U13C1 Asthma

Question 1

Chronic vs acute asthma

Answer 1

• CHRONIC: a common chronic inflammatory condition of the airways, associated with airway hyperresponsiveness and variable airflow obstruction. The most frequent symptoms of asthma are cough, wheeze, chest tightness, and breathlessness.
  • Coughing and wheezing are the most common symptoms of childhood Asthma
  • Breathlessness, chest tightness or pressure, and chest pain also are
  reported
  • Poor school performance and fatigue may indicate sleep deprivation from nocturnal symptoms
• ACUTE: the progressive worsening of asthma symptoms, including breathlessness, wheeze, cough, and chest tightness. An acute exacerbation is marked by a reduction in baseline objective measures of pulmonary function, such as peak expiratory flow rate and FEV₁.
  • SOB
  • Cough +/- green phlegm
  • Chest pain/ tightness
  • Difficulty completing sentences
  • Wheeze

Question 2

What is the pathophysiology of asthma?

Answer 2

• Bronchospasm (immediate phase)
• Reversible airflow obstruction- Smooth muscle contraction → constriction of airways
• As a result of: Genetic predisposition: → hyperresponsiveness And Environmental triggers: allergens, pollution, smoking, drugs → IgE, histamine, leukotrienes, cytokines etc…
• Inflammation (later phase)
• Reversible airflow obstruction- ↑ exudate, mucus, oedema → narrowing of airways (tumor = swelling)
• As a result of inflammatory cells/mediators in wake of immediate phase: Th cells, eosinophils, IL-5, IL-4, IL-13 etc, etc…

Question 3

What is the role of IgE in asthma?

Answer 3

Question 4

What is the pathophysiology of COPD?

Answer 4

Question 5

Asthma vs COPD histology

Answer 5

Question 6

What is the MRC dyspnoea scale?

Answer 6

Question 7

What are the clinical signs of respiratory illness

Answer 7

• finger clubbing
• fine tremor
• asterixis (flapping tremor)
• respiratory rate
• scars
• chest wall deformities
• cricosternal distance
• chest expansion
• percussion
• tactile vocal fremitus / vocal resonance
• breath sounds
• lymph nodes
• peripheral odema

Question 8

What are the breath sounds?

Answer 8

• Vesicular: the normal quality of breath sounds in healthy individuals.
• Bronchial: harsh-sounding (similar to auscultating over the trachea), inspiration and expiration are equal and there is a pause between. This type of breath sound is associated with consolidation.
• Quiet breath sounds: suggest reduced air entry into that region of the lung (e.g pleural effusion, pneumothorax).
• Wheeze: a continuous, coarse, whistling sound produced by turbulent airflow respiratory airways during breathing. May be polyphonic (obstructive airway disease) , or monophonic (large airway obstruction)
• Stridor: Inspiratory - a high-pitched extra-thoracic breath sound resulting from turbulent airflow through narrowed upper airways. Stridor implies large airway obstruction, exadurated by huffing
• Coarse crackles: discontinuous, brief, popping lung sounds typically associated with pneumonia, bronchiectasis and pulmonary oedema.
• Fine end-inspiratory crackles: velcro - syynonymous with pulmonary fibrosis

Question 9

Which is eosinophilic and neutrophilic out of asthma and COPD?

Answer 9

• Asthma - eosinophillic
• COPD - neutrophilic
• Neutrophilic asthma- very severe and persistent, with frequent
  exacerbations, and characterized by fixed airway obstruction. It is associated with comorbidities such as respiratory infections, obesity, gastroeosophageal reflux disease, and obstructive sleep apnoea
• COPD exacerbations (and inflammation may be eosinophilic) 30%. Does this represent misdiagnosis / codiagnosis / another entity

Question 10

What is the Pathophysiology of eosinophilic asthma?

Answer 10

Question 11

Conducting vs respiratory zone

Answer 11

Question 12

What are the types of asthma?

Answer 12

• Atopic (Allergic)- Most common,example of a Type 1 IgE-mediated hypersensitivity reaction, usually triggered byallergens in dust, pollen, animal dander, or food, or by infections
• Non-atopic (Non-allergic)- Less common, no evidence of allergen sensitivity, usually triggered by weather conditions, exercise,infections and stress
• Eosinophilic- Severe asthma often seen in adults, caused by high levels of eosinophils which results in inflammation in the airways (leads to fluid, mucus, spasms, tissue damage)
• Non-eosinophilic- Airway inflammation with the absence of eosinophils, due to activation of non-predominant type 2 immunologic pathways
• Drug-Induced- Several pharmacological agents provoke asthma,a key example is aspirin
• Occupational- Triggered by fumes (plastics), organic and chemical dusts (wood, cotton, platinum), gases (toluene), and other chemicals

Question 13

What is the pathophysiology of allergic asthma?

Answer 13

Question 14

What are the signs and symptoms of asthma?

Answer 14

Acute airway changes:

• Smooth muscle contraction (bronchoconstriction) → shortness of breath, chest tightness, wheezing
• Mucus hypersecretion → persistent cough, chest congestion
• Oedema → coughing, difficulty breathing
• Sensory nerve activation → coughing, chest tightness, discomfort

Less common symptoms:

• Blue lips/fingernails (cyanosis)- Inadequate oxygenation in blood
• Tachypnea- Compensatory mechanism to maintain oxygen levels
• Stridor- High-pitched wheezing noise. Suggests potentially critical airway obstruction -> impending respiratory failure
• Arrhythmia
• Silent chest- phenomenon occurs when airflow is severely limited or absent, and there is minimal or no audible wheezing or breath sounds

Question 15

What are the risk factors and triggers of asthma?

Answer 15

Question 16

What are the diagnostic tests for asthma?

Answer 16

Question 17

How do you use an inhaler?

Answer 17

Question 18

Asthma vs COPD

Answer 18

Question 19

Obstructive vs restrictive

Answer 19

Question 20

How to interpret an ABG?

Answer 20

SMORE- same metabolic opposite respiratory