Randomised controlled study of clinical efficacy of spacer therapy in asthma with regard to electrostatic charge

Background-Inhalation therapy using a pressured metered dose inhaler (pMDI) and a spacer is frequently used in the treatment of airway disease in chil dren. Several laboratory studies found a clear negative influence of electr ostatic charge (ESC) on plastic spacers on the delivery of aerosol. Aims-To investigate whether ESC on plastic spacers could diminish bronchodi lating responses to salbutamol. Methods-Ninety asthmatic children (aged 4-8 years) were randomised into thr ee groups: metal Nebuchamber, plastic Volumatic, and plastic Aerochamber. T he bronchodilating response was measured by the change in peak expiratory f low rate (PEF) after 100 mug and 400 mug salbutamol. Within the Volumatic a nd Aerochamber groups, a crossover comparison was made between electrostati c and non-electrostatic spacers. Results-We found no significant effect of ESC on the bronchodilating respon se to salbutamol with any of the doses in the Aerochamber and Volumatic gro ups. For the plastic spacers, the mean difference of the change in PEF afte r 100 mug salbutamol between non-electrostatic and electrostatic spacers wa s only +1.7% (95% CI -1.3% to 4.7%). After 400 mug salbutamol this was +1.9 % (95% CI -1.4% to 5.1%). A comparable efficacy was found for the Nebuchamb er, the Aerochamber, and Volumatic with respect to the change in PEF after 100 and 400 mug salbutamol. Conclusion-This study showed no negative influence of ESC on plastic spacer s with regard to clinical efficacy of a beta (2) agonist (salbutamol) in ch ildren with asthma. The metal Nebuchamber, plastic Aerochamber, and plastic Volumatic were equally effective.