Approach to Wheezing Child Dr. Mohamed Haseen Basha Assistant professor ( Pediatrics) Faculty of Medicine Al Maarefa College of Science and Technology

Wheeze Wheeze is a continuous & musical sound that originates from oscillations in narrowed airways, mostly heard in expiration due to critical airway obstruction. Sign of lower (intra-thoracic) airway obstruction. If there is widespread narrowing of airways leading to various levels of obstruction to airflow (eg. asthma), polyphonic wheeze is heard i.e. sounds of various pitches. Monophonic wheeze (single pitch) is produced in larger airways during expiration eg. distal tracheomalacia, bronchomalacia.

Infants & children are prone to wheeze due to different set of lung mechanics ( as compared to older children & adults) Obstruction to airflow  airway caliber Resistance to airway: In children < 5 years, small caliber peripheral airways can contribute upto 50% of airway resistance, marginal additional narrowing can cause further flow limitation & subsequent wheeze.  compliance of lung Differences in tracheal cartilage composition & airway muscle tone causes further increase in airway compliance.

All these mechanisms combine to make the Infant more susceptible to airway collapse  Increased resistance  Subsequent wheeze Many of these are outgrown in the 1 st year of life itself

The most likely diagnosis in children with recurrent wheezing is asthma. However, other diseases can present with wheezing in childhood, and patients with asthma may not wheeze. Some experts distinguish between wheezes and rhonchi based upon the dominant frequency, or pitch, of the sound. Wheezes have a dominant frequency greater than 400 Hz, whereas rhonchi are of lower frequency. However, the clinical significance of this distinction, if any, is not well defined.

Types of Wheezers Transient wheezers - Risk factor is primarily diminished lung size Persistent wheezers - Initial risk factors being exposure to passive smoking, Maternal asthma, Persistent rhinitis, Eczema <1yr age, H/O Allergy. At an increased risk of developing clinical asthma Late onset wheezers

Causes of Wheezing a) Infections Viral : RSV (bronchiolitis) Human meta pneumovirus Influenza, parainfluenza Adenovirus Rhinovirus Others: TB, Chlamydia trachomatis, Histoplasmosis b) Asthma c) Immunodeficiency states: IgA deficiency, B cell deficiency, AIDS, d) Mucociliary clearance disorders: Cystic fibrosis, Primary ciliary dyskinesias Bronchiectasis

e) Anatomic abnormalities: Central airway abnormalities: - Malacia of larynx, trachea, bronchi - Tracheoesophageal fistula ( H type) - Laryngeal cleft (leading to aspiration) Extrinsic airway anomalies (leading to compression) - Vascular ring/ sling - Mediastinal LN’pathy (infection/ tumor) - Esophageal foreign body Intrinsic airway anomalies: - Airway hemangioma - Cystic adenomatoid malformation - Bronchial/ lung cyst - Congenital lobar emphysema - Aberrant tracheal bronchus - Sequestration - CHD with L  R shunt ( pulmonary edema) - Foreign body

f) Bronchopulmonary Dysplasia g) Aspiration Syndromes - GERD - Pharyngeal/ swallow dysfunction h) Interstitial lung disease i) Heart Failure j) Anaphylaxis k) Inhalation Injury – Burns l) WALRTI, Wheeze a/w URTI m) Drugs: Ibuprofen, Aspirin, Rifampicin, Erythromycin

Causes of wheezing in children Acute Asthma Bronchiolitis Bronchitis Laryngotracheobronchitis Bacterial tracheitis Foreign body aspiration Esophageal foreign body

Causes of wheezing in children Chronic or recurrent Structural abnormalitiesFunctional abnormalities Tracheo-bronchomalaciaAsthma Vascular compression/ringsGastroesophageal reflux Tracheal stenosis/websRecurrent aspiration Cystic lesions/massesCystic fibrosis Tumors/lymphadenopathyImmunodeficiency CardiomegalyPrimary ciliary dyskinesia Bronchopulmonary dysplasia Retained foreign body (trachea or esophagus) Bronchiolitis obliterans Pulmonary edema Vocal cord dysfunction Interstitial lung disease

