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Pediatric Upper Airway Obstruction and Infections
Key Concepts
Respiratory arrest precedes most pediatric cardiac arrests. Quick recognition of an airway problem and intervention in potentially life-threatening upper airway obstruction in children are critical.
Retropharyngeal Abscess
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This is a potentially life-threatening emergency in young children with signs of upper airway obstruction or meningismus; a retropharyngeal abscess is often related to oral trauma.
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Retropharyngeal abscess is most frequently caused by Staphylococcus aureus, group A streptococci, and anaerobes. Treatment is admission, IV antibiotics, and for more severe cases, surgical drainage.
Epiglottitis
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Epiglottitis may be caused by many bacteria or local injury. In the post– Haemophilus influenzae type b vaccine era, the incidence of pediatric epiglottitis has decreased, and epiglottitis is now more likely in older patients.
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Clinical features of epiglottitis are often subtle, such as in the older adolescent, (e.g., sore throat out of proportion to physical findings, anterior neck tenderness), but may also be dramatic, as in infants and young children (i.e., drooling, stridor, toxicity, severe respiratory distress).
Croup
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Viral croup is the most common infection of the upper airway in young children.
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Glucocorticoids (usually given as a single oral dose of dexamethasone) reduce symptoms, hospitalizations, and length of stay in the emergency department (ED).
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Treatment of moderate to severe croup includes vaporized epinephrine in addition to glucocorticoids. Patients can be discharged from the ED after a posttreatment observation period. We recommend discharge after a period of observation, if the child is free of resting stridor and distress and has access to follow-up care.
Bacterial Tracheitis
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Suspect bacterial tracheitis when an upper respiratory infection (URI) progresses to acute toxicity and marked respiratory distress and stridor. Standard treatment for croup may be tried, but usually does not significantly improve the patient’s symptoms. Antibiotic therapy should include a cephalosporin plus coverage for S. aureus , which is the most common cause of this infection.
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Bronchoscopy is diagnostic and therapeutic and should be emergently performed.
Airway Foreign Body
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Complete obstruction due to an airway foreign body requires emergent life support procedures for removal of the foreign body.
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Plain films may be negative in aspirated foreign bodies. Bronchoscopy should be performed with a clinical suspicion of aspiration.
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Emergency cricothyroidotomy may be required for obstructed patients who cannot be intubated or ventilated as a lifesaving temporizing measure; needle cricothyroidotomy is preferred for infants and young children because of the challenges in identifying landmarks and associated complications of surgical cricothyrotomy.
Foundations
Respiratory distress from upper airway obstruction is a rare but potentially a catastrophic emergency in young children. Causes include acute infectious processes, congenital anomalies, or a foreign body in the airway or esophagus. Children are predisposed to respiratory failure due to increased airway resistance (small, compressible airway), low functional residual capacity, high oxygen metabolism, which leads to quicker fatigue, and shorter safe apnea time, with precipitous hypoxia.
Clinical presentations of children with upper airway disease vary with cause, predisposing factors, and age at presentation:
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Acute infections of the upper airway range from relatively mild distress and self-limited signs and symptoms, to the abrupt onset of a rapidly progressive airway obstruction.
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Undiagnosed congenital anomalies of the airway and surrounding structures may be manifested as chronic or progressive stridor, or simply difficulty with feeding.
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An infant with a congenital airway anomaly in whom an acute airway infection develops is at higher risk for decompensation and respiratory failure.
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Upper airway obstruction from a foreign body in the airway or esophagus can cause partial or complete airway obstruction and may require urgent, advanced, airway management skills.
