An integrative review on the positive expiratory pressure (PEP)-bottle therapy for patients with pulmonary diseases

Background and Purpose: Positive expiratory pressure (PEP)-bottle device delivers a PEP within a range of 10–20 cmH2O. PEP treatment is applied to different pathological conditions also in combination with other physiotherapeutic techniques. The primary aim of the present review was to investigate the effects of PEP-bottle therapy in patients with pulmonary diseases and, secondarily, to provide a physiological analysis of its use. Methods: The databases PubMed, Scopus, Web of Science, Cinahl, and Cochrane Library were searched for citations published from their inception until May 2019. Adult participants (>18 years) with pulmonary disease who underwent PEP-bottle treatment, with no restriction on gender, were included in the study. There were no restrictions about the therapeutic settings and the condition of the disease (either acute or chronic). Results: The literature review returned 97 citations. After duplicates removal, the remaining 77 articles have been screened: 66 have been assessed as not eligible at first because the abstract did not meet the inclusion criteria. Eleven articles were left after the first two steps of selection: four have been excluded after full-text reading. Conclusion: PEP-bottle therapy has been proved to improve lung volume, to reduce hyperinflation, and to remove secretions. The device delivers a pressure equal to the water column only if the inner diameter of the tubing and the width of the air escape orifice are equal or greater than 8 mm, and the length of tubing ranges between 20 and 80 cm. The cost of a PEP-bottle device is significantly lower if compared with other commercially available devices having the same therapeutic purposes.