Energy expenditure during physiotherapist-assisted and self-treatment in cystic fibrosis

Cystic fibrosis (CF) results in increased energy requirements at rest. However, the energy expended during physiotherapy management is unknown. The aim of this study, therefore, is to examine the energy expended during two commonly used forms of chest physiotherapy in CF subjects. Twenty-six CF subjects completed a randomised crossover trial with 48 hours between treatments. Two regimens of treatment were conducted: therapist-assisted treatment (active cycle of breathing, ACBT, with percussion, vibration), and independent treatment (ACBT alone, under the supervision of a physiotherapist). Subjects completed pulmonary function tests before and after either treatment. Indirect calorimetry and oximetry parameters were recorded at rest, during, and following treatment. Treatment groups were compared using ANOVA and two-sample crossover t-tests. When compared to resting values, physiotherapy treatment resulted in significant increases in VO₂, VCO₂ and respiratory exchange ratio. No difference was evident between treatment regimens for the change in VO₂ between baseline and treatment. The increase in ventilation (baseline to treatment) was significantly greater for the therapist-assisted treatment. The therapist-assisted ACBT was associated with a significant carryover effect for forced expiratory flow at 50% of vital capacity (FEF₅₀). Oxygen requirements for the two treatments were similar. However, the assisted regimen resulted in greater changes in minute ventilation during treatment and improved 48-hour post-treatment pulmonary function after only one treatment session. These findings suggest that the inclusion of percussion and vibration within the ACBT may influence respiratory muscle activity during treatment and result in improved pulmonary function.