key: cord-0036815-ytp5bl96 authors: Martínez-Fernández, Tanya; Rivera-Sánchez, Yadira; Sharma, Preeti title: Pulmonology date: 2019-11-07 journal: Pediatric Board Study Guide DOI: 10.1007/978-3-030-21267-4_20 sha: 8be76e4a74807da6576c1af78e4023e7d440ab00 doc_id: 36815 cord_uid: ytp5bl96 Respiratory conditions are very common among children. This chapter aims to provide a quick review of common respiratory conditions with which the general pediatrician preparing for the certifying board exam should be familiar. The chapter begins with a review of common diagnostic testing methods used in the evaluation of respiratory diseases. Subsequently, the reader will find a description as well as recommended evaluation, differential diagnosis, and management of general signs and symptoms frequently encountered in respiratory medicine. Summaries of specific conditions follow, which provide brief high-yield facts on background, clinical presentation, evaluation, and management. Specific conditions are grouped similarly to the content outline for the ABP into conditions of the upper airway, lower airway, pulmonary parenchyma, chest wall disease, and disorders in breathing. More extensive summaries regarding asthma and cystic fibrosis are also included. Definition of lung volumes and capacities: • 4 volumes: -IRV inspiratory reserve volume -TV tidal volume -ERV expiratory reserve volume -RV residual volume: Volume at maximal expiration • Capacities are sums of volumes -TLC total lung capacity (all four volumes) -volume at maximal inspiration -IC inspiratory capacity: (TV + IRV) -FRC functional residual capacity (RV + ERV) -resting volume at the end of normal expiration -VC vital capacity: (RV + ERV + TV = TLC -RV) • Provides objective measurements that can be tracked over time • Forced maneuver breathing from full inspiration (TLC) to RV capturing VC • Displays volume exhaled and flow rates -FVC-volume after full-forced exhalation -FEV1-volume exhaled during first sec -FEV1/FVC ratio-low with obstruction -FEF 25-75-average flows between 25% and 75% of the maneuver • Interpreted to show obstruction (low flow), restriction (low volume), or mixed process ( Fig. 20 • Noninvasive, continuous, and rapid measure of peripheral oxygen saturation (SpO2) • SpO2 estimates percentage of hemoglobin bound by oxygen • Oxyhemoglobin curve dissociation curve = relation between partial pressure oxygen (pO2) and hemoglobin saturation (Fig. 20 .2 ) -In hypoxia, pO2 is on steep part of curve = small pO2 changes, but large SpO2 changes -Acidosis, hyperthermia, increase in CO2 shifts curve to the right (lower SpO2 for same pO2) • Limitations of pulse oximetry -Inaccurate readings with poor perfusion, severe anemia, motion artifact, shifts in oxyhemoglobin dissociation curve (e.g., acidosis), deep pigmentation of the skin, dark nail polish -Presence of methemoglobinemia and carboxyhemoglobin not recognized by most oximeters and may overestimate SpO2 -Co-oximeter used to measure effect of dyshemoglobinemias • Gold standard for blood gas analysis is an arterial blood gas (ABG) sample. • ABG interpretation (see Table 20 .1 for ABG values associated with various conditions) • Upper airway obstruction -Early increase in pCO2 and proportionate decrease in pO2. Initially responds well to supplemental oxygen • Intrapulmonary airway obstruction -Mild: Decrease in pCO2, normal to decreased pO2 -Moderate: Normal pCO2, decrease pO2 moving toward failure -Severe: Increase pCO2 and decrease pO2 -Supplemental oxygen will support patient, but imperative to monitor carbon dioxide as well • R-L shunt -Early decrease in pO2 -Normal or low pCO2, high pCO2 with development of fatigue -Testing with 100% oxygen helps to define: Response to supplemental oxygen is fair to poor, depending on degree of shunt • Arterialized CBG obtained by warming of a well-perfused heel or earlobe • CBG is more easily attainable than arterial sample • Values are comparable to arterial pH and pCO2, but pO2 measurement in CBG is less reliable • Inaccuracy of blood gas measurements increased if sample processing is delayed, white blood cell (WBC) metabolism continues to consume oxygen and results in acidosis Suggested modalities for various issues Background • Wheezing -A musical, high-pitched whistling sound produced by airflow turbulence -One of the most common symptoms in asthma (see amplified discussion) • Stridor -High-pitched, harsh sound often audible without the stethoscope -Results from rapid, turbulent airflow through a partially obstructed airway • Inspiratory versus expiratory -Inspiratory-Extrathoracic swelling