Two important aspects of the medical history include the Patient's age at the onset of wheezing The course of onset (acute versus gradual)

Clinical Manifestations HISTORY Onset, Duration & associated factors of wheezing Birth history: weeks of gestation, NICU admission, h/o intubation / O2 requirement, maternal complications eg. Infection- HSV, HIV; prenatal smoke exposure Past medical history: co-morbid conditions eg. syndromes or association. Social history: Environmental history of smokers at home, number of siblings, occupation of inhabitants at home, pets, TB exposure. Family history: Cystic Fibrosis, immunodeficiency, asthma in 1 st degree relatives OR any other recurrent respiratory conditions should be obtained.

RISKS OF FAMILY HISTORY OF ATOPY  No family history:16%  Single parent atopy:22%  Maternal Atopy:32 %  Both parents atopic:50%

Medical history in wheezing infant: Did the onset of symptoms begin at birth or thereafter? Is the infant a noisy breather & when is it most prominent? Is there a history of cough apart from wheezing? Was there an earlier LRTI? Have there been any emergency department visits, hospitalizations, or ICU admission for Respiratory Distress ? Is there a history of eczema? How is the infant growing & developing? Is there associated failure to thrive? Are there s/o intestinal malabsorption including frequent, greasy, or oily stools? Is there a maternal history of genital HSV infection?

What was the gestational age at delivery? Was the patient intubated as neonate? Does the infant bottle feed in the bed or crib, especially in propped position? Are there any feeding difficulties including choking, gagging, arching, or vomiting with feeds? Any new food exposure? Is there a toddler in the home or lapse in supervision in which foreign body aspiration could have happened? Change in caregivers or chance or non accidental trauma?

Features in the history that favor the diagnosis of asthma include: Intermittent episodes of wheezing that usually are the result of a common trigger (ie, upper respiratory infections, weather changes, exercise, or allergens) Seasonal variation Family history of asthma and/or atopy Good response to asthma medications Positive asthma predictive index

Features suggestive of a diagnosis other than asthma in children History Onset of symptoms in early infancy Neonatal respiratory distress +/- ventilator support Neonatal neurologic dysfunction Intractable wheezing unresponsive to bronchodilators Wheezing associated with feeding or vomiting Difficulty swallowing +/- recurrent vomiting Diarrhea Poor weight gain Stridor Oxygen requirement >1 week after acute attack

PHYSICAL EXAMINATION: Measurement of Weight and Height Vitals especially RR, SPO2 Growth charts for signs of FTT Upper airway signs of atopy: boggy turbinates, posterior oropharynx cobble stoning Evaluate skin for eczema, hemangioma Midline lesions may be associated with intrathoracic lesions Clubbing Stridor +/-

Signs of Respiratory Distress- Tachypnea, nasal flaring, tracheal tugging, SCR/ICR, excessive use of accessory muscles Prolonged expiratory time, expiratory whistling sounds. Auscultation: aeration to be noted, expiratory wheeze, lack of audible wheeze due to complete airway obstruction. Trial of bronchodilators to evaluate change of wheezing

Chest examination should focus on the following features: Inspection: For the presence of respiratory distress, tachypnea, retractions, or structural abnormalities. Pertinent findings include an increased anteroposterior (AP) diameter associated with chronic hyperinflation, pectus excavatum caused by chronic airway obstruction and exaggerated swings in intrathoracic pressure, or scoliosis complicated by airway compression. Palpation: To detect supratracheal lymphadenopathy or tracheal deviation. Percussion: can define the position of the diaphragm and detect differences in resonance among lung regions and is the most underperformed part of the examination.

