Asthma – Definition Significance - Napa Valley College ...€¦ · Pathophysiology of asthma. IL, Interleukin. Pathophysiology ... Acute asthma episode ... exacerbation of asthma

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(Relates to Chapter 29, “Nursing Management: Obstructive Pulmonary Diseases,” in the textbook)

Focus on Asthma

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

Asthma – DefinitionChronic inflammatory disorder of

airwaysCauses airway hyperresponsiveness

leading to wheezing, breathlessness, chest tightness, and cough

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. 2

SignificanceAffects about 16 million AmericansWomen are 66% more likely to have

asthma than men.Older adults may be undiagnosed.


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Triggers of Asthma AllergensTriggers of Asthma Allergens

May be seasonal or year round depending on exposure to allergenHouse dust mitesCockroachesFurry animalsFungiMolds


Triggers of Asthma Exercise

Induced or exacerbated after exercisePronounced with exposure to cold airBreathing through a scarf or mask may ↓

likelihood of symptoms


Triggers of Asthma Air Pollutants

Can trigger asthma attacksCigarette or wood smokeVehicle exhaustElevated ozone levelsSulfur dioxide


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Triggers of Asthma Occupational Factors

Most common form of occupational lung diseaseExposure to diverse agentsArrive at work well, but experience a

gradual decline


Triggers of Asthma Respiratory Infection

Major precipitating factor of an acute asthma attack ↑ inflammation hyperresponsiveness of

the tracheobronchial system


Triggers of AsthmaNose and Sinus Problems

Allergic rhinitis and nasal polypsLarge polyps are removed Sinus problems are usually related to

inflammation of the mucous membranes


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Triggers of AsthmaDrugs and Food Additives

Asthma triad: Nasal polyps, asthma, and sensitivity to aspirin and NSAIDsWheezing develops in about 2 hours.Sensitivity to salicylates Found in many foods, beverages, and

flavoringsβ-Adrenergic blockers


Triggers of AsthmaDrugs and Food Additives

Food allergies may cause asthma symptoms.Rare in adultsAvoidance diets


Triggers of AsthmaGastroesophageal Reflux Disease

Exact mechanism is unknown.Reflux of acid could be aspirated into

lungs, causing bronchoconstriction.


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Triggers of AsthmaEmotional Stress

Psychologic factors can worsen the disease process.Attacks can trigger panic and anxiety.Extent of effect is unknown.


Pathophysiology


Fig. 29-1. Pathophysiology of asthma. IL, Interleukin.

PathophysiologyPrimary response is chronic

inflammation from exposure to allergens or irritants. Leading to airway hyperresponsiveness

and acute airflow limitations


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Pathophysiology Inflammatory mediators cause early-

phase response.Vascular congestionEdema formationProduction of thick, tenacious mucusBronchial muscle spasmThickening of airway walls


Early Phase Response of Asthma Triggered by Allergen


Factors Causing Obstruction


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PathophysiologyLate-phase responseOccurs within 4 to 10 hours after initial

attackOccurs in only 30% to 50% of patientsCan be more severe than early phase

and can last for 24 hours or longer


PathophysiologyLate-phase response If airway inflammation is not treated or

does not resolve, it may lead to irreversible lung damage.


Clinical ManifestationsUnpredictable and variableRecurrent episodes of wheezing,

breathlessness, cough, and tight chestMay be abrupt or gradualLasts minutes to hours


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Clinical ManifestationsExpiration may be prolonged. Inspiration-expiration ratio of 1:2 to 1:3

or 1:4Bronchospasm, edema, and mucus in

bronchioles narrow the airways.Air takes longer to move out.


Clinical ManifestationsWheezing is unreliable to gauge

severity. Severe attacks may have no audible

wheezing.Usually begins upon exhalation


Clinical ManifestationsCough variant asthmaCough is only symptom.Bronchospasm is not severe enough to

cause airflow obstruction.


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Clinical ManifestationsDifficulty with air movement can

create a feeling of suffocation.Patient may feel increasingly anxious.


