Acute Severe Asthma

Question 1

Main presentation:

Answer 1

1. Acute breathlessness
2. Wheeze

Question 2

Differential diagnosis:

Answer 2

1. Acute infective exacerbation of COPD
2. Pulmonary oedema
3. Upper respiratory tract obstruction
4. PE
5. Anaphylaxis

Question 3

Investigations:

Answer 3

1. PEF
2. Bloods: FBC; U&E, ABG if saturations < 94%
3. CXR

Question 4

Fts of severe asthma attack:

Answer 4

1. Unable to complete sentences
2. RR >25/min
3. ** PR >110** beats/min
4. PEF 33–50% of predicted or best

Question 5

Fts of life-threatening asthma attack:

Answer 5

1. Peak expiratory flow < 33% of predicted or best
2. Silent chest
3. Cyanosis
4. Reeble respiratory effort
5. Bradycardia or hypotension
6. Exhaustion
7. Confusion
8. Coma
9. ABG - PaCO2 >4.6kPa (32mmHg), PaO2 <8kPa (60mmHg), low pH

Question 6

Initial Mx of acute severe asthma:

Answer 6

1. Assess severity of attack - PEF, ability to speak, RR, pulse rate, O2 sats
2. Salbutamol 5mg (or terbutaline 10mg) nebulized with O2
3. Hydrocortisone 100mg IV or prednisolone 40–50mg PO or both if very ill
4. Start O2 if saturations <92% (also check ABG), aim sats 94–98%

Question 7

Mx if If life-threatening features present:

Answer 7

1. Inform ICU and seniors
2. Give salbutamol nebulizers every 15min, or 10mg continuously per hour
3. Monitor ECG - watch for arrhythmias
4. Add in ipratropium 0.5mg to nebulizers
5. Give single dose of MgSO4 1.2–2g IV over 20min
   6.

Question 8

When to use IV salbutamol for Mx of acute severe asthma:

Answer 8

1. Deteriorating PEF
2. Persistent/worsening hypoxia
3. Hypercapnia
4. ABG showing low pH or high H+
5. Exhaustion, feeble respiration
6. Drowsiness, confusion, altered conscious level
7. Respiratory arrest

Question 9

Mx of pt. if improving within 15–30 minutes:

Answer 9

1. Nebulized salbutamol every 4 hours
2. Prednisolone 40–50mg PO OD for 5–7 days
3. Monitor peak flow
4. Monitor O2 sats - aim 94–98% with supplemental if needed

Question 10

Criteria for D/C:

Answer 10

1. Been stable on discharge medication for 24h
2. Had inhaler technique checked
3. **Peak flow rate >75% **predicted or best with diurnal variability <25%.
4. Steroid (inhaled and oral) and bronchodilator therapy
5. Own PEF meter and have Mx plan
6. GP appointment within 1wk
7. Respiratory clinic appointment within 4wks