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1.
Thorax ; 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34462346

RESUMO

BACKGROUND: The impact of pulmonary rehabilitation (PR) on survival in patients with fibrotic interstitial lung disease (ILD) is unknown. Given the challenges conducting a large randomised controlled trial, we aimed to determine whether improvement in 6-minute walk distance (6MWD) was associated with better survival. METHODS: This retrospective, international cohort study included patients with fibrotic ILD participating in either inpatient or outpatient PR at 12 sites in 5 countries. Multivariable models were used to estimate the association between change in 6MWD and time to death or lung transplantation accounting for clustering by centre and other confounders. RESULTS: 701 participants (445 men and 256 women) with fibrotic ILD were included. The mean±SD ages of the 196 inpatients and 505 outpatients were 70±11 and 69±12 years, respectively. Baseline/changes in 6MWD were 262±128/55±83 m for inpatients and 358±125/34±65 m for outpatients. Improvement in 6MWD during PR was associated with lower hazard rates for death or lung transplant on adjusted analysis for both inpatient (HR per 10 m 0.94, 95% CI 0.91 to 0.97, p<0.001) and outpatient PR (HR 0.97, 95% CI 0.95 to 1.00, p=0.042). Participation in ≥80% of planned outpatient PR sessions was associated with a 33% lower risk of death (95% CI 0.49% to 0.92%). CONCLUSIONS: Patients with fibrotic ILD who improved physical performance during PR had better survival compared with those who did not improve performance. Confirmation of these hypothesis-generating findings in a randomised controlled trial would be required to definitely change clinical practice, and would further support efforts to improve availability of PR for patients with fibrotic ILD.

2.
Respir Res ; 22(1): 222, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362372

RESUMO

The COVID-19 pandemic has resulted in significant acute morbidity and mortality worldwide. There is now a growing recognition of the longer-term sequelae of this infection, termed "long COVID". However, little is known about this condition. Here, we describe a distinct phenotype seen in a subset of patients with long COVID who have reduced exercise tolerance as measured by the 6 min walk test. They are associated with significant exertional dyspnea, reduced health-related quality of life and poor functional status. However, surprisingly, they do not appear to have any major pulmonary function abnormalities or increased burden of neurologic, musculoskeletal or fatigue symptoms.


Assuntos
COVID-19/complicações , Dispneia/fisiopatologia , Tolerância ao Exercício/fisiologia , Pulmão/fisiologia , Fenótipo , Esforço Físico/fisiologia , Adulto , Idoso , COVID-19/epidemiologia , COVID-19/fisiopatologia , Dispneia/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Teste de Caminhada/métodos
3.
J Appl Physiol (1985) ; 131(2): 794-807, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34197227

RESUMO

The baroreflex integrity in early-stage pulmonary arterial hypertension (PAH) remains uninvestigated. A potential baroreflex impairment could be functionally relevant and possibly mediated by enhanced peripheral chemoreflex activity. Thus, we investigated 1) the cardiac baroreflex in nonhypoxemic PAH; 2) the association between baroreflex indexes and peak aerobic capacity [i.e., peak oxygen consumption (V̇o2peak)]; and 3) the peripheral chemoreflex contribution to the cardiac baroreflex. Nineteen patients and 13 age- and sex-matched healthy adults (HA) randomly inhaled either 100% O2 (peripheral chemoreceptor inhibition) or 21% O2 (control session) while at rest and during a repeated sit-to-stand maneuver. Beat-by-beat analysis of R-R intervals and systolic blood pressure provided indexes of cardiac baroreflex sensitivity (cBRS) and effectiveness (cBEI). The PAH group had lower cBEI for all sequences (cBEIALL) at rest [means ± SD: PAH = 0.5 ± 0.2 vs. HA = 0.7 ± 0.1 arbitrary units (a.u.), P = 0.02] and lower cBRSALL (PAH = 6.8 ± 7.0 vs. HA = 9.7 ± 5.0 ms·mmHg-1, P < 0.01) and cBEIALL (PAH = 0.4 ± 0.2 vs. HA= 0.6 ± 0.1 a.u., P < 0.01) during the sit-to-stand maneuver versus the HA group. The cBEI during the sit-to-stand maneuver was independently correlated to V̇o2peak (partial r = 0.45, P < 0.01). Hyperoxia increased cBRS and cBEI similarly in both groups at rest and during the sit-to-stand maneuver. Therefore, cardiac baroreflex dysfunction was observed under spontaneous and, most notably, provoked blood pressure fluctuations in nonhypoxemic PAH, was not influenced by the peripheral chemoreflex, and was associated with lower V̇o2peak, suggesting that it could be functionally relevant.NEW & NOTEWORTHY Does the peripheral chemoreflex play a role in cardiac baroreflex dysfunction in patients with pulmonary arterial hypertension (PAH)? Here we provide new evidence of cardiac baroreflex dysfunction under spontaneous and, most notably, provoked blood pressure fluctuations in patients with nonhypoxemic PAH. Importantly, impaired cardiac baroreflex effectiveness during provoked blood pressure fluctuations was independently associated with poorer functional capacity. Finally, our results indicated that the peripheral chemoreflex did not mediate cardiac baroreflex dysfunction among those patients.


