Exercise tolerance in children with cystic fibrosis undergoing lung transplantation assessment

Quality of life and exercise tolerance tools in children/adolescents with cystic fibrosis: Systematic review

INTRODUCTION

This systematic review aims to analyze the validity and reliability of available tools to assess health-related quality of life (HRQoL) and exercise tolerance in children and adolescents with cystic fibrosis (CF).

MATERIALS AND METHODS

A review of observational studies studying the validity and reliability of the tools was conducted. The COSMIN (COnsesus-based Standards for the selection of health Measurements INstruments) guide was followed to analyze the quality of these tools.

RESULTS

A total of 18 studies were selected. Of the eight HRQoL tools, five generic and three specific, analyzed in 14 studies, the Cystic Fibrosis Questionnaire-Revised (CFQ-R) presents the best properties. Of the four tools analyzed to assess exercise tolerance, cycle ergometry and the modified shuttle test are the most valid and reliable.

CONCLUSIONS

The CFQ-R, cycloergometry and the modified shuttle test have the best properties for the assessment of children with CF, but more studies are needed.

Home-based or remote exercise testing in chronic respiratory disease, during the COVID-19 pandemic and beyond: A rapid review

Objectives:

To identify exercise tests that are suitable for home-based or remote administration in people with chronic lung disease.

Methods:

Rapid review of studies that reported home-based or remote administration of an exercise test in people with chronic lung disease, and studies reporting their clinimetric (measurement) properties.

Results:

84 studies were included. Tests used at home were the 6-minute walk test (6MWT, two studies), sit-to-stand tests (STS, five studies), Timed Up and Go (TUG, 4 studies) and step tests (two studies). Exercise tests administered remotely were the 6MWT (two studies) and step test (one study). Compared to centre-based testing the 6MWT distance was similar when performed outdoors but shorter when performed at home (two studies). The STS, TUG and step tests were feasible, reliable (intra-class correlation coefficients >0.80), valid (concurrent and known groups validity) and moderately responsive to pulmonary rehabilitation (medium effect sizes). These tests elicited less desaturation than the 6MWT, and validated methods to prescribe exercise were not reported.

Discussion:

The STS, step and TUG tests can be performed at home, but do not accurately document desaturation with walking or allow exercise prescription. Patients at risk of desaturation should be prioritised for centre-based exercise testing when this is available.

Exercise testing for children with cystic fibrosis: A systematic review

BACKGROUND

Exercise testing is routinely used to measure exercise capacity in children with cystic fibrosis (CF). Various tests are available, however the psychometric properties of these measures have not been systematically reviewed for this population.

METHOD

A systematic search of electronic databases (PubMed, Web of Science, Medline, CINHAL, Cochrane, and PEDro) was performed to identify papers that: (a) reported original psychometric data, (b) examined a measure of exercise capacity, (c) examined children with CF aged eight to 18 years; and (d) were published in English after 1950. The level of psychometric evidence was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.

RESULTS

Searches identified 1025 papers. Forty-six papers were included, covering 15 tests: incremental cardiopulmonary exercise test using a cycle ergometer (CPET(cycle)) or treadmill (CPET(treadmill)), 6 minute walk test (6MWT), modified shuttle test (MST), 3-minute step test (3MST), 2 minute walk test (2MWT), Bratteby walk test, intermittent sprint test, speed ramp test, incremental step test, forward-backwards jump test (FBJT), astride jump test (AJT), motor quotient test, Munich fitness test, and Glittre ADL test.

CONCLUSION

There is a plethora of exercise tests available with varying psychometric robustness. The CPET, 6MWT, and MST have fair to good psychometric properties, but each with their clinical advantages and limitations. Thus, a Selection Guide was developed to assist clinicians and researchers in selecting the most appropriate exercise test for various situations.

