A cheap, relatively easy, home-based method could improve the lives of breathless covid patients, research suggests.
Inspiratory muscle training could help relieve breathlessness in some people with long covid symptoms, and act as a cheap and home-based non-pharmacological alternative.
These exercises have long been used to alleviate breathlessness in people with COPD and bronchiectasis. Patients use a small, hand-held device to challenge respiratory muscles by restricting airflow.
Now UK researchers have found that the same breath training may also help people experiencing breathlessness following covid.
“In other chronic respiratory conditions, the association between breathlessness and vicious cycles of physical, cognitive/emotional and functional deterioration, often referred to as the spiral of disability, is well evidenced,” the authors of the study wrote.
Breathlessness is one of the many symptoms associated with long covid. It has a big impact on quality of life and can predict poor outcomes following infection.
“With the potential deleterious consequences of this downward spiral in people living with long covid, the need for safe and effective rehabilitation strategies to help combat this global health and economic crisis cannot be overstated,” the authors said.
The study was carried out in the UK, where almost 2% of people are estimated to have long covid. The researchers studied the effects of breath training on 148 participants who had a covid infection between five and 13 months prior, but still had lingering breathlessness. Participants were randomly assigned to receive either usual care or to undertake three electronically monitored breathing exercise sessions at home each week, for eight weeks.
Those who underwent training were shown how to set up their handheld device and synch it to an app that would monitor their performance. They were able to adjust each training session to suit their capacity on the day of each session, to accommodate fluctuating capabilities that occur with long covid.
Patients undertaking the training improved across several clinically meaningful measures.
Those undertaking the training had less breathlessness, with an average King’s Brief Interstitial Lung Disease score of 62.2 in this subdomain, compared with 59.8 in the control group.
Chest symptom scores also improved in this evaluation, with an average score of 64.5, compared with 59.2 in the control group.
Aerobic fitness also improved in those who undertook the training, with an estimated VO2max of 42 compared with 36.8 in the control group.
There were also some benefits for respiratory muscle strength, such as a maximal inspiratory pressure of 108.9% in the training group compared with 92.3% in the control group.
Nevertheless, total King’s Brief Interstitial Lung Disease scores were no different between groups, nor did Transition Dyspnoea Index scores, which rose in both groups, from 0.9 at baseline to 2.1 in the intervention group, and to 2.0 in the control group.
“I would suggest that [inspiratory muscle training] is most appropriate for patients who are primarily experiencing shortness of breath and for whom this shortness of breath is limiting their ability and/or confidence to engage in other activities,” said lead author, physiologist Professor Melitta McNarry of Swansea University in the UK.
“It is probably most suited to those who are familiar with technology and have a reasonable level of self-motivation as it is largely self-directed, at least in the way that we conducted it.”
Professor McNarry noted there were many devices already available on the market, and recommended using one that allowed remote monitoring.
Children were capable of the training too, she said.
“We have previously used inspiratory muscle training in children with cystic fibrosis and their healthy peers and they enjoyed the training and found it beneficial.
“We haven’t conducted any research in children post-covid but I don’t see a reason why it wouldn’t be similarly effective in this population.”
One limitation of the study was that only 148 of the 281 participants initially recruited to the study completed it, raising questions about adherence to the method.
“At the time we started this study, many of the participants were desperate for something that would help them, so if it didn’t show improvements in a short timeframe, they moved on to something else,” Professor McNarry said.
While the study protocol required only up to 20 minutes three times a week, she said some treating clinicians might instruct their patients to train as frequently as 20 minutes twice a day.
Inspiratory muscle training was like any other muscle training, explained physiotherapist Associate Professor Kylie Hill, from Curtin University. It required individual calibration to load the muscles correctly, and expertise in changing and maintaining health behaviours.
Treating breathlessness required a multidisciplinary team, said Dr Hill, and the training was best done by a physiotherapist.
“Our brain perceives breathlessness very similarly to pain. Anything around dealing with people with fear and symptoms around breathlessness is far from easy. It looks simple, but it’s not easy,” said Professor Hill.
But she said that inspiratory muscle training would not currently be her first therapy option in treating breathlessness, as there was stronger evidence for other methods such as pulmonary rehabilitation and whole-body exercise training.
“This is an exciting piece of research, but there are some limitations,” she cautioned.
“The effect size that they saw was quite small. And it’s hard to say with some of these things, like quality of life and breathlessness, how much was about the fact that the participants are interacting with someone who’s caring and watching and supporting them. It’s hard to say how much it’s about training versus how much of it is about the trial effect.”
Professor Hill was eager to see research emerging on non-pharmaceutical therapies to treat the disability and other problems associated with the infection.
“We’re probably going to be left with this legacy of long covid. And we’re not really quite sure how to treat it.”
