Chapter 6. Respiratory Disorders

Clinical Features

Foreign body (FB) aspiration, though uncommon, accounts for 7% of deaths in children under 4 years of age. Most aspirated FBs become lodged in the bronchi because their size allows for passage through the larynx and glottis. Large FBs may become impacted in the larynx or trachea, potentially causing complete obstruction, a true emergency. Nuts and seeds are the most commonly aspirated objects. Beans and seeds absorb water and can swell in the airway over time. Organic FBs can cause a surrounding tissue reaction leading to severe inflammation; nuts and seeds release linolic acid, which can cause unilateral or bilateral wheezing.

Aspirated FBs can be difficult to diagnose as clinical symptoms may mimic asthma, recurrent pneumonia, or URI. Sudden choking and gagging with dyspnea are the first signs of aspiration. However, in up to 50% of cases, the choking episode is not witnessed. After the initial phase of choking and paroxysms of cough, children often enter into an asymptomatic phase that lasts for hours or even weeks as the FB becomes lodged. In cases of FBs of the larynx or trachea, children may present with hoarseness, stridor, and possibly cyanosis. Children with bronchial FB often present with a triad of cough, wheezing, and decreased breath sounds. However, only about two-thirds of children have all components of this triad. When these symptoms are prolonged or atypical, FB should be suspected. Unilateral decreased air entry on chest auscultation is only present in one-third of cases. Untreated, patients may enter into the third phase of the disease course, resulting in complications from atelectasis to pneumonia.

Most FBs are not radiopaque and small FBs may cause symptoms but no radiologic changes. Frontal view of chest may show air trapping secondary to obstructive emphysema. Bronchial FB results in obstruction during expiration, where air entry is possible during inspiration due to a partial obstruction (“ball-valve”) or can result in complete obstruction with poor pneumatization and atelectasis. The sensitivity of plain chest radiograph is increased when inspiratory and expiratory films are taken. Mediastinal shift to the opposite side on the expiratory phase is diagnostic. Patients who are not old enough to obtain inspiratory and expiratory films should have right and left lateral decubitus radiographies performed. The lung positioned in the dependent position will deflate under the weight of the heart unless it is obstructed. Fluoroscopy is also an option, if available, and may demonstrate air trapping or mediastinal shift. Computed tomographic scan of the chest may also be useful in detection of an FB but is not obtained initially unless the patient presents with complications or plain radiographs are nondiagnostic.

Emergency Department Treatment and Disposition

The criterion standard for the diagnosis and management of tracheobronchial FB is bronchoscopy and removal. Patients with suspected airway FB must have specialty evaluation early. Consult otolaryngology and pediatric pulmonary services. Children with laryngotracheal FBs may present in acute and severe airway obstruction. Attempt standard back blows or abdominal thrusts first and if unsuccessful in dislodging the FB, attempt laryngoscopy and removal. If the FB cannot be removed by direct laryngoscopy in the emergency department (ED), use intubation to advance the FB into a bronchus. Bronchial FBs rarely require emergent intervention. Give supportive care with oxygen or heliox and monitor closely, including continuous pulse oximetry. Give steroids to reduce airway inflammation as needed.

Pearls

1. Lack of witnessed choking episode and/or normal chest films are the most important factors contributing to delayed diagnosis.

2. The presence of an airway FB should be considered for all patients with new onset of noisy breathing or wheezing (especially in toddlers) or unexplained persistent or recurrent pulmonary findings (eg, pneumonia) regardless of the history of an aspiration event.

The authors acknowledge the special contributions of Binita R. Shah, MD, to prior edition.

Clinical Summary

Pertussis, or whooping cough, is infection of the respiratory tract by Bordetella pertussis, a gram-negative pleomorphic bacillus. Humans are the only known hosts and transmission is by respiratory droplets.

A viral prodrome and mild cough (catarrhal stage) is followed by a paroxysmal stage of progressive, repetitive, and severe episodes of coughing that lead to a forceful inspiration, producing the characteristic whoop. Symptoms take weeks to months to resolve (convalescent stage). Pertussis is most severe in the very young, presenting as gagging, gasping, or apnea without characteristic whoop. Complications among infants include bronchopneumonia, seizures, encephalopathy, cerebral anoxia, and sudden unexpected death. Submucosal bleeding, diaphragmatic rupture, umbilical and inguinal hernias, and rectal prolapse have been reported. Complications among adolescents include syncope, sleep disturbance, incontinence, rib fractures, and pneumonia. A number of other pathogens can cause pertussis-like symptoms (eg, adenoviruses, RSV, para influenza viruses, influenza viruses, mycoplasma). Leukocytosis with absolute lymphocytosis (total count >50,000 cells/mm) may be seen at the beginning of the paroxysmal stage. Chest radiograph may show perihilar, patchy, or diffuse infiltrates. Diagnosis is confirmed by culturing a nasopharyngeal sample on special media (Regan-Lowe; a negative culture does not exclude the diagnosis) or polymerase chain reaction assay using a nasopharyngeal sample for detection of B pertussis. In the absence of immunization within 2 years, an increasing titer or a single IgG anti-Pertussis toxin value 100 EU/mL or greater can be used for diagnosis.

