The aims of this study were to compare the effect of bubble-positive expiratory pressure with a commercial positive expiratory pressure device and standardised physiotherapy in patients with an acute exacerbation of chronic obstructive pulmonary disease, and to assess the feasibility of inpatient research methods. Patients admitted to a medical ward at Middlemore Hospital, Auckland, New Zealand, with an acute exacerbation of chronic obstructive pulmonary disease were randomly assigned to a treatment group. Participants undertook one supervised treatment, then independently completed two further sessions. Participants' symptoms and ease of sputum expectoration were measured using the Breathlessness, Cough and Sputum Scale. Health-related quality of life and length of hospital stay were also recorded. Only eleven participants were recruited, over ten months. The study was, therefore, underpowered to show differences in end points. Useful findings were uncovered relating to the feasibility of the protocol. Limitations to the recruitment process were identified, including staffing issues and the assessment schedule. Findings from this study will enable revision of the study protocol to allow a modified trial to be performed in the future. B, Jepsen N, Coulter K, Wong C, Zeng I (2016) Challenges of undertaking a clinical trial using bubble-PEP in an acute exacerbation of chronic obstructive pulmonary disease: A feasibility study. Eastwood