Asthma

Question 1

LOs

Answer 1

• Understand and describe the physiology of common causes of wheeze
• Understand the causes, presentation, diagnosis, monitoring and management of acute and chronic asthma

Question 2

What is asthma?

Answer 2

• It is a chronic inflammatory airway disease characterised by:
  
  • Chronic bronchiole inflammation
  • Airway hyper-responsiveness
  • Bronchoconstriction (obstructive airflow limitations)
• Day to day diurnal variability in symptoms → PEFR (peak expiratory flow rate) variation >20%

Question 3

What are the forms of bronchial asthma?

Answer 3

• Eosinophilic
• Non eosinophilic
• Occupational (due to something in the workspace)
• Irritant induced,
• Exercise induced bronchospasm

Question 4

What causes wheeze?

Answer 4

• COPD (fixed)
• Asthma (reversible)
• Pulmonary oedema (cardiac wheeze)
• Bronchiectasis
• Upper airway obstruction (STRIDOR)
• Foreign body
• Gastro-oesophageal syndrome
• Eosinophilic vasculitis
• Respiratory bronchiectasis (post viral infection)

Question 5

What are the signs & symptoms of asthma?

Answer 5

• Wheeze → widespread polyphonic wheeze
• Intermittent breathlessness → diurnal (at night worse)
• Cough
• Triggers e.g. dust, pets
• Hyper-inflated chest

Question 6

Draw and label the bronchiole tree

Answer 6

Question 7

What is the pathophysiological role of eosinophils?

Answer 7

• End stage granulocytes
• IL-5 is the principle growth factor
• Migrate into tissue from peripheral blood – commonly from intestinal mucosa
• If hyper-E0 syndromes correct with steroids: inflammatory; if fails – malignant

Question 8

What are the causes of hypereosinophilia?

Answer 8

• Drugs
• Allergic fungal disease eg allergic bronchopulmonary aspergillosis
• Eosinophilic granulomatosis – polyangiitis
• Eosinophilic pneumonia
• Asthma
• Parasitic infection

Question 9

What are the clinical features of asthma? (history and examination)

Answer 9

History

• Symptoms of respiratory pathology e.g. wheeze, cough, SOB & if diurnal
• Triggers? → pets, temp, occupational exposure, smoking (makes asthma worse)
• Personal or family history → ATOPY (allergies)
• Assessing asthma severity:
  
  • Peak expiratory flow rate (PEFR)
  • Adherence to treatment
  • Attendance hospital/ICU
  • Normal requirement for SABA

Examination

• Sometimes normal respiratory exam
• BEDSIDE → Oxygen, inhaler, spacer, PEFR meter
• INSPECTION → cyanosis, increased work of breathing, audible wheeze
• Peripheries → fine tremor, tachycardia, oral candida (steroid inhaler us)
• Chest → polyphonic expiratory wheeze

Question 10

What are the risk factors & triggers for asthma?

Answer 10

• Pets (allergic/sensitiser induced asthma)
• Stress
• Certain medications
  
  • Beta-blockers and NSAIDs can exacerbate asthma
• Dust → trigger history e.g. occupation
• Chemicals and perfumes
  
  • Irritant induced asthma
    
    • Substance caused irritation and then inflammation lining the airways (damage recognised leading to immune system response)
• Air pollutants
• Smoking
• Genetic
  
  • Atopic history
  • Prematurity and low birth weight
• Respiratory infections
• Some foods and beverages

Question 11

What is occupational asthma?

Answer 11

• Considered when patient symptoms IMPROVE when not at work
• Usually >1 year after started work as takes time for sensitivity to develop
• Sensitiser induced (enzymes classical ‘allergen’ response) OR irritant induced (chemicals cause inflammation → immune response → inflammed

Question 12

How to diagnose asthma?

Answer 12

• Symptomology: day to day diurnal variability in core symptoms; history of triggers (allergic / non allergic)
• Functional: Peak expiraotry with diurnal variability (20%); dynamic airflow obstruction >15% post BD FEV1, CXR → hyperinflation, IgE blood test, sputum eosinophilia
• CLINICAL
  
  • Day to day diurnal variability
  • Episodic symptoms
  • Relationship to exposures
  • Occupational/irritants
• Allergic/non-allergic
  
  • History
  • RAST (rapid antigen specific testing)
  • IGE blood tests

Question 13

How to assess the impact of asthma?

Answer 13

• Number of SABA uses per day/week
• Number of days missed from school/work
• Nocturnal symptoms
• Any recent exacerbations
• Ever required hospital attendance?
• Ever been admitted to intensive care?

Question 14

Explain the chronic management of asthma

Answer 14

• CONSERVATIVE
  
  • Smoking cessation/avoiding triggers
  • PEFR daily
  • Regular asthma reviews → personal asthma plan & inhaler technique education
  • Vaccinations
• MEDICAL
  
  • Salbutamol (side effects: tachycardia, tremor)
  • Inhaled corticosteroid (side effect: oral candida → thrush)

Question 15

How would you safety net an asthma patient?

Answer 15

• Use SABA >3x a week = GP
• <4 hour gaps between weekly requirements of salbutamol = GO A&E
• 10 puffs salbutamol with NO symptom relief → call 999

Question 16

What are the complications of asthma?

Answer 16

Exacerbations

• Can be infective OR non-infective
• Triad: bronchospasm (hyperresponsiveness to something), mucosal thickening, mucous production → all of these usually lead to hyperventilation

Pneumothorax

• Secondary pneumothorax may develop during an asthma exacerbation → drain required

Question 17

What are normal PEF rates for different ages?

Answer 17

Question 18

Illustrate the difference in obstructive and restrictive spirometry readings

Answer 18

Question 19

How to grade different severities of asthma?

Answer 19

Question 20

What investigations would you do to someone with asthma?

Answer 20

BEDSIDE

• Peak flow → mild <100%, moderate <75%, severe <50%, life threatening <33%)
• Obs
• Sputum culture
• ECG (salbutamol → tachycardia and arrythmias)

TESTS

• FBC (raised eosinophils)
• CRP
• ABG (assess perfusion)
• Specific RAST test (identify specific IgE to allergens → confirm trigger)

IMAGING

• CXR → rule out pneumothorax
• Spirometry → confirm obstructive disease

Question 21

What is the management of someone with asthma?

Answer 21

Acute management

Oxygen

Help

Salbutamol

Hdrocortisone

Ipratropium

Theophyline

Magnesium

Escalate

1. Salbutamol nebulisers 5mg+/- ipratropium
2. PO prednisolone 40mg OR IV hydrocortisone
   
   1. Antibiotics
3. If life threatening → ICU
4. Discharge → ensure stable for 4 hours following discharge (& PEFR returned to >75%)

Question 22

When is it not safe to send an acute asthmatic home?

Answer 22

• Exacerbation whilst on steroidds
• History of poor compliance to treatment
• History of depression/anxiety
• History of severe/refractory asthma (e.g. ICU)
• Pregnancy
• Poor social circumstances

Question 23

Chart of treatment of asthma

Answer 23