Emergency Department Treatment and Disposition

Provide supportive care, including suctioning of secretions, humidified oxygen for hypoxia, and maintenance of adequate hydration and nutrition, and treat both the patient and his or her contacts with macrolide antibiotics (azithromycin, erythromycin, or clarithromycin). Use azithromycin in patients under a month old as there is an association between orally administered erythromycin and infantile hypertrophic pyloric stenosis. Trimethoprim-sulfamethoxazole is an alternative for patients more than 2 months old who cannot tolerate macrolides. Macrolides given as soon as possible to an exposed person (preferably during the incubation period) will prevent or modify the course of the disease. Pertussis vaccine (follow standard immunization schedule) should also be given to unimmunized or incompletely immunized exposed children who are under 7 years of age. Admit patients under 1 year of age and those with apnea or cyanosis during episodes, pneumonia, or respiratory distress. Initiate respiratory droplet precautions for 5 days after initiation of antibiotic therapy or until 3 weeks after the onset of paroxysms without antibiotic therapy.

Pearls

1. Pertussis is a life-threatening infection and is preventable by universal immunization.

2. Neither infection nor immunization provides lifelong immunity to pertussis.

Clinical Summary

Croup is an acute viral inflammation of the larynx and structures inferior to the larynx classically described as acute laryngotracheitis or laryngotracheobronchitis. A distinction is made from spasmodic croup, which is thought to have an allergic component and presents with noninflammatory edema in the subglottic region.

Croup affects children aged 6 months to 6 years and occurs in early fall and winter. Patients present with 1 to 3 days of upper respiratory tract symptoms and fever with progression to the characteristic barking cough, hoarseness, stridor, and respiratory distress. Tachypnea, retractions, hypoxia, and altered mental state are often ominous signs of worsening obstruction. The commonest etiologic agents include Para influenza viruses (two-thirds cases), respiratory syncytial virus (RSV), influenza viruses A and B, and adenovirus. Differential diagnosis includes epiglottitis, bacterial tracheitis, foreign body aspiration, retropharyngeal abscess (RPA), peritonsillar abscess, angioneurotic edema, congenital anomaly, mediastinal mass (eg, lymphoma), and diphtheria. Routine laboratory studies are not helpful. Plain radiographs of the neck are not routinely indicated and should be used only when diagnosis is unclear to exclude other conditions such as retropharyngeal abscess or foreign body aspiration.

Emergency Department Treatment and Disposition

Management of croup depends on the severity of upper airway obstruction. For mild to moderate croup, the treatment is oral or parenteral or nebulized steroids, including dexamethasone, prednisolone, or nebulized budesonide. For severe croup, nebulized racemic epinephrine should be given urgently as 2.25% solution diluted in 3 mL of normal saline given over 15 minutes. If racemic epinephrine is not available then nebulized l-epinephrine 1:1000 can be administered. Improvement of symptoms should occur within 10 to 30 minutes of administration. If after 2 hours of observation, there is no stridor or chest retractions and the child appears well, he or she may be discharged home. Hospitalize any child who does not improve after adrenaline administration. Intubate and admit patients with signs of respiratory failure who do not respond to racemic epinephrine and steroids. Helium oxygen mixture (Heliox) may be useful in the treatment of severe croup as it reduces work of breathing enough to prevent intubation and allow other medications to reach therapeutic peak. There is no evidence for the use of humidified or cold air, prophylactic antibiotics, or antitussive agents.

Pearls

1. Croup is the most common form of acute upper airway obstruction in infants and children.

2. Regardless of the level of illness acuity, corticosteroid therapy (dexamethasone either orally or intramuscularly) is now the standard of care.

3. Drooling, dysphagia, high fever, and toxic appearance are notably absent in viral croup suggesting another diagnosis.

Clinical Summary

Bacterial tracheitis is a potentially fatal acute infectious upper airway obstruction, occurring in children of age 3 months to 5 years, predominantly in fall and winter. A prodrome of coryza, sore throat, cough, and pyrexia of 1 to 3 days is followed by acute onset of stridor and rapidly worsening respiratory distress, which can lead to airway obstruction and respiratory arrest. Patients with bacterial tracheitis are toxic appearing and show little response to inhaled steroids or adrenaline. Visualization of the airways reveals subglottic inflammation, edema of the tracheal mucosa, and copious purulent endotracheal secretions. Staphylococcus aureus is the most common bacterial pathogen followed by Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae nontypeable, Moraxella catarrhalis, and Pseudomonas aeruginosa. Viral coinfection is common with Influenza A, Parainfluenza, RSV, and adenovirus. Differential includes viral croup, epiglottitis, foreign body aspiration, and retropharyngeal abscess. Complications include cardiorespiratory arrest, acute respiratory distress syndrome, hypotension, toxic shock syndrome, renal failure, pneumothorax, pulmonary edema, and subglottic stenosis. White blood cell count is usually elevated or abnormally low. Chest and lateral neck radiographs show subglottic narrowing on posterior-anterior view, a hazy tracheal air column and irregular soft-tissue densities in trachea (indicating purulent exudate), pneumonia, and pulmonary edema.

Emergency Department Treatment and Disposition

Adequate airway protection with intubation is the single most important therapeutic intervention. Obtain tracheal bacterial cultures at intubation and send secretions for direct immunofluorescent identification of viral agents. Treat hypotension aggressively with normal saline fluid boluses and inotropic support. Begin empirical therapy with anti-staphylococcal agent (eg, vancomycin) and a third-generation cephalosporin (eg, ceftriaxone or cefotaxime). Admit all intubated patients to the intensive care unit (ICU). With appropriate antimicrobials and aggressive supportive care, rapid improvement and extubation within 72 to 96 hours is possible.

Pearls

1. The clinical hallmark of bacterial tracheitis is toxic appearance and worsening stridor 1 to 3 days after a viral prodrome.

2. In contrast to viral croup, patients with bacterial tracheitis show little response to inhaled steroids or adrenaline.