Clinical ManifestationsAn acute attack usually reveals signs

of hypoxemia.Restlessness ↑ anxiety Inappropriate behavior


Clinical ManifestationsMore signs of hypoxemia ↑ pulse and blood pressurePulsus paradoxus (drop in systolic BP

during inspiratory cycle >10 mm Hg)


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Classification of AsthmaMild intermittentMild persistentModerate persistentSevere persistent


ComplicationsSevere acute attackRespiratory rate >30/min Pulse >120/minPEFR is 40% at best.Usually seen in ED or hospitalized


ComplicationsLife-threatening asthmaToo dyspneic to speakPerspiring profuselyDrowsy/confusedRequire hospital care and often

admitted to ICU


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Diagnostic StudiesDetailed history and physical examPulmonary function testsPeak flow monitoringChest x-rayABGs


Diagnostic StudiesOximetryAllergy testingBlood levels of eosinophilsSputum culture and sensitivity


Collaborative CareEducationStart at time of diagnosis. Integrate through care.

Self-managementTailored to needs of patientCulturally sensitive


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Collaborative CareDesired therapeutic outcomesControl or eliminate symptomsAttain normal lung functionRestore normal activitiesReduce or eliminate exacerbations and

side effects of medications


Drug Therapy


Fig. 29-4. Drug therapy: stepwise approach for managing asthma.

Asthma Control Test


Fig. 29-5.

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Collaborative CareMild intermittent and mild persistent

asthmaAvoid triggers of acute attacks.Premedicate before exercising. Choice of drug therapy depends on

symptom severity.


Collaborative CareAcute asthma episodeRespiratory distressTreatment depends upon severity and

response to therapy. Severity measured with flow rates


Collaborative CareAcute asthma episodeO2 therapy may be started and

monitored with pulse oximetry or ABGs in severe cases.


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Collaborative CareSevere exacerbationsMost therapeutic measures are the

same as for acute episode. ↑ in frequency and dose of bronchodilators


Collaborative CareSevere exacerbations IV corticosteroids are administered

every 4 to 6 hours, then are given orally.Continuous monitoring of patient is

critical. IV magnesium sulfate is given as a

bronchodilator.


Collaborative CareSevere exacerbationsSupplemental O2 is given by mask or

nasal cannula for 90% O2 saturation.Arterial catheter may be used to facilitate

frequent ABG monitoring. IV fluids are given because of insensible

loss of fluids.


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The nurse anticipates intubation and mechanical ventilation for the patient with a severe exacerbation of asthma (status asthmaticus) when:

1. The PaCO2 is 60 mm Hg.2. The PaO2 decreases to 70 mm Hg.3. Severe respiratory muscle fatigue occurs.4. The patient has extreme anxiety and fear of

suffocation.

Audience Response Question


Drug TherapyLong-term control medicationsAchieve and maintain control of

persistent asthmaQuick-relief medicationsTreat symptoms of exacerbations


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Drug TherapyThree types of antiinflammatory

drugsCorticosteroidsLeukotriene modifiersMonoclonal antibody to IgE


Drug TherapyCorticosteroids (e.g.,

beclomethasone, budesonide)Suppress inflammatory response Inhaled form is used in long-term

control.Systemic form to control exacerbations

and manage persistent asthma


Drug TherapyCorticosteroidsReduce bronchial hyperresponsivenessDecrease mucous productionAre taken on a fixed schedule


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Drug TherapyCorticosteroidsOropharyngeal candidiasis, hoarseness,

and a dry cough are local side effects of inhaled drug. Can be reduced using a spacer or by gargling

after each use


Spacer


Fig. 29-6. Example of an AeroChamber spacer used with a metered-dose inhaler.

