asthma & bronchiolitis in the hospitalized pediatric patient
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Asthma & Bronchiolitis in the Hospitalized Pediatric Patient. October 2008 Brian W. Temple, MD Childhood Health Associates of Salem. Goals for today. General definition of asthma and bronchiolitis Natural history of both disease processes What’s happening in the lungs? Treatment - PowerPoint PPT PresentationTRANSCRIPT
Asthma & Bronchiolitis in
the Hospitalized Pediatric Patient
October 2008
Brian W. Temple, MDChildhood Health Associates of Salem
Goals for todayGeneral definition of asthma and bronchiolitis
Natural history of both disease processes
What’s happening in the lungs?
Treatment
Asthma vs Viral Bronchiolitis
What is asthma?
•Asthma is a chronic disease characterized by increased responsiveness of the airways to various stimuli and manifested by widespread obstruction, which changes in severity either spontaneously or as a result of therapy.
Chronic disease
When can you diagnose?
When do you treat?
Don’t fear “label” since correct diagnosis leads to correct treatment.
Natural HistoryMedian age of onset is 4 years with 20% developing symptoms in first year of life.Risk factors include family history, presence of other inflammatory diseases (like eczema), and early RSV infection.60% resolve by young adulthood.50% that remit during adolescence will return as adultHistory of RSV without family history of asthma or eczema more likely to improve in first few years.
Pathophysiology • Asthma is an inflammatory
disease!• Asthma is an inflammatory
disease!• Asthma is an inflammatory
disease!
Common TriggersInfections: viral respiratory illness (rhinovirus, influenza, RSV, parainfluenza, human metapneumovirus), sinus infections
Allergens: seasonal allergens, indoor allergens, pets
Irritants: cigarette smoke, wood smoke, other pollutants, weather changes
Airway hyperresponsivenes
sPrimarily smooth muscle mediated. Can occur at any age. Reversible with albuterol. Primarily expiratory wheezes.Results in air trapping / obstruction (can be quantified on PFT’s).Variable throughout lungs. May cause atelectasis on x-ray.Primary process for wheezing due to cold air, exercise, pet allergens.
Airway Inflammation
More often triggered by infections and chronic allergies.
IgE mediated triggering mast cell release.
Causes “fixed” obstruction not responsive to albuterol and more often has an inspiratory component.
Strong genetic contribution.
Needs steroids.
A Closer Look
Symptoms• Coughing and wheezing are the most
common symptoms of childhood Asthma
• Breathlessness, chest tightness or pressure, and chest pain also are reported
• Poor school performance and fatigue may indicate sleep deprivation from nocturnal symptoms
Cough• Nocturnal cough, recurring seasonal
cough, or cough in response to specific exposures
• Although wheezing hallmark of asthma, cough is often sole presenting complaint
• Most common cause of chronic cough in children older than 3 years is asthma
Wheeze• Wheezing is a high-pitched, expiratory
sound produced when air forced through narrow airways
• Asthma wheeze tends to be polyphonic (varied in pitch)
• When airflow obstruction severe, can appreciate wheeze with inspiration and expiration.
Acute Treatment
Albuterol and steroids.Neb vs MDIPO vs IV steroids
Oxygen for hypoxiaFluid support if dehydration
Oxygen• Hypoxia primarily due to ventilation /
perfusion mismatch and air trapping
• Albuterol may actually worsen V/Q mismatch.
• Don’t use oximetry alone in assessing response to therapy.
Asthma Classification
•
Mild intermitten
tdaily symptoms < 2/week
night symptoms < 2/month
Mild persistent
daily sx >2 per week but < dailynight > 2/month
Moderate persistent
daily symptomssx > 2x / week affect activity
night symptoms > 1/week
Severe persistent
continuous symptomslimited activity
Outpatient Chronic Treatment
•
Mild intermitten
talbuterol prn
Mild persistent
low dose inhaled corticosteroid or Singulair©
albuterol prnModeratepersistent
low to medium dose inhaled corticosteroid and long acting beta2-agonist
Severepersistent
high dose inhaled corticosteroid and long acting beta2-agonist
consider daily po corticosteroids
What else can be done?