Clinical Features
Recent history and observation of the child typically provide clues to the cause of the airway obstruction. Important items to elucidate in the history include the following:
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Onset and duration (acute vs. chronic)
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Associated symptoms (e.g., respiratory distress, fever, toxicity, drooling, cyanosis, neck stiffness, or torticollis)
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Progression with age (number of bouts and severity of “croup” with increasing age)
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Exacerbating factors (supine vs. prone position, upper respiratory infection [URI], crying)
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Feeding abnormality or dysphagia
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Prior airway procedures, such as intubation in the neonatal period
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Choking episode indicating possible foreign body aspiration
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Baseline noises, quality of cry and voice to assist the emergency clinician in pinpointing the location of obstructive lesion
Initial observation can be quickly assessed utilizing the Pediatric Assessment Triangle (see Chapter 155 ). Observation and physical examination should include vital signs (respiratory rate, heart rate, oxygen saturation) and indicators of increased work of breathing (retractions, flaring, grunting, stridor, wheezing) to gauge the severity of distress. Observe the character and timing of stridor, as well as the symmetry and quality of breath sounds. Respiratory failure is identified by the presence of extreme distress: hypoventilation or hyperventilation; altered mental status; pale, mottled, or cyanotic skin color; or hypotonia. Stridor may not be present in respiratory failure due to the lack of airflow.
Stridor (from the Latin, stridulus, indicating creaking, whistling, or grating) is the classic sound associated with upper airway obstruction. Stridor is a harsh vibratory sound of variable pitch caused by partial airway obstruction or collapse and the resultant turbulent airflow through some portion of the airway, from the nose to the trachea. Stridor is described by timing in the respiratory cycle (inspiratory, expiratory, biphasic) and quality (coarse or high-pitched; Table 162.1 ). Inspiratory stridor is usually associated with obstruction above the glottis, expiratory stridor with intrathoracic obstruction, and biphasic stridor typically with a critical or fixed obstruction at any level. Stridor character differs by cause and anatomic location ( Fig. 162.1 ).
TABLE 162.1
Causes of Stridor: Anatomic Location, Sound, and Quality
| Features (Structures) | Supraglottic (Nose, Pharynx, Epiglottitis) | Glottic (Larynx, Vocal Cords) | Subglottic Trachea (Lower Trachea) |
|---|---|---|---|
| Sound | Sonorous (stertor) | Biphasic stridor | High-pitched stridor |
| Gurgling | Inspiratory stridor | ||
| Coarse | Expiratory stridor (if intrathoracic) | ||
| Expiratory stridor | |||
| Congenital | Micrognathia | Laryngomalacia | Subglottic stenosis |
| Pierre Robin syndrome | Vocal cord paralysis | Tracheomalacia | |
| Treacher-Collins syndrome | Laryngeal web | Tracheal stenosis | |
| Macroglossia | Laryngocele | Vascular ring | |
| Down syndrome | Hemangioma cyst | ||
| Storage diseases | |||
| Choanal atresia | |||
| Lingual thyroid | |||
| Thyroglossal cyst | |||
| Acquired | Adenopathy | Papillomas | Croup |
| Tonsillar hypertrophy | Foreign body | Bacterial tracheitis | |
| Foreign body | Subglottic stenosis | ||
| Pharyngeal abscess | Foreign body | ||
| Epiglottitis | |||
| Positional stridor | Micrognathia, macroglossia | Laryngomalacia |
Snoring or stertor is low-pitched inspiratory noise caused by nasal or nasopharyngeal obstruction. Stertor and stridor can coexist. Stridor from the pharynx, such as from a peritonsillar abscess (PTA), tends to have a sonorous, gurgling, and coarse quality. The voice may be altered and have a muffled or “hot potato” quality to it. High-pitched inspiratory stridor occurs in the supraglottic and immediate subglottic trachea, as in croup and laryngomalacia. The voice may sound hoarse or weak, but a normal voice may be heard, even with a laryngeal cause of stridor.
Biphasic stridor is heard with inspiration and expiration and usually suggests a fixed lesion. Examples include laryngeal webs and vocal cord paralysis. Stridor from the lower part of the trachea is usually expiratory, such as in bacterial tracheitis or aspirated foreign bodies ( Fig. 162.2 ).