or obstruction will lead to airway collapse on inspiration. Example: Laryngomalacia -Expiratory-Intrathoracic swelling or obstruction will lead to airway collapse on expiration. Example: Tracheomalacia -Biphasic stridor-Indicates fixed airflow obstruction, subglottic space obstruction • Croup or laryngotracheobronchitis (see amplified discussion) • Foreign body aspiration (see amplified discussion) -Most common between 1 and 3 years of age -Sudden onset with cough, stridor, or wheezing • Bacterial tracheitis (see amplified discussion) • • Type 1 respiratory failure characterized by low blood oxygen levels (hypoxemia, low pO2, normal or decreased pCO2, and alveolar-arterial oxygen gradient (pA-aO2) is increased) -Causes: V/Q mismatch, decreased minute volume, diffusion impairment or shunt • Type 2 respiratory failure affects both oxygen and carbon dioxide levels -Low pO2, high pCO2, normal pA-aO2 -Causes: Reduced breathing effort, increased airways resistance, neuromuscular disease • Treating the underlying cause is paramount. In severe cases, intubation and mechanical ventilation are required • If related to respiratory depression is related to narcotics, reversal can be of benefit Apnea • Defined by reduced or cessation in respiratory airflow Three main types • Central -Cessation of airflow secondary to reduction or lack of excitatory signals from central nervous system (brain stem) to respiratory muscles -No chest wall effort -Prolonged episodes (> 20 s) are more clinically significant and usually associated with cyanosis and/or bradycardia -Shorter episodes can be seen in periodic breathing, which is common in premature infants and decreases with age/maturation • Obstructive -Airway (usually upper airway) obstruction/collapse leading to partial or complete obstruction of airflow in spite of chest wall effort • Mixed -Combination of both central and obstructive components -Usually central component followed by obstructive (heliox) may be effective in children with severe croup -Turbulent flow through large airways is density-dependent. -By decreasing gas density, airflow resistance can be decreased. • Admit for severe distress, hypoxia, and inability to feed/drink or if requiring 2 or more racemic epinephrine treatments • Endotracheal intubation recommended before patient is restless and cyanotic • Endotracheal intubation using an ETT one size smaller than predicted tube size (based on age and weight) is the preferred method of establishing an artificial airway in patients with viral croup • Intubation more likely for bacterial tracheitis and epiglottitis and rare in croup • If intubation needed, consider measles or influenza A • Course of viral croup in infants younger than 1 year of age is prolonged • Symptoms often improve during the day with recurrence of symptoms in the early hours of the morning • Most common pathogen Haemophilus influenzae • Rare in children due to H. influenzae vaccination, which leads to individual and herd immunity • More common in the elderly and immunecompromised children than in the general population • Uncommon pathogens that can cause epiglottitis: Herpes viruses and fungi • Pathology involves the epiglotis and other supraglottic structures, but the subglottic space and trachea are usually spared • Rapid onset of illness (hours) with high fever, sore throat, drooling with difficulty swallowing, and difficulty breathing • Patient sitting up and leaning forward position to enhance airflow • Stridor is not a prominent feature • Radiograph lateral neck view: Thumb sign • Patients with acute epiglottitis should undergo endotracheal intubation to ensure an adequate airway until inflammation subsides • In severe cases, avoid unnecessary studies until airway is secured • A skilled provider needs to remain with a patient with epiglottitis until the airway is visualized and secured • Nasal congestion, rhinorrhea, and cough • Tachypnea or elevated respiratory rate is the earliest and most sensitive vital sign change • Nasal flaring, grunting (in infants), and suprasternal, intercostal, and subcostal retractions are evidence of increased respiratory effort • Nasal suctioning and repositioning may allow for a more accurate assessment of lower respiratory tract involvement • Common: Crackles, wheezing, and referred upper airway sounds upon auscultation • Apnea may be more prominent than wheezing in infants < 2 months or former preterm infants • Symptoms can range from mild tachypnea to frank respiratory failure • Clinical course is expected to worsen, with peak symptoms noted around days 3-4 of illness ("day of illness") • "Day