Questions and Answers
What is the characteristic PEFR reading for acute mild asthma?
Which symptom is NOT associated with acute severe asthma?
What would be a common pulse rate in a patient experiencing acute moderate asthma?
Which of the following is a feature of life-threatening asthma?
Signup and view all the answers
What is the maximum range for pulsus paradoxus in acute moderate asthma?
Signup and view all the answers
Which feature is most indicative of acute severe asthma?
Signup and view all the answers
What is a notable symptom when assessing a patient with acute asthma exacerbation?
Signup and view all the answers
Which of the following statements about respiratory rates in asthma exacerbations is true?
Signup and view all the answers
Which category of asthma exacerbation requires immediate medical attention?
Signup and view all the answers
What is the significance of a PEFR reading of 50-69% in asthma management?
Signup and view all the answers
Study Notes
Definition of Asthma
- Asthma is a heterogeneous disease characterized by chronic airway inflammation.
- Defined by respiratory symptoms: wheeze, shortness of breath, chest tightness, and cough that vary in intensity and over time.
- Associated with variable expiratory airflow limitation.
Epidemiology of Asthma
- Asthma has a global prevalence with variations by country and geographic region.
- Approximately 5.4% of Nigerians are asthmatic; about 10-12% in adults and 15% in children.
- In 2019, WHO estimated 262 million people worldwide had asthma, leading to 455,000 deaths.
- Increasing prevalence in developing countries linked to urbanization; common onset age is around 3 years.
- Male-to-female ratio of asthma in children is 2:1, equalizing at puberty.
Classification of Asthma
- Extrinsic Asthma: Triggered by specific external factors; often in atopic individuals with positive skin reactions to allergens.
- Intrinsic Asthma: No identifiable external cause; typically begins in middle age.
Risk Factors for Asthma
- Result from interaction between genetic and environmental factors.
-
Host Factors:
- Genetic predisposition
- Atopy (allergic conditions)
- Airway hyperresponsiveness
- Obesity
-
Environmental Factors:
- Indoor allergens (dust mites, pet dander)
- Outdoor allergens (pollen)
- Occupational sensitizers (isocyanates, wood dust)
- Passive smoking
- Diet and paracetamol use.
Asthma Triggers
- Common triggers include:
- Allergens
- Upper respiratory tract viral infections
- Exercise and hyperventilation
- Cold air
- Irritant gases (sulfur dioxide)
- Specific drugs (β blockers, aspirin)
- Stress
- Household irritants (sprays, paint fumes).
Pathogenesis of Asthma
- Inhalation of allergens in sensitized patients causes bronchoconstriction via IgE-dependent mechanisms.
- Release of mediators like histamine and leukotrienes leads to airway constriction.
- Inflammatory cells including eosinophils and macrophages play vital roles in chronic inflammation.
- Increased microvascular leakage results in airway edema, mucous plugging, and inflammation.
- Ongoing inflammation causes airway wall thickening due to edema, cellular infiltration, smooth muscle mass increase, and gland hypertrophy.
- Chronic disease can lead to airway remodeling, resulting in fibrosis, fixed narrowing, and reduced bronchodilator response.
Clinical Features of Asthma
- Characterized by recurrent exacerbations; patients are usually asymptomatic between episodes.
- Symptoms worsen at night and include breathlessness, cough, wheeze, and chest tightness.
- Signs include agitation, tachypnea, and tachycardia.
- Acute flare-ups exhibit progressively worsening symptoms and decreased lung function.
- Assessment includes FEV1, PEFR, PaO2, PaCO2, and arterial oxygen saturation.
Severity Categorization of Asthma Flare-Ups
- Flare-ups classified as mild, moderate, severe, life-threatening, or near-fatal, based on symptoms and functional lung assessment.
Acute Mild Asthma
- Symptoms: Breathlessness while walking, possible agitation, end expiratory wheeze.
- PEFR: ≥ 70%; relief using SABA (+/- steroid).
Acute Moderate Asthma
- Symptoms: Breathless at rest, usually agitated, tachypnoea.
- Pulse rate: 100-109 bpm; PEFR: 50-69% of best/predicted; relief from repeated steroid doses.
Acute Severe Asthma
- Symptoms: Breathless at rest, unable to complete sentences, loud wheezing, use of accessory muscles.
- Pulse rate: ≥ 110 bpm; PEFR is critically low; potential presence of pulsus paradoxus.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the definition and epidemiology of asthma through this quiz. Understand the characteristics, symptoms, and global prevalence of asthma, including specific statistics from various regions. Test your knowledge of this chronic airway disease and its impact on populations.
