Comparing airways clearance techniques in chronic obstructive pulmonary disease and bronchiectasis: positive expiratory pressure or temporary positive expiratory pressure? A retrospective study.

Background
Airway clearance techniques include positive expiratory pressure, commonly used in our clinical practice, and a recently introduced temporary positive expiratory pressure device called UNIKO®. It is unclear which one provides the best benefit to patients.

Objectives
The aim of this observational 4-year study was to retrospectively compare the efficacy of and specific indications for temporary positive expiratory pressure compared to positive expiratory pressure in a standard rehabilitation program.

Method
We retrospectively collected data from 162 subjects (107 males, mean age 70 ± 9 years, 97 with primary diagnosis of chronic obstructive pulmonary disease, 65 with bronchiectasis), 51 treated with temporary positive expiratory pressure and 111 with positive expiratory pressure.

Results
Subjects showed significant improvement in ratio of partial pressure arterial oxygen and fraction of inspired oxygen (p < 0.001), forced vital capacity, forced expiratory volume in one second, peak expiratory flow, arterial oxygen saturation, and partial pressure arterial oxygen with no significant difference between positive expiratory pressure and temporary positive expiratory pressure groups apart from forced expiratory flow, which increased only in the positive expiratory pressure group. Evaluating specific subgroups, temporary positive expiratory pressure was more effective than positive expiratory pressure in improving gas transfer in subjects with emphysema and in those on oxygen therapy, as the effective supplement oxygen flow decreased significantly (p = 0.034 and 0.046 respectively for temporary positive expiratory pressure vs. positive expiratory pressure). In subjects on mechanical ventilation, positive expiratory pressure was superior to temporary positive expiratory pressure in increasing forced expiratory flow (p = 0.018).

Conclusion
The physiological parameters of both groups improved significantly and similarly. Subgroup analysis suggests that temporary positive expiratory pressure could provide some advantage to subjects with emphysema and those on oxygen therapy, while positive expiratory pressure would benefit patients on mechanical ventilation. Randomized clinical trials are necessary to confirm our preliminary results indicating that different subgroups/phenotypes can benefit more from one type of treatment.