Laryngeal and Upper Airway Disease

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[edit] Laryngeal and Upper Airway Disease

Andrew Shapiro

James Malone

The larynx is a complex organ designed to serve several functions, most notably as the instrument of human voice. Because of its tenuous location at the junction of the respiratory and digestive tracts, the larynx also protects the lower airway during swallowing, ensures airway patency during inspiration, and provides sufficient resistance during expiration to prevent atelectasis. These disparate functions demand complex sensory and motor capabilities and close interactions with other organ systems.

The larynx is generally divided into three regions (Fig. 181-1). The supraglottis comprises the epiglottis, aryepiglottic folds, arytenoids, and false vocal folds and provides a dynamic valve mechanism that occludes the lower airway during swallowing. The glottis, or true vocal folds, consist of an underlying muscular layer, a surface squamous epithelium, and an intervening loose connective tissue layer that allows for a flowing mucosal “wave” to maintain normal voice quality. The subglottis extends from the vocal cords to the upper trachea, largely corresponding to the cricoid cartilage, the only complete cartilaginous ring within the airway. Sensory and motor innervation is provided by two branches of the vagus nerve, the superior and recurrent laryngeal nerves.

Figure 181-1 Sagittal view of larynx.

[edit] PATIENT EVALUATION

The evaluation of patients with airway disorders begins with a complete history and physical examination. Although the duration, severity, and concurrent symptoms of airway disorders may vary depending on the underlying etiology, certain similarities prevail. In adults, hoarseness or a change in the quality of the voice is often the earliest symptom. Other common features include cough, hemoptysis, and pain with swallowing or speech. Dyspnea and airway obstruction are late indicators and demand immediate intervention. Essential components of the history include concurrent medical problems and therapy, occupational or recreational voice use and abuse, prior surgeries or intubations, and tobacco and alcohol use.

The physical examination is comprehensive but emphasizes particular aspects of the head and neck. The oral and nasal mucosa are examined for acute or chronic inflammatory changes. Palpation of the neck may identify cervical masses, thyromegaly, deviation, or tenderness of the larynx or trachea. Direct inspection of the larynx and hypopharynx presents a challenge in a primary care setting. Specialized training and experience are required even to visualize this area, let alone identify subtle pathologic changes in an active larynx. Thus consultation with an otolaryngologist may be beneficial when patients have either severe or persistent (e.g., more than 3 weeks) symptoms.

Indirect transoral examination using a head light and mirror is a useful technique in adults and some children. An overactive gag reflex or anatomic variations may limit this method. Flexible fiberoptic nasopharyngeal laryngoscopy allows a more prolonged and comprehensive examination of laryngeal morphology and function. Patients with disorders of voice quality may benefit from a stroboscopic examination of the larynx. This technique provides detailed stop-action visualization of mucosal lesions and evaluation of the waveform morphology. Laryngeal electromyography is useful in the diagnosis of neuromuscular disorders of the larynx, such as paralysis or focal dystonia. Finally, cross-sectional imaging with computed tomography (CT) or magnetic resonance imaging (MRI) plays an important role in the management of laryngeal and extralaryngeal neoplasms.

[edit] PEDIATRIC CONSIDERATIONS

[edit] Stridor

Children are subject to numerous congenital, inflammatory, and even neoplastic diseases that may produce upper airway symptoms. The cross-sectional area of the airway lumen in children is smaller than that of the adult, and a small amount of edema produces a greater degree of airway compromise (Fig. 181-2). In contrast to adults, in whom diseases of the airway usually manifest as hoarseness, infants and young children with airway disorders most often present with obstructive symptoms, in particular, stridor, a harsh sound produced by abnormal turbulence in the airway. Unlike respiratory distress, which may result from disease in a variety of systems, stridor always implies obstructive disease of the airway. Stridor is loudest over the site of obstruction. In contrast, wheezing is produced by the small airways and is therefore loudest over the chest. Stertor is a coarse inspiratory sound from a pharyngeal source (e.g., snoring). Distinguishing these characteristic sounds allows rapid localization of the site of the problem. The quality and timing of stridor can further define the site of disease within the larynx or trachea. Disorders above the larynx produce stridor on inspiration. Disorders of the subglottis result in biphasic (inspiratory and expiratory) stridor, whereas intrathoracic pathology usually produces stridor on exhalation. Any child with stridor and concurrent signs of respiratory distress (e.g., tachypnea and tachycardia, intercostal or substernal retractions, nasal flaring) should be transferred immediately to an emergency room for airway support.

