os 213 pediatric asthma

Pediatric Asthma

OS 213: Pulmunology Maria Liza B. Zabala, M.D.

Exam 1

Dec 11, 2008 | Thursday 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


Exam 1


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


Exam 1


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


Exam 1


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


Exam 1


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


Exam 1


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


Exam 1


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

os 213 pediatric asthma

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