Effects of aerobic interval training on glucose tolerance in children and adolescents with cystic fibrosis: a randomized trial protocol

Background

Individuals with cystic fibrosis (CF) may develop CF-related diabetes (CFDR). This comorbidity is related to a poorer quality of life, microvascular complications, a decline in lung function, and an increase in exacerbations, as well as delayed growth and puberty. Evidence exists that physical exercise contributes to glycemic control in individuals with non-CF-related diabetes. This exercise is usually continuous with moderate intensity and long duration, which can cause muscle dyspnea and fatigue in CF individuals. Aerobic interval training (AIT) emerges as a safe and effective alternative for treating these individuals. The objective of this study is to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF.

Methods

This study will be a two-arm, prospectively registered, randomized controlled trial with blind assessors and twenty 6- to 18-year-old individuals with cystic fibrosis (CF) from two different Brazilian states. People with CF will be randomly allocated to either the experimental or control group using block randomization, stratified by puberty stage,. Participants from both groups will receive an educational intervention and will be asked to continue their usual daily treatment for the full duration of the study. Those in the experimental group will perform AIT on a cycle ergometer at home three times a week, for 8 consecutive weeks. The sample characterization will include an assessment of puberty stage, socioeconomic status, dyspnea, and anthropometry. The primary outcome will be the change in glucose tolerance, while the secondary outcomes will include lung function, exercise tolerance, respiratory muscle strength, quality of life, and CF exacerbations. All outcomes will be assessed at baseline, week 9, and week 17.

Discussion

This is the first study to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF. This study will serve as a basis for guiding clinical practice and decision-making in treating glucose intolerance and CF-related diabetes (CFRD) in children and adolescents with CF.

Trial registration

ClinicalTrials.gov Protocol Registration System: NCT03653949. Registered on August 31, 2018.

Six-minute walk test as a determinant of the functional capacity of children and adolescents with cystic fibrosis: A systematic review

Cystic Fibrosis (CF) is a multisystem disorder. The involvement of the respiratory system is frequent and culminates in dyspnea and exercise intolerance. Functional capacity is an important diagnostic tool, because it reflects the cardiorespiratory status, quality of life and prognosis. This systematic review aims to assess the reproducibility and validity of the six minute walk test (6MWT) to reflect the functional capacity of children and adolescents with cystic fibrosis, and also the correlation between 6MWT and lung function. Searches for articles were performed in eight databases using MeSH/DeCS keywords. A total of 695 articles were found and, after verifying all eligibility criteria, six articles were included for analysis and scoring regarding the methodological quality according to the QUADAS scale (Quality Assessment of Diagnostic Accuracy Studies). All articles had good methodology (QUADAS between 9 and 11 points). The 6MWT is not correlated with lung function. There is a strong indication that the 6MWT is a reproducible test to assess the functional capacity of children and adolescents with CF. The validity assessment could not be reached because the studies included in this systematic review did not use adequate statistical tools to carry out such an evaluation.

How does heart rate recovery after sub-maximal exercise correlate with maximal exercise testing in children with CF?

BACKGROUND

Disease progression in cystic fibrosis (CF) is marked by worsening exercise tolerance. Further, maximal exercise capacity (VO2 peak) correlates with survival in CF, but maximal tests are uncomfortable and resource-intensive. A three-minute step test (STEP) has been validated in CF. Heart rate (HR) recovery after exercise correlates with all-cause mortality in adult non-CF populations. We compared HR recovery after the three-minute step test with VO2 peak in children with CF.

METHODS

Twenty-four children with CF performed STEP and a maximal exercise test. Correlation between the tests was assessed.

RESULTS

Maximum HR on STEP was lower than on the maximal test (140 vs. 190, p<0.01). Peak HR during STEP correlated inversely with VO2 peak. In subjects with mild lung disease, faster HR recovery after STEP correlated with higher VO2 peak.

CONCLUSIONS

The three-minute step test is a feasible submaximal test in this patient population. HR during and after a three-minute step test may reflect VO2 peak in children with CF.