of illness" is an important variable for providing anticipatory guidance for outpatient management and in making decisions regarding admission and discharge of patients • Clinical symptoms lead to diagnosis; subsequent evaluation is important in determining treatment • Initially must assess respiratory rate and oxygen saturation because work of breathing, tachypnea, and hypoxia are most clinically significant in determining severity • CXR warranted for infants in respiratory distress • CXR commonly demonstrates hyperinflation, patchy atelectasis, and infiltrates • Early onset < 3 years • Abnormal lung function by 3 years • Most patients are atopic • Asthma symptoms are more common in boys before puberty, but more severe in girls after puberty • The asthma predictive index was developed to help predict which children would be likely to develop persistent asthma symptoms -Its negative predictive value is better than its positive predictive value -Positive if: • 1 or more major risk factors: Parental history of asthma, atopic dermatitis, sensitization to aeroallergen OR • 2 or more minor risk factors: Sensitization to food, more than 4% eosinophilia, wheezing apart from upper respiratory tract infections • Inflammation plays a key role in asthma pathophysiology • Important contributors to the inflammatory response include: -Cell types including lymphocytes, eosinophils, mast cells, neutrophils, macrophages, smooth muscle cells, and epithelial cells -Inflammatory mediators such as IL-5, IL-4, and IL-13 • IgE plays an important role in activation and maintenance of allergic disease -Early-phase reaction or Type I IgEmediated reactions occur within minutes of an allergen-related trigger • Cells (such as mast cells) release preformed inflammatory mediators that can lead to vasodilation, edema, bronchoconstriction, and increased airway mucus secretion • Early airway obstruction occurs, in addition, there is activation of leukocytes, which in turn leads to late-phase IgEmediated reactions -A late-phase IgE-mediated reaction follows 2-12 h later • Characterized by persistent obstruction and mucus hypersecretion • The late reaction is the consequence of inflammatory mediators • Respiratory infections -Viral respiratory infections are the most common trigger of exacerbations in children (especially those < 10 years) and have been associated with future development of asthma -Bronchiolitis associated with RSV and rhinovirus in early childhood increases risk of developing asthma • There is no diagnostic test for asthma • Diagnosis is based on constellation of clinical symptoms including presence of airflow limitation that is at least partially reversible • Exclusion of alternative diagnoses (Table 20 .2) • Assess for associated comorbidities, including obesity, GER, rhinitis/sinusitis, depression, anxiety, sleep-disordered breathing, and allergic bronchopulmonary aspergillosis • Typical symptoms: -Wheezing, chest tightness, shortness of breath, cough -Symptoms are usually worse at night and early morning -The more symptoms, the more likely the diagnosis -If cough only symptom or chronic sputum production reported, broaden your differential -Respiratory infections (especially viral infections) -Exercise -Inhaled allergens (e.g., pollen, pet exposure, dust mites, cockroaches, mold) -Irritants (tobacco smoke, air pollution) -Medications (e.g., nonsteroidal antiinflammatory medications, beta-blockers) -Changes in weather • Physical findings and objective data: -Wheezing on exam, especially on forced exhalation; signs of atopy such as allergic shiners, rhinitis, or eczema -PFT • Spirometry measurements before and after bronchodilator recommended in the assessment of patients ≥ 5 years/o ▪ Look for obstruction on spirometry ▪ Use bronchodilator response to assess reversibility ▪ Decline in lung function (FEV1 and FEV1/FVC ratio) can usually be seen in those with symptoms starting < 3 years and is noted by 6 years -Exercise challenge can be used to evaluate for exercise-induced asthma • Baseline spirometry obtained prior to treadmill challenge • Spirometry obtained after exercise to document drop in pulmonary function -CXR • May show hyperinflation, peribronchial wall thickening, atelectasis • Most helpful to evaluate for differential causes of symptoms -Allergy testing • Skin testing or serum testing may help in identifying sensitization to inhaled perennial allergens • Severity is best assessed prior to initial controller therapy (Table 20. 