OS 213 Pediatric Asthma
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Transcript of OS 213 Pediatric Asthma
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 1 of 7SexyBacks
Lecture Outline
I. Epidmemiology
II. Definition
III. Review of Anatomy
IV. Pathophysiology
V. Risk Factors
VI. Clinical Features/Diagnosis
VII. Management
EPIDEMIOLOGY
Asthma ranked number 1 among the non-infections admissions in 57 of accredited hospitals
PPS Registry of Diseases, 1994
Prevalence of wheezing among 6-19 years in Metro Manila schools was 27.45%
Del Mundo, textbook of Pediatrics 2002
A large international survey study of childhood asthma prevalence in 56 countries found a wide range in asthma prevalence, from 1.6 to 36.8%
ISAAC Study
Source: Masoli M et al. Allergy 2004
DEFINITION
a chronic inflammatory disorder of the airways in which many cells play a role, including mast cells and eosinophils
this inflammation causes symptoms that are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment, and causes associated increase in airway hyperresponsiveness to a variety of stimuli.
a disorder defined by its clinical, physiological and pathological characteristics
Clinically, asthma is characterized by airway hyperresponsiveness presenting as widespread narrowing of the airway which results from a variety of stimuli like allergens, exercise, physical factors and irritant gases
Primary physiologic manifestation is spontaneously variable airway obstruction which can be modulated by:
Increased obstruction caused by many stimuli
Alleviation of obstruction by bronchodilators and/or anti-inflammatory agents
REVIEW OF ANATOMY
PATHOPHYSIOLOGY
is complex and involves the following components:
1) Airway inflammation2) Intermittent airflow obstruction3) Bronchial hyperresponsiveness
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 2 of 7SexyBacks
Asthma Inflammation: Cells and Mediators
Key Mediators of Asthma:
Chemokines recruitment of inflammatory cells into the
airways and are mainly expressed in airway epithelial cells
Cysteinyl leukotrienes potent bronchoconstrictors and
proinflammatory mediators mainly derived from mast cells and eosinophils
only mediator whose inhibition has been associated with an improvement in lung function and asthma symptoms
Cytokines orchestrate the inflammatory response
in asthma and determine its severity Histamine
contributes to bronchoconstriction and to the inflammatory response
Nitric Oxide a potent vasodilator, produced
predominantly from the action of inducible nitric oxide synthase in airway epithelial cell
Asthma Inflammation: Cells and Mediators
Mechanisms Of Airway Narrowing in Asthma
Contraction of Airway smooth muscle (ASM) is the predominant mechanism largely reversed by bronchodilators
Airway wall thickening Accumulation of airway secretions,
mucus casts, and cellular debris may partially occlude the lumen
Regulation of Airway Caliber Cholinergic (parasympathetic) motoneurons
innervate the airways via the vagus nerve Nonadrenergic Noncholinergic (NANC) Nervous
system NANC system neurons in the vagus nerve
release the peptides, SUBSTANCE P and VASOACTIVE INTESTINAL PEPTIDE
Appears to be the most potent relaxant component of the nervous system involved in regulation of airway diameter
Factors that Influence Asthma Development and Expression
Host Factors Genetic
Atopy Airway hyperresponsiveness
Gender Obesity
Environmental Factors Indoor allergens Outdoor allergens Occupational sensitizers Tobacco smoke Air Pollution Respiratory Infections Diet
RISK FACTORS FOR ASTHMA
Host factors: predispose individuals to, or protect them from, developing asthma
Environmental factors: influence susceptibility to development of asthma in predisposed individuals, precipitate asthma exacerbations, and/or cause symptoms to persist
Who gets asthma? Anyone!!! Most children develop asthma before age 8 years
and over half before 3 years 30% < 1 year 80-90% before 4-5 years old
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 3 of 7SexyBacks
Before puberty: asthma occurs 11/2-3x male > female
Adolescence male=female
Predisposing Factors involved in the Development of Asthma
Atopy defined as the preponderance to
produce abnormal amounts of IgE in response to environmental allergens
Familial association among asthma, allergic rhinitis and atopic dermatitis suggests a common genetic basis-chromosomes 5, 11
90% of asthmatic children have an allergic component
64-84% (+) family history of asthma among 1st degree relatives