Test-retest reliability and developmental evolution of the 6-min walk test in Caucasian boys aged 5-12 years

The 6-min walk test (6MWT) assesses functional capacity and has been used as outcome measure in therapeutic studies in childhood neuromuscular disorders. The objectives were to evaluate test-retest reliability of the 6MWT and to generate normative data for healthy boys aged 5-12 years. Ninety boys (mean age 8 years 10 months) were recruited over four age subcategories (5-6, 7-8, 9-10, 11-12 years). Mean 6MWT distance and velocity (±standard deviation) for the total group were 555.5±93 m and 92.6±16.6 m/min. The 6MWT distance increased significantly with age. Test-retest reliability (mean interval 12 days) was very high for the total group (ICC>0.95) and for all age subcategories (ICC>0.80) a moderately high reliability (ICC>0.75) was found from 3 min onwards for each age subcategory. There was a mean difference of 5.2 m between test and retest without systematic bias. The standard error of measurement and smallest detectable difference were 20.7 and 57.4 m, respectively. These findings demonstrate the reliability of the 6MWT in young children, underscore its evolution with age, and indicate that a shorter version of the test is also reliable.

The use of step tests for the assessment of exercise capacity in healthy subjects and in patients with chronic lung disease

Step tests are typically used to assess exercise capacity. Given the diversity of step tests, the aim of this review was to describe the protocols that have been used in healthy subjects and in patients with chronic lung disease. Step tests for use in healthy subjects have undergone a number of modifications over the years. In most step tests, the duration is variable (90 s-10 min), but the step height (23.0-50.8 cm) and stepping rate (22.5-35.0 steps/min) remain constant throughout the test. However, the use of a fixed step height and constant stepping rate might not provide adequate work intensity for subjects with different levels of fitness, the workload therefore being above or below individual capacity. Consequently, step test protocols have been modified by introducing changes in step heights and stepping rates during the test. Step tests have been used in patients with chronic lung diseases since the late 1970s. The protocols are quite varied, with adjustments in step height (15-30 cm), pacing (self-paced or externally paced), and test duration (90 s-10 min). However, the diversity of step test protocols and the variety of outcomes studied preclude the determination of the best protocol for use in individuals with chronic lung disease. Shorter protocols with a high stepping rate would seem to be more appropriate for assessing exercise-related oxygen desaturation in chronic lung disease. Symptom-limited testing would be more appropriate for evaluating exercise tolerance. There is a need for studies comparing different step test protocols, in terms of their reliability, validity, and ability to quantify responses to interventions, especially in individuals with lung disease.

Awake and asleep oxygen saturations in infants with chronic neonatal lung disease

AIM

There is uncertainty about the best method of withdrawing supplemental oxygen in babies with chronic neonatal lung disease (CNLD). Some authors advocate withdrawal of oxygen in the day, but continuing supplementation during sleep, based on early work suggesting that oxygen saturations are lower during sleep, which did not accord with our clinical impression. We re-examined the hypothesis that babies have lower saturations while asleep.

METHODS

We studied infants with CNLD during the day, while awake and asleep. We recorded video with simultaneous real-time capture of oxygen saturation (SpO2), heart rate and plethysmographic waveform from pulse oximetry. Behavioural state was scored using observation and video and classified as awake (feeding, active or quiet) or sleep.

RESULTS

Thirteen infants had analysable data, although one had strikingly lower SpO2 values while awake and was excluded from analysis. The infants had a median gestation of 26 weeks and were studied at a median (range) postmenstrual age of 66 (37-130) weeks, for 229 (89-330) min. Mean SpO2 was 97.6% during sleep and 97.0% awake (p=0.011).

CONCLUSION

Babies with CNLD have lower oxygen saturation while awake. There is no physiological justification for increasing oxygen during sleep, or withdrawing selectively during the daytime, although larger studies are needed to confirm this finding.

Reference values on the 6-minute walk test for children living in the United States

PURPOSE

: The purpose of this study was to investigate reference values for the 6-minute walk test (6MWT) and the relationship between 6-minute walk distance (6MWD) and age, sex, and anthropometric variables in children who are healthy, aged 7 to 11 years and living in the United States.

METHODS

: The sample included 100 children, 57 female, 43 male, mean age 9.66 ± 1.08 years. Measures included height, weight, body mass index, leg length, and 6MWD.