Figure 181-2 Effect of edema on cross-sectional airway diameter.

[edit] Disorders in the Infant

Congenital lesions are the most common cause of infantile stridor (Box 181-1). The three most common problems are likely to be seen in a primary care setting.

[edit] Laryngomalacia.

Laryngomalacia is the most common cause of stridor in infants. The supraglottic structures collapse into the airway lumen on inspiration, producing a coarse to musical sound. The noise begins in the first few weeks after birth and is often accentuated in the supine position. Eating, crying, and sleep increase the intensity in some infants. Gastroesophageal reflux (GER) appears to be strongly related to laryngomalacia. In most patients the disease is self-limited and should resolve by 18 months of age. Approximately 5% of patients have serious sequelae, such as failure to thrive or episodes of respiratory distress and cyanosis. Medical therapy for GER is helpful in some patients. Rarely, surgical therapy is required for symptom relief.

[edit] Subglottic Stenosis.

Defined as a narrowing in the area of the cricoid cartilage, subglottic stenosis may be congenital but results more often from an intubation injury. The subglottic anatomy is unique because it represents both the narrowest segment of the neonatal airway and the only complete cartilaginous ring. Infants with subglottic stenosis manifest biphasic stridor and a characteristic barking cough. Milder cases may present as recurrent episodes of “croup.” Children who experience croup before 6 months of age may also benefit from an airway evaluation. Depending on the severity of the stenosis, treatment ranges from observation to medical therapy to endoscopic or external procedures to widen the subglottis.

[edit] Vocal Cord Paralysis.

Most cases of unilateral vocal cord paralysis result from injury to the recurrent laryngeal nerve. A weak, breathy voice and choking with feedings are the most common presenting symptoms. A difficult delivery can lead to traction on the cervical portion of the nerve, and injury is particularly common after pediatric heart surgery. Bilateral vocal cord paralysis presents with respiratory distress and inspiratory stridor. The voice may be surprisingly strong in these patients, which may delay recognition, with disastrous results. The most common cause of bilateral vocal cord paralysis is central nervous system (CNS) disease, especially the Arnold-Chiari malformation.

[edit] INFECTIOUS AND INFLAMMATORY DISORDERS

[edit] Laryngitis

Laryngitis refers to any inflammatory process involving the larynx and may result from infections, environmental irritants, or other inflammatory processes involving the pharynx. Laryngitis also may result from habitual factors, such as voice abuse, coughing, or throat clearing.

[edit] Acute Laryngitis.

Viral laryngitis is probably the most common inflammatory disorder of the larynx. The patient usually has an associated prodrome of low-grade fever, myalgias, and upper respiratory congestion. The voice is characteristically hoarse, with breaks and reduced pitch. A number of viruses are responsible. Treatment is supportive, with an emphasis on voice rest and humidification.

[edit] Noninfectious Laryngitis.

Chronic noninfectious laryngitis may result from prolonged exposure to tobacco smoke and alcohol, which are strongly associated with the development of laryngeal cancer. More recently, GER has also been noted to play a similar role in laryngeal disease.

[edit] Croup

Croup (acute laryngotracheobronchitis) is most common in children between 1 and 3 years of age. After a 24- to 72-hour prodrome of upper respiratory symptoms, a characteristic nonproductive seal-like cough is associated with stridor and sometimes wheezing. Illness is most common in the late fall and winter and may progress to respiratory distress. Parainfluenza virus is the most common cause. Treatment varies with severity and includes cool mist humidification, racemic epinephrine, systemic steroids, and rarely intubation.

[edit] Spasmodic Croup.

A common cause of stridor in children 1 to 3 years of age, spasmodic croup has an unknown etiology, but viral infection, allergies, and GER are suspected. Typically, barking cough and stridor begin suddenly at night, with no prodromal symptoms. Humidity and cold air seem to alleviate the symptoms, but racemic epinephrine and glucocorticoids may be required to provide relief.

