Approach to a child with bronchial asthma Ibrahim Alsaif Consultant Pediatrician Pediatric Emergency...

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Approach to a child with bronchial asthma

Ibrahim AlsaifConsultant Pediatrician

Pediatric Emergency ConsultantAl Yamammah Hospital

3/9/2015


Learning objectives

By the end of this lecture , each student should be able to: Know about the pathophysiology and etiology behind

childhood asthma. Identify the clinical presentation and recognize the triggering

factors of bronchial asthma in children. Develop a rational approach to the differential diagnosis Classify the severity of asthma. Discuss the management strategies of bronchial asthma. Define status asthmaticus. Recognize the signs and symptoms of status asthmaticus. Outline the emergency management of status asthmaticus.

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Bronchial Asthma

What is the asthma?Asthma is a chronic, inflammatory lung disease characterized by: Symptoms of cough, wheezing, dyspnea, and are usually

related to specific triggering factors. Reversible Airway narrowing. Increased airways responsiveness to a variety of stimuli.The prevalence in different countries …… 1 to 18 %

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Pathophysiology

Pathology The symptoms of asthma are due to airflow obstruction resulting from: Constriction of smooth muscle around airways Edema of airway wall Accumulation of intraluminal mucus Inflammatory cell infiltration of the submucosa Thickening of basement membrane PhysiologyThe physiologic changes of asthma (reduction in airway luminal diameter) Airway inflammation Reversible bronchoconstriction Increased airways hyperresponsiveness to a variety of stimuli.

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Bronchial AsthmaEtiology and risk factors

Why the frequency of asthma in all age groups is increased?Hypotheses?? Improved hygiene resulting in less exposure to infectious

pathogens. Increased indoor air pollution, irritant gases, cigarette smoke

and other allergens Increased incidence of early-onset respiratory viral infections. More premature infants surviving with chronic lung disease. Increased awareness and recognition of asthma by patients

and clinicians. Psychosocial factors, including stress

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Bronchial AsthmaEtiology and risk factors

The etiology Complex interactions between multiple environmental and genetic influences: Asthma in children: boys > girls. Family history of asthma: genetic influences More with other atopic diseases, such as atopic dermatitis and allergic

rhinitis, and with Increased total serum levels of IgE. Early Exposure to bacteria and bacterial products may influence the

development of allergen sensitization and asthma. Active smoking and exposure to environmental tobacco smoke

(particularly maternal) Patients with an increased body mass index (BMI) Prenatal and perinatal factors (eg, maternal age, smoking, diet, and

medication use)3/9/2015


Clinical presentation History

The history in a child with suspected asthma centers on: Presence of symptoms Typical symptom patterns Risk factors Precipitating factors or conditions (ie, atopy)Symptoms80 % of children with asthma < 5 year of age.Most common symptoms: Coughing and wheezingAsthmatic Cough: characteristics? Nocturnal cough Seasonal cough After specific exposures (eg, cold air, exercise, laughing, or crying) Lasts more than three weeks Typically dry

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History symptoms

Wheeze? A high-pitched sound produced when air is forced through narrow airways. The characteristics of wheezes in asthma: Polyphonic (varied in pitch), reflecting the heterogeneous distribution of affected

airways. Expiratory When airflow obstruction becomes severe, wheezing can be heard on both

inspiration and expiration. If harsh expiratory monophonic wheeze, consider central airway obstruction eg,

tracheomalacia. If inspiratory monophonic wheeze, consider Upper airway obstruction (eg, vocal

cord dysfunction)Seasonal symptomsSymptoms that are worse in certain pollen seasons are characteristic of atopic asthma

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Precipitating factors

Respiratory tract infections Viral upper respiratory infections (URIs) are the most

important triggering factor for patients with asthma of all ages

Chronic sinusitis Respiratory infections due to Mycoplasma or Chlamydia.Exercise (Exercise-induced bronchospasm) May be the only manifestation of asthma in children . 90 % of children with asthma Symptoms usually resolve with rest over 30 to 60 minutes.Stress : Various types of stress can trigger or exacerbate asthma