3. Visualization of airway shows presence of purulent tracheal secretion.

Clinical Summary

Epiglottitis is an acute life-threatening inflammation of supraglottic structures involving the epiglottis, aryepiglottic folds (false vocal cords), arytenoids, and vallecula. It is usually seen in children aged 2 to 7 years and has become rare since the introduction of H influenzae type b (Hib) conjugate vaccines in 1991. The most common organisms include S pyogenes, S aureus, S pneumoniae, Moraxella, and Candida species. H influenzae type b is still seen in nonimmunized children. Non infectious causes include direct trauma and thermal injuries (eg, scalding burns of face, drinking hot liquids). Symptoms occur with rapid progression and include fever, irritability, and toxic appearance, difficulty swallowing, and drooling. Croupy cough is absent and stridor is a late finding. The child usually sits upright with the chin pushed forward (tripod position) to open the airway. Gentle visualization of the oropharynx without the use of a tongue depressor may reveal an erythematous epiglottis protruding at the base of the tongue. Use radiographs when the diagnosis of epiglottitis is unlikely and to exclude retropharyngeal abscess and foreign bodies. Lateral neck radiograph is the image of choice, and the classic finding of epiglottitis is the “thumbprint sign.” Contrasted CT scan of the neck may also indicate the presence of epiglottic edema and possibly phlegmon or abscess in the epiglottis or the base of tongue.

Emergency Department Treatment and Disposition

Assemble a multidisciplinary team including pediatric intensive care, anesthesiology, and otolaryngology. Bring the patient to the operating room emergently to confirm diagnosis by direct visualization. Edema with intense erythema of epiglottis (often described as cherry-red appearance) and surrounding structures including arytenoids and aryepiglottic folds and vocal cords are seen. Perform intubation or tracheostomy as needed. Admit the patient to the ICU for continuous monitoring. Postpone diagnostic tests and placement of IV lines until the airway is secure. Obtain CBC with differential and cultures of the blood and epiglottal surface for precise microbiologic diagnosis. Treat empirically with a second- or third-generation cephalosporin or ampicillin/sulbactam. Children usually require intubation for 24 to 72 hours, until reduction in airway edema occurs.

Pearls

1. Do not force the patient to lie in a supine position as a gravity-induced change in the position of the epiglottis may lead to total obstruction.

2. Do not use a tongue blade to examine the pharynx as it may induce life-threatening laryngospasm.

3. Confirm epiglottitis with direct visualization rather than radiography as patients may develop life-threatening laryngospasm when attempting to hyperextend the neck for the radiograph.

Clinical Summary

Bronchiolitis is defined as a constellation of clinical symptoms and signs including a viral upper respiratory prodrome followed by increased respiratory effort and wheezing. It occurs in children under 2 years old, primarily between late fall and spring. RSV account for 50% to 80% of cases followed by para influenza viruses, influenza, and human metapneumovirus. An upper respiratory tract infection (URI) prodrome is followed by cough, tachypnea, tachycardia, grunting, flaring, supraclavicular and intercostal retractions, and head bobbing. Nonspecific symptoms include poor feeding and irritability. Examination may reveal chest hyperinflation with costal retraction, and fine inspiratory crackles and expiratory wheeze on auscultation. Hypoxemia is primarily due to ventilation/perfusion mismatch, and hypercapnia is a late phenomenon. Progression to respiratory failure may occur. Factors associated with severe disease include age <3 months, gestational age <34 weeks, toxic appearance, respiratory rate >70 breaths per minute, chronic lung disease, congenital cardiac abnormalities, neuromuscular disease, or immune deficiencies. Differential diagnosis includes pneumonia, laryngotracheomalacia, foreign body, gastroesophageal reflux, congestive heart failure, vascular ring, cystic fibrosis, mediastinal mass, bronchogenic cyst, and tracheoesophageal fistula.

Emergency Department Treatment and Disposition

Measure O2 saturation because a pulse oximetry level of <94% is associated with a more than 5-fold increase in likelihood of hospitalization. Chest radiograph is not recommended routinely and classically shows hyperinflation. Rapid viral antigen tests, in outpatient cases, have little impact on management (in hospital setting, it is used to reduce nosocomial infection). In a neonate with a fever, a positive RSV test may be all that is needed as concomitant bacterial infection is rare (0.2%).

Provide supportive therapy including O2 therapy and fluid replacement. Admit to the hospital or ICU if warranted by age, prematurity, chronic lung disease, or significant cardiac disease. There is no proven pharmacologic treatment. Do not routinely use α- or β-agonists, ipratropium bromide, inhaled or systemic corticosteroids, ribavirin, antileukotriene antagonists, and antibiotics. A trial of albuterol may be given and should be continued only after a documented beneficial response. Epinephrine may provide short-term benefits in the outpatient setting. Use antibiotics only in neonates with fever and suspected bronchiolitis pending cultures or if chest radiograph demonstrates pneumonia or superinfection. Nebulized hypertonic saline has been associated with improvement in clinical score and duration of hospitalization.

Consider using ribavirin if there is documented RSV bronchiolitis with severe disease or in immunocompromised and/or hemodynamically compromised patients. Intravenous RSV immune globulin is ineffective in the acute treatment of RSV lower respiratory tract infection.

Pearls

1. Bronchiolitis is the most common wheezing-associated respiratory illness in infants <2 years of age.

2. Apnea may be the presenting manifestation of RSV bronchiolitis in the neonate.

3. Preventive strategies such as RSV immunoglobulin or the anti-RSV monoclonal antibody, palivizumab, can decrease disease severity and need for hospitalization.

Clinical Summary

Pneumonia is an infection of the lung parenchyma, and 10% to 40% of cases are bacterial in origin. Bacterial pneumonia occurs throughout the year with no seasonal peaks.