30% & 3.5% of asthmatic patients reported asthma in one parent and in none respectively
Gender Male preponderance
Triggers
Risk factors that cause asthma exacerbation by inducing inflammation or provoking acute bronchoconstriction or both
Trigger Factors of Asthma in Various Age Groups
Anatomic and physiologic peculiarities that predispose to obstructive airway disease
1. Decreased amount of smooth muscle in peripheral airways
2. Mucosal gland hyperplasia in the major bronchi compared to adults favors increased intraluminal mucus production
3. Disproportionately narrow peripheral airways up to 5 years of age
4. Decreased static elastic recoil of the young lung predisposes to early airway closure during tidal breathing
5. Highly compliant rib cage and mechanically disadvantageous angle of insertion of diaphragm to ribcage increases diaphragmatic work of breathing
6. Decreased number of fatigue-resistant skeletal muscles in the diaphragm
7. Deficient collateral ventilation with the pores of Kohn and the Lambert canals deficient in number and size
Masqueraders of asthma in children
Upper airway noise/congestion
Cystic fibrosis (CF) Gastroesophageal reflux disease (GERD) Bronchopulmonary dysplasia (BPD) Foreign body aspiration Immunodeficiency (ID) Vocal cord dysfunction
CLINICAL FEATURES
Frequent episodes of wheeze (more than once a month)
Activity induced cough or wheeze Nocturnal coughs in periods without viral
infections Absence of seasonal variations in wheeze Symptoms that persist after the age of 3 Wheeze before the age of 3 and one major risk
factor parental history of asthma or eczema or
two or three risk factors (eosinophilia, wheezing without colds, and allergic rhinitis) has been shown to predict the presence of asthma in later childhood
DIAGNOSIS
Signs and symptoms to look for include: Frequent coughing spells, which may occur
during play, at night, or while laughing. It is important to know that cough may be the only symptom present.
Less energy during play Rapid breathing Complaint of chest tightness or chest "hurting” Whistling sound (wheezing) when breathing in or
out See-saw motions (retractions) in the chest from
labored breathing Shortness of breath, loss of breath Tightened neck and chest muscles Feelings of weakness or tiredness
Spirometry
Recommended in the initial assessment of patients suspected to have asthma
Usually feasible in children from age >5 years Useful in assessing
Degree of airway obstruction Disturbances in gas exchange
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 4 of 7SexyBacks
Response of airways to inhaled allergens/ chemicals/exercise
Assessing response to therapeutic agents
Evaluating long-term course of disease FEV1 is the single best measure for assessing
severity of airflow obstruction FEV1 measurements <80% of predicted value is
evidence of airway obstruction and reversibility with use of inhaled ß2-agonist (increase in FEV1 by 15%) makes a definitive diagnosis of asthma
Portable Peak Flow Meter
measure PEFR where spirometry is not available less sensitive, but correlates well with FEV1 offers an acceptable alternative to assess
response to exercise challenge and peak flow variability
The predicted normal PEFR for Filipino children between 6 and 17 years of age with height of at least 100 cm can be calculated:
Males: (Height in cm - 100) 5 + 175 Females: (Height in cm - 100) 5 + 170
Diagnosis of Asthma
Other Tests to help establish the diagnosis of asthma
1) Methacholine/Histamine bronchoprovocation test2) Exercise challenge test3) Twice daily recording of peak flow to determine
diurnal variation4) Therapeutic trial of five days steroid and
bronchodilator course
MANAGEMENT
“Basically longterm, involving both pharmacological and non pharmacological interventions”
Philippine Consensus Report 2002
Goals of Therapy
1. to maintain normal activity levels including exercise;
2. to maintain ( near ) normal pulmonary function test;
3. to prevent chronic and troublesome symptoms;4. to prevent recurrent exacerbations; and,5. to avoid adverse effects from asthma
medications
Components of asthma care
1) Develop patient/doctor partnership2) Identify and reduce exposure to risk factors3) Assess, treat and monitor asthma4) Manage asthma exacerbations
OutcomeSuccessful management of asthma should lead to an improvement or normalization of the child’s daily activities, respiratory symptoms, pulmonary function and personal and family psychosocial functioning.
