HFNT during exercise in CF
Research type
Research Study
Full title
High-flow nasal therapy during exercise in patients with cystic fibrosis and severe lung disease: a pilot study to assess feasibility
IRAS ID
262095
Contact name
Giulia Spoletini
Contact email
Sponsor organisation
Leeds Teaching Hospital NHS Trust
Duration of Study in the UK
1 years, 6 months, 0 days
Research summary
Research Summary:
Cystic fibrosis (CF) is a inherited chronic conditions which involves different organs, with the lungs being the most seriously affected. Individuals with CF develop progressive lung disease which ultimately leads to respiratory failure (reduced oxygen levels and potentially increased carbon dioxide levels in the bloods).Most patients with severe lung disease have a limited tolerance to exercise, often associated with reduced oxygen levels. This can feed a vicious cycle in which patients limit their exercise because of breathlessness, become deconditioned due to lack of training, and ultimately suffer from detrimental effects on their health conditions.
While supplemental oxygen can improve oxygenation during exercise, it does not relieve breathlessness, and is thus not deemed an effective complement to exercise in these patients.
High flow nasal therapy (HFNT) is a way to deliver a mixture of air and oxygen at higher flows compared to standard oxygen therapy. It has been shown to improve oxygenation, reduce breathlessness and breathing rate, and is quite comfortable. Recently HFNT has been shown to improve exercise capacity and tolerance in patients with other lung diseases. HFNT is routinely used in clinical practice in patients with CF who present acutely unwell during hospital admissions.We believe that HFNT could be used by patients with CF during exercise in order to improve their tolerance, lengthen their exercise sessions, and allow them to be less symptomatic.
We propose an initial, small-scale pilot study to assess the feasibility of a larger trial to assess efficacy. We aim to enrol 20 patients with severe lung disease, during a hospital admission. On top of their routine 6-minute walking test, patients will be asked to have a repeated test on HFNT and to fill in a questionnaire on their physical activity. As exploratory outcomes, we will measure distance walked during the tests, oxygen and carbon dioxide levels, breathing rate, and time to recover to baseline. Patients will be asked to rate their comfort and their breathlessness.Lay summary of study results:
We wanted to explore if nasal high-flow therapy (NHFT) can be used by people with CF during physical exercise. NHFT is a system which delivers air and oxygen at flows higher than traditional therapies. We monitored performance and to see if using NHFT was beneficial to the people involved.This is important because we know that exercise is beneficial to the health of people with CF by slowing down the decline in lung function, improving bone health and quality of life. However, people with CF, especially in the advanced stages of their disease, often struggle with exercise because of breathlessness and drops in oxygen levels. Traditional oxygen therapy helps with oxygen levels, but not with shortness of breath or discomfort. As such, finding an alternative without these limitations would be important to help people with CF exercise more.
NHFT, which has been successfully used in other lung diseases, might be the alternative we are looking for.
We studied twenty-two adults with CF and advanced lung disease. All patients, who took part in the study, performed two treadmill 6-minute walking tests 24-48 hours apart. Treadmill walking test are used to evaluate exercise tolerance in people with CF. One test was performed on each patient’s usual conditions (with or without supplemental oxygen). The second test was performed with NHFT. Before, during and after the tests, we recorded breathing rate, oxygen and carbon dioxide levels, and we asked patients to rate their breathlessness and comfort.
Twenty subjects had an overall positive experience and stated that they would take part in longer-term studies using NHFT during exercise. Only two people did not tolerate the device. No side effects were linked to the use of NFHT.
The distance walked during the test was significantly longer using NHFT, by an average of 19 meters. Oxygen levels were similar, but breathing rate was lower on NHFT compared to standard conditions.
Breathlessness and discomfort are always higher at the end of the exercise compared to the beginning. When using NHFT, this effect was a lot lower than without it.
These results showed that NHFT might improve exercise tolerance among individuals with CF and advanced lung disease. NHFT appears to maintain breathlessness, comfort and oxygen levels more stable throughout exercise. This potentially means that people could exercise longer and more frequently.
However, we have to be cautious as this study was a proof of concept on a small number of participants. We also only looked at effects in the short term, while any real-world use would be repeated and extensive. Therefore, while these findings are very promising, further studies to explore the use of NHFT during a longer-term physical training programme in people with cystic fibrosis are needed. These studies need to involve larger number of participants and monitor them for longer period of training.
REC name
London - Brent Research Ethics Committee
REC reference
19/LO/0671
Date of REC Opinion
10 May 2019
REC opinion
Further Information Favourable Opinion