Twice-weekly sessions of airway clearance physiotherapy over eight weeks led to clinically meaningful reductions in respiratory symptoms in people with cystic fibrosis (CF) in a small clinical trial.
These preliminary findings, based on patient-reported measures, support the need for further studies to determine the most effective airway clearance technique, as well as its optimal duration and frequency to achieve the best outcomes, the researchers noted.
The study, “Airway clearance physiotherapy and health-related quality of life in cystic fibrosis,” was published in the journal PLOS One.
Airway clearance aims to promote mucus clearance from the lungs
CF is caused by mutations in CFTR, a gene that codes for a protein of the same name, which in the lungs is key for the production of a lubricating, watery mucus that helps keep the airways clean. The disease’s sticky and thick mucus clogs the airways, making breathing more difficult and leading to inflammation and an increased susceptibility to lung infections.
Airway clearance physiotherapy involves the use of an airway clearance technique to enhance mucus clearance, aiding breathing and reducing the risk of lung infections.
However, “there is a lack of evidence supporting the use of one particular airway clearance technique” in people with CF, the researchers wrote.
Also lacking are “data demonstrating the impact of airway clearance interventions on HRQoL [health-related quality of life] and … clear evidence for its optimal duration and frequency,” they added.
In a clinical trial (NCT01266473), a team of researchers at Oslo University Hospital, in Norway, evaluated the efficacy, safety, and patient perceptions of a novel airway clearance technique called specific cough technique (SCT) against standard forced expiration technique (FET). It enrolled six adults with CF who used both these techniques.
SCT, developed in Norway in the late 1990s, comprises one gentle cough to first localize and collect mucus, followed by two to three stronger coughs to expel it. FET, or huffing, involves taking a breath in followed by a fast breath out with an open “O”-shaped mouth, as if to fog up a mirror.
The six patients, four men and two women with a mean age of 35.3, all underwent two, roughly one-hour airway clearance physiotherapy sessions each week: one with SCT and one with FET, given in a random order. Their total 16 treatment sessions over eight weeks took place on two consecutive days, separated by 24 hours.
This type of individualized study, also known as N-of-1 trial, gives information about the best treatment for a patient, rather than working with the group average determined in a randomized and controlled trial.
Published study results showed that three of these six patients produced significantly more sputum, or lung mucus, with SCT than FET, up to 38% more. Five patients also reported that SCT was easy to use as a daily intervention, and all six considered it effective at clearing sputum.
Now, the researchers analyzed one of the trial’s pre-specified secondary goals: changes in the health-related quality of life.
HRQoL was assessed using the patient-reported CF Questionnaire-Revised (CFQ-R), particularly its respiratory symptoms domain, with responses given at study’s start compared with those given after the intervention.
Patients in study had chronic lung infections
The CFQ-R consists of 49 questions covering 12 topics, including nine on quality of life, an overall health perception scale, and three on symptoms (weight, respiratory, and digestion). Scores range from zero to 100, with higher scores indicating better HRQoL.
Half of these patients were positive for chronic lung infections caused by Pseudomonas aeruginosa and the other half by Staphylococcus aureus.
During the study, participants were asked to continue with their routine, at-home airway clearance treatment.
All used bronchodilators, or medications that ease breathing by relaxing muscles in the lungs and widening the airways, and inhaled saline solutions. Four patients were taking Pulmozyme (dornase alfa), a mucolytic or mucus-thinning agent by Genentech, while the other two used inhaled antibiotics regularly.
CFQ-R scores increased (improved) in all patients after the eight-week sessions, with gains ranging from 11 to 22.3 points, the trial found.
The respiratory symptom domain also showed a meaningful score increase, of at least four points, in five out of six patients, reflecting fewer symptoms. One patient’s scores fell, representing worsening symptoms.
“We found a clinically important change in respiratory symptoms score in the majority of the participants … an important finding with relevance to the airway clearance management of CF pulmonary disease,” the researchers wrote.
Potential links between HRQoL and other clinical outcomes, such as sputum production and lung function, were also assessed.
Researchers found that a greater amount of sputum produced (weight in grams) significantly associated with a larger increase in CFQ-R respiratory symptom scores. A similar link was seen between positive changes in FEV1, or how much air can be exhaled in one second after a deep breath, and the CFQ-R respiratory symptom score.
“The association between HRQoL and lung function may reflect the effect of increased sputum removal related to the airway clearance intervention,” the team wrote.
Overall, “the airway clearance intervention was associated with clinically meaningful changes in patient-reported symptoms on the CFQ-R in the majority of the participants,” the researchers wrote, adding that “findings warrant further investigation with regard to ACP [airway clearance physiotherapy] and its content, duration and frequency.”