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WeatherCold air, hot, humid air, rain or windTobacco smokePassive cigarette smoke is the single most common external risk factor.Allergens Indoor and outdoor allergens: House dust mites, and rodents Pet exposures (cats and dogs) Pollens Molds3/9/2015



Inhaled Irritant exposures Nitrogen dioxide (from gas stoves) Particulates and smoke from wood fires, pellet stoves, or

kerosene space heaters. Cleaning sprays Perfumes, hair sprays Paint Room deodorizers Cleaning products with strong odors.

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History

Additional history Personal history of other atopic diseases Family history of asthma or other atopic diseases

(eg, allergic rhinitis, atopic dermatitis, and food allergy)

Environmental history Past medical history Medication use, medical utilization. School attendance, and psychosocial factors.3/9/2015


PHYSICAL EXAMINATION Generally normal if performed when the patient

does not have an acute exacerbation. Abnormal findings in the absence of an acute

exacerbation may suggest: Severe disease Suboptimal control Associated atopic conditions.

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PHYSICAL EXAMINATION

Signs Dry cough Signs of respiratory distress An increased anterior-posterior diameter of the chest

due to air trapping Decreased air entry or wheezing A prolonged expiratory phase Signs of rhinitis, conjunctivitis, and sinusitis (nasal

discharge, inflamed nasal mucosa, sinus tenderness, dark circles under the eyes)

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PHYSICAL EXAMINATION

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PHYSICAL EXAMINATION Allergic salute : a transverse nasal crease due to frequent

itching. Halitosis due to chronic rhinitis, sinusitis, and mouth

breathing. Eczema/atopic dermatitis Nasal polyps. WT (Obesity)

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DIAGNOSISDiagnosis depends on: A history of intermittent or chronic symptoms typical of asthma + the finding on physical examination of characteristic musical

wheezingConfirmation Spirometry Exclusion of alternative diagnoses Spirometry Demonstration of reversible airflow obstruction establishes the

diagnosis of asthma and facilitates the assessment of severity. For patients five years of age and older.

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DIAGNOSIS

Other studies:Chest x-ray

Only if no respond to initial therapy.

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DIAGNOSIS

Other studies:Allergy testing Bronchoprovocation testing Methacholine, cold air, or exercise Used when the clinical features are suggestive of asthma but

spirometry is normal and there is no response to asthma medications.

Sweat chloride test If the cystic fibrosis is suspectedBarium swallowIf swallowing dysfunction with aspiration is a consideration.

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DIFFERENTIAL DIAGNOSIS

DIFFERENTIAL DIAGNOSIS

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Assessment of severity Initial assessment of severity

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TREATMENT OF ACUTE EXACERBATION OF ASTHMA

Prehospital care Use Inhaled Beta2 agonist (MDI) via Spacer/ AeroChamber

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After assessment of severity:Mild to Moderate exacerbation use albuterol as MDI (Dose

is 2-4 puffs) or Nebulizer every 20 min up to 4 hr. then every 1-4 hrs as needed

Moderate to Sever exacerbation use albuterol + (Ipratropium ) as Nebulizer:

Dose of albuterol is 2.5-5 mg every 20 min for 3 doses with Ipratropium (250 mic for wt<20kg, 500mic for wt>20kg)

then every 1-4 hrs as needed If poor response in first hour…..next

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If poor response in first hour start: Continuous nebulization of albuterol at 0.5 mg/kg/h IV magnisium sulfate (25-75 mg/kg, maximum 2 g over 20

minutes). Still no response start: IV terbutaline after completion of the magnisium sulfate infusion. Bolus with 10mic/kg over 10 minutes. Then 0.3 to 0.5 mic/kg/min; infusion may be increased by

0.5 mic/kg /min every 30 minutes to a maximum of 5mic/kg /min. Or aminophylline (6 mg/kg intravenous loading dose, followed by

infusion of 0.5 to 1 mg/kg per hour that is titrated based upon levels).

