Avaliação da cinética on da frequência cardíaca em pacientes asmáticos e em indivíduos saudáveis durante o Endurance Shuttle Walk Test / Evaluation of heart rate on kinetics in asthmatic patients and in healthy individuals during the endurance shuttle walk test

Introdução: O comportamento cinético da frequência cardíaca (FC) na transição do repouso para o exercício nos informa sobre a integridade do sistema nervoso autônomo. Recuperações mais lentas associam-se ao risco de mortalidade por eventos cardiovasculares, tornando-se imprescindível sua avaliação. Objetivo: Avaliar e comparar a resposta da cinética on da FC em pacientes asmáticos e indivíduos saudáveis durante o Endurance Shuttle Walk Test (ESWT). Métodos: Trata-se de um estudo prospectivo, transversal e controlado, com 14 adultos asmáticos e 8 controles saudáveis. Os indivíduos realizaram as seguintes avaliações: Teste de função pulmonar, Variabilidade da Frequência Cardíaca (VFC) e Incremental Shuttle Walk Test e ESWT. Resultados: O grupo asmático apresentou um atraso da cinética on da FC na transição do repouso para o teste, e uma correlação negativa moderada (r=-0,60; p<0,05) entre a distância percorrida (m) e o tempo de resposta (TRM) cinética on da FC. Conclusão: Os pacientes asmáticos apresentaram um atraso da cinética "on", quando comparados ao grupo de indivíduos saudáveis, demonstrando ser um importante marcador na avaliação da performance física.

Introduction: The kinetic behavior of heart rate (HR) in the transition from rest to exercise, as this assessment informs us about the integrity of the autonomic nervous system. Slower recoveries are associated with the risk of mortality from cardiovascular events, making their evaluation, essential. Objective: To evaluate and compare the HR on kinetics response in asthmatic patients and healthy individuals during the Endurance Shuttle Walk Test (ESWT). Methods: This is a prospective, cross-sectional, controlled study with 14 asthmatic adults and 8 healthy controls. Subjects performed the following assessments: Pulmonary Function Test, Heart Rate Variability (HRV) and Incremental Shuttle Walk Test and ESWT. Results: The asthmatic group showed a delay in the HR on kinetics in the transition from rest to the test, and a moderate negative correlation (r=-0.60; p<0.05) between the distance covered (m) and the response time (TRM) kinetics on from FC. Conclusion: Asthmatic patients showed a delay in "on" kinetics, in comparison to the group of healthy individuals, proving to be an important marker in physical performance assessments.

The untapped potential of physical activity monitoring for quality assurance of field-based walking tests in clinical respiratory trials.

Field-based walking tests are well-established outcome measures in clinical research trials and in the evaluation of routine clinical services, including pulmonary rehabilitation. Despite widespread use, there has been little attention to, or reporting of, the quality assurance of these tests. Physical activity monitoring has become increasingly popular and data from activity monitors could be used for quality assurance of field-based walking tests. We provide examples in this article of data-driven insights possible with this approach, using data from waist-worn accelerometry, for the incremental shuttle walking test (ISWT), endurance shuttle walk test (ESWT) and six-minute walk test (6MWT). Given the multitude of devices to measure physical activity and the range metrics to describe physical activity, we also comment on some of the technical considerations to using activity monitors for walking test quality assurance. Data-driven approaches to quality assurance are already commonplace for other outcome measures in clinical respiratory trials, but little is known about this approach for field-based walking tests. The application of physical activity monitoring may be extended to other field-based exercise tests and additional rehabilitation services. This may be more challenging for self-paced walking tests such as the 6MWT. Future work should apply this approach to research trials and service evaluations to explore the impact of field-based walking test quality on performance (e.g. distance on the ISWT or time achieved for the ESWT), responsiveness to interventions (e.g. pulmonary rehabilitation) and effectiveness of training procedures (e.g. remote training for multi-site trials).

Changes in Exercise Capacity and Health-Related Quality of Life at Four and Eight Weeks of a Pulmonary Rehabilitation Program in People with COPD.

Pulmonary Rehabilitation (PR) is a key intervention in the management of people with chronic obstructive pulmonary disease (COPD), though few studies have assessed where changes in outcomes occur during a PR program. The aim of this study was to determine the changes in exercise capacity and health-related quality of life at four and eight weeks during a twice-weekly supervised PR program in people with COPD. Fifty participants with COPD were recruited and attended PR twice-weekly for eight weeks. The outcome measures were the endurance shuttle walk test (ESWT), six-minute walk distance (6MWD), St George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT) and the Hospital Anxiety and Depression Scale (HADS) which were measured at baseline, four and eight weeks. Compared to baseline, at week four there were significant improvements in ESWT (mean difference [95%CI] 197 [89 to 305] seconds), 6MWD (22 [8 to 36] metres), SGRQ symptom score (-6 [-12 to -1] points) and SGRQ total score (-4 [-7 to -1] points). Between week four and eight there were further significant improvements in ESWT (94 [8 to 181] seconds) only. By week eight, ESWT, 6MWD, SGRQ symptoms and total score, and CAT had all improved significantly compared to baseline measures. This study demonstrated that participants with moderate to very severe COPD who participated in a twice weekly, eight-week PR program (16 sessions) had significant improvement in ESWT, 6MWD, SGRQ, and CAT score with the greatest improvements occurring in the first four weeks of the program.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.2013793 .