Group B Streptococcus and gram-negative bacilli are common neonatal bacterial pathogens. Chlamydia trachomatis is seen at about 6 weeks of age, presenting with tachypnea, staccato cough, and absence of fever. S pneumoniae is the most common pathogen followed by S aureus and Group A streptococcus beyond 3 months of age. Community-acquired multiresistant S aureus resulting in a necrotizing fulminant pneumonia has emerged. Chlamydophila pneumoniae infections occasionally are seen in preschool-age children and once children reach school age, Mycoplasma pneumoniae becomes an important pathogen. Symptoms of fever and cough or difficulty breathing are hallmarks; tachypnea (breathing >50/min for infants aged 2 months up to 1 year; breathing >40/min for children aged 1 to 5 years) is the most sensitive and specific sign. Severity is based on presence of retractions, grunting, hypoxia, inability to drink, vomiting, or altered mental status. Lung examination demonstrates dullness to percussion, crackles, decreased breath sounds, and bronchial breathing. Diagnosis is suspected clinically and confirmed by chest radiograph. However, clinical findings may precede radiologic evidence; thus, a negative chest radiograph does not exclude pneumonia (eg, sickle cell disease with acute chest syndrome). Outpatient management requires no laboratory evaluation. In admitted patients, CBC, electrolytes, and blood culture are usually obtained. Perform tuberculin skin testing especially in areas with a high incidence of tuberculosis. In patients with empyema, pleural fluid typically reveals an exudate with polymorphonuclear cells, elevated protein, and a low glucose concentration; Gram stain and cultures will identify the pathogen. A chest tube drain or VATS (video-assisted thoracoscopic surgery) is usually required if pleural fluid is exudative (empyema).

Emergency Department Treatment and Disposition

Admit patients who are in respiratory distress with or without hypoxia, have a toxic appearance, are age <3 months, are immunocompromised, are not able to maintain adequate hydration, or have pneumonia with pleural effusion/empyema. Administer oxygen, IV fluids, and antibiotics.

Choice of antibiotics depends on the organism suspected. Treat neonates with ampicillin and cefotaxime. A macrolide will cover C trachomatis pneumonitis (first 3 months of life). For older infants and children, give ceftriaxone or ampicillin to cover pneumococcus. If Staphylococcus is a concern (including methicillin-resistant S aureus), give clindamycin or vancomycin. Give ampicillin-sulbactam or clindamycin to children with aspiration pneumonia. In some patients, for example, SCD with pneumonitis, therapy with 2 agents may be necessary (macrolide combined with a third-generation cephalosporin). If the initial response to IV antibiotics is good, institute oral treatment to complete a 10- to 14-day course.

Children not requiring hospitalization can be treated as outpatients. The first-line agent is high dose amoxicillin. A dose of ceftriaxone may be given parenterally on day 1 to achieve rapidly effective serum concentrations. For children who have non–type 1 allergy to amoxicillin, a cephalosporin (eg, cefdinir or cefpodoxime) may be used. For those with a history of type 1 reactions, a macrolide may be chosen. Use macrolide antibiotics (eg, azithromycin or clarithromycin) in older children for clinically suspected M pneumoniae. If the child’s condition deteriorates or does not improve in 2 or 3 days, consider other pathogens, and obtain a chest radiograph to exclude parapneumonic effusion or empyema. For children who improve with treatment, a repeat chest radiograph is not recommended.

Pearls

1. The sine qua non of infectious pneumonia is fever and tachypnea.

2. Most children with cough, runny nose, and fever without the presence of “fast breathing” do not need antibiotics.

3. Lower lobe pneumonia can present with signs of paralytic ileus and/or referred pain to the right lower quadrant (with right lower lobe pneumonia), mimicking acute abdomen.

Clinical Summary

Pneumonia is an infection of the lung parenchyma, most commonly caused by viruses in patients 3 months to 5 years of age. Incidence peaks in cold months, and transmission includes droplet spread of respiratory pathogens directly or indirectly by fomites. RSV and parainfluenza viruses predominate. Other agents include human metapneumovirus, bocavirus, rhinovirus, influenza, and adenovirus. Signs and symptoms include a well-appearing infant or child with low-grade fever, a viral prodrome including sore throat, nasal congestion, rhinitis, prominent cough, and mild respiratory distress. Wheezing and/or diffuse crackles or rhonchi are typical auscultatory findings. Presence of fever of ≥39°C, retractions, and grunting may suggest a complicated pneumonia or bacterial coinfection. Specimens for viral culture and rapid antigen identification can be used to detect the viruses in nasopharyngeal secretions obtained by swab, aspirate, or wash. CBC and chemistry are not required. Afebrile children normally do not require chest radiography. Those who are ill appearing or highly febrile may benefit with both a blood culture and chest radiograph, for detection of a complicated pneumonia.

Emergency Department Treatment and Disposition

Management of viral pneumonitis is supportive and includes monitoring for cardiac and oxygen status, providing humidified O2 if indicated, maintaining good hydration, and bronchodilator therapy if indicated. Infants and young children who are only mildly ill and afebrile do not need antibiotics. Admit those who are unable to tolerate oral fluids, dehydrated, have moderate to severe tachypnea or oxygen saturation of <94%. Evaluate ill-appearing children or have severe influenza for possible bacterial coinfection and potential need for antimicrobial therapy. Use antiviral medications, oseltamivir or zanamivir, for treatment of influenza A and B. Most patients with viral pneumonia recover uneventfully without any sequelae. Rare complications include chronic lung disease leading to bronchiolitis obliterans (eg, adenoviral infection).

