Respiratory Disorders

31 Respiratory Disorders



Rita Marie John, Margaret A. Brady


Respiratory problems are a leading cause of illness in children and a major reason for health care visits. Viral upper respiratory infections (URIs), pharyngitis, and otitis media are common diagnoses seen every day by practitioners. Parents seek health care to confirm the appropriate management of upper respiratory disorders for common cold, otitis media, rhinosinusitis, and tonsillopharyngitis. Parents seeking to relieve their child’s upper respiratory tract symptoms may use a variety of over-the-counter medications or try to pressure the primary care provider to prescribe cold medications or antibiotics. In contrast, a child with a lower respiratory tract disorder such as asthma or bacterial pneumonia can experience a potentially life-threatening illness that demands prompt attention. Providers who ask key questions about the history of the respiratory symptoms; do a systematic and complete examination of the upper and lower airways, including the sinuses; and, if indicated, order specific laboratory tests and radiographic examinations can determine an accurate diagnosis and develop a successful treatment plan in most cases. When children have complicated problems, they can be referred with baseline information to the appropriate medical specialist for additional studies and treatment.



image Anatomy and Physiology



Upper Respiratory Tract


The upper respiratory tract includes the nostrils, nasopharynx, larynx, upper part of the trachea, eustachian tubes, and sinuses. Air is warmed and humidified as it travels through the nasal passages, and particles are filtered out by coarse nasal hairs. The nasal passages are lined with lysozymes, secretory immunoglobulin A (IgA) and IgG in nasal mucus to defend against microbial invasion. The nasal mucosa is continuous and similar to the sinus mucosa except that the nasal mucosa is thicker with more glands (Cherry and Shapiro, 2010). A blanket of mucus covers the surface epithelium of the nasal and sinus mucosa. The mucociliary action of the paranasal epithelium moves secretions from the sinuses to the nasal cavity. The frontal, maxillary, and anterior parts of the ethmoid sinuses drain to the middle meatus of the nose, whereas the sphenoid and posterior parts of the ethmoid sinuses drain to the superior meatus of the nose (DeMuri and Wald, 2010). Secretions need to be able to move through patent ostia into the nose. The quality of secretions and normally functioning cilia are key factors in the movement of secretions into the nose. Inflammation of nasal mucosa frequently causes edema and disruption of the sinus secretions. If there is significant swelling of the ostia due to URI or allergic inflammation, or mechanical or local obstruction, ostial obstruction results and obstruction of the sinus secretions occurs. Cilia movement and mucus flow allow the sinuses to be free of pathogens.


The maxillary sinuses are present by the second trimester of gestation but are not fully pneumatized until a child is about 4 years old. Ethmoid sinuses develop by the fourth month of gestation and form the thin lateral walls of the orbit of the eye. They are pneumatized at birth and can be visualized on plain radiographs when the child is 1 to 2 years old. The sphenoid sinuses start to form in the first 2 years of life but remain rudimentary until age 6 when they become visible on radiographs. They reach their permanent size, but not shape, by age 12 years. As a result, the nasal cavity and paranasal sinuses reach adult proportion by age 12 (Cherry and Shapiro, 2010). The sinuses become clinically significant sites of infection as follows:



• Maxillary and ethmoid sinuses as early as late infancy


• Sphenoid sinuses around the third and fourth years of life


• Frontal sinuses around the sixth to tenth years of life


The epiglottis deflects swallowed material toward the esophagus to protect the larynx. The vocal cords form a V-shaped opening known as the glottis. The subglottic space is beneath the vocal cords, and its walls converge toward the cricoid ring to form a complete ring of cartilage around the larynx. In children less than 2 to 3 years old, the cricoid ring is the narrowest part of the airway; in older children and adults, the glottis is narrowest. The rings of tracheal cartilage support the trachea and the mainstem bronchi.


The trachea and airways of the infant and young child are more compliant than those of an adult. Hyperextension of the neck can constrict the airway of infants. Consequently, changes in intrapleural pressure lead to greater changes in an infant’s or young child’s airways compared with the effect that such changes would exert on adult airways, thereby causing an increased risk of airway collapse. Similarly, increased chest wall compliance in young infants makes them more vulnerable to adverse events, and their respiratory muscles cannot effectively handle sustained, intense respiratory workload that occurs during severe pulmonary illnesses (Sarnaik and Heidemann, 2007).



Lower Respiratory Tract


The right lung has three lobes, upper, middle, and lower, with the upper and middle being separated by a minor fissure. The left lung has two lobes, upper and lower, separated by a major fissure. The upper left lobe has an area called the lingula that corresponds to the right middle lobe. The right mainstem bronchus is shorter and wider than the left bronchus. It forms a smaller angle away from the trachea than the left bronchus does. This anatomic variation explains why foreign bodies (FBs) usually lodge in the right mainstem bronchus. Although the body surface and the number of respiratory airways and alveoli increase 10-fold from birth to adult life, the tissue available for gas exchange increases approximately 20-fold. The newborn’s chest is cylindrically shaped and has relatively horizontal ribs, which limits the infant’s ability to expand his or her chest. Because there is greater transverse growth in the lower part of the chest wall, the shape of the chest changes during the first few years of life. This differential growth results in the ribs being positioned lower anteriorly than posteriorly. The change in positioning of the ribs adds rigidity to the thorax of older children.


The diaphragm is the main muscle of respiration, and the intercostal, sternocleidomastoid, spinal, neck, and abdominal muscles are accessory muscles that can be used to increase effort. Normal exhalation occurs from elastic recoil of the lung.


Primitive airways appear at approximately the fourth week of gestation. At about the sixteenth week of gestation, the number of bronchial branches equals that in adults. Subsequent growth continues by increasing the length of the respiratory tract. During the sixteenth to twenty-sixth weeks of gestation, vascularization of the future respiratory portion of the lung occurs. Cartilage, glands, and muscles of the airways and type II alveolar cells are formed by week 28. Type II cells allow the fetus to produce a phospholipid called surfactant. The airways continue to grow, and terminal sac formation occurs. At approximately week 36, the terminal sacs divide, and alveoli are formed. Approximately 50 million primitive alveoli are present at birth.


