Factors that influence adherence to exercise and their effectiveness: application to cystic fibrosis

Role of mechanical stress in regulating airway surface hydration and mucus clearance rates

Effective clearance of mucus is a critical innate airway defense mechanism, and under appropriate conditions, can be stimulated to enhance clearance of inhaled pathogens. It has become increasingly clear that extracellular nucleotides (ATP and UTP) and nucleosides (adenosine) are important regulators of mucus clearance in the airways as a result of their ability to stimulate fluid secretion, mucus hydration, and cilia beat frequency (CBF). One ubiquitous mechanism to stimulate ATP release is through external mechanical stress. This article addresses the role of physiologically relevant mechanical forces in the lung and their effects on regulating mucociliary clearance (MCC). The effects of mechanical forces on the stimulating ATP release, fluid secretion, CBF, and MCC are discussed. Also discussed is evidence suggesting that airway hydration and stimulation of MCC by stress-mediated ATP release may play a role in several therapeutic strategies directed at improving mucus clearance in patients with obstructive lung diseases, including cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD).

From child to adult: An exploration of shifting family roles and responsibilities in managing physiotherapy for cystic fibrosis

Although chest physiotherapy is central to the management of cystic fibrosis many report problems with adherence. Research in other long-term conditions suggests that non-adherence may be exacerbated as the child grows older and self-care responsibilities are transferred to the young person. We explored the nature and variation in roles of family members, how responsibility was transferred from the parent/family to the child, and what factors aided or hindered this process. We conducted in-depth interviews with 32 children with a diagnosis of cystic fibrosis aged 7-17 years, and with 31 parents attending cystic fibrosis clinics in two Scottish regions. Family responsibilities were primarily focused on mothers. The level and nature of involvement varied along a continuum that separated into six parental and five child roles and changed over time. However, this movement was frequently reversed during periods of illness or mistrust. The day to day experience of such a transfer was not straightforward, linear or unproblematic for any of the family members. Three factors were identified as assisting the transfer of responsibility: parents' perceptions of the benefits of transferring responsibility, children's perceptions of the benefits, and the available physical, social and psychological resources to support such a transfer. The principles and lessons from "concordance" (a therapeutic alliance based on a negotiation between equals and which may lead to agreement on management or agreement to differ) may provide a foundation for newly developing relationships between parents and their children emerging into adulthood. Further research is required to develop more specifically the content and structure of required support, its effectiveness in achieving more concordant relationships, and the resulting impact on adherence, perceived health and well-being from the perspective of the young person and parent.

Exercício aeróbico, treinamento de força muscular e testes de aptidão física para adolescentes com fibrose cística: revisão da literatura

São reconhecidos os benefícios da prática do exercício físico regular para pacientes com fibrose cística. Entretanto, poucos estudos envolvem pacientes adolescentes. O objetivo deste artigo foi revisar os efeitos da prática regular de exercícios aeróbicos e de força e resistência muscular para adolescentes com fibrose cística. Os principais testes de aptidão física para esta faixa etária e a importância deles para melhora do prognóstico e tratamento da doença também foram avaliados. As informações foram coletadas a partir de livro-texto e artigos publicados na literatura nacional e estrangeira nas seguintes bases de dados: LILACS, MEDLINE/PubMed, Biblioteca Cochrane e SciELO, abrangendo o período de 1994 a 2004. Foram utilizados os termos "exercise" e "cystic fibrosis" para seleção dos artigos. Esta pesquisa demonstrou que a prática de exercício aeróbico e treinamento de força muscular melhoram a desobstrução da árvore brônquica, diminuem a queda progressiva da função pulmonar, aumentam a massa muscular e a resistência ao exercício, promovem o desenvolvimento ósseo e melhoram a auto-estima e a qualidade de vida. Os melhores resultados foram obtidos com os programas de treinamento assistido, devido a sua maior regularidade.

Adherence of adult cystic fibrosis patients with airway clearance and exercise regimens

BACKGROUND

Regular airway clearance and exercise form an important part of the physiotherapy management of patients with cystic fibrosis (CF). Previous research has found that adherence of these patients with physiotherapy regimens is variable and influenced by factors such as sex and disease severity. To date, the adherence of Australian patients with CF has not been investigated. The aim of this study was to measure the adherence of a sample of Australian adult patients with CF and to ascertain factors that improved or decreased their adherence with physiotherapy.

METHODS

Patients attending an Australian CF Unit were surveyed by an independent physiotherapist using a questionnaire based on the Manchester Cystic Fibrosis Compliance Questionnaire.

RESULTS

Fifty seven of the 84 patients registered with the Unit (67.9% response rate) completed the survey. Over the previous six months, 96.5% of patients reported doing some form of airway clearance, with 70.2% doing this daily or only occasionally missing one or two days. Regular exercise was performed by 91.2% of patients when well, with 77.8% also exercising regularly when unwell. The most common reasons for non-adherence with airway clearance regimens were being too busy and not being bothered. Being too busy and too tired were the most frequent reasons for decreased adherence with exercise. Frequency of performing airway clearance regimens significantly improved when patients felt unwell. Adherence with exercise regimens was significantly higher in those who worked or studied full time.