Respiratory tract secretions are infectious and good hand hygiene is important. Because viral infections usually are either the direct cause of pneumonia or predispose children to infection with bacterial or atypical pathogens, immunization against influenza is particularly helpful.

Pearls

1. Respiratory viruses are the most common etiology of pneumonia in the first few years of life.

2. Children with severe influenza should be evaluated carefully for possible coinfection with bacterial pathogens and may require antimicrobial therapy.

3. Children and adolescents with influenza should not receive aspirin or any salicylate-containing products because of the resulting increased risk of developing Reye syndrome.

Clinical Summary

Tuberculosis (TB) is infection caused by Mycobacterium tuberculosis (MTB) and may be latent or active. Latent tuberculosis infection (LTBI) is a positive tuberculin skin test (TST) without physical findings of disease, and a chest radiograph that is either normal or shows granulomas or calcification in the lungs and/or regional lymph nodes. Active MTB is the presence of clinical and/or radiographic findings consistent with active pulmonary and/or extrapulmonary MTB disease. Active MTB may cause fever, weight loss, and night sweats.

Clinical manifestations of pulmonary TB (PTB) may include cough, localized wheezing (endobronchial involvement), hemoptysis (cavitary lesions), ausculatory findings consistent with consolidation or atelectasis, or dullness to percussion with pleuritic chest pain (pleural effusion). However, many children with PTB and intrathoracic adenopathy and/or infiltrates will be asymptomatic. Extrapulmonary manifestations are more common in children younger than age 3 years and may include meningitis, osteomyelitis (Pott’s disease of the spine; see Figure 19-91), TB arthritis, infection of the middle ear, and mastoiditis. Infants and toddlers may also have miliary tuberculosis with dissemination involving lungs, central nervous system (CNS), liver, spleen, and kidneys. The differential diagnosis of PTB includes acute pneumonia, intrathoracic adenopathy from another etiology (eg, lymphoma, sarcoidosis), parapneumonic effusion from another etiology (bacterial, viral, autoimmune), foreign body aspiration, and infection with nontuberculous Mycobacteria.

After initial infection, TST may become positive in 2 to 12 weeks; however, in some cases, the TST may remain negative (eg, malnutrition, HIV infection, immunosuppression, lymphoma). A Mantoux test containing 5 tuberculin units of purified protein derivative (5 TU PPD) is used for the TST. Blood-based tests such as the QuantiFERON-TB Gold, an interferon gamma release assay, are more reliable but not as readily available. Chest radiograph is recommended for all children with a positive TST. Radiographic findings may include none (LTBI), intrathoracic lymphadenopathy, infiltrate(s) and/or atelectasis, pleural effusion, miliary disease, cavitary lesion(s), or residual calcification of the primary focus with local lymphadenopathy. Isolation of MTB by culture of sputum, gastric aspirate, pleural fluid, or intrathoracic lymph node biopsy is confirmatory for PTB. With associated extrathoracic disease, isolation of MTB from other culture sites (CSF, bone, joints, or lymph nodes) is also diagnostic.

Emergency Department Treatment and Disposition

Admit all patients with active MTB for collection of appropriate diagnostic specimens, initiation of anti-TB drugs (usually isoniazid, rifampin, and pyrazinamide with addition of ethambutol if drug resistance is suspected), investigation of the source case(s), and any further diagnostic workup (eg, bronchoscopy, CT scan, lumbar puncture). Sputum is helpful in patients with cavitary disease; however, pediatric patients are often sputum acid-fast bacillus (AFB) negative and gastric aspirates are more helpful. Respiratory isolation is required for children with cavitary disease, possible laryngeal involvement, immunosuppression, or an AFB positive smear from a pulmonary source. Children younger than 12 years of age with primary pulmonary TB (noncavitary pulmonary lesions, absent or minimal cough with no sputum production and no expectoration of bacilli) are not contagious and do not require respiratory isolation. Patients with LTBI do not need hospitalization; begin INH therapy and refer patient to their PCP for ongoing follow-up. Notify the local public health agency especially if the child has a recent exposure to a known case of PTB (in many hospitals, the infection control department can assist with this process).

Pearls

1. Diagnosis of active or latent TB infection in children indicates recent transmission in the community and mandates a thorough health department investigation to find the source.

2. Children usually have paucibacillary pulmonary disease but develop extrapulmonary disease more frequently than adults, especially children aged <3 years.

3. Reactivation TB or adult-type TB (ie, cavitary disease) is quite rare in children (less than 6% of cases in children aged <13 years) but can occasionally occur in adolescents.

4. Localized wheezing and collapse/consolidation findings seen on radiograph in endobronchial TB are similar to those seen in foreign body aspiration.

5. Although most young children with PTB are not contagious, the source case is often a parent. Rapid screening of all close household contacts, especially adolescents and adults, is essential. Send parents for chest radiograph immediately to prevent the potential risk of exposing the pediatric ER/ward to a case of active TB.

Clinical Summary

Miliary tuberculosis (TB) results from widespread hematogenous dissemination of MTB and is characterized by a high load of TB bacilli. It can be fatal if misdiagnosed. Risk factors include age (<5 and >65 years), poor nutritional status, and immunocompromise.

The term miliary refers to numerous small, scattered pulmonary nodules (usually 1 to 2 mm in size) resembling millet seeds seen on chest radiograph; this pattern of scattered nodules can also be seen in other affected organs including spleen, liver, and brain. Approximately 25% of patients have CNS involvement, and this commonly occurs in children <5 years of age. Children may present with nonspecific symptoms including fever, weight loss, weakness/lethargy, nausea, poor appetite, headache, cough, and myalgia. Generalized lymphadenopathy, hepatosplenomegaly, adrenal insufficiency, and meningeal and/or focal neurologic signs may be present. Some patients may present with fulminant disease manifested by multiorgan failure, septic shock, and ARDS. Differential diagnosis includes pyogenic bacterial infection (eg, S aureus, Haemophilus influenzae), endemic fungal infection (eg, histoplasmosis, blastomycosis), Histiocytosis X, sarcoidosis, pneumoconiosis, hypersensitivity pneumonitis, lymphoma, and lymphangitic spread of malignancy (such as hepatoblastoma).