RESULTS

: Mean 6MWD was 518.50 ± 73.56 m. Values were lower than those reported for children living in other countries with the exception of England. There were no significant associations between the 6MWD and other variables with the exception of body mass index in males.

CONCLUSION

: Our findings suggest 6MWT values for children living in other countries may not be directly applicable to children living in the United States.

Exercise training before and after lung transplantation

The benefits of exercise training in individuals with chronic lung diseases such as chronic obstructive pulmonary disease, cystic fibrosis, and interstitial lung disease have been well documented. Although there is limited research available, it appears that exercise is safe and beneficial for people with severe end-stage chronic lung disease who are awaiting lung transplantation in addition to recipients of lung transplants. Evidence-based guidelines for exercise training in the pre- and post-lung transplantation phases have not yet been developed. However, by considering exercise guidelines for people with chronic lung disease and in older adults in light of the physiological changes that can occur either pre- or post-lung transplantation, a safe and appropriate exercise training program can be developed. Depending on the individual's exercise capacity and goals, the training program may include aerobic and resistance exercise, and flexibility and balance training. In the pre-transplant and acute post-transplant phases, the intensity of exercise is dictated primarily by symptom limitation and adequate rest, which is required between exercise bouts to allow for recovery. In the post-transplant phase, it is possible for lung transplant recipients to increase their exercise capacity and even participate in sports. Further research needs to be conducted to determine the optimal training guidelines and the long-term benefits of exercise, both in lung transplant candidates and recipients.

Clinical exercise testing in children and adolescents with cystic fibrosis

PURPOSE

To review the most common field and laboratory exercise tests available for children and adolescents with cystic fibrosis (CF).

METHODS

Relevant studies for this review were identified by electronic search of Medline and PubMed databases between the years 1958 and 2008. The bibliographies of all accessed publications were also searched. Key descriptors were cystic fibrosis, exercise testing, aerobic fitness, children, and adolescents.

RESULTS

Five field tests were selected for presentation, including discussion of their strengths and weaknesses. Laboratory tests measuring aerobic and anaerobic responses to exercise in children with CF were also selected for presentation and discussed along with a summary of safety considerations for exercise testing of children with CF.

CONCLUSION

Exercise testing is regarded an important prognostic tool in CF care. However, despite its beneficial effects, clinical exercise testing seems underused. Clinicians and their staff should encourage patients with CF to be physically active and recommend exercise testing annually.

[3-min step test: feasibility study for children with bone marrow transplantation]

INTRODUCTION

Bronchiolitis obliterans following a bone marrow transplantation needs an early diagnosis for a better evolution. First signs are exercise dyspnea and hypoxemia. A walking test evaluating the tolerance for effort could have an interest in detecting such symptoms. We report a preliminary study of feasibility of the 3-minute step-test in children with a bone marrow transplantation.

METHODS

Ten patients (5 boys, median 11.7 years, range 5.1-15.5 years) were included within at least 3 months away from a bone marrow transplantation. After clinical examination and realisation of pulmonary function tests, the test was to step up and down a single step which is 15 cm high, rhythmically (30 per minute) during 3 minutes. Heart rate and pulsed oxygen saturation were registered, dyspnea being assessed before and after the test by means of a visual analogue score and the fifteen-count breathlessness score.

RESULTS

All the children realised the 3-minute step-test successfully and with excellent tolerance. Only 1 child made an effort judged maximum. No hypoxemia caused by the effort was highlighted.

CONCLUSION

The 3-minute step-test is easy to achieve in a population of paediatric patients who have undergone a bone marrow transplantation. It could be a valuable tool in the respiratory follow up of these children.