3) • Assess components of severity: impairment and risk -Impairment: Relates to the frequency and intensity of symptoms, how the disease affects day-to-day function -Risk estimates likelihood of exacerbations or having reduced lung function SABA short-acting beta-2 agonist, FEV1 forced expiration volume in 1 s, FVC forced vital capacity -Shortness of breath, coughing, wheezing, chest tightness, or pain associated with physical activity. Can present in isolation or associated with symptoms of poorly controlled asthma -Symptoms present during or minutes after exertion, peak after 5-10 min of exercise, and improve within 20-30 min -Usually self-limited but may result in a severe asthma attack • Management of EIA -Warm-up period 15 min prior to exercise and wearing scarf/mask may reduce symptoms -In 80% of patients, short-acting beta-agonists (SABAs) before exercise prevent symptoms for about 2-3 h -Montelukast can lead to decrease in bronchospasm in about 50% of patients, but onset of action is several hours after administration • After initial diagnosis: Review response to therapy, reassess severity and control, adjust therapy to reduce impairment and risk • Periodic reassessment recommended due to variable nature of asthma • Annual increase in asthma exacerbations seen in September • Reassess patients every 2-6 weeks initially to gain disease control and then every 1-6 months • Assess frequency of daytime symptoms, nighttime symptoms, and reliever use over the past month • Can use asthma control tools such as the Asthma Control Test (ACT) or Asthma Control Questionnaire (ACQ) as part of assessment • Evaluate technique and compliance with controller therapy • PFT at initial assessment, after treatment and stabilization of symptoms, during periods of uncontrolled symptoms, and at least every 1-2 years • Increased risk of exacerbation if 1 or more: -Uncontrolled asthma symptoms, increased use of SABA, inadequate dose or use of ICS, < 60% FEV1, psychological and/or socioeconomic barriers, comorbidities, eosinophilia, exposure to known triggers, history of pediatric intensive care unit or intubation, ≥ 1 severe exacerbation in the last year • Consider step-down in therapy if asthma under good control for at least 3 months Education: • Self-management education (patient and families) key in individual asthma control and improve outcomes • Provide asthma action plan that provides guidance in daily management as well as plan of care for worsening symptoms • Assess for allergen exposures either by skin testing or serum testing and correlate with medical and exposure history • Patients should reduce exposure to allergens, irritants, and pollution to which they are sensitized or have a reaction • Assess for and control comorbidities associated with increased risk for poor control: Obesity, allergic rhinitis/sinusitis, allergic bronchopulmonary aspergillosis, OSA, depression, and other psychosocial factors. • Initial treatment based on severity category (Table 20 .4) • On reassessment of asthma control, adjust therapy regardless of initial severity classification. Step 1 Step 1 SABA as needed SABA as needed Consider intermittent ICS Persistent symptoms or high-risk factor for exacerbations Step 2 Uncontrolled asthma symptoms, > 3 exacerbations/y or consider trial in those with frequent wheezing (every 6-8 weeks) Step 2 Low-dose ICS Daily low-dose ICS Asthma symptoms/SABA use > 2X/week Step 2 Uncontrolled asthma on low-dose ICS Step 3 Low-dose ICS Double low-dose ICS Consider LRTA Asthma symptoms most days or waking > 1X/ week Step 3 Uncontrolled asthma on double low dose Step 4 Medium-/high-dose ICS or if ≥ 12 years, low-dose ICS/ LABA Refer to specialist Add LTRA Add intermittent ICS or increased ICS frequency Severe initial presentation (uncontrolled asthma or acute exacerbation) Step 4 Short OCS course AND High-dose ICS or if ≥ 12 years, moderate dose ICS/LABA Uncontrolled asthma after initial therapy Step up therapy or use adjunct therapies Step 3: Can add LTRA to low-dose ICS Step 4: Can add ipratropium (if > 12 years) to ICS or add LTRA to high-dose ICS Step 5: Refer to specialist for add-on therapy (e.g., tiotropium, anti-IgE, anti-IL-5, low-dose OCS) Adapted with modifications from Global Initiative for Asthma Report [1] SABA short-acting beta-2 agonist, ICS inhaled corticosteroid, LRTA leukotriene receptor antagonist, LABA long-acting beta-2 agonist, OCS oral corticosteroid • Block leukotriene, which acts as a potent mediator leading to bronchoconstriction, vascular permeability, and increased mucus production and activates inflammatory cells • Usually an add-on therapy and not preferred treatment option in mild persistent asthma • Adverse effects -Generally, well tolerated, but associated with upper respiratory tract infection, fever, headache, sore throat, behavior/ mood-related changes Acute asthma exacerbations • Patients present with acute or subacute worsening from baseline symptoms and/or pulmonary function • Brief initial assessment should concentrate on time of onset and possible triggers, severity compared to previous exacerbations, recent use of asthma medications, and associated cardiorespiratory process • Severe exacerbation presentation: shortness of breath, inability to speak in full sentences, sitting hunched, agitated, accessory muscle use, tachypnea and tachycardia, pulsus paradoxus > 20 mmHg, SpO2 < 92% (after an hour of therapy is a good predictor for hospitalization needs), PEF < 40% baseline • Life-threatening exacerbations can present with silent chest, drowsiness, or confusion • CXR not recommended routinely, but patient can present with atelectasis, which needs to be clinically differentiated from pneumonia • Therapy for acute exacerbations: - • Findings on exam may be dullness to percussion, crackles, decreased breath sounds, and bronchial breaths • In the absence of fever, tachypnea, increased work of breathing, or auscultatory abnormalities, bacterial pneumonia is unlikely • Clinical diagnosis as above • Rapid influenza test may help to identify the cause of fever and to reduce unnecessary use of antibiotics • CBC, chemistry, or serology will not help in identifying etiology or aid in management • Blood culture rarely helpful (only 10% of the time organism is recovered) • ESR and C-reactive protein (CRP) may be elevated but are not specific • Tuberculin test if there are TB risk factors or TB is being considered • CXR (Fig. 20.3) Fig. 20.3 A 9 -year-old female presents with cough and fever. Chest radiograph shows right upper lobe infiltrate. -A CXR will not change clinical management for patients being treated as outpatient -Afebrile children do not need a CXR -CXR always lags behind clinical response. No need to obtain to confirm response to antibiotics -Obtain a CXR if: • Complicated pneumonia is being considered • Clinical deterioration • Prolonged fever with no obvious source of infection • Abdominal pain with normal appendix • National guideline for antibiotic initiation with community-acquired pneumonia: -High-dose amoxicillin (80-90 mg/kg/day) for uncomplicated cases being treated as outpatient -Augmentin or cefuroxime as outpatient, if resistant -School age or > 5 years of age azithromycin to cover for Mycoplasma • Indication for hospitalization: Suspected sepsis, severe dehydration, toxic appearance, hypoxemia (SpO2 < 90%), unresponsive to outpatient therapy, inability to drink -Intravenous fluids and O2, if needed, and antibiotics -Consider blood culture, CXR, chemistry profiles, and CBC -If inpatient: Cefuroxime, ceftriaxone, or cefotaxime are the antibiotics of choice -Adolescents: Fluoroquinolones (levofloxacin, gatifloxacin, moxifloxacin) may be used for atypical pneumonia -If Staphylococcus is considered, add clindamycin or vancomycin -Uncomplicated pneumonia responds to antibiotics in 48-96 h -If no response or persistent pneumonia • Repeat CXR • Consider empyema, bacterial resistance, and nonbacterial pneumonia (FB, CF, pulmonary sequestration, bronchiolitis obliterans, aspiration, and hypersensitivity pneumonitis) • Destruction of the airway wall (bronchi and bronchioles) leads to loss of integrity of the muscular and elastic layers of the bronchial wall, results leading to dilated and collapsible airway • Productive cough is most common symptom • Dyspnea, rhinosinusitis, and hemoptysis are less common • Crackles, wheezing, and rhonchi are often heard; digital clubbing may be present • CF is the most common cause of bronchiectasis in pediatric patients in the USA. • Impaired mucociliary clearance (CF and ciliary dyskinesia) • Infections (Mycobacterium tuberculosis, Pseudomonas, adenovirus) • Immunodeficiency syndromes • Immune-mediated (connective tissue diseases), allergic bronchopulmonary aspergillosis (ABPA), inflammatory bowel disease (IBD) • Airway injury (chronic aspiration, inhalation of toxic fumes, hot gases) • Congenital or connective tissue abnormalities (yellow nail, Marfan syndrome, alpha-1 antitrypsin deficiency, airway cartilage deficiency, tracheobronchomegaly, Young syndrome) • Obstructed airways (retained FB, intraluminal masses, extraluminal compression) • PFT may show obstruction, restriction, or both, depending on etiology and severity • CXR may reveal airway dilation, increased pulmonary markings with "tram tracking" (thickening