• Avoid and manage triggers
Treatment of allergies.
Treatment of chronic infections.
Management of household irritants and allergens.
Is it really asthma?Foreign body
Laryngotracheomalacia
Other congenital abnormalities (congenital heart disease, vascular ring, TE fistula)
Gastroesophageal reflux
Cystic fibrosis
Is it really asthma?•Asthma vs CroupInspiratory problem or expiratory
problem?
Course of illness?
Age of patient?
Patient’s and family’s history?
Is it really asthma?•Asthma vs bronchiolitisAge of the patient?
Patient’s history of wheezing?
Family history of asthma or other allergic disorders?
Response to therapy?
Bronchiolitis
• Bronchiolitis, a lower respiratory tract infection that primarily affects small airways (bronchioles), is a common cause of illness and hospitalization in infants and young children
Definition of Bronchiolitis
• First episode of wheezing in a child younger than 12 to 24 months with physical findings of a viral respiratory infection and has no other explanation for wheezing
• Broader definition: an illness in children <2 years of age characterized by wheezing and airways obstruction due to primary infection or re-infection, resulting in inflammation of the bronchioles
Microbiology• Typically caused by viral infection
• Respiratory Syncytial Virus (RSV) is the most common cause
• Less common causes include parainfluenza virus, human metaneumovirus, influenza virus, adenovirus, rhinovirus, coronavirus, and human bocavirus
Respiratory Syncytial Virus
• RSV is most common cause of bronchiolitis
• RSV is ubiquitous throughout world and causes seasonal outbreaks
Epidemiology• RSV is responsible for major of cases of
bronchiolitis
• Bronchiolitis typically affects infants younger than 2 years of age
• Peak incidence is 2 to 6 months of age
• Leading cause of hospitalization in infants and young children
Risk Factors for severe disease
• Prematurity (<37 weeks gestation)
• Low birth weight
• Age less than 6 to 12 weeks
• Chronic pulmonary disease
• Significant congenital heart disease
• Immunodeficiency
Pathogenesis
• Viruses penetrate the terminal bronchiolar epithelial cells, causing direct damage and inflammation in small bronchi and bronchioles
• Edema, excessive mucus, and sloughed epithelial cells lead to obstruction of small airways and atelectasis
The Bronciolitic Lung
Clinical Features• Increased respiratory effort and
wheezing
• Tachypnea and intercostal and subcostal retractions with expiratory wheezing
• Auscultation: expiratory wheeze, prolonged expiratory phase, and both coarse and fine crackles
• Bronchiolitis is diagnosed clinically
Hospital Treatment of Bronchiolitis
• Respiratory support: keep oxygen saturation above 90%
• Fluid administration to ensure adequate hydration and avoid aspiration
• Chest PT does not appear to improve clinical course
• Pharmacologic therapy: a number of therapies of been shown to improve outcome
Pharmacologic Therapy
• Inhaled Bronchodilators (e.g. albuterol, Epinephrine), Do they work?
• No to oral bronchodilators
• Glucocorticoids may be beneficial to infants with chronic lung disease and/or asthma component to illness
• Ribavirin is not routinely recommended
Nonstandard Therapies
• Heliox- mixture of helium (70-80%) and oxygen (20-30%)
• Anti-RSV preparations: Palivizumab
• Surfactant
• Hypertonic saline
Inhaled Bronchodilators
• Trial of bronchodilator medication is an option-varied clinical results
• Albuterol should be tried first with assessment within 1 hour of use, if no improvement,
• Epinephrine should be tried, if no improvement within hour,
• Consider discontinuation of bronchodilators
Discharge Criteria• Respiratory rate <70 breaths/min
• Caretaker can clear infants airway
• Patient is stable without supplemental O2
• Adequate oral intake
• Caretaker confident they can provide care
• Education of family is complete
Education
• Expected clinical course: <24 months is 12 days
• Proper techniques for suctioning the nose
• Indications to contact primary care provider