Diagnostic Testing and Management
Definitive airway management takes precedence in an acute airway emergency. An individualized diagnostic evaluation can be undertaken in a less critical, stable patient with an uncertain diagnosis. Lateral and anteroposterior radiographs of the soft tissues of the neck may be helpful to assess the adenoid and tonsillar size, contour of the epiglottis, thickness of the retropharyngeal soft tissue space, vallecula, aryepiglottic folds, and tracheal air column ( Fig. 162.3 ). The child’s head should be positioned in extension and film taken during inspiration. However, plain radiographs are commonly misleading and may be normal, even with significant underlying pathology. Chest views assess the heart size, trachea and bronchi, location of the aortic arch, and presence of other pulmonary pathologic processes.
Additional studies may be indicated in specific settings. Bedside fiberoptic nasopharyngoscopy allows for the visualization and assessment of the supraglottic structures and vocal cords and can assist with intubation when indicated. Esophagography can define lesions compressing the airway and trachea; computed tomography (CT), magnetic resonance imaging (MRI), or bronchoscopy may be needed to evaluate the upper airway.
Specific Disorders
Supraglottic Airway Diseases
The supraglottic portion of the airway includes the nose, pharynx, epiglottis, and surrounding structures. Diseases of the nose and pharynx are commonly associated with noisy congested breathing and respiratory distress. Congenital lesions involving these structures may cause mild symptoms at baseline, but dramatic distress when there is a superimposed infectious process. Congenital lesions include choanal atresia, macroglossia, micrognathia, thyroglossal duct cyst, and lingular thyroid. Acquired causes of supraglottic disease include a nasal foreign body, nasal polyps, hypertrophic tonsils and adenoids, epiglottitis, retropharyngeal abscess (RPA), PTA, pharyngitis, mononucleosis, and upper airway foreign body. The most common conditions are discussed in the following sections.
Congenital Lesions
Choanal atresia
All infants are obligate nose breathers; they breathe nasally when the mouth is closed to allow breathing while feeding. In choanal atresia, the most common congenital anomaly of the nose, there is persistence of the bucconasal membrane or a bony septum in the posterior naris. The posterior aspect of the infant’s soft palate extends downward and contacts the tip of the epiglottis. Bilateral choanal atresia is a life-threatening emergency that is almost always identified early, as neonates become acutely distressed and cyanotic at birth. Immediate airway management is with oral airway and definitive surgical correction of the obstructing membrane. Unilateral choanal atresia is often initially undetected. Infants may present in respiratory distress with a URI when the normal patent naris is obstructed by swelling or secretions. Immediate nasal suction should be performed along with urgent referral for surgical repair.
Macroglossia
Macroglossia, an abnormally large tongue that protrudes posteriorly into the hypopharynx, is associated with conditions such as Down syndrome, glycogen storage disease, and congenital hypothyroidism. The increased secretions with a URI exacerbate underlying obstruction and may induce stridor or labored breathing. Good head positioning with nasal suctioning should be performed to relieve the obstruction.
Micrognathia
With micrognathia, an abnormally small mandible posteriorly displaces the normal-sized tongue (e.g., Pierre Robin and Treacher-Collins syndromes). Obstructive symptoms typically worsen when supine.
Pharyngitis
Infection is the most common cause of sore throat in children. Viruses cause the majority of infections. Certain viruses have characteristic features such as coxsackie A viruses that manifest as herpangina or hand, foot, and mouth disease. Herpes simplex more commonly causes stomatitis and less commonly may cause pharyngitis. Streptococcus pyogenes (Group A streptococcus) is the most common bacterial infectious etiology (see Chapter 19 ). Diphtheria can cause a thick exudative tonsillar membrane. Acetaminophen (15 mg/kg/dose q4h) or ibuprofen (10 mg/kg/dose q6h) is sufficient supportive treatment for most causes of pharyngitis.
