Evaluation of a novel sputum clearance technique—hydro-acoustic therapy (HAT) in adult patients with cystic fibrosis: A feasibility study

Abstract

This study was designed to investigate the efficacy, safety and patients' acceptance of a novel system for sputum clearance--Hydro Acoustic Therapy (HAT) in patients with cystic fibrosis (CF). This is a prospective crossover study where 18 patients received 6 sessions of physiotherapy over 6 separate days. These consisted of 2 sessions of either HAT, flutter valve or and sitting in the bath with sounds without vibration (placebo) for 30 minutes each. The efficacy was investigated by measuring the weight of wet and dry sputum after each session and by change in spirometry values. The preference was assessed by a questionnaire completed by patients at the end of the study about their preference of which type of physiotherapy received. The weight of both dry and wet sputum produced was similar in the 3 arms of the study. Spirometry values but not oxygen saturation were reduced after HAT and flutter therapy sessions. HAT therapy was preferred to flutter and placebo in terms of breathlessness, ease of sputum production and relaxation. Of the patients, 70% stated that they would choose HAT as their preferred physiotherapy method compared to 0% for flutter (χ(2) = 20.3, p < 0.0001). There were no procedure-related complications in any of the 3 arms of the study. HAT was found to be safe, well tolerated and favoured by the majority of CF patients. The effect of HAT, however, on sputum production was not superior to flutter or placebo.

Outcome Measures for Respiratory Physiotherapy in Cystic Fibrosis — Challenges and Advances

“…Pfleger et al (1992) found significant improvements in FEV 1 after autogenic drainage and high-pressure PEP-mask (n=14, Cohen's d z 0.09 and 0.22) [9]. Jarad, Powell and Smith (2010) reported a statistically significant reduction in FEV1 following hydro-acoustic therapy (n=19, Cohen's dz=0.12) or flutter (n=19, Cohen's dz=0.06) [10]. Nevertheless, these changes returned to baseline on the second study day [10].…”

“…Jarad, Powell and Smith (2010) reported a statistically significant reduction in FEV1 following hydro-acoustic therapy (n=19, Cohen's dz=0.12) or flutter (n=19, Cohen's dz=0.06) [10]. Nevertheless, these changes returned to baseline on the second study day [10].…”

“…Although no mean and standard deviation was provided, Rossman et al (1982) also found a higher volume of expectorated secretions during the different forms of chest physiotherapy compared to a control session (n=6) [31]. However, Jarad et al (2010) found no significant differences in wet or dry sputum weight between a positive expiratory pressure (PEP) device (flutter) or a placebo [10].…”

Evaluation of a novel technique in airway clearance therapy – Specific Cough Technique (SCT) in cystic fibrosis: A pilot study of a series of N-of-1 randomised controlled trials

“…Previous studies have validated sputum production as a reproducible outcome measure in CF and reported sputum production to be similar within a week interval 27 and on a day-to-day basis during disease stability. 28 In this study, sputum production was relatively similar in each pair when the techniques were compared.…”

“…29 Although dry weight of sputum has been considered as more accurate in reflecting sputum quantity, contradictory findings exist in the literature regarding the correlation between wet and dry weight. While some studies found no difference in the ratio of dry to wet sputum weight, 21 and no significant difference in wet or dry sputum weight between treatment groups and placebo, 28 other studies have found a significant difference between treatments when considering both wet and dry weight. 30 Although a standardised protocol was used in this study, the lack of sufficient recoding of total coughs in the interventions, as spontaneous coughs can influence sputum production, may have affected sputum weight.…”