Emergency Department Treatment and Disposition

Perform a tuberculin skin test in all suspected cases, noting that a negative TST does not exclude the diagnosis. Blood-based tests such as QuantiFERON-TB Gold can also be used but are not as readily available as the TST. Obtain a chest radiograph, which may show the classic miliary pattern, as well as other findings of pulmonary TB (lymphadenopathy, pleural effusion, infiltrates, cavities). Use high-resolution chest CT scanning when a chest radiograph is inconclusive as this is very sensitive and specific and may detect nodules. Obtain a head CT with contrast and/or magnetic resonance imaging (MRI) of the brain to exclude CNS involvement. Use abdominal sonography to detect diffuse liver disease, hepatosplenomegaly, or para-aortic adenopathy and echocardiography to test for pericardial involvement and effusion. Obtain cultures from any site (eg, sputum, gastric aspirate, urine, blood, lymph node, CSF, other body fluids) for diagnosis and sensitivity testing.

All patients with suspected miliary TB require pulmonary consultation and hospitalization. Early treatment greatly reduces mortality and improves long-term outcome. Stabilize patients presenting with septic shock and/or ARDS and manage accordingly. Initiate antituberculous therapy even if all diagnostic specimens have not yet been collected. Notify the hospital infection control department and local health department immediately as a TB-infected child represents recent transmission in the community.

Pearls

1. Miliary TB may cause disturbed regulation of antidiuretic hormone and present with hyponatremia (most common electrolyte disturbance). Less commonly, hypercalcemia may be present (like other granulomatous diseases).

2. Untreated, miliary TB is almost always fatal, and most deaths occur within the first 2 weeks in hospitalized patients. Early treatment of suspected cases is essential.

3. Patients with major CNS involvement may have very mild or nonspecific findings. Post-contrast head CT and/or MRI followed by lumbar puncture (without evidence of mass lesion or hydrocephalus on imaging) should be routinely performed.

Clinical Summary

Obstructive sleep apnea syndrome (OSAS) is disordered breathing during sleep characterized by intermittent complete airway obstruction and/or prolonged partial obstruction. OSAS disrupts normal ventilation during sleep and normal sleep patterns. Predisposing conditions for OSAS include adenotonsillar hyperplasia (most common cause), obesity, and genetic syndromes with associated craniofacial anomalies such as Pierre-Robin syndrome and Down syndrome. Peak incidence occurs in preschool-aged children between 2 and 6 years when the tonsils and adenoids are largest in relation to airway size. Nasal polyps (from severe allergic rhinitis or cystic fibrosis), nasal septal deviation, and choanal stenosis are less common causes of OSAS. Once a history of nightly snoring or worsening of snoring with URI is elicited, a more detailed history needs to be obtained. Inquire about repeated URIs and/or recurrent otitis media, labored breathing during sleep, observed apnea episodes described as snoring followed by “choking” or “gasping,” restless sleep, enuresis, behavioral issues, school performance, daytime somnolence or fatigue, and morning headaches. Physical examination while awake may be normal or reveal findings related to adenotonsillar hypertrophy such as adenoidal facies, mouth breathing, enlarged tonsils, nasal obstruction during wakefulness, and hyponasal speech. Children may show failure to thrive (inadequate caloric intake during the day and hypermetabolic state at night) or obesity. In longstanding OSAS, pectus excavatum, systemic hypertension, pulmonary hypertension and cor pulmonale with pulmonary edema (severe cases) may be seen. The main differential diagnosis for OSAS is primary snoring, which is a clinically benign condition (seen in 7%–10% of children) and represents snoring without obstructions, disrupted sleep, or gas exchange abnormalities. Primary snoring is usually exacerbated by URI but does not lead to obstructive apnea.

Emergency Department Treatment and Disposition

Admit any patient presenting with cardiorespiratory failure or worsening of airway obstruction (eg, during URI) to the ICU for continuous cardiac and pulse oximetry monitoring. Use a nasopharyngeal airway to bypass the obstruction, or continuous positive airway pressure (CPAP) therapy to establish a temporary airway until a more definitive procedure such as an adenoidectomy and/or tonsillectomy can be performed. A short course of oral or parenteral corticosteroids can be given to reduce nasopharyngeal lymphoid tissue that may worsen OSAS (eg, in patients with infectious mononucleosis). Refer patients not requiring hospitalization to their PCP to arrange for a polysomnogram.

Pearls

1. OSAS is a becoming more common in childhood as rates of childhood obesity increase.

2. The 2 most common presenting symptoms of OSAS are snoring and sleep disturbances; however, many children will have behavioral manifestations. Ask parents about sleep-disordered breathing in any child with poor school performance or behavioral problems.

3. A child with suspected OSAS must be examined during sleep including observation of pulse oximetry readings as physical signs of obstruction may be absent or subtle when the child is awake.

4. Children with OSAS may have an impaired swallowing mechanism or gastroesophageal reflux disease. Both of these entities can lead to aspiration, especially in neurologically impaired children who are also at a higher risk for OSAS.

