Use of Airway Clearance Techniques Rises With Flares and Infections

Use of Airway Clearance Techniques Rises With Flares and Infections

People with bronchiectasis and a productive cough are more likely to use airway clearance techniques (ACTs) if they experienced exacerbations and were hospitalized due to lung infections, a study revealed.

The findings suggest that patients who use these techniques have more severe disease, its researchers said, and utilization across-the-board is lower than advised. They added that further studies are needed to find the best candidates for ACTs.

The study, “Airway Clearance Techniques in Bronchiectasis: Analysis From the United States Bronchiectasis and NTM Research Registry,” was published in the journal Chest

Bronchiectasis is characterized by inflammation, dilatation, and irreversible damage to the bronchial tubes — the tubes conducting air to the lungs — leading to airway blockage, mucus buildup, and chronic infection. 

ACTs aim to ease symptoms, reduce exacerbations, and improve quality of life in people with bronchiectasis. They work by loosening thick, sticky mucus so it can be cleared out of the lungs.

These techniques include instruments that create pressure in the lungs to keep airways open, vests that generate high-frequency chest wall vibrations (oscillations), and approaches such as physical therapy, chest percussion, lung drainage through body posture, and active breathing therapy. 

Despite clinical guidelines supporting use of ACTs, their effectiveness in bronchiectasis patients is mostly unknown. 

Researchers based at New York University School of Medicine, in collaboration with investigators at multiple sites across the U.S., evaluated the clinical outcomes in adults with bronchiectasis using ACTs and having a productive (wet) cough. 

Their study’s main goal was to describe differences between patients who used ACTs and those who did not, with a focus on the numbers of exacerbations and hospitalizations before the study (baseline measure), and the presence of infectious microorganisms. Secondary outcomes included a one-year, follow-up assessment on lung function.

The team accessed the medical records of bronchiectasis patients from the United States Bronchiectasis Research Registry, selecting 905 adults who had used ACTs continuously (at baseline and follow-up), intermittently — meaning either at baseline or follow-up — or not at all. 

Patients’ mean age was 63 years, and they were predominantly Caucasian (91%) and female (78%). About 25% were using ACTs continuously, 39% intermittently, and 36% had not used ACTs.

In the two years before the study, those using ACTs continuously were more likely to have had an exacerbation (81% vs. 59%) or be hospitalized for lung disease (32% vs. 22%), compared with those not using such techniques. Similar differences were found comparing prior exacerbations and hospitalizations between those using ACTs intermittently and patients not using ACTs. 

At baseline, a larger number of patients in the continuous (47%) or intermittent groups (40%) had Pseudomonas aeruginosa infections than those not using ACTs (36%). 

Also at baseline, a total of 535 patients (59%) used ACTs, which were mostly positive expiratory pressure devices that create resistance in the lungs to keep the airways open. Among this group, 288 people (58%) did not use ACTs at the one-year follow-up. 

This finding “highlights the under-utilization of ACTs, and a significant decrease in their use over time,” the researchers wrote. 

In all three groups, no significant difference in lung function — as measured by forced expiratory volume and forced vital capacity — was found at follow-up compared to baseline. According to the investigators, other factors may influence pulmonary function in bronchiectasis, such as older age, comorbidities, and persistent inflammation.

At the one-year, 47% of patients did not report exacerbations, while 28% had one exacerbation, and 25% had two or more within the previous year. 

A statistical analysis found that patients who continuously or intermittently used ACTs had higher odds of an exacerbation compared with those who did not these techniques.

Similar results were found after adjusting for the number of exacerbations and the presence of P. aeruginosa infections at baseline. The odds for one bronchiectasis exacerbation versus none were again higher in patients who used ACTs compared to those who did not. 

“ACTs are utilized more often in bronchiectasis patients with productive cough if they have experienced a prior exacerbation, hospitalization for pulmonary illness, or had Pseudomonas aeruginosa,” the investigators wrote. “The odds of developing an exacerbation are higher in those that utilize ACTs continuously, suggesting more frequent use in a sick bronchiectasis population.”

“Further studies assessing the best candidates for ACT use, and factors to improve accessibility and adherence to ACTs, are needed,” they added.