[edit] Epiglottitis

Acute epiglottitis is a rapidly progressing infection of the supraglottic larynx most often caused by Haemophilus influenza type B (HIB). This disease can be distinguished from croup by the sudden onset of stridor, dysphagia, drooling, high fever, and the absence of a cough. The voice is muffled. Patients characteristically hold the neck in extension to maintain airway patency. Although this disease most often affects children 2 to 7 years of age, adults may be affected. Emergency airway support is essential, and patients in distress should be kept comfortably in their parents' arms until the airway can be assured, forgoing examination of the throat or radiologic studies. The use of conjugated vaccine for HIB has significantly reduced the incidence of epiglottitis, but the disease may be associated with other organisms.

[edit] Diphtheria

Diphtheria is fortunately a rare disorder in the United States because of widespread immunization. Infection by Corynebacterium diphtheriae leads to inflammation and membrane formation in the oropharynx and larynx that can result in airway obstruction and death.

[edit] Fungal Infections

Fungal infection of the larynx typically occurs in the setting of disseminated disease and results in hoarseness and cough. Treatment with amphotericin B typically produces satisfactory results. Histoplasmosis is endemic to the Ohio and Mississippi River valleys, where 80% to 90% of the population is infected. Painful granulomas are noted, particularly on the anterior aspect of the larynx. Blastomycosis is most common in the southeastern United States. Laryngeal infection results in a granular laryngitis. Biopsy often demonstrates thickened squamous epithelium, which may be confused with squamous cell carcinoma. Coccidioidomycosis is endemic to the southwestern United States and may occur in any age group. Laryngeal involvement occurs less often than lung disease.

[edit] Granulomatous Diseases

Granulomatous diseases of the larynx most often occur in the setting of systemic disease. The most common cause is tuberculosis. Syphilis, sarcoidosis, Wegener's disease, leprosy, and rhinoscleroma are also associated with granuloma formation in the larynx, although definitive diagnosis may be difficult.

[edit] Angioedema

Angioedema is an acute inflammatory process affecting the soft tissue of the face, oropharynx, and larynx. It may be precipitated by insect bites and stings, irritants, and medications. Hereditary angioedema is a relatively rare disorder that may be associated with a deficiency in C1 esterase. Treatment for acute events includes racemic or subcutaneous epinephrine, antihistamines, and steroids.

[edit] Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD), also known as laryngopharyngeal reflux, is a well-known clinical entity involving reflux of gastric acid into the esophagus and upper aerodigestive tract (see Chapter 102 ). Upper airway manifestations of GERD are common, and up to 25% of patients with GERD may have symptoms isolated to the head and neck region. Although symptoms vary in frequency and severity, the patient typically describes a lump in the throat, “globus” sensation, throat tightness, burning or sore throat, hoarseness, and odynophagia. The patient may describe symptoms of dysphagia or food sticking in the throat. GERD should be considered in patients with postnasal drip, chronic cough, and throat clearing. Patients may awaken during the night with a coughing episode, and symptoms may be worse in the morning hours after recumbency. In addition to underlying anatomic or medical disorders, reflux of gastric contents may be exacerbated by various lifestyle behaviors. The use of caffeine, alcohol and tobacco products, meals less than 2 hours before bedtime, tight clothing, obesity, stress, and depression are just a few of the factors that promote GERD in adults. Vomiting, failure to thrive, apnea, laryngospasm, and respiratory distress are seen in infants with acid reflux, and GERD has been documented in approximately 50% of infants presenting with life-threatening events.

Physical examination of the larynx in patients with laryngopharyngeal reflux reveals mucosal erythema and edema of the posterior commissure and arytenoid processes. The vocal cords may be inflamed or edematous. In more severe cases, vocal cord ulcers or granulomas may form posteriorly on the vocal process of the arytenoid cartilages. The posterior pharyngeal wall and hypopharynx may be erythematous and have a cobblestone appearance.

The diagnosis of GERD can often be made based on history and physical examination. The gold standard in diagnostic testing is a 24-hour pH probe for continuous monitoring of esophageal pH at both the upper and the lower esophageal sphincters. This test provides useful information about the pH of the environment around the larynx and upper aerodigestive tract.

The treatment of GERD involves medical therapy with antacids, H₂ blockers, and proton pump inhibitors. In addition, patients should be counseled in necessary lifestyle changes to eliminate factors that aggravate or promote GERD. Adherence will result in elimination of symptoms and reversal of laryngeal mucosal and vocal cord changes.