Comparison of supplemental oxygen delivery by continuous versus demand based flow systems in hypoxemic COPD patients - A randomized, single-blinded cross-over study.

BACKGROUND: Supplemental oxygen is a recommended therapy option in stable hypoxemic COPD patients. Often, supplemental oxygen is provided by continuous flow (CF). However, demand oxygen delivery systems (DODS) that provide an oxygen bolus only during inspiration have gained increasing use as they prolong oxygen cylinder life (beside battery life). However, there is a lack of evidence if different DODS and CF devices are equivalent. METHODS: Seventy hypoxemic COPD patients (FEV1 32 ±â€¯9% predicted, PaO2 56±7 mmHg) on long-term oxygen therapy were included in this prospective single-blinded, randomized cross-over trial. Following an initial incremental shuttle walk test, patients performed 3 endurance shuttle walk tests (ESWT) at 85% of their maximum walking speed in random order with: (A) CF (ESWT-CF), (B) a DODS based on liquid oxygen (ESWT-DL) and (C) an DODS oxygen concentrator (ESWT-DC). The primary outcome was oxygen saturation (SpO2) at ESWT isotime. Secondary outcomes were total ESWT duration, heart rate (HR) and breathing frequency (BF) at isotime and dyspnea at end-exercise. RESULTS: SpO2 at ESWT isotime was not clinically different between devices: 90 ±â€¯4% (CF), 89 ±â€¯5% (DL) and 90 ±â€¯5% (DC). However, 20% of the patients showed a ≥4% lower oxygen desaturation while using a DODS device. Secondary outcomes were similar under the three conditions. CONCLUSION: Oxygen supplementation via DODS (based on liquid oxygen or as a concentrator) yielded comparable physiological effects during standardized walking in stable hypoxemic COPD patients like CF. However, 20% of patients showed a clinically relevant lower oxygen saturation while using a DODS device. Therefore, we suggest individual testing of oxygen saturation of DODS suitability.

The minimal detectable difference for endurance shuttle walk test performance in people with COPD on completion of a program of high-intensity ground-based walking.

BACKGROUND: In people with moderate-to-severe chronic obstructive pulmonary disease (COPD), the minimal detectable difference (MDD) in endurance shuttle walk test (ESWT) performance following exercise training is unclear. We sought to determine the MDD for ESWT performance following supervised ground-based walking training using anchor- and distribution-based approaches and report whether these values exceeded random variation in test performance. METHODS: Participants with COPD trained for 30-45 min, 2-3 times weekly for 8-10 weeks. The ESWT was performed before and after the training period. Immediately after training, participants rated their change in walking ability using a Global Rating of Change scale. Receiver Operating Characteristic curves were used to derive the value that best separated those who perceived their improvement in walking ability to be at least 'a little' better from 'almost the same, hardly any change'. These values were compared with those calculated using a distribution-based method. Random variation in test performance was defined as the minimal detectable change (MDC), calculated using the standard error of measurement. RESULTS: 78 participants (aged 70 ±â€¯8 yr and FEV1 43 ±â€¯15% predicted) completed the ESWT before and after training. The value that best separated those who perceived their walking ability as 'a little' better was 70 s. The 95% confidence intervals around this estimate traversed zero. The distribution-based estimate was 156 s. The MDC was 227 s. CONCLUSIONS: The MDD established using the anchor- and distribution-based approaches differed considerably. Large variation in test performance cautions against using the MDD to interpret changes in an individual. CLINICAL TRIALS REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12609000472279).

Estimating endurance shuttle walk test speed using the six-minute walk test in people with chronic obstructive pulmonary disease.

The objective of this study was to derive and validate an equation to estimate the speed for the endurance shuttle walk test (ESWT) using results from the six-minute walk test (6MWT) in patients with chronic obstructive pulmonary disease (COPD). Participants with diagnosed COPD (n = 84) performed two incremental shuttle walk tests (ISWTs) and two 6MWTs. ESWT speed was calculated from the ISWT results using the original published method. An equation was derived, which directly related six-minute walk distance (6MWD) to ESWT speed. The derived equation was validated in a different group of people with COPD (n = 52). There was a strong correlation between average 6MWD and the calculated ESWT speed (r = 0.88, p < 0.001). The ESWT speed (kilometre per hour) was estimated using the following equation: 0.4889 + (0.0083 × 6MWD). The mean difference (±limits of agreement) between ESWT speeds was calculated using the original published method and found to be 0.03 (±0.77) km/hour. When the ISWT is not the test of choice for clinicians, the 6MWT can be used to accurately estimate the speed for the ESWT.