A prospective study of salvational intervention with ICS/LABA for reducing chronic obstructive pulmonary disease exacerbation under severe air pollution (SIRCAP) in Beijing: protocol of a multi-center randomized controlled trial

Table 2 Inhaled pharmacological wash-out

Inhaled medication used before wash-out	Inhaled medication used during wash-out	Duration of wash-out
Tiotropium (18μg once q.d)	Maintain the original regimen	No washout, go directly into randomization
Budesonide/formoterol (160μg/4.5μg once or twice b.i.d)
Tiotropium (18μg once q.d) + budesonide/formoterol (160μg/4.5μg once or twice b.i.d)
No use of inhaled medication	Tiotropium (18μg once q.d)	Four weeks
Anticholinergic agents except tiotropium	Tiotropium (18μg once q.d)
Inhaled corticosteroids only	Tiotropium (18μg once q.d) + budesonide/formoterol (160μg/4.5μg once or twice b.i.d)
Inhaled β2-agonist only
ICS/LABA except budesonide/formoterol
LAMA+ICS/LABA except Tiotropium + budesonide/formoterol

ISSN: 1471-2466