of the bronchial walls), and areas of atelectasis • High-resolution CT scan is the gold standard and reveals detailed anatomy of the bronchial tree • There is a lack of airway tapering with luminal dilation, bronchial wall thickening, honeycombing, and mucous plugging • Determining the primary cause is of critical importance and is best done with direction from pediatric pulmonologist • Evaluation may include swallow study, sweat chloride testing, and bronchoscopy • Mucus clearance should be enhanced with hypertonic saline nebulization, inhaled mucolytics, and chest physiotherapy • ICS can reduce airflow obstruction • Chronic macrolide therapy has been found to be as beneficial as anti-inflammatory drugs • Culture should be obtained • Aggressive treatment of Pseudomonas and Staphylococcal infections is indicated, but antimicrobial therapy should be targeted to specific pathogens • If bronchiectasis is localized and severe, lobectomy is a last resort in cases without systemic etiology • Autosomal recessive inheritance pattern due to a mutation on the long arm of chromosome 7 • Highest incidence in Caucasians, highly prevalent in Latinos and African Americans. Less frequently seen in Asians and Native Americans • CF transmembrane regulator (CFTR) dysfunction/absence leads to: -Excessive reabsorption of sodium and deficient chloride secretion -Passive movement of water is decreased, and airway secretions are dehydrated with very low surface liquid layer -Cilia become compressed, inhibiting ciliary clearance and cough clearance -Bacteria thrive, and the immune function at the airway surface is also abnormal -Repeated bacterial infection leads to airway damage and bronchiectasis in the lung • CFTR dysfunction leads to dysfunction in other organ systems: ▪ Organ systems primarily involved: respiratory, GI, genitourinary, and integumentary (sweat glands) • There are > 1700 mutations in the CFTR protein • Different classes of mutations result in different levels of CFTR function/production, thus variable clinical presentation • The most prevalent mutation is F508 deletion (F508del), associated with both pulmonary disease and pancreatic insufficiency -85% of the US population have one copy • Pulmonary manifestations -Cough is most common and consistent symptom. Often productive but can also be dry -Increased anteroposterior (AP) diameter of the chest due to hyperinflation associated with airway obstruction -Hyperresonance, diffuse or localized crackles -Nasal obstruction, nasal polyps, recurrent sinusitis -Clubbing -In advanced disease: Cyanosis, exercise intolerance, shortness of breath, growth failure, respiratory failure, and death -Common bacterial pathogens include Staphylococcus aureus and Pseudomonas aeruginosa -Multidrug-resistant organisms are becoming more common (MRSA, Stenotrophomonas maltophilia, and Burkholderia cepacia complex). -Meconium ileus is seen in up to 20% of newborns with CF -Characterized by abdominal distention, emesis, and failure to pass meconium in the first 24-48 h -Abdominal radiograph (KUB) shows air fluid level with ground glass-appearing material in the central abdomen -Gastrografin enema diagnostic and therapeutic -Can give hyperosmolar contrast as well -May need to consider surgery if medical management fails -Pancreatic-insufficient (PI) patients will progress to complete or almost complete disruption of pancreatic acini and replacement with fibrous tissue. Lack of endogenous digestive enzymes causes fat malabsorption • Symptoms: Frequent, loose, foul smelling, and greasy stools, flatus, and poor weight gain • PI also associated with fat-soluble vitamins (ADEK) deficiency ▪ Deficiencies can cause night blindness, decreased bone density, and neurologic dysfunction (neuropathy, dementia) • Genitourinary manifestations -Pubertal development is often delayed, particularly if nutrition is poor -Females have decreased fertility related to thick cervical mucus -Many females with CF carry pregnancies to term, without detriment to lung function -> 95% of males are infertile due to absence or atretic vas deferens • Integumentary manifestations -Excessive salt loss in sweat predisposes children to hyponatremia, particularly when hot or exercising -Hypochloremic alkalosis and dehydration, especially in hot environments, can be deadly in infants • Distal intestinal obstruction syndrome (DIOS) -More commonly seen with poor enzyme adherence, also in those with a history of meconium ileus -Fecal material accumulates in the terminal portion of the ileum and cecum -Osmotic agents such as polyethylene glycol (MiraLAX®) are