[edit] MISUSE AND ABUSE OF THE VOICE

Misuse or abuse of the voice occurs in avocational and professional speakers or singers and may result in structural changes to the vocal folds. These changes produce alterations in vocal quality with loss of pitch and intensity, often leading to a monotonous, harsh, or breathy voice. Attempts to overcome poor vocal quality frequently lead to further voice misuse. A speech pathologist, speech therapy, and behavioral modifications are key in restoring normal vocal cord form and function.

[edit] Reinke's Space Edema

Structural changes on the vocal cords due to abuse or misuse of the voice begin with edema of Reinke's space. This is a potential space between the vocal cord epithelium and underlying lamina propria. Reinke's edema results in a lower fundamental voice frequency that the patient perceives as a lower vocal pitch. The edematous changes in Reinke's space are reversible if appropriate compensatory techniques are instituted to eliminate vocal misuse. Speech therapy and elimination of contributing factors (e.g., smoking, GER) are essential for successful long-term management. If Reinke's space edema persists despite these interventions, evaluation for an underlying disease process should be pursued (e.g., hypothyroidism). Progression of Reinke's edema may lead to more permanent pathologic changes of the vocal cords, including vocal cord nodules and polyps.

[edit] Vocal Cord Nodules

Chronic vocal abuse from yelling, talking, or using an unnaturally low-pitched voice can lead to hyalinization of Reinke's space and the development of vocal fold nodules. Most often seen in boys and women, these lesions are often referred to as “singer's,” “preacher's,” or “screamer's” nodules. The history reveals chronic hoarseness and difficulty attaining high notes with singing. A harsh or breathy vocal quality is observed depending on the nodule's size. The nodules are usually bilateral and symmetric and originate at the junction of the anterior one third and posterior two thirds of the vocal cord. In children, vocal cord nodules may spontaneously regress with puberty. In adults, the nodules are best managed conservatively by maintaining adequate hydration and controlling sources of laryngeal irritation (e.g., smoking, GER). With speech therapy, behavior modification, and a speech-language pathologist, most nodules are reversible. If conservative therapies fail, the nodules may be removed surgically, followed by voice rest and further speech therapy. Failure to correct abusive vocal behaviors will likely lead to recurrence.

[edit] Vocal Cord Polyps

The etiology of vocal cord polyps is similar to that of vocal cord nodules. Chronic allergic reactions and inhalation of irritants may serve as contributing factors. The patient typically reports persistent hoarseness and difficulty maintaining adequate vocal intensity or loudness when speaking. A breathy quality to the voice may also be noted. Polyps are the result of subepithelial edema that may be localized or extend along the entire length of the vocal fold's free edge. Unlike vocal cord nodules, polyps are frequently unilateral, although both cords may be involved depending on the underlying cause. Abrupt or forceful voice abuse may rupture capillaries or ectatic vessels on the surface of the vocal fold and lead to the formation of a hemorrhagic polyp. Surgical removal of the polyps using microlaryngoscopy under general anesthesia is necessary to restore vocal function. Speech therapy before and after surgery is essential in eliminating patterns of vocal abuse to prevent polyp recurrence. Concomitant therapy for other inciting factors, such as allergies, GER, and inhalational irritants (e.g., smoking), should be initiated.

[edit] Vocal Cord Granulomas

Vocal cord granulomas, or contact ulcers of the larynx, result from misuse and abuse of the voice or mucosal injury from endotracheal intubation. Symptoms consist of hoarseness and pain with swallowing or phonation. The lesions may be unilateral or bilateral and usually form over the vocal process of the arytenoid cartilage. GER may predispose or contribute to the development of granuloma formation. Treatment for vocal cord granulomas is dictated by the underlying etiology. Granulomas from intubation trauma are readily managed by surgical excision. In contrast, surgical removal of granulomas due to vocal abuse or misuse often results in rapid recurrence. Therefore, as directed by a speech pathologist, voice therapy and voice rest are important. Additional treatment includes GER medication and antireflux precautions, such as elevating the head of the bed on blocks, avoiding alcoholic beverages and caffeinated products, and avoiding meals at least 2 hours before bedtime.