Drug TherapyLeukotriene modifiers or inhibitors

(e.g., zafirlukast, montelukast, zileuton)Block action of leukotrienes—potent

bronchoconstrictors


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Drug TherapyLeukotriene modifiers or inhibitors Have both bronchodilator and

antiinflammatory effects Not indicated for acute attacksUsed for prophylactic and maintenance

therapy


Drug TherapyAnti-IgE (e.g., Xolair) ↓ circulating free IgE levelsPrevents IgE from attaching to mast

cells, preventing release of chemical mediatorsSubcutaneous administration every 2 to

4 weeks


Drug TherapyThree types of bronchodilatorsβ2-Adrenergic agonists MethylxanthinesAnticholinergics


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Drug Therapyβ-Adrenergic agonists (e.g.,

albuterol, metaproterenol)Effective for relieving acute

bronchospasmOnset of action in minutes and duration

of 4 to 8 hours


Drug Therapyβ-Adrenergic agonists Prevent release of inflammatory

mediators from mast cellsNot for long-term use


Drug TherapyMethylxanthines (e.g., theophylline)Less effective long-term bronchodilatorAlleviates early phase of attacks but has

little effect on bronchial hyperresponsivenessNarrow margin of safety


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Drug TherapyAnticholinergic drugs (e.g.,

ipratropium)Block action of acetylcholineUsually used in combination with a

bronchodilatorMost common side effect is dry mouth.


Patient Teaching Related to Drug Therapy

Correct administration of drugs is a major factor in success. Inhalation of drugs is preferable to

avoid systemic side effects.MDIs, DPIs, and nebulizers are devices used

to inhale medications.


Patient Teaching Related to Drug Therapy

Correct administration of drugs Using an MDI with a spacer is easier and

improves inhalation of the drug. DPI (dry powder inhaler) requires less

manual dexterity and coordination.


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Example of DPI


Fig. 29-8. Example of a dry powder inhaler (DPI).

Nebulizer

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

Nonprescription Combination Drugs

Should be avoided in generalEpinephrine can also increase heart rate

and blood pressure.Ephedrine stimulates CNS and

cardiovascular system.Dietary supplements were banned in 2004.


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Nursing ManagementNursing Assessment

Health history Especially of precipitating factors and

medicationsABGsLung function tests


Nursing ManagementNursing Assessment

Physical examinationUse of accessory musclesDiaphoresisCyanosisLung sounds


Nursing ManagementNursing Diagnoses

Ineffective airway clearanceAnxietyDeficient knowledge


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Nursing ManagementPlanning

Overall GoalsMaintain greater than 80% of personal

best PEFRHave minimal symptomsMaintain acceptable activity levels


Nursing ManagementPlanning

Overall GoalsFew or no adverse effectsNo recurrent exacerbations of asthma

or decreased incidence of asthma attacksAdequate knowledge to participate in

and carry out management


Nursing ManagementHealth Promotion

Teach patient to identify and avoid known triggers.Use dust coversUse scarves or masks for cold airAvoid aspirin or NSAIDs


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Nursing ManagementHealth Promotion

Prompt diagnosis and treatment of upper respiratory infections and sinusitis may prevent exacerbation.

Fluid intake of 2 to 3 L every day


Nursing ManagementNursing Implementation

Acute interventionMonitor respiratory and cardiovascular

systems: Lung soundsRespiratory rate PulseBP



An important goal of nursing is to ↓the patient’s sense of panic. Stay with patient.Encourage slow breathingPosition comfortably.


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Ambulatory and home careMust learn about medications and

develop self-management strategiesPatient and health care professional

must monitor responsiveness to medication.



Ambulatory and home care Patient must understand importance of

continuing medication when symptoms are not present.



Important patient teachingSeek medical attention for

bronchospasm or when severe side effects occur.Maintain good nutrition.Exercise within limits of tolerance.


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Important patient teachingMeasure peak flow at least daily.Asthmatic individuals frequently do not

perceive changes in their breathing.



Peak flow should be monitored daily and a written action plan should be followed according to results of daily PEFR.



Peak flow resultsGreen ZoneUsually 80% to 100% of personal bestRemain on medications.


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Peak flow resultsYellow ZoneUsually 50% to 80% of personal best Indicates caution Something is triggering asthma.



Peak flow results Red Zone 50% or less of personal best Indicates serious problemDefinitive action must be taken with health

care provider.


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Asthma – Definition Significance - Napa Valley College ...€¦ · Pathophysiology of asthma. IL, Interleukin. Pathophysiology ... Acute asthma episode ... exacerbation of asthma