Chest Physiotherapy and Cystic Fibrosis: Positive Expiratory Pressure Mask
Positive expiratory pressure treatment can be used independently by the patient and is delivered via a face mask with a one-way valve to which expiratory resistors are attached, giving pressures ranging from 10 to 20 (cm H2O). The patient sits comfortably, holds the mask firmly over the nose and mouth, and breathes at tidal volumes, with a slightly active expiration, for about 2 mins. The mask is then removed and the FET is performed. canada health and care mall
The application of resistance to expiration is thought to limit compression of compliant airways and assist in collateral airflow between ventilated and atelectatic alveoli.
High-pressure PEP is a modification of the original technique and can result in improved pulmonary function in acutely ill CF patients. High-pressure PEP includes forced expiratory maneuvers from maximal inspiration performed directly into the PEP mask, which results in expiratory pressures ranging from 26 to 102 cm H2O.53 It was proposed that forcibly expiring against resistance would promote secretion movement through increased expiratory flows. Van der Schans (1991) however, could show no relationship between mucociliary clearance rates and variations in positive pressure levels, though lung volume did increase in proportion to the level of positive pressure applied. Van der Schans et al (1992) expressed concern regarding the extremely high levels of positive pressure reached by high-pressure PEP. Complications such as pneumothorax, barotrauma, and arterial rupture may result from increased airway pressure but only two complications, one spontaneous pneumothorax and one episode of severe hemoptysis, have been reported after 3,866 patient treatment months
Positive expiratory pressure can have an immediate effect on facilitating secretion clearance and improving pulmonary function by reducing residual volume and increasing functional residual capaci-ty.58-60 Positive expiratory pressure has been shown to maintain or improve pulmonary function and to be as effective as conventional CPT from 8 weeks to 4 years.’ However, comparisons between PEP and other physiotherapy regimens produce conflicting results.