[edit] Vocal Cord Cysts

Vocal abuse may lead to the development of vocal cord cysts. These lesions are classified as either mucous retention cysts, caused by an occluded mucous gland duct, or epidermoid cysts containing keratin. The patient has a similar history and symptoms as the patient with vocal cord nodules. Epidermoid cysts are more common and are best managed with voice therapy. Patients with mucous retention cysts may also be treated with speech therapy, but in the absence of voice abuse, surgical removal by microlaryngoscopy typically results in improvement. Occasionally the cysts rupture spontaneously. Adjunctive measures such as adequate hydration, antireflux management, and smoking cessation are helpful in obtaining resolution.

[edit] NEUROMUSCULAR LARYNGEAL DYSFUNCTION

Alterations in the form and function of the vocal cords present as changes in voice or speech patterns. These changes may be caused by abnormalities of the intrinsic or extrinsic laryngeal musculature, neurologic dysfunction, or the aging process.

[edit] Vocal Cord Paralysis

Diseases affecting the vagus nerve or its laryngeal branches result in vocal cord paralysis and impaired laryngeal sensation. Although the exact incidence of vocal cord paralysis is unknown, unilateral vocal cord paralysis accounts for approximately 75% of all cases. The left vocal cord is more frequently affected, presumably because of its longer length and more circuitous route. The etiology of vocal cord paralysis can be divided into CNS lesions and peripheral lesions involving the vagus nerve (Box 181-2). Approximately 90% of the lesions are peripheral. In adults, neoplasm is the most common cause of unilateral vocal cord paralysis, followed by postsurgical, idiopathic, medical/inflammatory, traumatic, and central lesions.

The symptoms associated with vocal cord paralysis vary depending on the nerves involved. Hoarseness is probably the most common complaint, but stridor, shortness of breath, changes in vocal quality, cough, and aspiration may also be noted. Some cases may be asymptomatic. The goal in evaluating vocal cord paralysis is to identify the underlying cause. A detailed history should include pulmonary or thyroid neoplasms, previous neck or chest surgery, endotracheal intubation, neck trauma, systemic diseases, recent viral infection, and previous hoarseness. Physical examination requires complete laryngeal examination by flexible laryngoscopy to assess vocal cord function and position and to evaluate laryngeal sensation. Cranial nerve examination may reveal other cranial neuropathies associated with the underlying etiology. Imaging begins with a chest radiograph. CT scan or MRI of the brain, neck, and chest can demonstrate the entire length of the recurrent laryngeal nerves in patients with vocal cord paralysis of unknown origin. Direct laryngoscopy and bronchoscopy are useful to assess the mobility of the cricoarytenoid joints and to evaluate for occult neoplasm. Laboratory tests (e.g., thyroid function tests, erythrocyte sedimentation rate, complete blood count) are of relatively low yield given the previous approach.

The management of vocal cord paralysis consists of surgical and nonsurgical interventions, depending on the cause and degree of laryngeal dysfunction. Every attempt is made to identify and treat the underlying etiology. Patients with minimal changes in voice and no evidence of aspiration may benefit from speech therapy alone. This provides the patient with appropriate vocal techniques to avoid the sequelae associated with vocal abuse and misuse. In patients with more severe vocal dysfunction or signs and symptoms of aspiration, surgical intervention is usually warranted.

Bilateral vocal cord paralysis is uncommon and results in inability to abduct the vocal cords. The causative factors include CNS abnormalities (e.g., Arnold-Chiari malformation, hydrocephalus, meningomyelocele) and postsurgical injury (e.g., total thyroidectomy). Symptoms include severe stridor, cyanosis, and respiratory distress, with the need to secure the airway urgently by endotracheal intubation or tracheotomy. Because both vocal cords remain adducted, patients with bilateral vocal cord paralysis may have a normal or near-normal voice.

[edit] Spasmodic Dysphonia

Spasmodic dysphonia is a focal dystonia involving the laryngeal musculature. It is similar to other focal dystonias (e.g., blepharospasm, torticollis, writer's cramp) and may coexist with them. Spasmodic dysphonia occurs in adulthood, frequently after an upper respiratory tract infection or a period of emotional stress. Spasm of the laryngeal muscular adductors or abductors produces a strained or choked voice quality with abrupt breaks in phonation and a staccato-like pattern. The voice is decreased in loudness or hypophonic, and speech intelligibility often is poor. Accurate assessment involves evaluation by a speech pathologist with videostroboscopic examination. At rest the larynx appears normal, but during phonation, spasms of the true and false vocal cords are intermittently observed. In addition to speech therapy, treatment of spasmodic dysphonia may require percutaneous injection of botulinum toxin to eliminate muscle spasm. This is performed safely in the outpatient setting every 3 to 4 months.