Richel: Haaaaaay. High stress itong trans na to. Half pa lang ng coverage ang nababasa ko :s at kailangan ko pa tong unahin, kaya basahin niyo to! Hello octetmates! Goodluck tom. Haha. :D
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 5 of 7SexyBacks
Objectives
IDEAL MINIMAL Minimal or no chronic symptoms Least symptomsMinimal episodes Least need for PRN b2- agonistNo ER visits Least limitation of activityMinimal need for PRN b2- agonist No limitation on activities Best PEFRPEF circadian variation < 20% Least adverse effects ( Near) normal PEF Minimal or no adverse effect
Long-term Management of Asthma in Children
ASSESSMENT
Asthmatic child is classified to an asthma severity categoryCategory of severity will suggest the initial pharmacologic treatmentPharmacologic therapy is described as “step care”
control of symptoms should be established as soon as possible
short course of oral corticosteroids or higher doses of inhaled corticosteroids may be considered for faster control
therapy should be decreased as soon as possible to that which is required based on the identified asthma severity category
On follow up: if control is attained and sustained for at least
three months, a gradual reduction in treatment may be possible
if control is not achieved within 2-6 weeks review patient’s inhaler technique review compliance and environmental
control measures (such as: avoidance of allergens or other triggers)
diagnosis should be re-evaluated and treatment should be advanced to the next step
*see Appendix for long term management
Monitoring to maintain control Control should be monitored to maintain control
and establish lowest step and dose Should be seen one to three months after the
initial visit and every 3 months thereafter After an exacerbation, follow-up should be within
two weeks to one month
ALLERGEN IMMUNOTHERAPY IN ASTHMA Administration of increasing quantities of specific
allergic extracts to patients with IgE-mediated allergic rhinitis, asthma or stinging insect anaphylaxis
Should be consideredo avoiding allergens is not possibleo less than complete control of symptoms
is achieved with bronchodilators or inhaled steroids
Greatest benefit of specific immunotherapy using allergen extracts has been obtained in the treatment of allergic rhinitis
Role of specific immunotherapy in asthma is limited
Specific immunotherapy should be considered only after strict environmental avoidance and pharmacologic intervention, including inhaled glucocorticosteroids, have failed to control asthma
Performed only by trained physician
MANAGING EXACERBATIONS OF ASTHMA
Exacerbations of asthma Acute or sub-acute episodes of progressively
worsening symptoms of shortness of breath, cough, wheeze and chest tightness or a combination of these
Exacerbations may be mild, moderate severe or even life threatening
Key points Prevention of exacerbations is the optimal goal Severity of future attacks cannot be predicted,
thus early recognition is imperativeNote: most cases of asthma morbidity and mortality are due to underassessment and undertreatment
In the event of an attack, early treatment is advised
o Recognition of early signs of attack or worsening asthma
o Appropriate use of relieverso Prompt communication between patient
and physician Management of asthma attack may include, but
is not limited to: o Inhaled short-acting b2 agonist for
immediate relief of airway obstruction o Systemic corticosteroidso Oxygen o Other agents (e.g. ipratropium bromide,
theophylline)Note: close monitoring of patient’s condition as well as response to therapy is crucial
Anticholinergics Recent studies have shown that anticholinergics
(e.g. ipratropium bromide) offer some benefit when used early and in combination with short-acting b2 agonists
In children with acute asthma, addition of anticholinergics to inhaled b2 agonists for 3 doses given every 20 minutes appears to improve lung function modestly and decrease hospital admissions.
High risk patientsThese are the patients who have the potential to go into
sudden and severe airway obstruction which may lead to respiratory failure or death.
They should be educated to seek medical care early during an exacerbation.
infants in moderate/severe exacerbation current use or recent withdrawal (< 1 week) from
systemic corticosteroids hospitalization for moderate or severe asthma in
the past year prior intubation or history of impending
respiratory failure from asthma psychiatric disease or psychosocial problems difficulty perceiving airflow obstruction or its
severity, and non-compliance with asthma medication plan
IMMEDIATE CASE OF ASTHMA EXACERBATIONS Treatment should be started as soon as an
asthma attack is recognized. Initial treatment will include inhaled short-acting
b2 and if necessary, oxygen. o PE should be done to determine
severity of exacerbation to serve as a guide to the type of management appropriate for the case.