Peritonsillar Abscess
PTA is the most common deep neck infection and usually occurs in older children and teenagers. Drooling and a muffled, hot potato voice is common, but severe respiratory distress is unusual. PTA is associated with trismus (in two out of three patients), bulging or asymmetry of the tonsils, and deviation of the uvula away from the abscess side (in 50% of patients). Throat pain may radiate to the ear. Treatment involves antibiotics and incision and drainage or needle aspiration. Antibiotics alone are insufficient management for an abscess but may resolve a phlegmon or cellulitis. Surgical intervention typically removes the majority of purulence, but additional antibiotics are recommended to clear the remaining infection.
PTAs are typically polymicrobial. Predominant bacterial species are S. pyogenes (group A streptococcus), Staphylococcus aureus (including Methicillin-resistant S. aureus [MRSA]), and respiratory anaerobes. Posterior pharynx ultrasonography can confirm the diagnosis and guide treatment. , A CT scan may be indicated if extension of infection is suspected. Any drainage effort should take great care to avoid puncture of the carotid artery (the carotid artery lies 25 mm posterolateral to the tonsillar pillar in children >12 years). Approximately 10% to 20% of patients have recurrent PTAs.
Mononucleosis
Infectious mononucleosis, caused by the Epstein-Barr virus (EBV), can lead to mucosal edema and an exudative pharyngitis. Uncommonly, massive tonsillar enlargement can occur and create upper airway distress. EBV IgM antibody is the preferred test for infective mononucleosis (>90% sensitive), particularly in children younger than 4 years who are less likely to generate heterophile antibodies with primary EBV infection. In older children and adults, the heterophile antibody can be detected in 50% of patients within the first week of illness and in 60% to 90% in weeks 2 and 3.
In addition to airway management and general supportive care, there may be additional benefits of steroids in reducing tonsillar edema and pain. Although steroids decrease pharyngitis symptoms, it is important to consider an underlying lymphoid malignancy. Children often present with sore throat prior to malignancy diagnosis. Treatment with glucocorticoids prior to the diagnosis of leukemia may delay leukemia diagnosis, increase the risk of tumor lysis syndrome, complicate risk stratification, and ultimately result in fatal complications. Therefore, great caution should be exercised in using glucocorticoids in children and adolescents and should be avoided in children younger than 14 years or in a child who has any signs of possible lymphoid malignancy such as lymphadenopathy, hepatosplenomegaly, rash, or abnormal complete blood count.
Retropharyngeal Abscess
A RPA is a potentially life-threatening airway emergency resulting from infection of the retropharyngeal soft tissue space. The retropharyngeal space is a potential space between the posterior pharyngeal wall and prevertebral fascia that extends from the base of the skull to the level of T2. It is rich in lymph tissue that drains the nose, pharynx, sinuses, and ears. An abscess may result from direct trauma from a fall with a hard object in the mouth that penetrates the soft tissue, suppuration of lymph nodes, contiguous spread of infection, or hematogenous seeding. RPA is usually a disease of young children because the lymphatic chains are prominent in the young and atrophy before puberty; RPA in older children often occurs after inciting trauma. These infections are commonly polymicrobial, with Streptococcus and anaerobes being the most commonly isolated organisms. MRSA is increasing in incidence and is commonly associated with severe infections such as jugular venous thrombosis or mediastinal extension.
Clinical features
Retropharyngeal infections typically progress from cellulitis to organized phlegmon to mature abscess. Presenting symptoms may vary. Common signs and symptoms include fever, sore throat, neck stiffness or nuchal rigidity, torticollis, trismus, neck swelling, drooling, stridor, and muffled voice. Stridor and respiratory distress may occur if a large abscess compresses the trachea; the clinical appearance can resemble that of epiglottitis. Reluctance to extend the neck and an unwillingness to look side to side is often seen with RPA and may help differentiate it from other supraglottic infections. With less obvious signs of airway obstruction, patients can exhibit a mixture of symptoms, including fever, neck stiffness, and generalized toxicity, which may suggest meningitis or sepsis. Other serious complications of a RPA include aspiration pneumonia, mediastinitis, and empyema.
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