Positive expiratory pressure – Common clinical applications and physiological effects

Abstract

Breathing out against resistance, in order to achieve positive expiratory pressure (PEP), is applied by many patient groups. Pursed lips breathing and a variety of devices can be used to create the resistance giving the increased expiratory pressure. Effects on pulmonary outcomes have been discussed in several publications, but the expected underlying physiology of the effect is seldom discussed. The aim of this article is to describe the purpose, performance, clinical application and underlying physiology of PEP when it is used to increase lung volumes, decrease hyperinflation or improve airway clearance. In clinical practice, the instruction how to use an expiratory resistance is of major importance since it varies. Different breathing patterns during PEP increase or reduce expiratory flow, result in movement of EPP centrally or peripherally and can increase or decrease lung volume. It is therefore necessary to give the right instructions to obtain the desired effects. As the different PEP techniques are being used by diverse patient groups it is not possible to give standard instructions. Based on the information given in this article the instructions have to be adjusted to give the optimal effect. There is no consensus regarding optimal treatment frequency and number of cycles included in each treatment session and must also be individualized. In future research, more precise descriptions are needed about physiological aims and specific instructions of how the treatments have been performed to assure as good treatment quality as possible and to be able to evaluate and compare treatment effects.

Evaluation of Pressure Generated by Resistors From Different Positive Expiratory Pressure Devices

“…The pressure produced and the breathing pattern, including expiratory force and expired volume, are important in achieving effective treatment. 15 Although known clinically, the significant differences between the resistors tested in this study had not been reported previously. It is hard to prove these differences in clinical settings because treatment depends on so many factors.…”

Oscillating Positive Expiratory Pressure Therapy May Be Performed Poorly by Children With Cystic Fibrosis

“…18,19 To our knowledge, there are no published studies that evaluated OPEP therapy at increased intrapulmonary pressure, and there is a known risk with high pressures of complications, for example, pneumothorax. 20 The increased pressures generated through the incorrect use of OPEP devices, such as those seen in this study, therefore, are potentially detrimental.…”

Therapeutic Blowing Toys: Does the Overlap of Ventilatory Stimuli Alter the Respiratory Mechanics of Healthy Schoolchildren?

“…Breathing exercises performed through nasal inspiration and slow and prolonged exhalation, such as the lip frenum, are expected to increase VT, promote pulmonary deflation and airway stability. 27,28 These effects, however, have not yet been fully elucidated in isolation or in association with wind toys.…”