National Taipei University of Nursing and Heath Sciences
Phase: NA
Conditions: Chronic Obstructive Pulmonary Disease With Exacerbation, Chronic Obstructive Pulmonary Disease Exacerbation, Chronic Pulmonary Disease
Sponsor: National Taipei University of Nursing and Health Sciences

 
 
 
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Title: Bubble PEP Training Among Patient 
With Chronic Obstructive Pulmonary 
Disease in Pulmonary Function Effects 
 
Study Protocol 
 
Principal Investigator : Szu-Yi Wang 
ClinicalTrials.gov number: NCT04828837 
 
2021/02/25 
 
 
 
 

 
 
 
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Material and Methods 
Design and Participants 
A randomized controlled trial with a single-blind study design was conducted. 
Using convenience sampling, data were collected from February 2021 to July 2021 at 
two teaching hospitals in northern Taiwan. Random serial numbers were generated by 
a research assistant using Random Allocation Software. The research assistant then 
put each serial number into an opaque envelope. After agreeing to participate in this 
study, each participant received an envelope and opened it to find out whether they 
belonged to the experimental group or the control group. The research assistant who 
assisted with recruitment did not engage in data collection or analysis.  
The inclusion criteria were patients who diagnosed AECOPD and were 40 years 
old or older, conscious, could read articles, agreed to participate in the study, and signed 
an informed consent document. Exclusion criteria included patients who had used non-
invasive PEP treatment before or during hospitalization, who had a mental disorder. 
The G*Power 3.1.9.7. software was used to estimate the sample size. A sample size of 
at least 26 has 80% power to detect the largest effect size of 0.5. An alpha level of 0.05 
was used.  
Measurements 
The participants’ demographics and clinical characteristics were collected, 
including gender, age, marital status, occupation, smoking history, chronic 
comorbidities (hypertension, diabetes mellitus, heart disease, lung cancer, and 
pneumothorax), COPD stage and dry powder bronchodilator use. 
Chinese Version of the CAT 
A total of eight items were used to assess the degree of dyspnea of the patients. 
Each item had a score ranging from 0 to 5 points, with the highest total score being 40 

 
 
 
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points. The higher the score, the higher the degree of dyspnea (Pothirat et al., 2015). 
The present study Cronbach's α was 0.88, and the Intraclass Correlation Coefficient 
(ICC) was 0.8. 
CSSAQ 
The CSSAQ was used to assess patients' cough and sputum symptoms. The content 
of the questionnaire was prepared with reference to published literature. The 
questionnaire consisted of 25 questions, including questions related to cough, sputum, 
and psychological symptoms and effects, on a four-point Likert scale with scores 
ranging from 0 to 4. The higher the score, the worse the cough or sputum symptoms 
(French et al., 2002). The index of content validity was 1, while Cronbach's α was 0.97. 
PEFR 
The patients’ pulmonary ventilation was assessed using the TruZone peak flow 
meter. This device was also used to monitor FEV1. Several studies showed good 
internal consistency of this measurement instrument, with a Cronbach's α of 0.99 
(Folgering et al., 1998; Martinez et al., 2017). In this study, Cronbach's α was 0.97. 
Bubble PEP bottle 
The bubble PEP device consisted of a 500cc water bottle and a short tube that was 0.8 
cm in diameter and 45 cm in length. The tube was inserted into the water bottle, and 10 
cm of the tube was placed underwater to form a breathing training water bottle with a 
positive pressure of 10 cmH2O. 
Bubble PEP training 
The patients trained three times a day with a bubble PEP bottle, and each training 
session lasted 20 minutes. During the training session, each patient maintained a 90-
degree sitting posture. After taking a deep inhalation, each patient held the bottle and 
blew air out through the tube into the water. The ratio of inhalation to blowing was 1 to 

 
 
 
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3 seconds. The patient rested for at least 1 minute after each bout of inhalation and 
blowing. After completing 10 blows, the patients exhaled 3 times, took deep breaths, 
and coughed. The breathing training continued for 30 days. The participants were 
advised to avoid training one hour before and two hours after meals. 
Procedures 
After the experimental and control groups agreed to participate in this study and 
completed the consent forms, the two groups took pre-tests, which measured the 
Chinese version of the CAT, the CSSAQ, and the PEFR, within 48 hours of 
hospitalization, which served as the baseline of the intervention (T0). Data were 
collected again on the 7th day (T1) and the 30th day (T2) of the intervention to evaluate 
the effect of the intervention on pulmonary function. Only the experimental group 
received bubble PEP training, while the control group had routine medical care. If 
participants were discharged from the hospital in the middle of the study, the 
investigator monitored the intervention effectiveness via weekly follow-up telephone 
calls.  
The study procedures are shown in Figure 1. Of the 57 patients who met the criteria 
were invited to participate for study eligibility. 14 of the remaining 27 participants, 13 
and 14 were assigned to the intervention and control groups, respectively. 7days follow-
up (T1) data were obtained for 17 of the participants. 1M follow-up (T2) analyses were 
performed among the 14 participants with complete data. The attrition rates were 30% 
and 71% for the experimental and control groups, respectively, with an overall attrition 
rate of 52%. 
Ethical considerations  
The study protocol was reviewed and approved by the Institutional Review Boards 
of Fu Jen Catholic University Hospital and En Chu Kong Hospital (FJUH109078 & 
ECKIRB1091006). Participants were required to sign informed consent forms before 

 
 
 
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the study and were allowed to terminate or withdraw from the study at any time. Data 
collected from the participants were coded, de-identified, and kept in a locked cabinet 
(ClinicalTrials.gov number: NCT04828837).