Asthma and COPD Quiz

Chronic Pulmonary Dysfunction - II

• Presented by Troy Seely BScPT, MScPT, DPT, FCAPMT
• Course focused on health conditions and diseases in rehabilitation
• RS 3060A

Group Assignment

• Due Monday, November 25th
• Hard copy of the group assignment due at the beginning of lecture next week
• Upload the assignment to UWO Brightspace (announcement will be posted later this week)
• Each group member must also complete and post a peer evaluation of their teammates to UWO Brightspace (announcement will be posted later this week)

Outline

• Introduction/Review:
  • COPD review
  • Ventilation-perfusion (V/Q) reviewed
• Discuss Asthma:
  • Epidemiology
  • Etiology: categories of provocative factors
  • Pathology: hyper-reactivity; 2-stage response
• Discuss Cystic Fibrosis:
  • Epidemiology: impact on life span
  • Etiology: hereditary
  • Pathology: mucus; some elements overlap COPD (chronic obstructive pulmonary disease)
• Discuss Restrictive Lung Disease:
  • Group of diseases
  • Etiology: many different causes (broad summary only)
  • Pathology: lung stiffness

COPD Review

• Diagram depicts patients with primarily emphysema, average COPD patients, and patients with primarily chronic bronchitis
• Diagram shows degrees of inflammation or alveolar destruction in varying stages
• Differences in air movement during inspiration and expiration with COPD

Abnormal Ventilation-Perfusion Reviewed

• In asthma, no pathology in alveoli; bronchospasm restricts ventilation.
• In chronic bronchitis, mucus plugs could block ventilation.
• If the alveolar wall is removed, you're removing the capillary bed on the opposite side (emphysema)

Asthma

• Defined as: reversible, obstructive lung disease characterized by airway inflammation and associated with airway hyper-responsiveness (reactivity of smooth muscle causing bronchospasm) to various stimuli
• Triggers vary

Asthma: Epidemiology

• Most common chronic disease of childhood, affecting 9.4% of all children
• Can occur at any age, though most likely first occurs before age 5
• More common and severe in boys than girls in childhood
• Young boys have 'dysanapsis' (smaller airway diameters relative to lung volumes compared to girls)

Asthma: Etiology

• Two main types: allergic and non-allergic
• Allergic (extrinsic) asthma is more common
• Allergic asthma involves an immunologic response driven by mast cells in the airways in response to environmental triggers like pollen, mold, dust, and animal dander
• Non-allergic (intrinsic) asthma is less common; causes are often unknown
• May be secondary to chronic or recurrent infections of the bronchi, sinuses, or tonsils.
• Also caused by hypersensitivity to bacteria or viruses causing infection
• Other recognized categories: exercise-induced, aspirin sensitive, occupational, smoke induced, latex induced, exposure to biologic dusts, gases, and fumes

Asthma: Pathology

• Inflammation of bronchial mucosa causes narrowing of the airways, bronchospasm, and increased bronchial secretions in response to a trigger.
• Narrowed airways increase resistance to airflow, cause air trapping during exhalation, resulting in hyperinflation
• Similar to COPD (chronic bronchitis) presentation.
• Narrowed airways cause abnormal distribution of ventilation to the alveoli, affecting ventilation/perfusion ratio
• Asthma exacerbations can self-resolve.

Asthma Pathology - Early Response

• Antibodies bind to foreign substances (allergens) causing airway mucosa inflammation
• Mediators like histamine cause smooth muscle constriction, mucosal edema, and mucus secretion

Asthma Pathology - Late Response

• Inflammatory cell recruitment after 4-8 hours (up to 24 hrs) from initial response in more severe asthma cases (50% of patients).
• Increased inflammatory mediators cause more bronchospasm, edema, and mucus secretion
• Epithelial damage and impaired mucociliary function from toxic inflammatory effects.
• Chronic increase in inflammation leads to long-term changes like goblet cell hyperplasia, airway wall remodeling, and smooth muscle hypertrophy

Asthma - Clinical Presentation

• Clinical symptoms during exacerbation: dyspnea (shortness of breath) on exertion or at rest, cough, chest pain, wheezing
• Posture: chest held in expanded position, showing hyperinflation
• Accessory muscles of ventilation may be required for breathing
• Auscultation: wheezing is characteristic, but crackles can also be present in severe airway obstruction
• Pulmonary function tests (PFTs): show decreased FEV1 (less than 70-80% of predicted value), and increased residual volume and FRC (functional residual capacity), due to air trapping
• Reversibility of abnormalities is characteristic of asthma
• During remission, patients have near-normal PFT results.

Asthma and Lung Volumes

• Diagrams illustrating normal & asthma lung volumes (IRV, TV, ERV, RV, FRC) and demonstrating differences between them. Asthma shows consistent with hyperinflation: FRC and RV increased

Asthma Classification

• Step 4 (severe persistent): continual symptoms; frequent exacerbations; limited physical activity
• Step 3 (moderate persistent): daily symptoms; effects activity
• Step 2 (mild persistent): exacerbations less than daily, but greater than 2 times per week. May impact activity
• Step 1 (mild intermittent): exacerbations two times a week (or less); asymptomatic otherwise.

