Valved holding chamber drug delivery is dependent on breathing pattern and device design

Abstract

0.87 and p<0.001 for both devices at both rates). The effect of RR was not as evident, but drug delivery tended to be higher at the higher rate. Drug delivery was significantly higher through the Optichamber Diamond as compared with the Babyhaler at every combination of RR and VT up to a 12-fold difference. We found marked differences in salbutamol delivery between the Babyhaler and Optichamber Diamond VHCs. The delivered dose of salbutamol increased with increasing VT and RR with both VHCs but with differences related to valve dead spaces. Instead of considering all VHCs equal in clinical paediatric practice, each device should be tested in vitro with respiratory patterns relevant to small children with respiratory difficulties.