Clinical Features

Asthma is reversible airway hyperresponsiveness to external stimuli (eg, viral infections, allergens, tobacco smoke, pollutants, strong odors, emotions, exercise) resulting in bronchial inflammation, edema, excess mucous production and bronchoconstriction of airway smooth muscle. This leads to airflow limitation, prolonged expiration, air trapping, and hyperinflation. Wheezing (result of airflow limitation) is the characteristic physical finding of high-pitched, polyphonic “whistling” sounds noted during an acute attack of asthma. Acute asthma is one of the most common entities treated in the pediatric ED. Asthma exacerbations are acute or subacute episodes of progressively worsening shortness of breath, cough, wheezing, and chest tightness, or some combination of these symptoms. Status asthmaticus occurs when a child continues to have significant respiratory distress and wheezing despite adequate treatment of the acute attack with appropriate bronchodilators. The differential for asthma includes any entity that can cause large airway obstruction (eg, foreign body aspiration, tracheomalacia, bronchomalacia, endobronchial masses, extrabronchial obstruction from an extrabronchial mass or vascular ring/sling, subglottic stenosis, vocal cord dysfunction) or small airway obstruction (eg, acute viral bronchiolitis, bronchopulmonary dysplasia, chronic aspiration).

Emergency Department Treatment and Disposition

First, quickly assess the severity of the current exacerbation with physical exam and a brief focused history including medications used at home especially bronchodilators, past history of hospitalizations, intubation, and known asthma triggers. Next determine possible cause(s) of the current exacerbation, and obtain a history of any known allergies. The physical exam should include evaluation of mental status, respiratory rate and effort, heart rate, blood pressure (including assessment for pulsus paradoxus in severe exacerbations), oxygen saturation, lung auscultation (focusing on severity and location of wheezing), and use of accessory muscles. In children older than 6 years, obtain peak expiratory flow with a peak flow meter. This value can help to provide an objective measurement of the degree of expiratory flow impairment. Order diagnostic tests as indicated (eg, ABG, chest radiograph, CBC, serum electrolytes).

Provide supplemental oxygen to maintain O2 saturation at or above 95%, and give inhaled short-acting beta agonists (SABA) in the form of albuterol (by nebulizer or metered dose inhaler and valved holding chamber) for 3 doses 20 minutes apart in the first hour of ED management. Administer systemic corticosteroids (oral or IV depending on the child’s overall clinical status). If the exacerbation is severe, add inhaled ipratropium bromide to the initial doses of SABA. In life-threatening attacks, use adjunct treatments such as IV magnesium sulfate, continuous nebulized albuterol, and IV or subcutaneous terbutaline to avoid intubation if possible.

Discharge children with mild to moderate attacks who have good response to ED management (ie, no respiratory distress, normal physical exam, response is sustained >60 minutes after last SABA, oxygen saturation is ≥95%, and peak expiratory flow [PEF] is ≥70%). Provide inhaled SABA, a short course of oral corticosteroids, and close medical follow-up. Admit patients with residual mild to moderate symptoms despite adequate ED management (ie, mild to moderate wheeze and distress, oxygen saturation <95%, and PEF 40% to 69%) to the pediatric ward for continued management. Admit those with severe symptoms, PCO2 >42 mm Hg, or intubation in the ED to the ICU. All medication dosages as well as detailed ED treatment strategies are contained in the “Summary Report of the Expert Panel 3 Guidelines for the Diagnosis and Management of Asthma” (pages 53 to 58). It is strongly recommended to download this document from the following link: www.nhlbi.nih.gov/guidelines/asthma.

Pearls

1. Chronic severity classification of asthma (intermittent, mild persistent, moderate persistent, or severe persistent) does not predict the severity of an individual exacerbation as intermittent asthmatics can have fatal exacerbations.

2. Infants and young children are more at risk because of their smaller airways, limited lung elasticity, limited collateral channels of ventilation, softer rib cage, and tendency of respiratory muscles for easy fatigability.

3. Current guidelines do not advocate methylxanthines, aggressive hydration, chest physiotherapy or mucolytics for status asthmaticus. However, adequate hydration is required when using IV magnesium sulfate as dehydration can potentiate adverse drug effects such as hypotension and hypotonia.

4. Do not forget to consider aspirated foreign bodies just because your patient has asthma. Consider this possibility in any asthmatic child who is not responding to therapy and note that in such cases, chest radiograph can be misleading as many asthmatics have atelectasis or asymmetric hyperinflation due to mucous plugging.

5. Monitor serum potassium as frequent dosing of albuterol can lead to hypokalemia.

Clinical Summary

Pneumothorax is the presence of air or gas between the visceral and parietal pleura and occurs when air enters the pleural space through the chest wall in penetrating trauma or across the lung parenchyma via the visceral pleura. Pneumothoraces may occur in diseased lung (secondary spontaneous pneumothorax), as a result of medical interventions (iatrogenic), or without any prior lung pathology or trauma (primary spontaneous pneumothorax [PSP]).

PSP is most commonly seen in adolescent males and is usually caused by rupture of asymptomatic blebs or bullae that were not clinically evident until they resulted in PSP. Although Valsalva maneuvers and increased intrathoracic pressures are described as triggering factors, PSP most commonly occurs at rest. Additional risk factors include a tall, lanky body habitus, smoking, and a prior history of PSP. When air enters the pleural space from a ruptured bleb, the lung will collapse until there is equilibrium or the air leak is sealed; therefore, as the pneumothorax enlarges, the lung volume is diminished. Young, healthy patients can tolerate the resulting reduction in partial pressure of oxygen and vital capacity with minimal to no respiratory distress even though the PSP may have been present for several days. Patients generally present with acute onset of chest pain (usually pleuritic in nature), shortness of breath, and sometimes cough. Chest pain will often improve after the first 2 hours even without medical intervention. Tachycardia, tachypnea, and hypoxia may be present. Lung auscultation of the affected side may reveal diminished or absent breath sounds and/or hyperresonance to percussion. Tension pneumothorax is rare in PSP. The differential diagnosis is mainly the differentiation of PSP from secondary or iatrogenic pneumothorax.

