Table 1.

Inclusion and exclusion criteria for randomisation

Inclusion criteria	Exclusion criteria
FEV1 <80% predicted	Personal history of asthma
FEV1/FVC ratio <70%	Marked use of accessory muscles
Minimental state score >7	Suspected underlying malignancy on chest x ray film
Pulse rate <100 beats/minute	Pneumothorax or pneumonia
Systolic blood pressure >100 mmHg	Uncontrolled left ventricular failure
pH >7.35	Acute changes on an electrocardiogram
pO2 >7.3 kPa	Requirement for full time nursing care
pCO2 <8 kPa	Requirement for intravenous therapy
Total white cell count 4-20×109/l