Chest Physiotherapy and Cystic Fibrosis: Cough
Since conventional CPT is time and labor intensive, a diverse array of techniques and regimens has been developed to improve the efficacy of treatment and to encourage independent management. These treatments include the active cycle of breathing technique (ACBT), the forced expiration technique (FET), autogenic drainage (AD), exercise programs, the positive expiratory pressure mask, continuous positive airway pressure, oral high frequency oscillation, high-frequency chest compression, and the Flutter device.
The most effective form of physiotherapy for CF has not yet been established, and currently both conventional and alternative treatment regimens are in widespread use. The recurring question is, “Which specific CPT technique is responsible for the effects seen in treatment?”
Comparisons of the Individual Components of Conventional Chest Physical Therapy
A session of directed coughing can be as effective as conventional CPT in improving the pulmonary function of CF patients.’ Rossman et al (1982) showed that vigorous directed coughing was as effective as therapist-administered CPT in the removal of isotope-labelled respiratory secretions in a group of six clinically stable CF subjects. CPT has been found to result in an increased volume of sputum expectorated and an increased peripheral isotope clearance.” Lorin and Denning (1971) proposed that CPT was more effective than coughing in mobilizing secretions from the peripheral airways. The clinical significance of the increased secretion clearance without improvements in pulmonary function is unclear, though it may result in a reduced reservoir for bacterial colonization. Additionally, Zapletal et al (1983) studied the effects of CPT on airway obstruction in a group of 24 CF patients. While there was a decrease in airway resistance, presumably by removing secretions, as measured by plethysmography, there was a significant increase in airway obstruction as measured by maximum expiratory flow volume curves. The authors believed this deterioration resulted from the compression and collapse of the central airways during the cough component of the treatment.