CHARO ASTHMA

8/7/2019 CHARO ASTHMA

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Ma. Rosario A. Angeles


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WHAT IS ASTHMA?

Diffuse, obstructive lung disease with (1)hyperreactivity of the airways to a variety of stimuliand (2) a high degree of reversibility of theobstructive process, w/c may occur either

spontaneously or as a result of treatment. Also known as Reactive Airway Disease, (RAD)


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PATHOPHYSIOLOGY

Manifestations of airway obstruction are due to: Bronchoconstriction Hypersecretion of mucus Mucosal edema Cellular infiltration Desquamation of epithelial and inflammatory

cells


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Mast cells in Asthma Pathogenesis:


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Components of an

Asthma AttackEarly Immune ResponseBronchoconstriction

the consequence of immunoglobulin Edependentmediator release upon exposure to aeroallergens and is theprimary component of the early asthmatic response

normal Asthma attack


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Components of an

Asthma AttackLate phase reactionMucosal edema

occurs 6-24 hours following an allergen challenge and is rto as the late asthmatic response.

Excessive Secretions

Chronic mucous plug formation consists of anexudate of serum proteins and cell debris that maweeks to resolve.

Airway remodeling

associated with structural changes due to long-standing inflammation and may profoundly affect the e

of reversibility of airway obstruction.


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Components of an Asthma

Attack- Edema and Bronchospasmreduction olumen size with resulting increase of wo

breathing and decrease in airflow.

- Mismatching of ventilation w/perfusion

alveolar hypoventilation & Inc work

breathing changes in blood gases


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Components of an Asthma

Attack Hyperventilationcompensates initially for higher CO2tension in the blood that perfuses poorly ventilatedregion, but it cannot compensate for hypoxemiabecause of patients inability to inc. partial pressure ofO2 and oxyhemoglobin saturation further alveolarhypoventilation and hypercapnia occurs

Hypoxia interferes w/conversion of lactic acid to CO2and H20 met acidosis

Hypercapnia increases carbonic acid w/c dissociates

into hydrogen and bicarbonate ions

respi acidosis


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SIGNS AND SYMPTOMS OF AN

ASTHMA ATTACK

Cough

Wheezing

Tachypnea

Dyspnea with prolonged expiration

Use of accesory muscle of respiration

Cyanosis

tachycardia


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Diagnosis- Recurrent episodes of coughing and

wheezing especially if trigerred by exercise, viral

infection or inhalled allergens are highly suggestive

of asthma

- Pulmonary function testing before and after

administration of methacholine or a bronchodilator

or before and after exercise may help establish the

diagnosis of asthma


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Causes:

Factors that can contribute to asthma or airway hyperreactivity mayinclude any of the following: Environmental allergens Viral respiratory infections Exercise; hyperventilation Gastroesophageal reflux disease

Chronic sinusitis or rhinitis Aspirin or nonsteroidal anti-inflammatory drug hypersensitivity, sulfite sensitivity Use of beta-adrenergic receptor blockers (including ophthalmic preparations) Environmental pollutants, tobacco smoke Occupational exposure Emotional factors Irritants such as household sprays and paint fumes


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Lab Studies:

Laboratory studies are not routinely indicated for asthma but maybe used to exclude other diagnoses.

Blood Eosinophilia greater than 250-400 cells/mm3 is usual. Allergy skin testing: useful adjunct in individuals with atopy

Chest radiography: findings are normal or indicatehyperinflation.

.


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Procedures:

Pulmonary function testing (spirometry) Perform spirometry measurements before and after inhalation of a

short-acting bronchodilator in all patients in whom the diagnosis ofasthma is considered. Spirometry measures the forced vital capacity,the maximal amount of air expired from the point of maximal inhalationand the FEV1. A reduced ratio of FEV1 to forced vital capacity, when

compared with predicted values, demonstrates the presence of airwayobstruction. Reversibility is demonstrated by an increase of 12% or 20mL after administration of a short-acting bronchodilator.

The diagnosis of asthma cannot be based on spirometry findings alonbecause many other diseases are associated with obstructivespirometry indices.


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Methacholine- or histamine-

challenge testing

Bronchoprovocation testing with either

methacholine or histamine is useful when

spirometry findings are normal or near normal

CLASSIFICATION OF ASTHMA SEVERITY


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CLASSIFICATION OF ASTHMA SEVERITY

Severity Prior to Initiation of Therapy

Mild Intermittent Mild Persistent ModeratePersistent

Severe Pe

Symptoms < or = 2 per week > 2 per week daily symptoms continual sy

Nighttimesymptoms

< or = 2 per month > 2 per month > 1 per week frequ

Lung function < or = 80%predicted

< or = 80%predicted

> 60% -< or = 80%

< or = 6

Peak flow variability < 20% 20-30% > 30% > 30%


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LONG TERM CONTROL Rx QUICK-RELIEF MEDICATIONS

Corticosteroids***

Cromolyn/nedocromil**Leukotriene modifiers**Methylxanthines**Long-acting beta-agonists*

Short-acting beta-agonists*

Anti-cholinergics*Systemic glucocorticosteroids***

STEP THERAPY BASED ON ASTHMA SEVERITY

Classification Quick Relief Long-Term Control

Step 1: Mild Intermittent prn None.

Step 2: Mild Persistent prn Single agent with anti-inflammatory activity.

Step 3: ModeratePersistent

prn Inhaled corticosteroids, add long-acting bronchodilatorneeded.

Step 4: Severe Persistent prn Multiple long-term control medications. Add oralcorticosteroids if needed.


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PREVENTION:

KNOW THE ASTHMA ATTACK

TRIGGERS!Pets Indoorpollution

Exercise

Pollens

Weather


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How to Use the

Students Health Care PlanRead the health care plan

developed by the school nurseKnow your students asthma

attack triggersBe familiar with emergency

action plansContact school nurse with

questions

Documents

CHARO ASTHMA