The repeatability of submaximal endurance exercise testing in cystic fibrosis

Submaximal endurance cycle ergometer exercise tests are used to measure the efficacy of an exercise intervention, but the repeatability of these tests in patients with cystic fibrosis (CF) has not been established. The purpose of this study was to examine the repeatability of submaximal endurance testing in stable CF. Fifteen adults with CF underwent two submaximal endurance tests carried out over a 7-day period. A subset of six subjects returned 28 days later for a third submaximal endurance test. Workload was set at 80% of maximum workload and exercise was performed to exhaustion. Oxygen consumption, minute ventilation, tidal volume, carbon dioxide output, respiratory rate, heart rate, and oxygen saturation were measured at rest, at end exercise and at four matched times during the submaximal endurance tests (20, 40, 60, and 80% of exercise duration calculated from the first endurance test). Submaximal endurance test time was highly repeatable with no significant learning effect identified on multiple testing. Submaximal endurance exercise time demonstrated a variability of 5.7% which is consistent with high levels of repeatability. Metabolic, ventilatory and cardiac variables were all also highly reproducible between test days. Submaximal endurance testing is repeatable in stable CF, confirming that submaximal endurance tests are a reliable tool for assessment of therapeutic benefit in patients with CF.

Modified shuttle test performance in hospitalized children and adolescents with cystic fibrosis

BACKGROUND

The Modified Shuttle Test (MST) is a valid and sensitive measure of exercise capacity in adult CF patients. Recently, its validity in children has been demonstrated. The aim of this study was to demonstrate the utility of the MST as a measure of responsiveness to hospitalisation for i.v. antibiotic and supportive therapy in children and adolescents with CF.

METHODS

28 children and adolescents (40 admissions) performed a MST and lung function within 48 h of admission and discharge to hospital for administration of intravenous antibiotics. Mean age was 12.7 years and antibiotic therapy length was 14.7 days.

RESULTS

Upon admission, the mean (S.D.) FEV(1) was 63 (19)% predicted, FVC was 80 (18)% predicted, FEF(25-75) 43 (29)% predicted and MST distance 718 (232) m. FEV(1) increased by 15% (p<or=0.001), FVC by 13% (p<or=0.001), FEF(25-75) by 39% (p<or=0.001) and MST distance by 102 m (p<or=0.001). The percentage improvement in MST distance at 18% (p<or=0.001) was similar to that for FEV(1), but could not be predicted by the change in FEV(1).

CONCLUSION

This study demonstrated the utility of the MST to assess the effect of hospitalisation for i.v. antibiotic and supportive therapy in children and adolescents with CF.

Tests de marche : une avancée dans l'évaluation fonctionnelle cardiorespiratoire

Exercise testing provides information on physical capacity during exercise in addition to spirometric measures of lung function or assessment on treadmills or ergonomic cycle. The "gold standard" assessment of exercise tolerance is measured in the laboratory using treadmills or ergonomic cycle but the necessary equipment is expensive and may not be readily accessible; such tests require people used to work with children. Walking tests are field tests providing a valid and easily accessible method of measuring function-limited exercise tolerance in patients with respiratory or cardiac chronic diseases. These walking tests are non-threatening, inexpensive, easy to perform and to understand for children. Walking tests performed in daily practice are the following: "time-based" tests (2-, 6- or 12-min walking test), 3-min step test (on a step) and the shuttle walking test. It may be a useful measure to assess therapeutic intervention and provide information on the prognosis. They are simple and safe methods to evaluate quality of life in these patients.

Three-minute step test to assess exercise capacity in children with cystic fibrosis with mild lung disease

The information obtained from a simple submaximal test (the 3-min step test) was compared with that from a maximal cycle ergometry study, in a group of children with CF with relatively mild abnormalities of lung function (FEV(1) > 50% predicted). Nineteen subjects with CF undertook both exercise tests on the same day. Measurements included heart rate (HR), oxygen saturations (SaO(2)), visual analogue score of perceived breathlessness (VAS), 15-count breathlessness score (15c), and peak oxygen consumption (VO(2)). There were significant differences in the median changes in HR and VAS during the cycle test compared to the step test, 78 vs. 46 beats per minute (P < 0.05) and 51 mm vs. 42 mm (P < 0.05), respectively. There were no differences between median changes in 15c and SaO(2), but 3 subjects had significant desaturations (>4%) during the cycle test only. Significant exercise desaturations may occur in mild CF lung disease and will not be detected by a 3-min step test. The 15c did not discriminate between a maximal and a submaximal test, and was less useful than VAS. Important information may be missed by the step test which is detected by more complex exercise tests.