After birth the alveolar ducts branch off the third respiratory bronchioles. Alveoli continue to form and number 100 to 200 million in older children and 200 to 600 million in adolescents. The alveolar sacs continue to increase in size. The adult lung contains approximately 300 million alveoli.


Other structures important for gas exchange and pulmonary function are present at birth and include cartilage, mucus glands, goblet cells, and ciliated cells of the conducting airways. The airways above the bronchioles are lined with ciliated pseudostratified columnar cells as well as goblet cells. Mucus is produced from the mucus glands that line the respiratory tract. The cilia play a critical role of sweeping mucus and debris toward the upper respiratory tract. Smooth muscle is also present; therefore, even very young infants can have bronchospasm. Beyond the bronchioles a thin layer of surfactant that reduces surface tension and prevents airway collapse.


Airway resistance is higher in newborns and young children than in adults. The airways of young infants and children are easily obstructed by inflammation, FBs, or mucous. The maximal inspiratory pressure generated by an infant is equal to that of an adult. However, the chest wall and supporting structures are softer and more flexible, so chest wall retraction is greatest in young infants. The chest wall of a newborn is highly compliant.



image Pathophysiology Involved in Airway Disease


All lung disorders cause some form of airway obstruction. Narrowing of the airway lumen results from one or more of the following:



• Presence of intraluminal material (e.g., secretions, tumors, or foreign matter)


• Mural thickening (e.g., edema or hypertrophy of the glands or mucosa)


• Contraction of smooth muscle (e.g., spasm)


• Extrinsic compression


These factors rarely occur in isolation. They cause pulmonary malfunction by impairing tracheobronchial hygiene and impeding normal airflow. Severe airway obstruction can occur in infants or young children from very small blockages because of their airway size.


The two major types of airway obstruction are complete and partial. In complete obstruction neither airflow nor drainage of secretions occurs. Such occlusion leads to lobar atelectasis after the residual gas diffuses into the pulmonary circulation. In partial airway obstruction, airflow and secretion drainage occur but are impaired. Partial obstruction can be further divided into two separate classifications. The first consists of a bypass valve obstruction caused by narrowing of the lumen; a wheeze may be produced. Although resistance to flow is increased, air can still flow in during inspiration and out during expiration. The second is a check-valve or ball-valve obstruction; air entry is possible, but during expiration the lumen is completely occluded so that escape of air is impossible. Bronchial FBs and emphysema are associated with bypass, check-valve, or ball-valve obstructions that result in overinflation of lung airways.


Airway obstruction that occurs above the level of the secondary bronchi generally interferes more with inspiration than expiration. If the obstruction is complete and above the bifurcation of the trachea, asphyxia and death can result. Partial obstruction may result in severe dyspnea, stridor (a harsh high-pitched inspiratory sound), and subcostal retractions. Coughing removes nonfixed, high airway obstruction. Poor inspiratory airflow limits the coughing effectiveness. The sound produced by coughing may indicate the level of airway obstruction and assists in making a diagnosis. Obstructions next to the larynx produce a cough that sounds croupy or barking. Obstructions in the trachea or major bronchi produce a brassy sound.


Lower airway obstructions result from peripheral lesions that are usually diffuse in location and involve bronchioles smaller than 3 mm. The usual mechanism of narrowing is spasm, accumulation of secretions, edema of the mucous membrane, extrinsic compression, or any combination of these factors. Complete airway obstruction causes atelectasis. A large percentage of the lung volume needs to be involved before symptoms become apparent; small atelectatic changes do not produce obvious clinical manifestations.


The primary clinical manifestation of lower airway obstruction occurs during expiration. Wheezing is the principal sound patients make if the obstruction allows enough air to pass through the narrowed lumen. Chest excursion diminishes, and the expiratory phase prolongs. Increased airway resistance during exhalation results in overinflation of the lungs, which in turn eventually increases the anteroposterior diameter of the chest. Chronic overinflation results in the “barrel chest” typical of a patient with chronic lung disease such as cystic fibrosis (CF) or emphysema. The accumulation of fluids and inflammation in the lower airways usually results in a repetitive hacking, ineffectual cough. On physical examination, percussing an overinflated chest elicits hyperresonance.


Symptoms worsen as obstruction increases. The body attempts to compensate by using accessory muscles to assist in breathing. Dyspnea can result and may include orthopnea and exercise intolerance. Cyanosis appears as the oxygen saturation drops below 85% and is an ominous sign. Mild obstruction is marked by reduced respiratory rate and increased tidal volume; severe obstruction is characterized by increased respiratory rate, increased retractions with the use of accessory muscles, anxiety, and cyanosis.


Fine crackles or rales indicate respiratory pathology and are short, crackling sounds heard during inspiration. These sounds are caused by airways suddenly opening after having been previously closed. The gas pressure between the compartments equalizes and creates the crackling sound. Fluid accumulation in the airways may also result in crackles. Crackles or rales are not cleared by coughing.


