Abstract
BACKGROUND: Prolonged slow expiration (PSE) is a physiotherapy technique often applied in infants to reduce pulmonary obstruction and clear secretions, but there have been few studies of PSE's effects on the respiratory system.
OBJECTIVE: To describe PSE's effects on respiratory mechanics in infants.
METHODS: We conducted a cross-sectional study with 18 infants who had histories of recurrent wheezing. The infants were sedated for lung-function testing, which was followed by PSE. The PSE consisted of 3 sequences of prolonged manual thoraco-abdominal compressions during the expiratory phase. We measured peak expiratory flow (PEF), tidal volume (VT), and the frequency of sighs during and immediately after PSE. We described the exhaled volume during PSE as a fraction of expiratory reserve volume (%ERV). We quantified ERV with the raised-volume rapid-thoracic-compression technique.
RESULTS: The cohort's mean age was 32.2 weeks, and they had an average of 4.8 previous wheezing episodes. During PSE there was significant VT reduction (80 ± 17 mL vs 49 ± 11 mL, P < .001), no significant change in PEF (149 ± 32 mL/s vs 150 ± 32 mL/s, P = .54), and more frequent sighs (40% vs 5%, P = .03), compared to immediately after PSE. The exhaled volume increased in each PSE sequence (32 ± 18% of ERV, 41 ± 24% of ERV, and 53 ± 20% of ERV, P = .03).
CONCLUSIONS: It was possible to confirm and quantify that PSE deflates the lung to ERV. PSE caused no changes in PEF, induced sigh breaths, and decreased VT, which is probably the main mechanical feature for mucus clearance.
- prolonged slow expiration technique
- physiotherapy
- infant
- pulmonary function test
- expiratory reserve volume
Footnotes
- Correspondence: Fernanda de Cordoba Lanza PT PhD, Department of Pediatrics, Federal University of São Paulo, Estado de Israel Street 465 ap 23, São Paulo, 04022-001 Brazil. E-mail: fernanda_lanza{at}hotmail.com.
The authors have disclosed no conflicts of interest.
- Copyright © 2011 by Daedalus Enterprises Inc.