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Systemic steroids: Recommended early in the course of acute exacerbation Oral vs IV------ equal in efficacy Prednisone 2mg/kg orally Dexamethasone 0.6mg/kg oral, IV, IM. Methyleprednisolone IV 1-2 mg/kgEpinephrine or terbutaline as IM or SC for Children with: Poor inspiratory flow. Children who cannot cooperate with nebulized therapy (0.01 mL/kg of a 1 mg/mL solution)

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Other treatment: Noninvasive positive pressure ventilation (NPPV): Delivery of positive airway pressure without placement of an

artificial airway. Continuous positive airway pressure (CPAP) Or bilevel positive airway pressure (BiPAP). Mechanical ventilation

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INDICATIONS FOR REFERRAL

When the diagnosis of asthma is uncertain. The asthma is difficult to control. Medication side effects are intolerable. Patient has frequent exacerbations.

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Status Asthmaticus

Acute, severe exacerbation of asthma that remains unresponsive to initial treatment with bronchodilators and steroids.

Associated with symptoms of potential respiratory failure.

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Status Asthmaticus Clinical presentation

Risk factors• History of increased use of home bronchodilator treatment without

improvement.• History of previous intensive care unit (ICU) admissions, with or

without intubation and mechanical ventilatory support• Asthma exacerbation despite recent or current use of corticosteroids• Frequent emergency department visits and/or hospitalization (poor

control)• Less than 10% improvement in peak expiratory flow rate (PEFR) from

baseline despite treatment• History of syncope or seizures during acute exacerbation• Oxygen saturation below 92% despite supplemental oxygen

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Clinical presentation

Physical Examination Tachypneic Significant wheezing. Initially, wheezing is heard only during expiration, but

wheezing later occurs during expiration and inspiration. The chest is hyperexpanded, and use of accessory muscles Silent chest Pulsus paradoxious (The difference in systolic blood pressure between inspiration

and expiration >15mm Hg ). An inability to speak Ventilation/perfusion mismatch results in decreased O2 sat and hypoxia. Vital signs may show tachycardia and hypertension. Change in the level of consciousness Syncope and seizures. If untreated, pending respiratory failure lead to bradycardia, hypoventilation, and

cardiorespiratory arrest.

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Management

laboratory studiesDepends on historical data and patient condition: CBC ABG Serum electrolyte levels Serum glucose levels Peak expiratory flow measurement Chest x-ray ECG Blood theophylline levels3/9/2015


Management stages of status asthmaticus

Blood gas progression in status asthmaticus: Stage 1 - hyperventilation (low PCO2 ) with a normal (PO2) Stage 2 - hyperventilation with hypoxemia. Stage 3 - a false-normal PCO2 which is an extremely serious

sign of respiratory muscle fatigue. Stage 4 - hypoxemia and a high PCO2, which occurs with

respiratory failure and needs ventilatory support.

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Management

PEF, FEV1, and spirometry Use peak expiratory flow (PEF) to evaluate the severity of an asthma attack.ICU admission criteria: Change in level of consciousness Use of continuous inhaled beta-agonist therapy Exhaustion Markedly decreased air entry Rising PCO2 despite treatment The PEF value or FEV1 is less than 50% of the predicted value after

treatment. Presence of high-risk factors for a severe attack Failure to improve despite adequate therapy

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Management

Indications for intubation and mechanical ventilation: Apnea or respiratory arrest Diminishing level of consciousness Impending respiratory failure marked by significantly

rising PCO2 with fatigue, decreased air movement, and altered level of consciousness

Significant hypoxemia that is poorly responsive or unresponsive to supplemental oxygen therapy alone.

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Thank you

3/9/2015

ped.emergency.Dr.Alsaif 413/9/2015

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