Airway obstruction is the underlying etiology for the most common forms of pediatric lung diseases. Restrictive disease is less common in pediatric patients and is characterized by decreased lung compliance with relatively normal flow rates. Examples of causative factors include neuromuscular weakness, lobar pneumonia, pleural effusion or masses, severe pectus excavatum, or abdominal distention. Key findings of restrictive lung disease are rapid respiratory rate and decreased tidal volume/capacity (Carter and Marshall, 2011; Sarnaik and Heidemann, 2007).



image Defense Systems


The respiratory defense system includes mechanical and biologic processes. Mechanical defenses include:



• Filtering of particles


• Warming and humidifying of inspired air


• Clearing of airway through mucociliary and coughing actions


• Spasm and breathing changes


Approximately 75% of inspired air is warmed as it passes through the nose, paranasal sinuses, pharynx, larynx, and upper portion of the trachea. Final warming and humidifying of the airstream take place in the trachea and large bronchi. Heat and moisture are removed during the expiratory phase of respiration. The nose has a large surface area on which particles larger than 5 mm are trapped and filtered to prevent them from entering the lower airways. The trachea and bronchioles are lined with various defensive cells and mucus glands. Goblet cells secrete the mucous layer that lies on the tip of cilia. Particles entering the conducting airway are quickly cleared by the mucociliary defenses. Coughing is a reflex mechanism that has three phases: (1) inspiratory, (2) compressive, and (3) expiratory (Chang, 2009). Through forceful expiration foreign bodies and other materials can be removed from the airways; coughing propels particles. Young infants and children cannot effectively expectorate mucus, so they swallow it. Cough reflex loss causes aspiration and pneumonia. Temporary breathing cessation, reflex shallow breathing, laryngospasm, and even bronchospasm are compensatory efforts aimed at stopping foreign matter from further entry into the lower respiratory tract. However, these respiratory efforts offer limited protection and have significant drawbacks.


Biologic processes that protect the respiratory system include:



• Phagocytosis


• Absorption of noxious gases in the vasculature of the upper airway


• Absorption of particles by the lymph system


Phagocytosis, aided by the secretory immunoglobulin IgA plus interferon, lysozyme, and lactoferrin, is the principal antimicrobial defense. Particles reaching the alveoli can be phagocytized by alveolar macrophages and polymorphonuclear cells, cleared from the lung by the mucociliary system, or carried by lymphocytes into regional nodes or the blood. These particles can take days to months to clear.


The respiratory defense system is at risk for compromise from numerous environmental factors. Damage to epithelial cells is caused by a variety of substances and gases such as sulfur, nitrogen dioxide, ozone, chlorine, ammonia, and cigarette smoke. Hypothermia, hyperthermia, morphine, codeine, and hypothyroidism can adversely alter mucociliary defenses. Dry air from mouth breathing during periods of nasal obstruction, tracheostomy placement, or inadequately humidified oxygen therapy results in dryness of the mucous membrane and slowing of the cilia beat. Cold air is also irritating to the lower airways.


Phagocytic ability is also reduced by many substances, including ethanol ingestion and cigarette smoke. Hypoxemia, starvation, chilling, corticosteroids, increased oxygen, narcotics, and some anesthetic gases also impair phagocytosis. Recent acute viral infections can reduce antibacterial killing capacity. Damage from infection and chemical irritants may or may not be reversible.


Recurrent respiratory infections in children merit investigation for immunodeficiencies or other underlying diseases such as primary ciliary dyskinesia or cystic fibrosis. The mnemonic SPUR can help determine which children need further workup:



S = severe infection


P = persistent infection and poor recovery


U = unusual organisms


R = recurrent infection (Bush, 2009)


Immunodeficiencies should be considered if the child has eight or more new ear infections in a year, two or more serious sinus infections, persistent oral candidiasis, 2 or more months on antibiotics without improvement, and/or the need for intravenous (IV) antibiotics to clear infections. Also consider immunodeficiencies if there is recurrent pneumonia, failure to thrive, a family history of immunodeficiency, or two or more deep skin infections (Bush, 2009).



image Assessment of the Respiratory System


The history provides valuable information about the causes, progression, and potential complications of a child’s respiratory condition. The physical examination and diagnostic testing allow the provider to determine the extent of respiratory distress.



History




• History of the present illness can be assessed using the mnemonic PQRST:


image P = Promoting, preventing, precipitating, palliating factors

• Contacts. Are any family members or close contacts (e.g., daycare, school) ill with similar signs and symptoms?

• Prevention. Are you using any medications to prevent colds (e.g., zinc lozenges, echinacea, and vitamin C are touted in the lay press as prevention measures, but may have negative side effects in children and adolescents)?

• Progression. Are the respiratory signs or symptoms increasing in severity, lessening, or about the same? Is the child easily fatigued, less active, having trouble sleeping, or working harder to breathe?

• Treatment. Have any over-the-counter or prescription drugs been used? Have any other treatment modalities been used, including folk cures, complementary therapies, or home remedies?

image Q = Quality or quantity

• How severe are the symptoms? Is the illness interfering with school attendance or play? Are breathing problems affecting the child’s ability to sleep and eat?

image R = Region or radiation

• Does the child complain of chest pain?

image S = Severity, setting, simultaneous symptoms or similar illnesses in the past

• Key signs and symptoms. Has the child had symptoms or signs of a daytime or nighttime cough, fever, vomiting, malaise, rhinorrhea, sore throat, lesions in the mouth, retractions, cyanosis, dyspnea, or increased respiratory effort? Table 31-1 lists key characteristics and causes of cough.

• Associated symptoms. Has there been a decrease in appetite or feeding? Any rashes, headaches, or abdominal pain?

• Similar illnesses in the past. Does the child have a history of respiratory tract infections, allergies, or asthma? How many similar infections has the child had (e.g., croup, pneumonia, rhinosinusitis, streptococcal tonsillopharyngitis, frequent colds)?

image T = Temporal factors

• When did the illness begin?

• Was the onset acute or insidious or proceeded by the common cold?

• How long has it lasted? How has it changed over time?

• Does the child have a history of respiratory tract infections, allergies, or asthma? How many similar infections has the child had (e.g., croup, pneumonia, rhinosinusitis, streptococcal tonsillopharyngitis, frequent colds)?

• Family history


image Do others in the family have a history of allergies or asthma?

image Is there any family history of immunodeficiency, ear-nose-throat, or respiratory problems?

image Does anyone in the family have genetic diseases such as CF or alpha 1-antitrypsin deficiency?

• Review of systems


image Note any infections, constitutional diseases, or congenital problems that might have a respiratory component.

• Environment


image Does anyone in the family or in the daycare setting smoke? Does the child live or attend school in an urban or industrial area subject to air pollution (e.g., near a major highway, industrial plant, or bus terminal)?

