Introduction Recovery from COPD exacerbation is associated with increases in respirable lung volume. Accelerating these changes through improved bronchodilator delivery could hasten recovery.

Hypothesis Vibrating mesh nebuliser (Aerogen® Ultra) results in greater change in lung physiology compared to standard small volume jet nebuliser.

Methods Patients with an exacerbation of COPD were randomised to receive combined salbutamol 2.5 mg/ipratropium bromide 0.5mg via vibrating mesh (Active group) or standard hospital jet nebuliser (Control) on one occasion between day 2–7 of hospitalisation. Spirometry, body plethysmography and impulse oscillometry were performed pre-bronchodilator and at 1 hour post. Borg breathlessness score was measured.

Results Thirty-one patients have been recruited to date, 16 to the active group and 15 control group. Mean FEV₁ was 48 ± 18% predicted. Baseline demographics were comparable between groups. Both groups had significant improvements in FEV₁ and Inspiratory Capacity post-bronchodilator, with greater increases in FVC in the active group (0.40 ± 0.39 L vs 0.19 ± 0.19 L, p = 0.06). Significant changes in operating lung volumes and airway impedance were seen in both groups. There was no significant difference in Borg score.

Conclusion Bronchodilator administration, during a COPD exacerbation, results in significant improvements in spirometry, lung volume and airway impedance. Drug delivery by vibrating mesh nebuliser results in greater absolute increases in FVC. Further studies will assess whether this translates into accelerated exacerbation recovery.