BRONCHIAL PROVOCATION TESTING
Simulated occupational type provocation tests were
made with the patient in hospital. He was off work,
and a minimum of one week was allowed to elapse
between exposures to new agents. FEV1 recordings
were made using a dry wedge spirometer (Vitalograph);
the higher of the two best readings within
0*05 1 of each other was chosen on each occasion. A
steady baseline was obtained for a 12 hour period
starting at 8.30 am with the patient receiving salbutamol
2 mg by mouth, a salbutamol inhaler 200
,ug, and an ipratropium inhaler 40 ,ug every two
hours on each of the exposure days. Provocation
testing was performed when the patient had a stable
FEV1 of around 2-11. Exposure started at 8.30 am
on each occasion and the table shows the results of
the bronchial provocation tests. He was exposed in
turn by tipping from one tray to another to fine dusts
of tungsten and cobalt up to a maximum of 30