TABLE 31-1 Key Characteristics of Cough, Common Causes, and Questions to Ask in a Pediatric History

















































Key Characteristics to Consider and Questions to Ask
Age factor Infants have a weak, nonproductive cough.
Quality Staccato-like (Chlamydia trachomatis in infants); barking or brassy (croup, tracheomalacia, habit cough); paroxysmal or inspiratory whoop (pertussis or parapertussis); honking (psychogenic).
Is the cough wet or dry?
Duration Acute (most causes are infectious and last less than 2 weeks), subacute cough lasts from 2-4 weeks; recurrent (associated with allergies and asthma), or chronic lasting greater than 4-8 weeks (e.g., CF, asthma).
Is the cough continuous or intermittent?
Productivity Mucus producing or nonproductive?
Timing During the day, night (associated with asthma), or both?
Effect on parent and child Are parents frustrated with the cough? Is it causing them to lose sleep and work time? Are they concerned that the child may have something serious?
Associated symptoms Fever—may indicate bacterial infection (pneumonia)
Rhinorrhea, sneezing, wheezing, atopic dermatitis—associated with asthma and allergic rhinitis
Malaise, sneezing, watery nasal discharge, mild sore throat, no or low fever, not ill appearing—typical of URI
Tachypnea—pneumonia or bronchiolitis in infants (infants may not have a cough)
Exposure to infection or travel Has the child been out of the country (tuberculosis)? Is there a member of the household being treated for “bronchitis” or another cough illness?
Causes
Congenital anomalies Tracheoesophageal fistula, vascular ring, laryngeal cleft, vocal cord paralysis, pulmonary malformations, tracheobronchomalacia, congenital heart disease
Infectious agent Viral (RSV, adenovirus, parainfluenza, HIV, metapneumovirus, human bocavirus), bacterial (tuberculosis, pertussis, Streptococcus pneumoniae), fungal, and atypical bacteria (Chlamydia and Mycoplasma)
Allergic condition Allergic rhinitis, asthma
Other FB aspiration, gastroesophageal reflux, psychogenic cough, environmental triggers (air pollution, tobacco smoke, wood smoke, glue sniffing, volatile chemicals), CF, drug induced, tumor, congestive heart failure

CF, Cystic fibrosis; FB, foreign body; HIV, human immunodeficiency virus; RSV, respiratory syncytial virus; URI, upper respiratory infection.


Adapted from Chang AB: Cough, Pediatr Clin North Am 56:19-31, 2009; Cherry JD: Croup (laryngitis, laryngotracheitis, spasmodic croup, laryngotracheobronchitis, bacterial tracheitis, and laryngotracheobronchopneumonitis. In Cherry J, Demmler-Harrison G, Kaplan S et al, editors:. Feigin & Cherry’s textbook of pediatric infectious diseases, ed 6, Philadelphia, 2010, Saunders, pp 254-268.



Physical Examination


When determining respiratory distress, think about the total presentation and not just individual isolated findings. Consider the anxiety level, respiratory rate and rhythm, use of accessory muscles, color, breath sounds, grunting, and pulse oximetry results. Information pertinent to the physical examination of a child with suspected respiratory disease includes the following:



• Measurement of vital signs and observation of general appearance:


image A normal respiratory rate is age dependent and, if elevated, is a key indicator of lower respiratory involvement.

image The level of anxiety, nasal flaring, and position of comfort are useful indicators of respiratory distress. Changes in skin color may be subtle or obvious depending on the level of deoxygenation. Grunting is a sign of small airway disease.

• Inspection of:


image Nose: Look for rhinorrhea—clear, mucoid, mucopurulent; FBs, erosion, polyps, lesions, bleeding; septal position; and color of the mucous membrane.

image Throat, pharynx, and tonsils: Look for lesions, vesicles, exudate, enlargement of any structure, or other abnormalities. If epiglottitis is a consideration, do not inspect the mouth or attempt to elicit a gag reflex.

image Chest: Look at the depth, ease, symmetry, and rhythm of respiration. These are key indicators of lower respiratory tract involvement. The use of accessory muscles and the presence of retractions should be noted. A prolonged expiratory phase is associated with respiratory obstruction in the lower airways.

• Palpation or percussion (or both) of:


image Paranasal and frontal sinus: Palpate for signs of sinus tenderness, knowing that this is a very insensitive physical assessment finding. Note: Take child’s age into consideration when determining likelihood of sinus pathology.

image Chest: Percuss for signs of dullness or hyperresonance caused by consolidation, fluid, or air trapping.

• Auscultation of the chest:


image Upper tract: Pathology frequently causes noisy breathing, snoring, stridor, rhonchi and can be a source of referred breath sounds (Mellis, 2009).

image Lower tract: Pathology is suggested by fine crackles or rales, rhonchi, rattles, and polyphonic and monophonic wheezing (Mellis, 2009).


Diagnostic Tests


Diagnostic procedures used to evaluate respiratory illness in children managed as outpatients include the following:



• Monitoring oxygenation by pulse oximetry and blood gases:


image Pulse oximetry can be used to continuously measure pulse rate and peripheral oxygen saturation in arterial blood. The oxyhemoglobin saturation percentage (Spo2) is digitally displayed. Results generally correlate well with simultaneous arterial saturation (Sao2). With anoxia, there is a rise in organic phosphate content within the red blood cells that results in more O2 available to tissues. People living at higher elevations suffer from chronic hypoxia. When first arriving at a high elevation, many individuals experience a transient mountain sickness with symptoms that include headache, insomnia, irritability, breathlessness, nausea, and vomiting. This phenomenon lasts approximately 1 week before acclimatization begins. The affected person begins to increase production of red blood cells (RBCs). Finally, a functional nonpathologic right ventricular hypertrophy takes place. These effects last as long as the person remains at high elevation. Severe altitude sickness can lead to cerebral and pulmonary edema and can be life-threatening.

image Blood gas studies can help the provider assess possible respiratory collapse and are used in acute care settings. A rising Paco2 is an ominous sign.