CONCLUSION

Overall, the levels of adherence with physiotherapy regimens found in this study were considered to be satisfactory and higher than those previously reported in the literature, with time related factors being the most commonly reported reasons for decreasing adherence.

Six-minute walk test in children and adolescents with cystic fibrosis

The 6-min walk test is a simple, rapid, and low-cost method that determines tolerance to exercise. We examined the reproducibility of the 6-min walk test in 16 children with cystic fibrosis (11 female, 5 male; age range, 11.0 +/- 1.9 years). We related the distance walked and the work performed (distance walked x body weight) with nutritional (body mass index and respiratory muscle strength) and clinical (degree of bronchial obstruction and Shwachman score) status. Patients were asked to walk as far as possible upon verbal command on two occasions. There was no statistical difference between distances walked (582.3 +/- 60 and 598.2 +/- 56.8 m, P = 0.31), heart rate, respiratory rate, pulse oxygen saturation, arterial blood pressure, dyspnea, and percentage of maximal heart rate for age in the two tests. Distance walked correlated (Pearson) with maximal expiratory pressure (98.6 +/- 28.1 cmH2O, r = 0.60, P < 0.01), maximal heart rate (157.9 +/- 10.1 bpm, r = 0.59, P < 0.02), Borg dyspnea scale (1.7 +/- 2.4, r = 0.55, P < 0.03), and double product (blood pressure x heart rate; r = 0.59, P < 0.02). The product of distance walked and body weight (work) correlated (Pearson) with height (r = 0.83, P = 0.000), maximal expiratory pressure (r = 0.64, P < 0.01), systolic blood pressure (r = 0.56, P < 0.02), and diastolic blood pressure (r = 0.55, P < 0.03). We conclude that the 6-min walk test is reproducible and easy to perform in children and adolescents with cystic fibrosis. The distance walked was related to the clinical variables studied. Work in the 6-min walk test may be an additional parameter in the determination of physical capacity.

Thin-Section CT in Patients with Cystic Fibrosis: Correlation with Peak Exercise Capacity and Body Mass Index

PURPOSE

To evaluate whether thin-section chest computed tomographic (CT) findings correlate with exercise capacity, body mass index (BMI), dyspnea, and leg discomfort in patients with cystic fibrosis (CF).

MATERIALS AND METHODS

Institutional ethics committee approval was obtained, and patients provided written informed consent. Twenty-two patients (13 male and nine female patients; mean age, 22 years +/- 5.9; age range, 17-41 years) with stable CF underwent thin-section CT and exercise testing on a cycle ergometer. Three radiologists blinded to the clinical severity of disease and the spirometric findings of all patients independently and randomly scored all scans with a modified Bhalla scoring system. The primary measurement of the outcome of exercise testing was percentage of predicted peak O2 uptake. Univariate (Spearman rank correlation) and multivariate analyses were used to compare thin-section CT, clinical (age, sex, spirometric data, and BMI), and exercise measurements.

RESULTS

The correlation between total thin-section CT score and percentage of predicted peak O2 uptake was stronger than the correlation between the percentage of predicted peak O2 uptake and any clinical measurement (R = -0.60, P < .01). The thin-section CT structural abnormalities that had the strongest correlation with percentage of predicted peak O2 uptake were severity of bronchiectasis and presence of sacculations or abscesses (R = -0.70 and -0.71, respectively; P < .01). Multivariate analysis showed total thin-section CT score to be the only significant predictor of exercise capacity, accounting for 42% of the variance in percentage of predicted peak O2 uptake.

CONCLUSION

In patients with CF, the correlation between thin-section CT score and exercise limitation is stronger than that between spirometry results or BMI and exercise limitation.

Effect of low altitude at the Dead Sea on exercise capacity and cardiopulmonary response to exercise in cystic fibrosis patients with moderate to severe lung disease

