Asthma

Exam Cram

• Asthma is a type 1 hypersensitivity reaction causing bronchiole constriction

• Presentation: wheeze, night time cough, upper respiratory tract infections 

• Diagnosis: clinical: presentation + airway constriction with allergen & reversibility with salbutamol

• Management

  • Acute: salbutamol

  • Chronic: LABA -> ICS -> LTRA -> LAMA -> high dose ICS

Outline

Background 

• Asthma is a type 1 hypersensitivity reaction, IgE mediated

• Asthma is part of the atopic triad with hayfever and eczema

• Common triggers include the cold, dust, viral urti

Assessment

History:

• Exertional wheeze

• Dry, night time cough

• SoB with URTI

Examination:

• Wheeze during exacerbation

• Normal when well

Investigations

• Peak flow

• Baseline: viral PCR, CXR, U&Es, FBC, LFTs

• Spirometry: reversible obstructive pattern- histamine induces narrowing & salbutamol reverses it 

Diagnosis 

Diagnostic criteria: clinical based upon multiple factors

• Presentation & response to treatment

• Evidence of reversible airway obstruction

Differentials: viral induced wheeze, (elderly) CHF & COPD

Management

Acute Exacerbation

Ward optimisation

1. Salbutamol nebuliser 2.5mg x3 20 mins apart (burst) -> then 1 hourly

2. Ipratropium 500mcg stat

3. Hydrocortisone/ Pred

4. Oxygen -> (ICU) Intubation

5. Antibiotics if focal consolidation

6. Magnesium 10mmol IV

7. Investigations: (septic screen +)- viral PCR, CXR, urine/ blood cultures, FBC, LFT, CMP

8. Discuss with registrar/ consultant ? IV Aminophylline 

9. Housekeeping: escalation status, vte as normal

Escalate to ICU for intubation if 

• Tiring on maximal ward medical therapy (my key criteria)

• Severe/ life threatening severity markers, particularly:

  • Normal or rising CO2

Discharge planning 

• Check inhaler Technique

• Respiratory Follow up (admission is indication of failed treatment)

• Emergency Action plan

• Discuss with Respiratory ?increase long term treatment

• Influenza, covid & pneumococcal

Long term: Combined NICE-BTS 2025 guidelines

1. SABA/ ICS low dose + inhaler technique

2. SABA/ ICS high dose + inhaler technique

3. If eosinophils raised, add monteleukast

4. Refer to specialist:

   • IgE & IL-5 inhibitor: Omalizumab, Benralizumab

Deeper Dive

Management II

Chronic Management

• No role for theophylline. 

• Increasing evidence LAMA may be of benefit, [2]

• Conflicting guidelines considering it after LTRA

Indications for IV aminophylline

• Life threatening exacerbation

• Consultant approval

Pregnancy Management

• Same flow chart as in adults till high dose ICS

• ICS, LABA and LTRA safe in pregnancy

Paediatrics Management

1. Low dose ICS

2. Montelukast

Indications to test for EGPA (Eosinophilic Granulomatosis with Polyangiitis) in asthmatic patients?

• Poorly controlled with multiple inhalers

• Systemic features: nerve palsy + haemoproteinuria

• 1/100,000 asthmatics have eGPA so not routinely tested

NIV in Asthma

Controversial whether helpful, never seen in clinical practice. Standard practice is to go to intubation. COPD patients commonly benefit from NIV. 

Occupational Asthma

Background 

• Commonly from isocyanates

Assessment

History: worsening wheeze/ sob / peak flow whilst at work

Examination: usually normal at clinic depending upon work schedule

Investigations: peak flow diary

Diagnosis 

Diagnostic criteria: variable peak flow- worsens during work periods, improves at weekends

Management

1. Avoidance of responsible allergen

References

1. Gokhale M, Bell CF, Doyle S, Fairburn-Beech J, Steinfeld J, Van Dyke MK. Prevalence of Eosinophilic Granulomatosis With Polyangiitis and Associated Health Care Utilization Among Patients With Concomitant Asthma in US Commercial Claims Database. J Clin Rheumatol. 2021 Apr 1;27(3):107-113. doi: 10.1097/RHU.0000000000001198. PMID: 31693654; PMCID: PMC7996234.

2. The latest on the role of LAMAs in asthma. Cazzola, Mario et al. Journal of Allergy and Clinical Immunology, Volume 146, Issue 6, 1288 - 1291

Resources

• BTS

• NICE

Page written in 2024.