral, and nasal) will be discussed later but it is critical to have a well-developed Plan B (and sometimes Plan C). The double set up is the recommended approach for most of these cases, meaning that the surgical team is ready to go should attempts fail to secure the airway from above. This may involve having the surgical team gowned and gloved, and the neck prepped. Many times a formal tracheotomy can be performed. But in the event of serious airway compromise, a cricothyrotomy may be a better choice.
The surgical airway typically represents Plan B and this may solve the airway problem. Surgical access could, however, prove difficult for any of the reasons discussed earlier. Loss of the airway during tracheotomy has been reported9 and such an eventuality must be prepared for with Plan C. This will typically involve sedation (IV or inhalation) to facilitate patient cooperation, but in rare circumstances could require muscle relaxation and an attempt at direct laryngoscopy while attempts at obtaining surgical access continue.
26.4.5 Discuss the Pros and Cons of Securing the Airway in the Awake or Anesthetized Patient
One must decide whether to perform tracheal intubation awake or asleep. As discussed earlier, these patients invariably have features that pose problems in airway management. The safest initial approach with these patients is to manage the airway while they are awake. Sedation may indeed be necessary in some cases, but it is preferred to keep the patient cooperative and spontaneously breathing. Reassurance and relieving the patient's fear and anxiety is crucial; repeated reassurance and a confident demeanor on the part of the practitioner are essential. As well, the patient will often need to be maintained in a sitting or semi-sitting position in order to help preserve the airway and increase comfort, thereby ensuring the patient's cooperation.
26.4.6 Discuss Reasons Why an Awake Intubation May Be Unsuccessful
While awake intubation remains the safest initial approach to airway management, it is important to realize that sudden deterioration may occur even in a fully awake or minimally sedated patient.10,11,12 Reports of complete airway obstruction and some of failed bronchoscopic intubation emphasize the importance of managing these patients under double set up.13 Inadequate airway anesthesia, practitioner's inexperience, over-sedation, copious secretions, bleeding are all reasons for failure of an attempt at awake intubation.
26.4.7 What Is the Plan If Awake Intubation Fails or Is Not an Option?
If an awake intubation fails or is not possible, then a complete, but rapid, reassessment of the situation is in order. The next safest approach may be an awake surgical airway, provided that the patient still has a patent airway and is at least minimally cooperative. In the rapidly deteriorating or actively uncooperative patient, a primary surgical airway may not be a practical alternative. It may then become necessary to induce general anesthesia in a patient with multiple predictors of difficulty with all aspects of airway management.
26.4.8 Discuss Options If General Anesthesia Becomes Necessary to Secure the Airway
Should it be necessary to induce general anesthesia, the ideal approach is a matter of opinion. There are pros and cons to all of the available choices. Induction of general anesthesia in this setting should always be done under double set up as discussed earlier.
Perhaps the classic approach is an inhalation induction in an attempt to induce general anesthesia while preserving spontaneous ventilation. Inhalation induction followed by direct laryngoscopy and intubation is a common practice in children with airway obstruction since awake intubation is rarely a practical option in children.
Inhalation induction of adults with airway obstruction may be more difficult in that the relatively longer excitement phase predisposes to aspiration, laryngospasm, or both. As anesthetic depth increases, complete airway obstruction can also occur due to the loss of muscle tone. Inhalation induction typically requires at least some degree of patient cooperation, but can be accomplished without.14 As with awake intubation, it is critical to have a well-rehearsed backup plan (Plan B and C).
Preservation of spontaneous ventilation under anesthesia may also be accomplished utilizing IV agents. Compared to inhalation agents, it may be more difficult to preserve adequate spontaneous ventilation and achieve adequate depth of anesthesia using IV agents. Recent evidence suggests that remifentanil may be a more attractive IV sedation option. Machata et al have demonstrated excellent intubating conditions when remifentanil was used for conscious sedation.15 A bolus of 0.75 ug·kg−1 followed by an infusion of 0.075 ug·kg−1·min−1 provided good intubating conditions.
Rapid-sequence intubation (RSI) is unlikely to represent a first-line management option in these patients. However, in the event that the airway is completely lost, consideration should be given to use of muscle relaxants to facilitate intubation while attempts continue to achieve surgical airway access. RSI may also be considered for the actively uncooperative patient provided there is a double set up.
26.4.9 Discuss the Pros and Cons of "Nasal or Oral" Intubation
Following the decision to attempt intubation from above, the next decision is whether to use the nasal or oral route. Each has its advantages and drawbacks.
The nasal route bypasses the tongue (which may be swollen) and often provides a convenient passage to the glottic opening. At one time, blind nasal intubation was a common choice in these patients, but with the general availability of flexible bronchoscopes, this technique is now seldom indicated. Furthermore, blindly advancing the endotracheal tube (ETT) into the glottic opening may rupture the abscess with resultant soiling of the trachea. The risk of epistaxis is a major concern with the nasal approach, as bleeding may hamper visualization and could trigger laryngospasm.
The oral approach avoids the risk of nasal bleeding and tube size is limited only by size of the glottic opening. Unfortunately, the massive tongue swelling combined with trismus, often seen in patients with Ludwig's, can make an oral intubation impossible.
26.4.10 How Can One Minimize the Risk of Bleeding Associated with Nasal Intubation?
The risk of bleeding during nasal intubation can be minimized with the liberal use of topical vasoconstrictors (eg, xylometazoline) and by using a small ETT (7.0 mm inner diameter [ID] or smaller). Reinforced ETTs are more flexible and may cause less trauma and are therefore preferable in these patients. Regular ETTs (including nasal RAE ETTs) may be made less damaging to tissues by softening the tubes in warm saline prior to use.