helpful -Can also give enemas and other stool softeners as an adjunct -If severe or complete obstruction, can require Gastrografin enema to relieve obstruction • Rectal prolapse -Due to combination of intestinal disease and poor supporting musculature from poor nutrition -Evidence of recurrent rectal prolapse in otherwise healthy children is an indication for sweat chloride testing to assess for CF • Nasal polyps -Most prevalent in teens and young adults -Local steroids and nasal rinses can be of benefit for symptom control -If there are nasal obstructive symptoms such as chronic rhinorrhea, snoring, and sinus pain or pressure, surgical intervention is warranted -Even with surgical resection, polyps are likely to return • CF-related liver disease -Found in 2-3% of cases -More common in those with severe mutations with little CFTR function -Mainstay of treatment is to prevent ongoing liver damage and associated complications of portal hypertension and cirrhosis • CF-related diabetes -Most common comorbidity -Affects 20% of adolescents and up to 40% of adults -Shares features of both Type I and Type II diabetes but is a distinct entity -Primarily caused by insulin insufficiency, but fluctuating insulin levels also play a part -Often clinically silent, screen with oral glucose tolerance test (OGTT) annually after age 10 years • Primary spontaneous pneumothorax -Occurs without trauma or underlying cause -More frequently in tall, thin males, likely related to subpleural blebs -Family history is positive in many patients -Usually occurs at rest, but can be precipitated by air travel in an unpressurized cabin, weight lifting, and Valsalva maneuver • Secondary pneumothorax -Related to an underlying lung issue (asthma, CF, necrotizing pneumonia, interstitial lung disease) -Trauma (blunt trauma) -Loud music (air pressure) -Catamenial pneumothorax (unusual condition associated with menses due to passage of intra-abdominal air through a diaphragmatic defect) • Onset is abrupt, and the severity depends on degree of lung collapse • In simple pneumothorax, the lung collapses up to 30% • In a tension pneumothorax, patient will be hypoxemic, dyspneic, and possibly cyanotic • OSA and primary snoring are part of a spectrum of sleep-disordered breathing -Primary snoring = Incidence 12-20%; no discrete obstructive events or gas exchange abnormalities -OSA = Prevalence 2-4% in healthy children; obstructive apnea and hypopneas often seen with arousals, disturbed sleep, and gas exchange abnormalities • The disorder can occur at any age but is most common in the preschool age group (2-6 years) and adolescents • A higher prevalence has been reported in African American and obese children Blood gas analysis • Arterial blood gas analysis (see Table 20 .1) • In capillary blood gases, values are comparable to arterial pH and pCO2, but pO2 measurement in CBG is less reliable. • Imaging in suspected FB: -Get inspiratory and expiratory or bilateral decubitus views. May be able to see asym- • A late-phase IgE-mediated reaction follows 2-12 h later. • Viral respiratory infections (such as RSV and rhinovirus) have been associated with future development of asthma and are the most common trigger of exacerbations in young children. • All that wheezes is not asthma! Think about the differential if diagnosis not clear. • If cough is the only symptom or chronic sputum production is reported, broaden your differential. • ICS are the most potent and effective medication for long-term control of asthma. • EIA: In 80% patients, SABA before exercise prevents symptoms for about 2-3 h. • Acute asthma exacerbation: SpO2 < 92% after an hour of therapy is a good predictor for hospitalization need. • Streptococcus pneumoniae is the most common bacterial cause in children older than 1 week of age. • Viruses account for 14-35% of cases. • For school-age children needing inpatient therapy: Cefuroxime, ceftriaxone, and cefotaxime are the antibiotics of choice. • CF is the most common cause of bronchiectasis in pediatric patients in the USA. • CFTR dysfunction/absence leads to thick secretions, impaired mucociliary clearance, recurrent inflammation, and infection, leading to development of bronchiectasis. • All US states have newborn screening, but results are not 100% sensitive. • Diagnostic tests include sweat testing and DNA testing. • Patients should be managed by a multidisciplinary team at a CF care center. • Pneumothorax/pneumomediastinum -Pneumothorax > 5% hemithorax will require chest tube drainage, but pneumomediastinum usually resolves spontaneously. • Pectus excavatum: > 90% of