Ra. Jorres et al., A SHORT PROTOCOL FOR METHACHOLINE PROVOCATION TESTING ADAPTED TO THE ROSENTHAL-CHAI DOSIMETER TECHNIQUE, Chest, 111(4), 1997, pp. 866-869
Background: The purpose of this study was to develop a rapid and safe
methacholine provocation protocol equivalent to the standard dosimeter
technique, Methods: The rapid protocol comprised a short and a long s
ubprotocol, The challenge was started with one of these subprotocols a
ccording to the subject's answers to a questionnaire and baseline lung
function. If FEV1 dropped by 10% during the short subprotocol, the te
st was continued with the long subprotocol. The concentrations of meth
acholine and numbers of inhalations were chosen to match the concentra
tions of the standard method as closely as possible, To verify the pro
tocol, we compared both methods in 38 subjects with asthma and 10 cont
rol subjects, Results: The provocative concentrations of methacholine
(PC20FEV1) obtained with the standard method and the rapid method were
within one doubling concentration in 38 of 40 subjects. None of the s
ubjects who were normoreactive according to the standard method (PC20F
EV1 > 8 mg/mL) responded in the rapid protocol, The standard method re
quired, on average (+/- SD), 34 +/- 11 min; the rapid method required
15 +/- 3 min. Conclusions: The rapid provocation protocol is equivalen
t to the standard method, without loss in precision and safety, but wi
th considerable saving in time. Therefore, it appears to be particular
ly suited for studies that require comparability with provocative conc
entrations obtained with the Rosenthal-Chai dosimeter method.