Short-term effects of positive expiratory pressure mask on ventilation inhomogeneity in children with cystic fibrosis: A randomized, sham-controlled crossover study.
Study design (if review, criteria of inclusion for studies)
Randomized, sham-controlled crossover trial
Participants
Children with cystic fibrosis
Interventions
Positive expiratory pressure (PEP) mask.
Outcome measures
Authors used the nitrogen multiple-breath washout (N(2) MBW) test to measure diffusion-convection-dependent inhomogeneity arising within the intracinar compartment (S(acin) *VT). Two N(2) MBW tests were performed near the hospital discharge date: one before and the other after PEP mask therapy (1âmin of breathing through a flow-dependent PEP device attached to a face mask, followed by three huffs and one cough repeated 10 times) by either a standard (10-15âcmH(2) 0) or a sham (<5âcmH(2) 0) procedure on two consecutive mornings. Deception entailed misinforming the subjects about the nature of the study; also the N(2) MBW operators were blinded to treatment allocation. Study outcomes were assessed with mixed-effect models.
Main results
The study sample was 19 cwCF (ten girls), aged 11.4 (2.7) years. The adjusted S(acin) *VT mean difference between the standard and the sham procedure was -0.015 (90% confidence interval [CI]: -â to 0.025)âL(-1) . There was no statistically significant difference in S(cond) *VT and lung clearance index between the two procedures: -0.005 (95% CI: -0.019 to 0.01)âL(-1) and 0.49 (95% CI: -0.05 to 1.03) turnovers, respectively.
Authors' conclusions
Findings do not support evidence for an immediate effect of PEP mask physiotherapy on S(acin) *VT with pressure range 10-15 cmH(2) 0. Measurement with the N(2) MBW and the crossover design were found to be time-consuming and unsuitable for a short-term study of airway clearance techniques.
Keywords: non pharmacological intervention - devices OR physiotherapy; Airway clearance technique; Airway clearance drugs -expectorants- mucolytic- mucociliary-; Chest physiotherapy; Positive-Pressure Respiration- PEP- pep mask; Active Cycle of Breathing Technique -ACBT-; forced expiration technique; High Frequency Chest Wall Oscillation -HFCWO-; VEST Airway Clearance System; oscillating devices; Acapella; flutter; Intrapulmonary Percussive Ventilation; Vibration; exercise; Autogenic drainage;