Oxygen supplementation may improve exercise tolerance and the physiological response to exercise in cystic fibrosis (CF) patients. Elevated barometric pressure at low altitude is a simple means of increasing the quantity of inspired oxygen. Our objectives were to examine the effect of natural oxygen enrichment (at the Dead Sea, 396 m below sea level) on exercise capacity, and the physiological responses to maximal and submaximal exercise in CF patients. Patients were tested twice: at sea level (barometric pressure, 754 +/- 6 mmHg, mean +/- SD), and at the Dead Sea (barometric pressure, 791 +/- 3 mmHg), in a randomized crossover design. We studied 14 CF patients (6 females, 8 males), aged 15-45 years, with moderate to severe lung disease (mean forced expired volume in 1 sec = 50.0 +/- 11.2% predicted). Tests at each site included resting spirometry, anthropometry, a graded submaximal exercise test, a maximal exercise test on a treadmill, and a 6-min walk test. Tests were performed in identical order at both sites. Tests at the Dead Sea were performed 72 hr after arrival. No differences between sites were observed in lung function at rest. Peak oxygen consumption was significantly improved at the Dead Sea compared with sea level (1.68 +/- 0.73 vs. 1.57 +/- 0.74 l/min, respectively, P = 0.05), along with an improvement in the ventilatory equivalent for oxygen (41.2 +/- 6.3 vs. 46.1 +/- 7.1, respectively, P < 0.05). During submaximal exercise, blood oxygen saturation improved at the Dead Sea compared with sea level at all exercise intensities (P < 0.05). In conclusion, these results suggest that even a brief stay at the Dead Sea area may have physiological benefits for CF patients with moderate to severe lung disease.

Relationship between breath-hold time and physical performance in patients with cystic fibrosis

Rehabilitation including physiotherapy is an important part of the treatment used to help improve the quality of life of patients with cystic fibrosis (CF). The aim of this study was to determine the value of the breath-hold time as an index of exercise tolerance in patients with CF. Eighteen patients in different states of CF were included. The breath-hold time was measured in all patients. The fitness level was assessed by means of a progressive exercise test on a cycle-ergometer. During the test, oxygen uptake (VO(2)) and carbon dioxide elimination (VCO(2)) were measured breath by breath. The VO(2) and working capacity (WC) were computed at the anaerobic threshold (AT) and at peak. Duration of breath-hold was 24.7 +/- 2.87 (mean +/- SEM) seconds, varying between 10 and 58. The breath-hold time (BHT) displayed a significant correlation with VO(2) (r = 0.898), WC (r = 0.899) at the AT, and the peak VO(2) (r = 0.895). Regression equations were: VO(2) at the AT (ml/kg) = 5.53 + 0.42 x BHT and WC at the AT (watt/kg) = 0.56 + 0.38 x BHT Our results suggest that the voluntary breath-hold time might be a useful index for prediction of the exercise tolerance of CF patients.

Trampoline use as physiotherapy for cystic fibrosis patients

Physicians and physiotherapists who care for CF patients have recommended the use of trampolines as a physiotherapeutic tool for enhancing cardiopulmonary performance, encouraging sputum production, and improving general well-being. Despite some therapeutic and recreational benefits associated with trampoline use, papers in the general pediatric population mostly document an increased incidence of injuries, ranging from minor trauma to spinal cord injuries and even death. The aim of this review is to examine the accumulated published data regarding the use of trampolines, to assess their potential contributions and disadvantages for CF patients, and to define whether trampoline use should be recommended. An extensive search in the published medical literature retrieved approximately 60 articles that primarily dealt with trampolines, out of which only two dealt with CF. The preponderance of these articles are reports pertaining to injuries related to the use of trampolines, with only a few describing the medical, physiologic, and/or psychological benefits of trampolines. Based on the accumulated data, the presumed benefits of trampoline use for CF patients are not proven. Furthermore, the suggested benefits could be acquired using other types of exercise. Weighing the known risks of trampolines against the potential benefits that are not unique to this modality suggests that the use of trampolines for CF should not be recommended.

Effects of Anaerobic Training in Children With Cystic Fibrosis

BACKGROUND

Children's physical activity patterns are characterized by short-term anaerobic activities. Anaerobic exercise performance in children with cystic fibrosis (CF) has received little attention compared to aerobic performance. This study investigated the effects of anaerobic training in children with CF.

DESIGN AND METHODS

Twenty patients were randomly assigned to the training group (TG) [11 patients; mean (+/- SD) age, 13.6 +/- 1.3 years; mean FEV(1), 75.2 +/- 20.7% predicted] or the control group (CG) [9 patients; mean age, 14.2 +/- 2.1 years; FEV(1), 82.1 +/- 19.1% predicted]. The TG trained 2 days per week for 12 weeks, with each session lasting 30 to 45 min. The training program consisted of anaerobic activities lasting 20 to 30 s. The control subjects were asked not to change their normal daily activities. Body composition, pulmonary function, peripheral muscle force, habitual physical activity, aerobic and anaerobic exercise performance, and quality of life were reevaluated at the end of the training program, and again after a 12-week follow-up period.

RESULTS

Patients in the TG significantly improved their anaerobic performance, aerobic performance, and quality of life. No significant changes were seen in other parameters, and no improvements were found in CG. After the follow-up period, only anaerobic performance and quality of life in TG were significantly higher compared to pretraining values.

CONCLUSIONS

Anaerobic training has measurable effects on aerobic performance (although not sustained), anaerobic performance, and health-related quality of life in children with CF. Therefore, anaerobic training could be an important component of therapeutic programs for CF patients.