• Unless there is chronic or complicated rhinosinusitis, imaging in acute rhinosinusitis remains controversial because uncomplicated URIs can cause abnormalities of the paranasal sinuses (Cherry and Shapiro, 2010; DeMuri and Wald, 2010). Radiographic imaging in respiratory disease may be necessary, including radiographs, ultrasonography, magnetic resonance imaging (MRI), and computed tomography (CT) of the sinuses, soft tissues of the neck, and chest. Abnormalities of the nasal mucosa such as thickening may reflect inflammation. Chest radiographs should be done in both posteroanterior and lateral positions because lesions may only be seen in one of the two views. Fluoroscopy is useful in the evaluation of stridor and abnormal movement of the diaphragm. Several other pulmonary studies may be ordered by the medical specialists to whom the child is referred. Contrast studies (e.g., barium esophagogram) are useful for patients with recurrent pneumonia, persistent cough, tracheal ring, or suspected fistulas. Other imaging studies that might be needed to assess these children include bronchograms (useful in delineating the smaller airways), pulmonary arteriograms (evaluation of the pulmonary vasculature), and radionuclide studies (evaluation of the pulmonary capillary bed). Pulmonary function tests are discussed in Chapter 24 in the section on asthma.


• Other specialized tests, including sweat testing, cultures and blood work, are addressed under the specific illness.


• Endoscopy (bronchoscopy and laryngoscopy), bronchoalveolar lavage, percutaneous tap, lung biopsy, and microbiology studies are other helpful diagnostic procedures if used appropriately. Children who have unusual signs and symptoms that require such procedures should be referred to medical specialists.



image Basic Respiratory Management Strategies



General Measures


Children who are significantly ill or have unusual manifestations need referral to or consultation with a pediatrician or pediatric subspecialist. General management measures include the following:



• Fluid. Hydration is important to keep mucous membranes and secretions moist. Intake of fluids should be encouraged and parents of young children should be given guidelines regarding the type, amount, and frequency of fluids and feedings that their child should take.


• Oxygen administration. The use of supplemental oxygen is important to help relieve hypoxemia in most children who have acute respiratory distress. Depression of the respiratory drive is possible with supplemental oxygen administration if the central nervous system (CNS) chemoreceptors are blunted by hypercapnia. However, children at risk for blunting are those with issues related to chronic hypercapnia and are generally easily recognized because they tend to have chronic severe respiratory diseases such as CF and bronchopulmonary dysplasia. In acute situations, administer oxygen using an appropriately sized mask or a high-flow O2 source held near the child’s face if a mask frightens the child. The safe, acceptable range of O2 saturation is 92% to 95%; higher levels may lead to oxygen toxicity (Chin, 2010; Robinson and Van Asperen, 2009). Children seen in primary care settings who require supplemental oxygen should be transported to an acute care hospital setting via emergency medical services for evaluation and stabilization.


• Humidification. For a child with laryngotracheobronchitis (LTB), taking the child out into the cold night air or opening a freezer door may be beneficial. There is no evidence for the use of steam or humidification in croup (Everard, 2009). A cold-mist vaporizer helps provide moisture to the nares and oropharynx during a common cold, but the vaporizer must be cleaned daily so that it will not become a source of infection.


• Bulb syringe. Because infants are obligate nose breathers, parents should be instructed in use of the nasal bulb syringe to relieve obstruction of the infant’s nares with mucus. Use the bulb syringe gently and intermittently because improper use can cause irritation, inflammation, and respiratory obstruction from tissue damage. Providing parents with written instruction on suctioning the infant’s nose with a bulb syringe is advantageous. Cincinnati Children’s Hospital Medical Center has home instructions for this technique available on its website.


• Normal saline nose drops, nasal rinses, or spray. Use before feedings and when mucus is thick or crusted. Follow by suctioning the nares with a bulb syringe. Saline nasal rinses are widely available commercially and are helpful for older children and adolescents.



Medications


The following pharmacologic agents may be needed to treat various respiratory illnesses:



• Antibiotics. Specific agents are discussed in the section on individual illnesses. If an antibiotic is prescribed, the drug should be taken until completed.


• Analgesics and antipyretics. Acetaminophen and ibuprofen may be prescribed for relief of pain or fever.


• Decongestants and antihistamines. The use of decongestants and antihistamines does not shorten the course of a disease, but can provide relief of nasal symptoms. However, due to the risk of overdosage and unsupervised ingestions, these agents should not be used in children younger than 4 years of age (Centers for Disease Control and Prevention [CDC], 2008). Practitioners need to use caution in prescribing these agents in children younger than 6 years.


• Expectorants. Water is one of the most effective expectorants. Over-the-counter agents provide some symptomatic relief, but do not shorten the course of respiratory illnesses. Do not use in children younger than 4 years (CDC, 2008).


• Cough medication. Cough suppressant medications should be prescribed judiciously because coughing is a protective mechanism to clear secretions. In review of evidence-based guidelines for the intervention in pediatric cough, the only cough medication that was recommended was honey, provided the child was more than 1 year old (Chang, 2009). However, the study results may be the result of a placebo effect (Paul et al, 2007).


All health care providers must be cognizant of their role in the prevention of superinfections caused by the indiscriminate use of antibiotics.



Patient and Parent Education


Frequent handwashing and avoiding touching eyes and nose can help prevent the spread of infection. Parents should be educated about assessment and management of changes in the child’s condition. Significant educational issues are identified in Box 31-1.



BOX 31-1 Parental Education for At-Home Care of the Child With a Respiratory Tract Infection



Infection: Issues to Discuss


Fluid: Give guidelines on type, amount, and frequency of fluids child should take.


Humidification: For laryngotracheobronchitis, take the child out into the cold night air or open a freezer door. In dry climates, humidifiers help in common colds; instruct about cleaning of nebulizers and humidifiers (see below).


Bulb syringe: Instruct to use the bulb syringe gently and intermittently for suctioning the nares.


