Applications of positive expiratory pressure in spontaneous breathing: why, when and how?

In spontaneously breathing patients, breathing exercises with positive expiratory pressure (PEP) can be used in various physiological ways to reopen closed airways by increasing the functional residual capacity (FRC) in hypoventilating patients, handle dyspnoea by decreasing the FRC, or reopen clogged airways and maintain an expiratory flow at low lung levels as part of airway clearance therapy. To make the most out of the treatment, the caregiver needs to know the pathophysiology and desired physiological effect of the treatment plan. This article presents the background of the application of PEP and gives information about frequently asked clinical questions. Based on this knowledge, individual prescriptions should be given to each patient including correct instruction and training on how to use PEP and how to adjust when the situation/condition changes. If daily long-term treatment is recommended, the patient needs regular return visits to monitor the effectiveness and evaluate it together with the patient, and to re-educate the patient as soon as needed.