Capsaicin provocation using two different inhalation devices

Summary Background Sensory hyperreactivity (SHR) has been suggested as one explanation for chemically induced airway symptoms; it can be diagnosed with a capsaicin inhalation test. Previous capsaicin inhalation studies of SHR have used a Pari Boy ® device. This model of inhalator device has become outdated, hence it is necessary to abandon it in favour of a new device. The aim of this study was to transfer the capsaicin inhalation test using the Pari Boy ® device to a corresponding model using the Maxin MA3 ® device. Methods Twenty-one patients with SHR and 44 healthy controls visited the clinic twice and underwent a randomised protocol. The participants were provoked with saline and capsaicin using one of two devices, Pari Boy ® and Maxin MA3 ® . Eight patients also underwent two additional capsaicin provocations with Maxin MA3 ® . A new series of capsaicin concentrations was chosen for Maxin MA3 ® . The results from each device were analysed, the agreement between the two devices and the repeatability of the Maxin MA3 ® were evaluated. Results Among all participants, the mean number of coughs with the Pari Boy ® was 5.5 (95% CI: 2.7; 8.2) after inhalation of 0.4μmol/L capsaicin and 20.0 (95% CI: 14.1; 25.9) after 2.0μmol/L. With the Maxin MA3 ® , the mean number of coughs was 3.6 (95% CI: 1.3; 4.0) after 0.06μmol/L capsaicin, and 17.8 (95% CI: 12.0; 23.6) after 0.3μmol/L. The Maxin MA3 ® showed good repeatability and the agreement between the devices with the capsaicin concentrations chosen for each device was considered to be good.