BTS
Guidelines
Moderate
asthma exacerbation
- Increasing symptoms
- PEF > 50-75% predicted
- No features of acute severe
asthma
Acute
severe asthma
Any one of:
- PEF 33-50% best or predicted
- Respiratory rate ≥
25/min
- Tachycardia (≥ 110 bpm)
- Inability to complete
sentences in one breath
Life-threatening
asthma
Any one of:
- PEF < 30%
- SpO2 < 92%; PaO2 < 8 kPa
- Normal PaCO2 (4.6-6 kPa)
- Silent chest
- Cyanosis
- Poor respiratory effort
(i.e. giving up)
- Arrhythmia (e.g. tachycardia)
- Exhaustion, altered
consciousness level
Near
fatal asthma
Raised PaCO2 and/or requiring
mechanical ventilation with raised inflation pressure.