[edit] Paradoxic Vocal Cord Motion

Paradoxic vocal cord motion (PVCM) is characterized by adduction of the vocal folds on inspiration and abduction on expiration. It typically occurs in young women and health care workers, often with a history of psychologic disorders. Presenting symptoms include inspiratory stridor, dyspnea, weak voice, and poor cough, which may be preceded by an upper respiratory tract infection. Patients with severe stridor from unrecognized PVCM occasionally undergo endotracheal intubation and tracheotomy. PVCM is a functional dyskinesia, and symptoms resolve with sleep but promptly return when the patient awakens. Diagnosis can only be made by visualization of vocal cord motion during an attack using indirect or flexible laryngoscopy. Routine laboratory studies, including an arterial blood gases, should be obtained to eliminate underlying organic etiologies for vocal cord dysfunction. The treatment for PVCM is mainly supportive, consisting of speech therapy and psychiatric counseling.

[edit] Presbyphonia

As part of the normal aging process, structural changes occur in the vocal cords and laryngeal musculature, including calcification of the laryngeal cartilage, loss of vocal cord elasticity, and decrease in muscle bulk. Presbyphonia is characterized by a breathy, weak, tremulous voice with alterations in pitch and early fatigability. Examination of the presbyphonic larynx typically reveals a posterior glottic gap, bowing of the vocal cords, and muscle atrophy. The physician must rule out any underlying medical problems that may be contributing to voice changes. Treatment strategies include voice therapy to eliminate vocal strain and maximize the functional capacity of the larynx. In addition, surgery to augment the thyroarytenoid muscles and vocal folds may be considered.

[edit] Parkinson's Disease

Patients with Parkinson's disease may develop vocal dysfunction secondary to bradykinesia and difficulty initiating voluntary muscle activity (see Chapter 169 ). The parkinsonian voice is characterized as breathy, hypophonic, tremulous, and of monotonous quality. The vocal folds are adynamic and bowed. Treatment is aimed at increasing vocal intensity and reducing vocal tremor through intensive speech therapy. Systemic treatment of Parkinson's disease with dopamine replacement for limb tremor may help to reduce vocal tremor as well.

[edit] Myasthenia Gravis

A disorder involving the neuromuscular junction, myasthenia gravis is characterized by weakness and fatigue of skeletal muscle. All age groups may be affected. The disorder typically presents with ocular involvement, including diplopia and ptosis of the eyelids. The voice may be altered by fatigue and weakness of the laryngeal muscles. Patients may note difficulty speaking and vocal fatigue, particularly with prolonged voice use. Vocal quality improves after a brief rest. Dysphagia and difficulty breathing may progress and require intubation and mechanical ventilation. Diagnosis of myasthenia gravis involves an anticholinesterase test and electrodiagnostic testing.

[edit] Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is caused by progressive degeneration of anterior horn cells in the spinal cord, resulting in wasting and weakness of skeletal muscle (see Chapter 170 ). Laryngeal involvement produces a raspy, monotonous voice, and involvement of the tongue may cause difficulty speaking. The gag reflex is depressed, and pooling of secretions in the hypopharynx and larynx may be observed. Aspiration of oral secretions occurs as the disease progresses. ALS is ultimately fatal primarily because of respiratory insufficiency and aspiration pneumonia. In the later stages, tracheotomy may be required to assist with ventilation, protection from aspiration, and pulmonary toilet.

[edit] LARYNGEAL TRAUMA

Endotracheal intubation is associated with a spectrum of injuries, ranging from mild mucosal inflammation to complete ulceration and necrosis of the underlying cartilage. The damage begins within hours of intubation; the degree of injury depends on duration and frequency of intubation, endotracheal tube size, presence of nasogastric tubes, and overall status of the patient. The cuff causes injuries in the subglottis, whereas the tube tends to damage the posterior glottis. Granulomata and ulcerations are common, and permanent sequelae may include stenosis and impaired vocal cord movement.