Normal saline nose drops or spray: Use before feedings and when mucus is thick or crusted. Follow by suctioning nares with bulb syringe.


Other educational issues to cover:



• Indications for immediate reevaluation of child:


image Signs and symptoms of respiratory distress

image Other indicators of worsening of illness (e.g., toxic appearance, malaise, feeding difficulty)

• Information on when to expect improvement in the child’s symptoms and, if symptoms do not improve as expected, what to do next


• Clear instructions about medications—how much to give, when to give, side effects to watch for, how long to give, and the necessity of completing the course of antibiotics


• Infection control information if needed—handwashing and disposal of infected secretions; the CDC has excellent written and video education materials available on handwashing at www.cdc.gov/Features/HandWashing.


• Care of nebulizers and humidifiers—to prevent the growth of organisms, nebulizers and humidifiers should be cleaned daily with soapy water, rinsed thoroughly, soaked for one half hour in a solution of one part vinegar to two or three parts distilled water, and then air-dried. Control III® disinfectant is a commercial product that can be substituted for vinegar; however, it is expensive.


• Instructions on next return visit



image Indications for Tonsillectomy and Adenoidectomy


Controversy remains about the need for tonsillectomy, adenoidectomy, or both, particularly for less affected children (Burton and Glasziou, 2009). Tonsillectomy has been found to be beneficial in children who are severely affected with recurrent tonsillitis (Morris, 2009). Tonsillectomy may be helpful in the syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA syndrome) (Garavello et al, 2009; Licameli et al, 2008) and in obstructive sleep apnea. The provider must weigh the pros and cons of recommending a tonsillectomy, adenoidectomy, or both and consider whether a wait-and-see approach is the best strategy to determine if growth and time will negate the need for surgery (Burton and Glasziou, 2009). Cold steel tonsillectomy is associated with less pain and bleeding postoperatively than the traditional method of diathermy (Morris, 2009).


Adenoidectomy can also be considered if appropriate medical treatment fails to correct obstructive adenoidal hypertrophy, recurrent or chronic otitis media (after tympanostomy tube placement has been tried), and chronic unresponsive rhinosinusitis. The treatment of choice for sleep obstructive apnea is a tonsilloadenoidectomy (Schechter and Section on Pediatric Pulmonology Subcommittee on Obstructive Sleep Apnea Syndrome, 2002). Children with behavioral problems including attention-deficit/hyperactivity disorder (ADHD) may have obstructive sleep apnea as the cause of their ADHD behaviors.


For any relative indication for tonsillectomy, the risk-benefit ratio of the procedure must be weighed. Significant morbidity and mortality rates are associated with tonsillectomy including complications such as anesthesia problems, hemorrhage, and infection (Burton and Glasziou, 2009). Approximately 6% of children who are younger than age 3 years experience respiratory complications following tonsillectomy. The morbidity and mortality rates connected with adenoidectomy are not as high as with tonsillectomy.



image Upper Respiratory Tract Disorders



The Common Cold



Description and Epidemiology


The common cold is a frequent problem seen in pediatric practice, and parents often seek information from their child’s primary health care provider as to whether their child’s symptoms represent a typical URI or indicate the beginning or advancing signs of a more serious illness. Young children have on average 6 to 10 URIs or colds per year. Viruses cause most common colds with 50% resulting from infection by the more than 100 serotypes of rhinoviruses. Parainfluenza viruses, respiratory syncytial virus, coronavirus, and human metapneumovirus are also common agents (Cherry and Nieves, 2010). Other agents that occasionally cause cold symptoms include adenovirus, enterovirus, influenza viruses, reoviruses, and human bocavirus. Daycare and preschool attendance are associated with an increased number of common colds in young children and their spread to school-age children in the family. The acquisition of a common cold virus occurs via inoculation of the nose and possibly the conjunctiva. Colds can be spread through direct inhalation of virus from a sneeze, nasal blowing, or inoculation via fingers from nasal secretions or fomites. Mental stress, lack of sleep, high basal levels of catecholamines, infrequent exercise, smoking, and low vitamin C intake are risk factors for colds in adults, but these have not been studied in children (Cherry and Nieves, 2010).



Pathophysiology


When a person has a common cold, there is an increase in the number of polymorphonuclear leukocytes (PMN) in the nasal submucosa and epithelium. The presence of PMN, rather than bacterial colonization, changes the color of nasal mucus, with green mucus due to PMN enzymatic activity and yellow mucus being caused by the simple presence of PMN (Winther et al, 1984). With rhinovirus there is an increase in bradykinins and albumin in the nasal secretions, but no increase in histamines. Rhinovirus and coronaviruses do not cause destruction of the nasal epithelium, but adenovirus and influenza have a significant destructive effect on the respiratory epithelium.



Clinical Findings


Symptoms of a viral cold include nasal congestion, cough, rhinorrhea, fever, and pharyngitis (Bush, 2009; Cherry and Nieves, 2010).



History


The following may be reported:



• Gradual onset


• Prominent nasal symptoms of rhinorrhea (key finding)


• Sore throat and dysphagia


• Mild cough


• Low-grade fever


• After a variable period of 1 to 3 days, nasal secretions are thicker and more purulent, leading to nasal excoriation.



Physical Examination


Virus-specific findings include:



• Conjunctiva: Mild injection


• Nose: Red nasal mucosa with secretions of varying colors depending on the degree of nasal mucosa destruction and PMN activity


• Throat: Mild erythema


• Lymph: Anterior cervical lymphadenopathy with freely movable nodes less than 2 cm


• Chest: Clear to auscultation and without adventitious sounds



Diagnostic Tests


Usually a throat culture is not done if the child has predominantly nasal symptoms but complains of throat irritation (Cherry and Nieves, 2010). However, if a diagnosis of common cold is in doubt, a rapid strep test followed by a culture if negative should be done. Cultures are useful in differentiating viral infection from group A beta-hemolytic streptococcus (GABHS) infection.



