Asthma

Question 1

Define asthma

Answer 1

Asthma is a chronic inflammatory airway disease characterised by varriable reversible airway obstruction, airway hyper-responsiveness and bronchial inflammation.

Normal asthamatic airway is relaxed but the wall is inflammed and thickened. During an attack, the smooth muscles tighten up and mucus is produced.

Question 2

Explain the aetiology/ risk factors for asthma

Answer 2

Pathophysiology: acute (30min) - mast cell antigen interaction and release of histamine. Bronchoconstriction and mucus plugs and swelling. Chronic (12h) - Th2 cells release IL3.4.5 which recruit mast cells and eosinophils and Bcells => airway remodelling

Atopy:

• FHx of atopy
• T1 hypersensitivity to variety od antigens and IgE px.

Stress:

• cold air
• RTI
• exercise
• emotions

Environmental:

• house dust mites
• pollen
• pets
• smoke, pollution, factory
• NSAIDs
• Aspergillus fumigatus spores

Risk factors:

• FH
• Atopy: rhinitis, eczema, hayfever
• obesity

Question 3

Summarise the epidemiology of asthma

Answer 3

Affects 10% of children and 5% of adults

Peaks at 5yo

Prevalence increasing

Question 4

Recognise the presenting symptoms of asthma

Answer 4

Episodic hx with diurnal variation

Wheeze

Breathlessness

Cough bad in morning and night

Precipitating factors:

• Cold
• RTI
• drugs - NSAIDs and BB
• exercise
• emotions

Question 5

Recognise the presenting signs of asthma

Answer 5

• Tachypnoea, tachycardia
• Widespread polyphonic wheeze
• Hyperinflated chest
• Decreased air entry
• Use of accessory muscles
• Porlonged expiratory phase
• Signs of steroid use

Severe attack:

• PEFR <50% predicted
• Pulse >110bmp
• RR >25/min
• cant complete sentences

Life-threatening attack:

• Cyanosis
• Hypotensive
• Exhausted, confusion, coma
• Silent chest, poor resp effort
• Tachy/ brady/arrhythmias
• PEFR <33%, SpO2 <92%, PaCO2 >4,6kPa, PO2<8kPa

Question 6

Identify appropriate investigations for asthma

Answer 6

ACUTE:

• PF
• SpO2
• ABG
• CXR - hyperinflation or exclude other (PMT, pneumonia)
• FBC, CRP, U&Es
• Blood and sputum cultures

CHRONIC:

• PF daily monitoring before and after reliever
• Pulm fx tests
• Bloods: eosinophilia, IgE levels, antibodies against Aspergillus fumigatus, RAST
• FE_no for oesinophilic asthma

Question 7

Generate a management plan for acute asthma

Answer 7

• ABCDE
• Resus
• ECG
• O2 Nebs and Steroids:
  
  • ​100% O2 via non rebreathe mask - 94-98% sats
  • Nebulised Salbutamol 5mg
  • Nebulised Ipatropium 0.5mg
  • Hydrocortisone 100-200mg IV
  • ±Prednisolone 40mg PO for 5-7 days
  • if improving - salbutamol every 4h + pred
  • if no improvement -
    
    • Salbutamol every 15 min
    • ipatropium every 4-6h
    • MgSO4 2g IVI over 20min
    • ±aminophylline or theophylline
    • ITU transfer
• Monitor:
  
  • ​PEFR every 15 min pre and post Bagonist
  • Keep SpO2 >92%
  • ABG if PaCO2 normal or high

Question 8

Discharging an acute asthma px

Answer 8

PEF >75%

Diurnal variation <25%

Stable on meds 24h

F/U:

• check meds therapy
• give spacer and PEF meter
• check technique
• give 1 week steroids
• educate: avoidance of triggers, compliance, emergency action plan
• arrange FU with asthma nurse and consultant in 1 month and GP within 1 week

Question 9

Generate a management plan for chronic asthma

Answer 9

Question 10

Identify the possible complications of asthma

Answer 10

Growth retardation

Chest wall deformities - pigeon or carinatum

recurrent infections

Pneumothorax

Respiratory failure

Death

GORD

Question 11

Summarise the prognosis for patients with asthma

Answer 11

Many children improve as they grow older

adult-onset asthma is usually chronic