Blunt trauma is usually the result of motor vehicle injuries or “clothesline” injuries in which the unprotected neck is struck focally by a horizontal object. Strangulation causes a widespread but usually less severe laryngeal injury. The evaluation and management of laryngeal trauma varies with the mechanism of injury. Patients with signs and symptoms of acute airway compromise must have airway support in the form of endotracheal intubation or tracheotomy. The larynx is then examined endoscopically, with direct repair of fractured cartilage and mucosal injuries. Patients with a stable airway and mild symptoms (e.g., hoarseness) should undergo flexible laryngoscopy to identify hematomas or mild mucosal injuries. Airway obstruction in patients with relatively mild laryngeal trauma may be delayed up to 24 hours, and careful observation is required. Patients with intermediate injuries should undergo flexible laryngoscopy and CT scan of the larynx to identify cartilaginous injuries. Treatment is based on the specific injury.

Penetrating trauma from knives and projectiles may result from “urban warfare.” Exploration of the wounds and repair of the larynx and trachea are indicated.

[edit] Burns

Thermal injury to the larynx may occur even in the absence of significant pulmonary insult because of protective mechanisms resulting in glottic closure. Steam tends to deliver more thermal injury than heated air. Patients with carbonaceous sputum and erythema of the laryngeal mucosa benefit from early airway control with intubation rather than observing while edema and inflammation may progress.

Accidental or purposeful ingestion of caustic substances also results in esophageal and airway injuries. Patients with stridor after caustic ingestion should have the airway assured as quickly as possible, because the inflammatory process can progress rapidly.

[edit] RESPIRATORY FOREIGN BODIES

Aspiration of foreign bodies is a relatively common cause of respiratory symptoms in children and is associated with approximately 3000 deaths per year in the United States. Vegetable material (e.g. peanuts) and toy parts are the most common objects aspirated by children. Foreign body aspiration should be suspected in any patient who suddenly develops localized wheezing with diminished breath sounds and cough. Although a witnessed choking episode provides supporting evidence, such a history is not required.

Inspiratory and expiratory chest radiographs may demonstrate air trapping in cases of major airway obstruction. Both rigid and fiberoptic techniques are used for foreign body removal. Rigid endoscopy provides the advantage of controlled airway and ventilation. In skilled hands the risks of a missed foreign body exceed the risks of a negative endoscopic evaluation. Therefore it is reasonable to proceed to endoscopy if foreign body aspiration cannot be eliminated from the differential diagnosis of a persistently wheezing child.

[edit] LARYNGEAL NEOPLASIA

The larynx may be involved with a variety of benign and malignant neoplastic lesions (Box 181-3). Manifestations of laryngeal neoplasia may include hoarseness, dysphagia, odynophagia, and aspiration depending on the site and extent of involvement.

[edit] Recurrent Respiratory Papillomatosis

Recurrent respiratory papillomatosis (RRP) is the most common benign neoplastic process involving the larynx (Fig. 181-3). This disease is caused by infection with human papillomavirus (HPV), most often types 6 and 11. Affecting both children and adults, RRP is characterized by the recurrent growth of exophytic warty lesions. Patients usually present with hoarseness, stridor, and cough. Typically, children have a more aggressive course, with numerous recurrences. Treatment is primarily surgical, with repeated endoscopic excision and vaporization of the papillomatous growth. Medical therapy is typically reserved for severe cases; at present only interferon has been conclusively demonstrated to impact the pattern of the disease, and this effect ends with cessation of therapy. Other medical therapies have been used, and new protocols are currently under investigation. Currently, neither surgical nor medical therapies are curative.

Figure 181-3 Recurrent respiratory papillomatosis of the larynx.

[edit] Leukoplakia

Leukoplakia is a clinical term denoting a white patch or plaque on the mucous membrane of the larynx or other sites of the upper aerodigestive tract. The most common inciting agent for the development of leukoplakia of the larynx is cigarette smoking. These lesions may be asymptomatic or may present with hoarseness or voice changes depending on location and extent of laryngeal involvement. Leukoplakia may be isolated to the vocal cord or may involve the larynx diffusely. Histologically, keratinization of the mucosa with or without dysplastic epithelial changes is observed. Leukoplakia is not necessarily a premalignant lesion, but carcinoma may develop in up to 3% of these lesions. Because of the risk of malignant degeneration, especially in a patient with a history of tobacco and alcohol abuse, excisional biopsy is both diagnostic and therapeutic. Close follow-up with indirect or flexible laryngoscopy is important to observe for recurrence or progression of the lesion.