Differential Diagnosis


The most common differentials are allergic rhinitis, rhinosinusitis, and adenoiditis (Table 31-2). Colds can be associated with pharyngitis or, when tonsillar involvement is significant, tonsillopharyngitis (tonsillitis). When tonsillar involvement is minor, the term nasopharyngitis is used.



TABLE 31-2 Differentiations of Common Upper Respiratory Infections in Children

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Management


Only supportive care is needed for a viral URI (see Basic Respiratory Management Strategies, General Measures and Patient Education, earlier). Antibiotics are not appropriate treatment. The use of decongestants, antihistamines, and cough medication is not indicated for children younger than 4 years old and should be used with caution in children younger than 6 years old. The child should receive symptomatic relief for fever, pain, and nasal congestion using normal saline and an antipyretic. Fluid intake should be encouraged. Controlled trials have not found sufficient evidence to recommend zinc lozenges, vitamin C, heated humidified air (Bukutu et al, 2008) or echinacea (Cherry and Nieves, 2010; Linde et al, 2006).



Complications


Common colds are self-limiting but can be complicated by otitis media, rhinosinusitis, or tonsillitis.



Pharyngitis, Tonsillitis, and Tonsillopharyngitis



Description


Pharyngitis is an inflammation of the mucosa lining the structures of the throat including the tonsils, pharynx, uvula, soft palate, and nasopharynx. The illness is generally acute and involves an inflammatory response including erythema, exudate, or ulceration. The etiology could include a number of viruses and bacteria. If there are nasal symptoms, it is called nasopharyngitis but if there are no nasal symptoms, the disease is called pharyngitis or tonsillopharyngitis. Most pharyngitis is caused by viruses (Cherry, 2010a; Martin, 2010). Adenovirus is the most common cause of nasopharyngitis (Cherry, 2010a). Other viruses include Epstein-Barr virus (EBV), herpes simplex virus (HSV), cytomegalovirus (CMV), enterovirus, influenza virus, parainfluenza, and human immunodeficiency virus (HIV). The viral organisms generally present with upper nasal symptoms. The common bacterial etiology includes Streptococcus pyogenes (group A streptococcus), Corynebacterium diphtheriae, Arcanobacterium haemolyticum, Neisseria gonorrhoeae, group C and group G streptococci, and Mycoplasma pneumoniae.



Acute Viral Pharyngitis, Tonsillitis or Tonsillopharyngitis



Epidemiology


Adenoviruses are more likely to cause pharyngitis as a prominent symptom. Other viruses (e.g., rhinovirus) are associated with pharyngitis as a minor symptom and rhinorrhea or cough as predominant features. The enterovirus (coxsackievirus, echovirus), herpesvirus, and EBV are also common. Viral infections occur year-round, but peak seasonally. Therefore, it is helpful to know what agents are currently infecting children in the community. It can be difficult to differentiate viral from bacterial infections because of overlapping symptoms (Morris, 2009). However, hoarseness, cough, coryza, conjunctivitis, diarrhea, enanthems, and exanthems are classic features of a viral infection, which is often spread to siblings and classmates via close contact (Cherry and Nieves, 2010).



Clinical Findings



History

The following may be reported:



• Pain


• Myalgia and arthralgia


• Fever


• Sore throat and dysphagia



Physical Examination

Common findings include:



• Reactive lymphadenopathy


Virus-specific physical findings include the following:



• EBV can produce exudate on the tonsils, soft palate petechiae, and diffuse adenopathy.


• Adenovirus can cause a follicular pattern on the pharynx (Cherry, 2010a).


• Enterovirus can produce vesicles or ulcers on the tonsillar pillars and posterior fauces; coryza, vomiting, or diarrhea may be present.


• Herpesvirus produces ulcers anteriorly and marked adenopathy.


• Parainfluenza and respiratory syncytial virus (RSV) cause more lower respiratory tract disease (e.g., croup, pneumonia, and bronchiolitis) with their typical respiratory signs of stridor, rales, or wheezing.


• Influenza usually has more systemic complaints.



Diagnostic Tests

If a diagnosis of viral infection is in doubt, a rapid strep test or a culture should be done. Cultures are useful in differentiating viral infection from GABHS infection. If infectious mononucleosis is suspected in a child, a complete blood count (CBC) can identify a lymphocytosis and atypical lymphocytes. However, heterophile antibody testing can be helpful in school-age children and adolescents but may yield a false negative in preschool and younger children and during the first weeks of infection (Bell and Fortune, 2006; Smellie et al, 2007). Epstein-Barr antibody titers to early antigen, EBV IgM, EBV IgG, as well as long-term antibodies (Epstein-Barr nuclear antigen [EBNA]) need to be done to confirm the diagnosis if the results of the tests are not diagnostic.



Management


For viral infection, only supportive care is needed, including fever and sore throat pain relief with acetaminophen or ibuprofen. Fluid intake should be encouraged.



Acute Bacterial Pharyngitis and Tonsillitis



Epidemiology


The most common bacterial cause of pharyngitis and tonsillitis in children and adolescents is GABHS, which accounts for about 15% to 30% of infections in children with acute sore throat and fever. Group C and group G streptococci can cause pharyngitis, but antibiotic treatment does not prevent its only nonsuppurative complication, glomerulonephritis (Gerber et al, 2009). Arcanobacterium haemolyticum is more common in adolescents but is difficult to culture because the organism grows slowly (Martin, 2010). Neisseria gonorrhoeae (GC) is a cause of adolescent pharyngitis if the patient engages in oral sex. Mycoplasma pneumoniae and Chlamydophila pneumoniae are associated with cough along with pharyngitis. C. diphtheriae is an extremely rare cause of pharyngitis in the United States. If the throat culture is positive for Staphylococcus aureus, Streptococcus pneumoniae or Haemophilus influenzae, treatment is not needed as these represent normal flora (Congeni, 2009).



