Asthma

Question 1

what causes airway narrowing in asthma?

Answer 1

• bronchial muscle contraction
• mucosal swelling/inflammation
• increased mucus production

Question 2

what is the presentation of asthma?

Answer 2

• intermittent dyspnoea
• wheeze
• cough (often nocturnal)
• sputum
  tight chest
• widespread wheeze and decreased air entry on auscultation
• tachypnoea
• hyper-inflated chest and hyper-resonant percussion note
• diurnal variation in FEV1 or PEF (symptoms worse in the morning or late in the night)
• eosinophilia
• family history of atopy /asthma

Question 3

what is the presentation of a severe asthma attack?

Answer 3

• inability to complete sentences
• pulse >110 bpm
• resp rate >25 /min
• PEF 33-50% of predicted

Question 4

what is the presentation of a life-threatening asthma attack?

Answer 4

• silent chest
• confusion
• exhaustion
• cyanosis
• bradycardia
• PEF <33% of expected

Question 5

what investigations are carried out when suspecting asthma?

Answer 5

• Peak expiratory flow (PEF)
• spirometry - obstructive pattern
• chest xray (hyperinflation)

Question 6

what investigations are carried out when a patient presents with an acute asthma attack?

Answer 6

• Peak expiratory flow
• sputum culture
• FBC
• U&Es
• CRP
• Blood cultures
• ABG (low paCO2 due to hyperventilation - if high or normal, transfer to high-dependency unit or ITU for ventilation as this suggests failing respiratory effort)

Question 7

how would you manage a severe acute asthma attack?

Answer 7

• salbutamol 5mg nebuliser with oxygen
• prednisolone 30 mg PO
• if PEF remains <75%, repeat salbutamol and add ipatropium
• monitor oxygen saturation, heart rate and respiratory rate

Question 8

how would you manage chronic asthma?

Answer 8

• lifestyle advice (stop smoking, avoid precipitants, weight loss, check PEF 2x per day)
• step 1: salbutamol (blue inhaler) as needed
• step 2: beclomethasone (brown inhaler) 2x per day alongside salbutamol when needed
• step 3: add salmeterol (long-acting beta 2 agonist) alongside salbutamol and beclamethasone. if no relief, stop salmeterol and increase dose of beclamethasone whilst trialling oral theophylline or leukotriene receptor antagonist (montelukast)
• step 4: high-dose beclametasone, modified release theophylline, modified release oral salbutamol, montelukast alongside salbutamol inhaler as needed
• step 5: step 4 + regular oral prednisolone