[edit] Laryngeal Cancer

Recent epidemiologic data indicate that the incidence of laryngeal cancer in the United States is about 11,100 new cases per year, with 4300 deaths. The most common type is squamous cell carcinoma, which accounts for more than 90% of all head and neck cancers. Laryngeal cancer has a male/female ratio of 5:1 to 10:1 and most often affects patients in the sixth to seventh decades of life. Major risk factors are tobacco and alcohol use. Ionizing radiation, viruses (e.g., HPV), occupational exposure (e.g., nickel), and GER are also implicated as risk factors.

The signs and symptoms of laryngeal cancer include hoarseness, stridor, dysphagia, odynophagia, hemoptysis, weight loss, and referred otalgia. Cancers arising from the true vocal cords present the earliest because of hoarseness, and a patient with hoarseness longer than 2 weeks should have careful inspection of the larynx to rule out a glottic carcinoma. In contrast, patients with supraglottic cancers tend to present with advanced disease because these lesions may grow to considerable size before becoming symptomatic. In addition to a patient history, accurate diagnosis requires a thorough head and neck examination with full visualization of the larynx, hypopharynx, oropharynx, and tongue base by indirect mirror examination or flexible endoscopy. The neck should be palpated for the presence of lymphadenopathy to assess for regional metastasis. Ultimately, direct laryngoscopy, bronchoscopy, and esophagoscopy with biopsies need to be performed to obtain a histologic diagnosis, document the extent of tumor involvement, and rule out synchronous primary lesions.

Treatment modalities for laryngeal cancer consist of surgery, radiation, and chemotherapy alone or in combination. Despite recent advances, no significant change in 5-year survival has occurred over the past 20 to 30 years. In general, for less extensive tumors, radiation alone is as effective as surgery. Larger or more extensive tumors typically require surgery with or without radiation therapy. Chemotherapy as a single-modality treatment is not very effective for laryngeal cancer. Multimodality therapy using induction chemotherapy with radiation therapy is currently in clinical trials and showing promising results. Chemoradiation holds the prospect of cure rates similar to surgery while preserving laryngeal function. Ultimately, treatment plans must be individualized by taking into account tumor stage and location, underlying medical problems, and socioeconomic factors.

[edit] EMERGENCY AIRWAY MANAGEMENT

Patients with disorders of the larynx or upper airway, such as acute epiglottitis, laryngeal cancer, or head and neck trauma, may present with severe upper airway obstruction and respiratory distress. Obtaining an adequate and secure airway is of paramount importance in the treatment of these patients. When routine orotracheal or nasotracheal intubation is unsuccessful or contraindicated, a surgical airway must be established. The preferred method for an emergent surgical airway is a cricothyroidotomy. This may be safely and rapidly performed by creating a vertical, midline incision through the cricothyroid membrane between the thyroid and cricoid cartilages and inserting an endotracheal or tracheostomy tube. The cricothyroidotomy site may be used for approximately 3 to 5 days, after which the site should be converted to a tracheotomy to avoid the risk of subglottic injury and stenosis.

An alternative to cricothyroidotomy is emergent tracheotomy. This procedure involves greater risks and is technically more difficult to perform in an emergency setting. Emergent tracheotomy should be performed only by those with sufficient surgical experience and expertise.

[edit] ADDITIONAL READINGS

• RW Bastian: Benign vocal cord fold mucosal disorders. Cummings CWet al.: Otolaryngology–head and neck surgery. St Louis: Mosby; 1998:
• JA Koufman: The otolaryngic manifestations of gastroesophageal refluz disease: a clinical study of 225 patients using ambulatory 24-hour pH monitoring and an experimental investigation of the role of acid and pepsin in the development of laryngeal injury. Laryngoscope 1991; 101 (suppl 53):
• JL Leach, SD Schaefer: Diagnosis and treatment of cancer of the glottis and subglottis : American Academy of Otolaryngology–Head and Neck Surgery; 1993:
• JB Snow: Surgical therapy for vocal dysfunction. Otolaryngol Clin North Am 1984; 17:91.
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