o Brief but focused history pertinent to the attack
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 6 of 7SexyBacks
Pertinent points to ask Severity of symptoms History of prior attacks Visits to the emergency room Hospitalization (including history of intubation)
due to asthma Current medications Any of other complicating illnesses (e.g. other
pulmonary or cardiac problems)
Particular attention should be given to patients who present with the following features, as they are the ones most prone to develop acute respiratory failure:
Cyanosis absence of wheeze bradycardia and bradypnea paradoxical thoraco-abdominal movement drowsiness or confusion a normal or elevated pCO2 in a patient with
severe distress
Appendix. Severity of Asthma Exacerbations
Admission to Intensive Care Unit
Recommended in the following situations:
1) progressive worsening of asthma symptoms despite initial Management 2) presence of sensorial changes (drowsiness, confusion) or loss of consciousness 3) signs of respiratory fatigue (e.g. declining respiratory rate) 4) impending respiratory arrest (paO2 < 60 mmHg on supplemental oxygen, pCO2 > 45 mmHg)
Patient Discharge
From the Emergency Room1) symptoms are absent or minimal2) PEFR > 80% predicted3) sustained response for at least four (4) hours
From the Hospital1) physical examination is normal or near normal2) no nocturnal awakenings3) PEFR > 80% predicted4) sustained response to inhaled short-acting b2 agonist (at least 4 hours)
Discharge Instructions Identify and avoid the trigger(s) that precipitated
the attack Prescribe sufficient medications to continue
treatment after discharge Review inhaler technique If peak flow meter is available, provide an action
plan Emphasize regular, continuous follow-up with the
physician
Drug Therapy
2 TYPES RESCUE/RELIEVER
-for acute relief of symptoms PROPHYLACTIC/CONTROLLER
-to prevent exacerbations
RELIEVER
-bronchodilators which relax airway muscles that tighten in and around the airways
-provide quick relief of symptoms but does not treat underlying airway inflammation
Reliever Medications: Rapid-acting inhaled beta2-agonist Systemic glucocorticosteroids Anticholinergics Theophylline Short-acting oral beta2-agonist
CONTROLLER
-Consists of anti-inflammatory agents which prevent asthma attacks by reversing the underlying inflammatory changes
-Prevents further inflammation of airways and controls chronic symptoms
Controller Medications: Inhaled glucocorticosteroids Leukotriene modifiers Long-acting inhaled β2-agonists Systemic glucocorticosteroids Theophylline Cromones Long-acting oral β2-agonists Anti-IgE Systemic glucocorticosteroids
Key Points to Inhalational Devices1) There is little difference in the therapeutic effect
between a correctly used MDI with or without a spacer, DPI, and a nebulizer
2) MDI spacer can increase ling deposition3) MDI spacer can decrease oropharyngeal
deposition4) MDI with a spacer, DPI, or nebulizers can be
used for patients who have difficulty coordinating with MDI activation, those with optimal breathing pattern, in children, and patients with severe illness
Non-pharmacologic interventions include Environmental control Monitoring of the status of the disease Asthma education
Action Plan
The asthma action plan is a written asthma management plan that is jointly prepared by the doctor and the patient.
This written instruction to the patient should be updated every visit as changes in peak flow measurements or asthma severity category may occur.
Pediatric Asthma
OS 213: Pulmunology Maria Liza B. Zabala, M.D.
Exam 1
Dec 11, 2008 | Thursday Page 7 of 7SexyBacks
GREEN ZONE: Doing Well- No symptoms day and night (cough, wheeze, chest tightness and shortness of breath)- Can do usual activities- Peak flow meter __________ (>80 % of your personal best or predicted) ACTION:- Continue with your current medication as prescribed _________
YELLOW ZONE: Acute Attack - Presence of at least 1 of the following: (cough, wheeze, chest tightness or shortness of breath) - Waking at night due to asthma - Can do some but not all usual activities - Peak flow meter: _____ to _____ (60 to 79% of your personal best)
ACTION: -Take your quick-relief inhaled brochodilator_______________ every 20 minutes up to 3 doses until relieved - Proceed to ER for further evaluation & possible admission if: 1. getting worse at anytime 2. if no relief after 3 doses of inhaled b2 agonistOn your way to ER, continue your quick relief inhaled bronchodilator every 20 minutes and take 1 dose of oral steroids _________
RED ZONE: EMERGENCY!!! - Presence of any:(Trouble walking or talking due to shortness of breath, lips and fingernails are blue) -Quick relief medicines have not helped -Cannot do usual activities -Symptoms are getting worse -Peak flow meter: _____ (< 60 % of your personal best)
ACTION: - Proceed to ER - Take immediately 1 dose of your quick relief inhaled bronchodilator and continue your inhaled bronchodilator every 20 minutes while in transit - Take 1 dose oral steroids __________
*may mga blanks talaga yan ha ;)
References Philippine Consensus For The Management Of Childhood Asthma Revised 2002 Global Initiative For Asthma Revised 2006 Nelson Textbook of Pediatircs Lippincott’s Pathophysiology Series Pulonary Pathophysiology 1995 By Michael Grippi Textbook Of Pediatric and Health Care 4th Edition By Del Mundo Kendig’s Disorders of the Respiratory Tract in Children 7th Edition
Richel: Greetings ulit Hello Phinoms! Sarap ng potatoes no? Hehe. Saka na ulit yung next supply. Family day ulit? :p Tinatamad na ako bumati, hello na lang to everyone! Malunggays, sana matapos na natin itong research. Pahiraaaaaaaap. :D Happy birthday Lani, Fides, and Dr.Gana! :D Hello Raphael. Thank you