Asthma - Clinical Course

• Most children with asthma no longer have symptoms in adulthood.
• Asthma onset later in life usually shows progressive pulmonary function changes even during periods of remission
• Possible airway remodelling in response to chronic inflammation

Cystic Fibrosis

• Inherited, chronic disease affecting excretory glands
• Secretions are thicker and more viscous than normal, affecting multiple body systems
• Includes pulmonary, pancreatic, hepatic, and reproductive systems

Cystic Fibrosis: Epidemiology

• Approximately 4,200 Canadians live with CF
• Roughly 1 child born with CF in every 3,600 live births in Canada

Cystic Fibrosis and Lifespan

• Data show the median predicted survival age differing from the 1990s cohort to the current cohort
• Significant improvement in life expectancies since the 1990's

Cystic Fibrosis: Etiology

• Autosomal recessive genetically transmitted disorder
• For a child to have CF, both parents must be carriers or have CF

Cystic Fibrosis: Etiology

• CF gene on the long arm of chromosome 7
• Gene functions in transporting electrolytes (chloride, sodium, and water) in and out of epithelial cells in many organs
• Defective transport leads to thickened, difficult-to-move mucus

Cystic Fibrosis: Pathology

• Chronic pulmonary component related to abnormally viscous mucus
• Altered secretions cause airway obstruction and hyperinflation
• Partial or complete airway obstruction reduces ventilation to alveoli where ventilation and perfusion are not matched
• Leads to infection susceptibility

Cystic Fibrosis: Pathology

• Obstruction of bronchi predisposes to infections (pneumonia, fibrosis, and cystic dilations)
• Recent research explores high salt concentration as an inhibitor to immune response
• Pulmonary system dysfunction is a significant cause of morbidity and mortality in CF patients

Atelectasis

• Lung tissue collapse.
• Can range from asymptomatic to respiratory failure.
• Two types:
  • Compression atelectasis: due to external pressure
  • Absorption atelectasis: air removal from obstructed or hypoventilated alveolus

Bronchiectasis

• Chronic lung condition where bronchus walls thicken due to frequent infection and inflammation.
• Destroys elastic tissue and muscle in bronchi.
• Leads to abnormal dilatation, bronchospasm, copious mucus production, and subsequent ventilation-perfusion abnormalities
• Occurs in all CF patients over 0.5 years of age

Cystic Fibrosis: Clinical Presentation

• Initial presentation of CF stems from involvement of different organ systems: -Diabetes due to pancreatic dysfunction -Failure to thrive due to gastrointestinal dysfunction -Frequent pulmonary infections and chronic cough
• Specific to lung function: -Thick secretions (difficult to clear) -Barrel-shaped chest wall (hyperinflation) -Decreased breath sounds with wheezing and crackles upon auscultation -Pursed-lip breathing, cyanosis, digital clubbing

Restrictive Lung Disease

• Group of diseases of varying etiologies leading to difficulty expanding the lungs and reduced lung volume
• Characteristics include: difficulty expanding lungs, reduced lung volume, and reduced lung capacities.

RLD: Epidemiology

• Adults aged 35-44 have 2.7 cases per 100,000 people
• Patients over 75 have >175 cases per 100,000 people

Restrictive Lung Disease: Etiology

• Caused by harmful effects of: -Radiation therapy, inorganic dusts (metal/minerals), noxious gases, asbestos exposure, and tuberculosis
• Idiopathic pulmonary fibrosis is most common

Restrictive Lung Disease: Pathophysiology

• Usually begins with inflammation, leading to thickening of alveolar walls (interstitium) and fibrosis of distal air spaces
• Distal air spaces become fibrotic and more resistant to expansion (increased stiffness)
• This differs from increased compliance in COPD

What is the Interstitium?

• The complex structural space between the airspace epithelium and the vascular endothelium in the lungs.

Role of the Interstitium

• Separates and binds vascular and pleural cell layers
• Includes connective tissue, immune cells, and communicates with the lymphatic system
• Provides integrity yet allows for deformation

RLD Symptoms

• Major symptom is shortness of breath (dyspnea)
• Cough is nonproductive
• Weakness and fatigue
• Limited chest expansion
• Rapid, shallow breathing

Elastic & Air Flow Resistive Components of Breathing

• Shows total work minimized by slow deep breathing in a normal lung, increased elastic resistance and air flow resistance in restrictive disease
• Diagram illustrates how total work in breathing is minimized by rapid shallow breathing

Lung Capacity : RLD vs Normal

• Illustrates TLC, VC, and FRC reduced in restrictive lung diseases compared to normal findings

Summary of Chronic Pulmonary Disease

• Presents a tabular summary of different pulmonary conditions with their corresponding etiologies, pathology, and primary symptoms.

Test your knowledge on asthma and chronic obstructive pulmonary disease (COPD) with this quiz. It covers key concepts such as inflammatory responses, airway narrowing, and patient characteristics. Challenge yourself with questions about triggers, pathology, and ventilation abnormalities.