Bubble‐positive expiratory pressure device and sputum clearance in bronchiectasis: A randomised cross‐over study

Abstract Objectives The bubble‐positive expiratory pressure (PEP) device may be used for sputum clearance in people with daily sputum production. However, this device has never been studied in people with bronchiectasis. Hence, the objective of this study was to compare the effect of bubble‐PEP device, the active cycle of breathing technique (ACBT) and no intervention (control) on sputum clearance in people with bronchiectasis. Methods This was a prospective, randomised cross‐over trial with concealed allocation, assessor blinding and intention‐to‐treat analysis. Adult participants with stable bronchiectasis and productive of sputum daily were recruited. Participants performed 30‐min of bubble‐PEP, ACBT or control in random order whilst sitting, followed by 60‐min of quiet sitting, on three separate days at the same time within a 10‐day period. Primary outcome measure was wet weight of expectorated sputum during 30‐min intervention, 60‐min post intervention and total wet weight (30 min plus 60 min). Results Thirty‐five‐participants (11 males, mean [standard deviation] age 75 [8] years, forced expiratory volume in 1 s 72 [20] % predicted) were recruited and 34 completed the study. There was no significant difference in sputum wet weight between bubble‐PEP and ACBT during 30‐min intervention (mean difference [95% confidence interval]) −0.59 g [−1.37, 0.19] and total wet weight (0.74 g [−0.54, 2.02]). Sputum wet weight was significantly greater in bubble‐PEP than ACBT at 60‐min post intervention (1.33 g [0.19, 2.47]). Conclusion Sputum wet weight was significantly greater with bubble‐PEP than control at all time periods, and greater than ACBT at 60‐min‐post. Bubble‐PEP could be considered an alternative sputum clearance technique to ACBT.