The practice of dilating up the nasal passage using different sizes of nasal trumpets may also decrease bleeding and allow for passage of a larger tube. Following application of local anesthesia and vasoconstrictors, a small soft nasal airway lubricated with 2% lidocaine jelly can be inserted into the right nasal passage (larger in most people). If resistance is encountered, the left nares can be tried. The process can then be repeated with the next larger size airway. The goal is to get easy passage of at least a size 8 nasal airway. An ETT a half size smaller can then be used for the intubation. A larger tube (7.0 mm ID or greater) is advantageous in that it allows for insertion of the adult flexible bronchoscope with its superior optics and suction capabilities.
26.4.11 What Is the Best Tool to Facilitate Intubation?
For the most part, the tool that one chooses to facilitate intubation in these patients is less important than the approach discussed earlier. The technique chosen should reflect the practitioner's skill, experience, and comfort with the technique, as well as the safety and practicality of the chosen technique. Nonvisual techniques are discouraged due to risks of soiling the airway and of possible laryngospasm. For reasons discussed earlier, techniques that allow visualization of the airway are preferred, usually either a direct-vision laryngoscopy or the flexible bronchoscope (FB). Other methods may be acceptable provided the practitioner is skilled in their use.
26.4.12 Discuss the Advantages and Disadvantages of Flexible Bronchoscopic Intubation
Flexible bronchoscopic intubation (FBI) offers the advantage of being able to see around the obstruction and is usually well tolerated in the awake patient. Unfortunately, heavy secretions, bleeding, or both, may limit the usefulness of the FBI. In addition, as the ETT is advanced blindly over the bronchoscope during intubation, careful attention is required to avoid rupturing the abscess and soiling of the infective materials into the trachea. Use of the adult FBI can lessen the effect of secretions compared to the pediatric FBI but necessitates the use of at least a size 7.0 mm ID ETT. FBI may be more difficult in the unconscious patient with decreased muscle tone.
26.4.13 Discuss the Advantages and Disadvantages of Direct Laryngoscopy
Direct laryngoscopy will often be advantageous in the presence of heavy secretions. It can be performed quickly and is generally the technique of choice in the unconscious patient. Direct laryngoscopy is highly stimulating and may not be tolerated in the awake patient, particularly if much force is needed to expose the glottis.
26.4.14 Describe the Plan to Secure the Airway in This Case
In the operating room, the airway was reevaluated and, in consultation with the ENT surgeon, the decision was made to perform an awake nasal tracheal intubation under double set up.
The patient was positioned semi-sitting and standard monitors were applied. Supplemental oxygen was delivered with nasal prongs during preparation and airway anesthesia. A judicious dose of midazolam (0.5 mg bolus) was administered intravenously to reduce the patient's anxiety and improve cooperation. The neck was prepped and the surgical team was gowned and gloved, and ready to perform an emergency surgical airway (Plan B).
26.4.15 Discuss Airway Anesthesia for Patients with Ludwig's Angina
There are multiple techniques to anesthetize the airway and these are discussed in Chapter 3. The chosen technique depends largely on the preference of the practitioner. However, care must be taken to avoid early stimulation of the airway which can result in fatal laryngospasm.7
Inflammation and infection can, in theory, decrease the efficacy of local anesthetics due to changes in local pH. However, this is generally not of any clinical significance. Heavy secretions, bleeding, or both, can decrease the amount of local anesthetic that actually reaches the mucosa and this should be taken into account, but there are many reports of successful airway anesthesia in the presence of infection.16
26.4.16 How Was Airway Anesthesia Achieved in This Case?
Airway anesthesia was achieved with a combination of lidocaine ointment and inhaled lidocaine. Xylometazoline (Otrivin nasal spray) was applied to both nasal passages in hopes of decreasing bleeding potential. Approximately 2.0 cm of 5% lidocaine ointment was applied to the back of the tongue with a tongue depressor. The DeVilbiss atomizer was then used to deliver 15 mL of 4% lidocaine as an aerosol via a nasal route. No attempts were made to specifically block the superior laryngeal nerve due to the possibility of disrupting the abscess and potentially soiling the airway.
26.4.17 How Was This Patient's Airway Secured?
The patient was asked to take a deep breath while occluding each nares. The right appeared more patent and was dilated up as described earlier (Section 26.4.10) so that a #8.0 nasal airway was easily accepted. A #7.0 reinforced ETT was then gently advanced into the nasopharynx. An adult 5.2 mm flexible bronchoscope was then passed through the ETT. After identifying the glottic opening, which was significantly deviated to the left, the bronchoscope was directed into the trachea and the ETT was then gently advanced off into the airway. Following CO2 confirmation of successful tube placement, general anesthesia was induced with fentanyl and propofol.
Surgical drainage of the abscess was then accomplished without incident. Following 36 hours of ventilation in the ICU, the patient was uneventfully extubated and made a full recovery.
It is clear that there is more than one approach to the management of the airway in these patients. The choice will be based on the particular patient presentation and the skills and experience of the airway team.
In 2002, Jenkins et al surveyed the management choices for the difficult airway by Canadian anesthesia practitioners.17 Regarding the management of a patient unable to swallow due to a retropharyngeal abscess, 70% chose an awake approach, 23% chose inhalation induction, and only 7% chose an IV induction of anesthesia. While 37% chose direct laryngoscopy and 8% chose primary surgical airway, FBI was the initial technique chosen by 50% of the responders. A 2004 study by Bross-Soriano et al reported on 107 patients with Ludwig's angina over 18 years.2 Surgical airway was required in 28%, when nasal intubation failed or was not possible.
Deep-neck infections with abscess formation resulting in airway compromise provide challenges for both the airway practitioner and the surgeon who are dependent upon each other for a successful outcome. The likelihood of a satisfactory result is enhanced by early involvement of the team planning an approach to such challenges.