Clinical Findings



History

The following characterize GABHS infection:



• Most commonly found in 5- to 15-year-old children; infrequent in children younger than 2 years old


• Abrupt onset without nasal symptoms


• Constitutional symptoms such as arthralgia, myalgia, headache


• Moderate to high fever, malaise, prominent sore throat, dysphagia


• Nausea, abdominal discomfort, vomiting, headache


• Presentation in late winter or early spring


• N. gonorrhoeae (GC) has no distinctive finding on examination from other pharyngitis.


• Lack of a cough or nasal symptoms, along with an exudative, erythematous pharyngitis with a follicular pattern and typical historical findings point to GABHS.


• A. haemolyticum causes an exudative pharyngitis with marked erythema and a pruritic, fine, scarlatiniform rash (Martin, 2010).



Physical Examination

The following may be seen:



• Petechiae on soft palate and pharynx, swollen beefy-red uvula, red enlarged tonsillopharyngeal tissue


• Tonsillopharyngeal exudate that is yellow, blood-tinged (frequently)


• Tender and enlarged anterior cervical lymph nodes


• Bad breath


• Stigmata of scarlet fever may be seen—scarlatiniform rash, strawberry tongue, circumoral pallor


• Variable presentation; may have mild pharyngeal erythema without tonsillar exudate or cervical adenopathy



Diagnostic Tests

A rapid strep test (rapid antigen detection test [RADT]) has a high specificity but variable sensitivity; therefore, a positive test indicates that a symptomatic person has strep infection and should be treated (Gerber et al, 2009). However, a negative test does not mean that streptococcal infection is not present (Gerber et al, 2009; Martin, 2010). Gerber and associates (2009) suggest that practices that do not perform a back-up test must show that their RADT has a sensitivity and specificity equal to culture. It is important not to do a strep test unless the patient has signs and symptoms, since a positive rapid strep test or a positive throat culture can identify a carrier state. The most common tests used to document past GABHS infection involve obtaining antibody titer to various streptococcal enzymes such as antistreptolysin O (ASO) or anti-deoxyribonuclease B tests (anti-DNase B) (Gerber et al, 2009). The ASO titer rises 1 week postinfection and peaks 3 to 6 weeks after infection. The DNase B test rises 1 to 2 weeks after infection, peaks 6 to 8 weeks following infection, and remains elevated for months even in the face of a mild infection with GABHS. As a result, these tests should not be used to diagnosis GABHS infection in a patient.



Management


The goal of antibiotic therapy is to shorten the course and severity of illness, prevent the spread of illness to others, and avoid the development of suppurative and nonsuppurative complications. Suppurative complications include otitis media, rhinosinusitis, peritonsillar abscess, mastoiditis, cervical adenoiditis, and meningitis, whereas nonsuppurative complications include acute rheumatic fever, acute glomerulonephritis, and poststreptococcal reactive arthritis. As stated, antibiotics do not prevent the development of acute glomerulonephritis. If the rapid strep test result is positive, antibiotics should be started immediately. The drug of choice for the treatment of GABHS is penicillin, for children not allergic to it, because of its cost, narrow spectrum of antimicrobial activity, and infrequent adverse reactions (Martin, 2010). The management plan includes the following:



• Antimicrobial therapy (based on clinical need)—one of the following (American Academy of Pediatrics [AAP], 2009; Gerber et al, 2009, Taketomo et al, 2011):


image Penicillins

• Phenoxymethyl penicillin (penicillin V potassium) orally for 10 days: for children less than 60 pounds (27 kg), 250 mg two or three times a day for 10 days; for children more than 60 pounds, adolescents, or adults, the dose is 500 mg two or three times a day for 10 days (AAP, 2009; Gerber et al, 2009).

• Amoxicillin suspension is often used with young children because it is more palatable (efficacy seems equal to penicillin). It must be taken for 10 days. Amoxicillin at 50 mg/kg once a day to a maximum of 1 g can be used orally for 10 days (AAP, 2009; Gerber et al, 2009).

• Benzathine penicillin G intramuscular (IM) (600,000 units as a single dose if less than 60 pounds [27 kg]; 1.2 million units as a single dose for larger children and adults).

image If allergic to beta-lactams:

• A 10-day course of a narrow-spectrum (first-generation), orally administered cephalosporin is acceptable, particularly if the child is allergic to penicillin. However, in up to 5% of penicillin-allergic patients, there is a crossover allergy to cephalosporin. Patients with a type I allergic reaction should not be treated with a first-generation cephalosporin (AAP, 2009).

• Clindamycin at 20 mg/kg/day divided in three doses for children older than 3 years.

• Azithromycin at 12 mg/kg once a day to a maximum of 500 mg. It should be noted that macrolide resistance is as high as 5% to 8% in some parts of the U.S. (Gerber et al 2009).

• Clarithromycin at 15 mg/kg/day divided in two doses (maximum 250 mg twice a day)

image If evidence of penicillin resistance is present, a beta-lactamase–resistant antibiotic can be used, such as amoxicillin-clavulanate or dicloxacillin.

• Supportive care—antipyretics, fluids, rest.


• Repeat culture is not generally needed except in situations in which it is necessary to ensure eradication of the organism.


• Continued symptoms of streptococcal pharyngitis and a positive culture for streptococcus may represent an actual treatment failure or a new infection with a different serologic type of streptococcus.


• Noncompliance with pharmacologic therapy can explain treatment failure, and in these instances, an injection of benzathine penicillin is recommended.


• For a compliant patient with recurrence, narrow-spectrum cephalosporins, clindamycin, or amoxicillin-clavulanic acid or a combination of penicillin with rifampin are reasonable alternatives (Gerber et al, 2009).


• If clinical relapse occurs, a second course of antibiotic is indicated, as discussed earlier. If recurrent infection is a problem, culturing of the family for the chronic carrier state is advised.


• Fomites such as bathroom cups, toothbrushes, or orthodontic devices may harbor GABHS and should be cleaned or discarded.


• Children can return to school when they are afebrile and have been taking antibiotics for at least 24 hours.

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Jul 24, 2016 | Posted by in PEDIATRICS | Comments Off on Respiratory Disorders

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