Positive expiratory pressure (PEP) is more effective than usual care or no intervention in patients with cystic fibrosis who are aged 16 or more years, according to a new study published in the journal Therapeutic Advances in Respiratory Disease. It is safe and has no adverse effects, researchers reported.

However, there is not enough evidence to confirm that PEP achieves improvements in lung function, compared to other techniques. Respiratory physiotherapy, with airway clearance techniques such as PEP, is often used in cystic fibrosis. 

The present study aimed to evaluate the efficacy of PEP devices in facilitating the removal of mucus as well as other outcomes in patients with cystic fibrosis. It also assessed possible adverse effects derived from the use of such devices.

Researchers led by Remedios López-Liria MD from the Health Research Centre at the Department of Nursing, Physiotherapy, and Medicine, the University of Almería in Spain conducted a systematic review and meta-analysis of the literature. This way, they identified 10 randomized clinical trials conducted over the last 10 years that included a total of 274 participants. 

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The researchers could not obtain clear evidence confirming that PEP achieves improvements in forced expiratory volume in the first second (FEV1) compared to other breathing techniques including airway clearance. However, they found that it does lead to a higher rate of lung clearance compared to physical exercise.

“We found moderate evidence that PEP therapy is more effective than both [control group] without intervention and usual physiotherapy care, both in-hospital and out-of-hospital (or outpatient) for most of the measures in this study,” the authors of the study wrote.

PEP devices create pressure opposite to that of the airways during expiration. This way, the formation of gas accumulated behind mucus increases airway diameter and temporarily increases functional residual capacity. The end result is improved mucociliary clearance.


Rocamora-Pérez P, Benzo-Iglesias MJ, Valverde-Martínez MLÁ, et al. Effectiveness of positive expiratory pressure on patients over 16 years of age with cystic fibrosis: systematic review and meta-analysis. Ther Adv Respir Dis. 2022;16:17534666221089467. doi:10.1177/17534666221089467