Chapter 13 Asthma Anatomic Alterations of the Lungs

Chapter 13 Asthma

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Anatomic Alterations of the Lungs

• Smooth muscle constriction of bronchial airways (bronchospasm)

• Excessive production of thick, whitish, tenacious bronchial secretions

• Hyperinflation of alveoli (air-trapping)

• Mucus plugging and, in severe cases, atelectasis

Etiology

• Extrinsic asthma

• Allergic or atopic asthma

• Intrinsic asthma

• Nonallergic or nonatopic asthma

Intrinsic Asthma (Nonallergic or Nonatopic Asthma)

• Infections

• Exercise and cold air

• Industrial pollutants or occupational exposure

• Drugs, food additives, and food preservatives

• Gastroesophageal reflux

• Sleep (nocturnal asthma)

• Emotional stress

• Premenstrual asthma

Additional Risk Factors

• Residence in a large urban area, especially the inner city

• Exposure to secondhand smoke

• A parent who has asthma

• Respiratory infections in childhood

• Low birth weight

• Obesity

Overview of the Cardiopulmonary Clinical Manifestations Associated with ASTHMA

• The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Bronchospasm (see Figure 9-10) and Excessive Bronchial Secretions (see Figure 9-11)—the major anatomic alterations of the lungs associated with asthma (see Figure 13-1).

 

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Clinical Data Obtained at the Patient’s Bedside

• Vital signs

• Increased respiratory rate

• Increased heart rate, cardiac output, blood pressure

Clinical Data Obtained at the Patient’s Bedside

• Use of accessory muscles of inspiration

• Use of accessory muscles of expiration

• Pursed-lip breathing

• Substernal intercostal retractions

• Increased anteroposterior chest diameter (barrel chest)

• Cyanosis

• Cough and sputum production

Clinical Data Obtained at the Patient’s Bedside

• Pulsus paradoxus

• Decreased blood pressure during inspiration

• Increased blood pressure during expiration

Clinical Data Obtained at the Patient’s Bedside

• Chest assessment findings

• Expiratory prolongation

• Decreased tactile and vocal fremitus

• Hyperresonant percussion

• Diminished breath sounds

• Diminished heart sounds

• Wheezing and rhonchi

Clinical Data Obtained from Laboratory Tests and Special Procedures

Pulmonary Function Study: Expiratory Maneuver Findings

• FVC FEVT FEF25%-75% FEF200-1200

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• PEFR MVV FEF50% FEV1%

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Pulmonary Function Study: Lung Volume and Capacity Findings

Arterial Blood Gases

Arterial Blood Gases

Oxygenation Indices

Abnormal Laboratory Tests and Procedures

• Abnormal laboratory tests and procedures

• Sputum examination
• Eosinophils
• Charcot-Leyden crystals (see next slide)
• Casts of mucus from small airways
• called Kirschman spirals
• IgE level (elevated in extrinsic asthma)

Charcot-Leyden Crystals

• Needle shaped crystals -

• Represents breakdown products of eosinophils

Radiologic Findings

• Chest radiograph

• Increased anteroposterior diameter

• Translucent (dark) lung fields

• Depressed or flattened diaphragm

Table 13-1. Asthma Classification Based on Severity—Excerpts

• Disease Symptoms

• Step 4: Continual symptoms

• Step 3: Daily symptoms

• Step 2: Symptoms > than twice weekly

• Step 1: Symptoms < than twice weekly

Table 13-2. Asthma Zone Management System—Excerpts

• Green zone

• 80% to 100% of personal best PEFR

• Yellow zone

• 50% to 80% of personal best PEFR

• Red zone

• <50% of personal best PEFR

General Management of Asthma

• Environmental control

• Respiratory care treatment protocols

• Oxygen therapy protocol
• Bronchial hygiene therapy protocol
• Aerosolized medication protocol
• Mechanical ventilation protocol

• Medications commonly prescribed

• Xanthines
• Corticosteroids
• Anti-inflammatory agents
• Leukotriene inhibitors

General Management of Asthma

• Monitoring

• Arterial blood gas measurements
• Pulse oximetry
• Serial PFTs
• PEFR
• FEV1
• Vital signs
• Chest radiographs

General Management of Asthma

• Patient compliance

• Asthma-symptom/medication-use diaries
• Serum theophylline levels
• Carboxyhemoglobin determinations
• Total (circulating) eosinophil counts
• No-show rates at physician offices
• Rate of medication use
• Frequency of emergency department visits and hospitalizations
• Number of red zone days per months (see Table 13-2)

Classroom Discussion Case Study: Asthma