Exercise as it relates to Disease/Exercise, Physiotherapy and Cystic Fibrosis

This fact sheet is in reference to the article: ‘Short-Term Effect of Different Physical Exercises and Physiotherapy Combinations on Sputum Expectoration, Oxygen Saturation, and Lung Function in Young Patients with Cystic Fibrosis.’

Created by u3099790.

Background
Cystic Fibrosis (CF) is one of the most common life shortening, hereditary diseases. It is a multi-system disease with progressive respiratory complications being the largest cause of morbidity and mortality. Problems reported by CF patients include excessive sputum production, decreased exercise tolerance and an increased feeling of breathlessness. CF care is a time-consuming regime involving daily physiotherapy, exercise, medications and vitamin supplements.

Exercise is a critical part of CF care and has been shown to improve airway clearance through three mechanisms:
 * Increased ventilation
 * Improved sputum viscosity
 * Shearing of sputum from the lung walls (from mechanical vibration)

Multiple studies have demonstrated the benefits of exercise for children with CF. With an increasing number of CF patients surviving to adulthood there was a demand for studies assessing exercise in adolescents with CF. This research aimed to determine the effect of different exercise modalities and combined exercise-physiotherapy sessions on sputum expectoration, lung function and oxygen saturation in people aged 16–29.

Where is the research from?
This study was conducted by researches from the University of Zurich, at the Triemli Hospital in Zurich, Switzerland. The Swiss government invests a large amount of money into research (2.2% of GDP), resulting in Swiss research being highly regarded worldwide. The authors of this study have produced other CF related studies, including a recent meta-analysis. This research was published in the peer-reviewed journal ‘Lung.’ There appears to be no conflicts of interest in the funding of this research.

What kind of research was this?
This study was a crossover trial, where each participant took part in each intervention in a randomized order. This is a type of randomized control trial, considered level two (fairly strong) evidence according to the National Health and Medical Research Council.

A crossover design allows for individual variances in baseline sputum (expectorated mucous) production and for individuals to express their preference (increasing future compliance). The main disadvantage with this study design is that carry-over effects from previous treatments could distort the subsequent results.

What did the research involve?
The research involved randomly allocating twelve participants to all three interventions on non-consecutive days of one week.

The three exercise interventions were: Each intervention lasted 30 minutes, followed by a 30-minute rest break and then a 30-minute standardized physiotherapy airway clearance session.
 * Billiards
 * Cycling
 * Trampoline

Outcomes measured:

What were the basic results?

 * 1) Sputum expectoration after the trampoline (7.6g) and cycling (6.0g) exercise sessions were significantly higher than after billiards (3.8g).
 * 2) Sputum weights pre and post physiotherapy were similar for all sessions.
 * 3) There was a statistically significant increase in oxygen saturation after the combined trampoline/physiotherapy (1.8%) and cycling/physiotherapy (1.7%) sessions but not after billiard/physiotherapy (0.5%).
 * 4) No effects were observed for lung function.
 * 5) The participant’s preferred trampolining.

The researchers interpreted that the exercise sessions helped expectorate more sputum than the sham exercise and had a positive effect on oxygen saturation but not lung function. They believe the improvement in oxygenation was due to the mobilization of blocked airways (greater area for oxygen to perfuse into the blood) and increased ventilation (more oxygen available). They concluded that it was hard to compare this study with existing studies due to differences in exposure times, order of interventions and sampling times.

Limitations:
 * 1) The small sample size reduced the applicability of results.
 * 2) Lung function was assessed after each session, although this is not enough time to see significant improvements given the physiological processes that must occur.
 * 3) No meaningful patient outcomes were assessed, such as number of hospital admissions. A long-term design would have allowed for this.
 * 4) Sputum weights may have been underestimated due to patients swallowing.

What conclusions can we take from this research?
This authors concluded that a combined approach of physiotherapy and exercise should be the treatment of choice in young adults with CF, although recognizes that further research is needed before specific prescriptions can be administered. As this was a small study, this research needs to be taken in context with the results of other studies. The authors mentioned one other study in detail, which found short-term exercise improves lung function although, was of poor quality and design. Further insight into two of the more recent high quality, long-term studies that showed a benefit of exercise on lung function would have strengthened the discussion.

Of interest to Australian readers, a 2011 study published in the well reputed journal ‘Chest’ supported this studies findings that exercise (cycling and treadmill walking) had a positive effect on the ease of sputum expectoration. Unfortunately, this study likewise had a small sample size and short follow up time.

The strongest evidence at present is a recent Cochrane review that found wide heterogeneity of studies regarding the effects of exercise on cystic fibrosis. It stated there was limited evidence that short and long-term exercise has a positive effect on exercise capacity, pulmonary function and health related quality of life, and highlights the need for further high-quality studies.

Practical advice
This study showed that cycling, trampolining and physiotherapy increases sputum expectoration and oxygen saturation in people aged 16–29 with CF. These results are only applicable to people aged 16–29yrs, although as the eligibility criteria was not listed the results are difficult to generalize. This study provides a useful starting point, although further high-quality studies with greater sample sizes and longer follow up should be conducted, to increase the strength of the research in this area before providing specific recommendations. It is important to note exercise has been shown to be safe and a part of regular care for patients with CF and therefore should not be discouraged.

Further information/resources
Cystic Fibrosis Federation Australia

Cystic Fibrosis Support Group