In vitro and in vivo assessment of a Tunisian spacer device.

Aerosol delivered through metered-dose inhalers offers an efficacious way t o deliver aerosols to asthmatics. Unfortunately, children and aged subjects are unable to coordinate satisfactory their use with inhalation, a problem overcome by using spacer devices. Purpose. - To compare, in vitro and in vivo, a new Tunisian spacer device: Airbox (R) (Omezine Laboratory) with Volumatic (R) (Glaxo Wellcome). Methods. - The experimental model includes an artificial ventilator, which simulates a seven-year-old child's respiration, connected to spacer devices . A millipore filter was placed in serie at the exit of the spacer. The fil ter was weighed blind by a high precision balance (+/- 0.01 mg) before and after the spray administration. Thirty-six children aged from 6 to 14 years were enrolled in a randomised, double-blind, crossover, in vivo study. All children have severe persistent asthma with forced expiratoty volume in a one-second (FEV,) baseline between 50 and 60% of reference value, The rever sibility of airway obstruction was assessed by the FEV, and the change afte r inhalation of 200 mug of salbutamol delivered via each spacer devices. A serie of 30 experiments was made with different doses of salbutamol. Results. - The amount of aerosol retained by the filter was statically simi lar for both spacer devices. Reversibility percentages measured by the two spacer devices was in the same confidence interval. Conclusions. - The salbutamol-Airbox (R) association was as efficient as th e salbutamol-Volumatic (R) association in vitro and in vivo. (C) 2001 Editi ons scientifiques et medicales Elsevier SAS.