congenital wall anomalies • Scoliosis: Curvatures > 50° more likely to be progressive. Extreme curvatures can lead to respiratory compromise due to restrictive chest wall disease. • Higher prevalence in African Americans and obese children • Polysomnography diagnostic test of choice • Adenotonsillectomy is first-line therapy and curative in about 80% of children with OSA. • Peaks at 2-4 months of age, male predo minance • "Back to sleep" supine position for sleep led to marked decline in SIDS rate Global strategy for asthma management and prevention. www.ginasthma.org Usefulness of chest radiographs in children with acute lower respiratory tract disease Disorders of the chest wall: clinical manifestations American Academy of Pediatrics Subcommitee on Diagnosis and Management of Bronchiolitis. Diagnosis and management of bronchiolitis Monoclonal antibody for reducing the risk of respiratory syncytial virus infection in children A 7-month old girl with cyanotic spells Diagnosis and management of common sleep problems in children Primary ciliary dyskinesia Spontaneous pneumomediastinum: a comparative study and review of the literature Pleural effusions and pneumothoraces Guidelines for evaluating chronic cough in pediatrics: ACCP evidence-based clinical practice guidelines Clinical practice Stridor and airway obstruction Imaging of the respiratory system Prenatal and post-natal environmental tobacco smoke exposure and children The development of allergic inflammation Global strategy for asthma management and prevention. www.ginasthma.org Pulmonary hemorrhage/hemoptysis in children Diagnosis approach to respiratory disorders Use of monitoring devices for assessing ventilation and oxygenation Case 1: persistent tachypnea in an infant Management of congenital tracheal stenosis Pediatric laryngology & bronchoesophagology Bronchopulmonary dysplasia Liver disease in cystic fibrosis Long-term complications of congenital esophageal atresia and/or tracheoesophageal fistula Diagnostic sweat testing: the Cystic Fibrosis Foundation guidelines Diagnosis and management of childhood obstructive sleep apnea syndrome Chest wall and spinal deformities Congenital lesions of the lung A clinical guide to pediatric sleep: diagnosis and management of sleep problems National Heart, Lung, and Blood Institute. National asthma education program Expert Panel Report 3 (EPR-3). Guidelines for the diagnosis and management of asthma. Bethesda: National Institutes of Health Pulmonary hemosiderosis Pediatric hypertension ATS Ad Hoc Committee on Infants with Recurrent or Persistent Wheezing, et al. Official American Thoracic Society clinical practice guidelines: diagnostic evaluation of infants with recurrent or persistent wheezing Official American Thoracic Society clinical practice guidelines: diagnostic evaluation of infants with recurrent or persistent wheezing Spontaneous pneumothorax Pediatric pulmonology Pediatric pulmonology British Thoracic Society Cough Guideline Group. BTS guidelines: recommendations for the assessment and management of cough in children Light MJ, editor. Pediatric pulmonology Subcommittee on Apparent Life Threatening Events, et al. Brief resolved unexplained events (formerly apparent life-threatening events) and evaluation of lowerrisk infants Light MJ, editor. Pediatric pulmonology The authors gratefully acknowledge the contributions of Karen Hardy, MD, Division of Pulmonary Medicine, Department of Pediatrics, Stanford Children's Health Specialty Services, Emeryville, California, to the first edition of this chapter, many of which have been incorporated into this edition as well. metric hyperinflation in side with foreign body.-Most foreign bodies are not seen, as they are radiolucent. Stridor/wheezing • Inspiratory-Extrathoracic swelling or obstruction will lead to airway collapse on inspiration. • With symptoms and presenting during infancy, most will require surgical intervention. • Most common lower respiratory tract infection in < 2 years • Etiology: RSV > 50% • Apnea may be more prominent than wheezing in infants < 2 months or former preterm infants. • Peak symptomatology at days 3-4 of illness ("day of illness") • "Day of illness": Important variable for providing anticipatory guidance in outpatient management and making decisions regarding admission/discharge • Routine use of bronchodilators or systemic steroids in management NOT recommended • Asthma symptoms are more common in boys before puberty, but more severe in girls after puberty. • Early-phase reaction or Type I IgEmediated reactions occur within minutes of an allergen-related trigger.