Auscultation: Allows identification of the characteristics and location of wheezing, as well as variations in air entry among different lung regions. A prolonged expiratory phase suggests airway narrowing. Wheezing caused by a large or central airway obstruction (eg, vascular ring, subglottic stenosis, tracheomalacia) has a constant acoustic character throughout the lung but varies in loudness depending upon the distance from the site of obstruction. Degree of narrowing varies from place to place within the lung in the setting of small airway obstruction (eg, asthma, cystic fibrosis, primary ciliary dyskinesia, aspiration). Focal wheezing is usually indicative of a localized and mostly structural airway abnormality,

Crackles can be present with wheezing in asthma and in a variety of other conditions, such as those leading to bronchiectasis (eg, cystic fibrosis, primary ciliary dyskinesia, immune deficiency). Early inspiratory crackles are often present in patients with asthma due to air flowing through secretions or slightly closed airways during inspiration. Late inspiratory crackles are usually associated with interstitial lung disease and early congestive heart failure. Thus, the presence of crackles does not exclude the diagnosis of asthma. Decreased wheezing after bronchodilator therapy is suggestive of asthma but does not rule comorbid conditions if clinically suspected.

Cardiac exam- Murmurs and signs of heart failure. Examination of the skin for eczema (common in atopic patients) or other cutaneous lesions may assist in diagnosis. Nasal examination may reveal signs of allergic rhinitis, sinusitis, or nasal polyps. The presence of nasal polyps in children necessitates an evaluation for cystic fibrosis.

Features suggestive of a diagnosis other than asthma in children Physical examination Failure to thrive Clubbing Cardiac murmur Stridor Focal lung signs Nasal polyps Crackles on auscultation Cyanosis Laboratory features Focal or persistent chest radiograph abnormalities Anemia Irreversible airflow obstruction Hypoxemia

Diagnostic evaluation Initial evaluation depends on likely etiology 1. Chest X-ray: hyperinflation, Space Ooccupaying Lesion, signs of chronic diseases like Bronchiectasis, Focal infiltrates 2. Trial of bronchodilators- Diagnostic & therapeutic in bronchiolitis & asthma, won’t effect fixed obstruction May worsen wheezing in tracheal/ bronchomalacia. 3. Baseline immunity in complicated cases

Exclude other conditions 4) Structural problems: bronchoscopy 5) Polysomnography 6) Esophageal disease: Barium swallow, pH probes, Upper GI scopy 7) Primary ciliary dyskinesia: Nasal ciliary motility, Exhaled NO, Electron Microscopy, saccharine test 8) TB: Mantoux, induced sputum/ gastric lavage/ BAL for Culture, microscopy & PCR 9) Bronchiectasis: HRCT scan, BAL 10) Cystic Fibrosis: Sweat chloride test, 11) Systemic immune deficiency: Ig subtypes, lymphocytes & neutrophil function, HIV 12) Cardiovascular disease: ECHO, Angiography 13) Viral testing (PCR, viral culture) is helpful if diagnosis is uncertain.

Treatment 1) Comfort the child: Try to keep your baby calm. Having a cough and a noisy wheeze frightens children and breathing is more difficult when they are upset. 2) Offer frequent liquids 3) Bronchodilators: Administer inhaled short acting beta-2 agonist (eg salbutamol) & observe the response. Response is unpredictable. Therapy to be continued in all asthma patients with exacerbations with viral illness. 4) Ipratropium bromide: Anticholinergic agent can be used as adjunct therapy Also useful in patients with significant Tracheal or Bronchomalacia

5) Oral/ IV steroids: Used for atopic wheezing infants thought to have asthma i.e. refractory to other medications 6) Inhaled steroids: Appropriate for maintenance therapy in known reactive airways but not useful in acute illness To be used if significant h/o atopy ( food allergy, eczema) present Maintenance treatment with inhaled steroids is recommended for multiple- trigger wheeze.