Emergency Department Treatment and Disposition

Take a thorough history focusing on preexisting lung diseases such as asthma, tuberculosis, cystic fibrosis, interstitial lung disease, or congenital pulmonary airway malformation. After initial evaluation and supportive care such as oxygen, obtain a chest radiograph. Use of inspiratory and expiratory chest films may help to better visualize the pneumothorax. CT is not generally indicated in the ED.

Manage stable, asymptomatic patients with a small PSP (<3 cm from the apex of the lung to the top margin of the visceral pleura) in a monitored bed and provide oxygen. Perform needle aspiration in those that are symptomatic, but stable, with small (<3 cm) PSP and observe for reaccumulation. Admit patients with a large (>3 cm) PSP to the ICU for aspiration by pigtail catheter placement to low suction or water seal. Treat patients with recurrent PSP (defined as ipsilateral relapse after more than 1 month) with a chest tube, and consult the surgeon for thoracoscopy (preferably video-assisted thoracoscopic surgery [VATS]) with pleurodesis and possible bullectomy/ blebectomy. Consult surgery for the first contralateral PSP.

Pearls

1. All patients with prior PSP must avoid exposure to cigarette smoke. Offer smoking cessation counseling to patients and close family members.

2. Patients with PSP should avoid activities that cause sudden changes in intrathoracic pressure for a minimum of 4 to 6 weeks.

3. Preventive intervention is not required unless patients had a chest tube and thoracoscopy (as part of initial management of PSP), failure of air leak to resolve after 5 to 7 days, or a vocation that puts them at high risk for recurrence and puts themselves or others at risk (eg, deep sea diver or airplane pilot).

4. Patients with a second ipsilateral PSP require intervention to prevent recurrence.

Clinical Summary

Pulmonary embolism (PE) is difficult to diagnose in children, as it is rare and the classic presentation does not occur in the majority of pediatric patients. PE is more prevalent in sickle cell patients and is precipitated by dehydration and infection. Other predisposing factors include nephrotic syndrome, cancer, chemotherapy, inherited coagulable states (eg, protein C or S deficiency, lupus anticoagulant, factor V Leiden), catheters, surgery, trauma, pregnancy, oral contraceptive use, prolonged immobilization, and cardiomyopathy.

Classic presentations include pleuritic chest pain, shortness of breath, cough and hemoptysis, but as noted, these complaints may be absent. Tachypnea is a common physical finding; tachycardia and respiratory distress may also be present. Lung exam may be significant for rales but most often is normal. Signs and symptoms of deep venous thrombosis may or may not be present. The classic Virchow’s triad predisposing to thromboembolism consists of any state of relative stasis, prothrombogenic tendency, and injury to the vascular wall. Consideration of disease processes that lead to these factors may aid in diagnosis. Differential diagnosis of PE includes more common diagnoses like pneumonia, acute chest syndrome in sickle cell patients, pneumothorax, myocarditis, pericarditis, pleural effusion, asthma, and anxiety.

Emergency Department Treatment and Disposition

Laboratory tests cannot definitively diagnose or exclude PE (often normal or nonspecific). ABG may demonstrate an elevated alveolar arterial gradient. Respiratory alkalosis may be present reflecting dyspnea and tachypnea. Conversely respiratory acidosis may be present reflecting ventilation-perfusion (V̇/Q̇) mismatch. Metabolic acidosis is an ominous sign and reflects poor perfusion. D dimer testing and enzyme-linked immunosorbent assay have not been specifically evaluated in the pediatric population. A positive D dimer is seen in 90% of adults with PE. A negative result makes PE unlikely; however, a positive result is not specific. Obtain an ECG, which may demonstrate tachycardia or right heart strain. Obtain a chest radiograph, which is abnormal in two-thirds of cases, usually with nonspecific findings, and also can be used to exclude pneumonia or pneumothorax. The most commonly noted abnormal radiographic findings of PE are atelectasis, effusions, and focal infiltrates. Two characteristic findings are uncommon, a localized area of hypoperfusion (Westermark sign), and a peripheral wedge-shaped density above the diaphragm (Hampton hump). Use ultrasound to evaluate for DVT; in the appropriate clinical setting a positive duplex indirectly corroborates with the presence of a PE. Echocardiography may be used to evaluate signs of right heart strain but is a late finding. CT angiography is rapidly becoming the test of choice and criterion standard for diagnosis of PE, because of its relative ease and availability, and has replaced conventional angiography and nuclear V̇/Q̇ scan. Of concern, CT angiography confers significant radiation, though less than V̇/Q̇ scanning.

Provide respiratory support, definitive airway management including endotracheal intubation and ventilation as needed for respiratory compromise. Patients with vital sign instability and hypotension refractory to fluid therapy may require pressor support. In the setting of cardiopulmonary instability, thrombolytic therapy (eg, tissue plasminogen activator) may be considered, though it has not been specifically evaluated in pediatric patients. Optimize precipitating factors like infection, trauma, and heart failure. Admit patients with PE to the ICU for oxygen therapy for hypoxemia and anticoagulation therapy like unfractionated or low-molecular-weight heparin.

Pearls

1. Physical exam and laboratory testing may be nonspecific, and definitive diagnosis is usually made by CT angiography.

2. Massive PEs may benefit from thrombolytic therapy.