7) In acute Bronchiolitis: -Mainstay of treatment is supportive -Hypoxemic child: cool humidified oxygen - Avoid sedatives -Nebulized epinephrine more effective 8) Montelukast is recommended for the treatment of episodic (viral) wheeze, to be started when symptoms of a viral cold develop 9) Ribavarine: antiviral administered by aerosol - Used for children with Congenital Heart Disease / Chronic Lung Disease 10) No role of antibiotics unless secondary bacterial infection

Prevention 1) Reduction in severity & incidence of ac. bronchiolitis due to RSV is possible through administration of pooled Hyperimmune RSV Intravenous Immunoglobulin (RSV IVIg, Respigam) 2) Palivizumab, a monoclonal antibody to the RSV F protein, before & during RSV season. It is recommended for children < 2yrs age with chronic lung disease (BPD) or prematurity 3) Inhaled corticosteroids and montelukast may be considered in preschool child with recurrent wheeze.

4) Avoid smoking – Smoking in the home increases the risk of respiratory problems in children 5) Educating parents regarding causative factors and treatment is useful. 6) Allergen avoidance may be considered when sensitisation has been established 7) Meticulous handwashing is the best measure to prevent nosocomial infection

Approach to evaluation of wheezing in children based upon suspected diagnosis Acute Suspected diagnosis Signs and symptomsDiagnostic evaluation Asthma History of recurrent wheeze, cough, at least partial response to bronchodilator History, PFT with bronchodilators, empiric trial of bronchodilators, exercise or methacholine challenge testing, chest radiography only if atypical, skin (or in vitro) testing for aeroallergen sensitization if history suggests inhalant allergen triggers Viral bronchiolitis Prodrome with rhinitis, occurs in infancy and early childhood, seasonal pattern History, age, season, rapid antigen testing (RSV, influenza), viral cultures, chest radiography Foreign body Sudden onset of coughing and wheezing History, physical examination, chest radiography, bronchoscopy

Approach to evaluation of wheezing in children based upon suspected diagnosis Chronic Suspected diagnosisSigns and symptomsDiagnostic evaluation AsthmaAs above Tracheomalacia Persistent wheeze, starts early in life, poor response to bronchodilators, varies with position and activity History, fluoroscopy, flexible bronchoscopy Cystic fibrosis Chronic productive cough, crackles, with or without clubbing, failure to thrive, recurrent respiratory infections Sweat chloride test, genetic testing Swallowing dysfunction Neurologic abnormality (nonuniversal), choking with eating, symptoms exaggerated by feeding Radiographic swallowing study Gastroesophageal reflux Symptoms sometimes related to eating, vomiting, refusal to eat, failure to thrive Barium swallow, pH probe, bronchoscopy and bronchoalveolar lavage Vascular ring or sling Persistent symptoms, starts early in infancy, may be exaggerated by position, homophonous wheeze Barium swallow, MRI

Chronic Suspected diagnosisSigns and symptomsDiagnostic evaluation Tracheal stenosis Persistent symptoms, with or without stridor, homophonous wheeze Chest radiograph, CT scan, bronchoscopy Mediastinal nodes or mass Persistent symptoms, localized wheezing, no response to bronchodilator, systemic symptoms of underlying disease Chest radiograph, CT scan Immunodeficiency Recurrent sinopulmonary infections, crackles, FTT, clubbing Immunoglobulins, vaccine responses Primary ciliary dyskinesia Persistent sinusitis and otitis media with draining ears, recurrent respiratory infection, wet cough with sputum production, crackles, clubbing, FTT Ciliary biopsy, with or without genetic testing Vocal cord dysfunction Inspiratory stridor, poor response to bronchodilators, absent symptoms during sleep, teenage, exercise related Exercise testing, pulmonary function tests, laryngoscopy while symptomatic Bronchiolitis obliterans History of predisposing disease, ie, viral infection or transplantation, dyspnea, persistent wheezing Chest CT scan, lung biopsy

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