Assuntos
Barorreflexo , Hipertensão Arterial Pulmonar , Pressão Sanguínea , Células Quimiorreceptoras , Frequência Cardíaca , Humanos
4.
Eur Respir Rev ; 30(161)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34289980

RESUMO

During submaximal exercise, minute ventilation (V' E) increases in proportion to metabolic rate (i.e. carbon dioxide production (V' CO2 )) to maintain arterial blood gas homeostasis. The ratio V' E/V' CO2 , commonly termed ventilatory efficiency, is a useful tool to evaluate exercise responses in healthy individuals and patients with chronic disease. Emerging research has shown abnormal ventilatory responses to exercise (either elevated or blunted V' E/V' CO2 ) in some chronic respiratory and cardiovascular conditions. This review will briefly provide an overview of the physiology of ventilatory efficiency, before describing the ventilatory responses to exercise in healthy trained endurance athletes, patients with asthma, and patients with obesity. During submaximal exercise, the V' E/V' CO2 response is generally normal in endurance-trained individuals, patients with asthma and patients with obesity. However, in endurance-trained individuals, asthmatics who demonstrate exercise induced-bronchoconstriction, and morbidly obese individuals, the V' E/V' CO2 can be blunted at maximal exercise, likely because of mechanical ventilatory constraint.

5.
Ann Am Thorac Soc ; 18(10): 1650-1660, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34004123

RESUMO

Rationale: Pulmonary rehabilitation (PR) is the most effective strategy to improve health outcomes in people with chronic obstructive pulmonary disease (COPD), although it has had limited success in promoting sustained physical activity. PR with a strong focus on disease self-management may better facilitate long-term behavior change. Objectives: To compare a newly developed enhanced PR (EPR) program with a traditional PR program on outcome achievement. Methods: In this randomized parallel-group controlled trial, PR classes were block-randomized to EPR or traditional PR and were delivered over 16 sessions each. The EPR program incorporated new and updated "Living Well with COPD" education modules, which had a stronger focus on chronic disease self-management. Fidelity of the intervention for content and delivery was assessed. Physical activity, self-efficacy, exercise tolerance, and health-related quality of life (HRQoL) were collected before, after, and 6 months after PR. Healthcare visits were collected 2 years before PR and 1 year after. Mortality was recorded 1 year after PR. Results: Of the 207 patients with COPD enrolled, 108 received EPR and 99 received traditional PR. Physical activity (steps) and self-efficacy improved from before to after PR in both programs, with no differences between groups. These effects were not sustained at 6 months. Exercise tolerance and HRQoL improved from before to after PR with no between-group differences and were maintained at 6 months. Visits to primary care providers and respiratory specialists decreased in the EPR program relative to the traditional PR program. EPR was delivered as intended, and there was no meaningful cross-contamination between the two programs. Conclusions: Enhancing PR to have a greater emphasis on chronic disease self-management did not result in a superior improvement of physical activity and health outcomes compared with traditional PR except for reduced resource usage from primary and specialist physician visits in the EPR program.Clinical trial registered with ClinicalTrials.gov (NCT02917915).


Assuntos
Doença Pulmonar Obstrutiva Crônica , Qualidade de Vida , Exercício Físico , Tolerância ao Exercício , Humanos , Autoeficácia
6.
CJC Open ; 3(3): 345-353, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33778451

RESUMO

Background: Fetuses of diabetic mothers develop left ventricular (LV) hypertrophy and are at increased long-term risk of cardiovascular disease. In our previous longitudinal study from midgestation to late infancy we showed persistence of LV hypertrophy and increased aortic stiffness compared with infants of healthy mothers, the latter of which correlated with third trimester maternal hemoglobin A1c. In the present study, we reexamined the same cohort in early childhood to determine if these cardiovascular abnormalities persisted. Methods: Height, weight, and right arm blood pressure were recorded. A full functional and structural echocardiogram was performed with offline analysis of LV posterior wall and interventricular septal diastolic thickness (IVSd), systolic and diastolic function, and aortic pulse wave velocity. Vascular reactivity was assessed using digital thermal monitoring. Participants also completed a physical activity questionnaire. Results: Twenty-five children of diabetic mothers (CDMs) and 20 children from healthy pregnancies (mean age, 5.6 ± 1.7 and 5.3 ± 1.3 years, respectively; P = not significant) were assessed. Compared with controls, IVSd z score was increased in CDMs (1.2 ± 0.6 vs 0.5 ± 0.3, respectively; P = 0.006), with one-fifth having a z score of more than +2.0. Aortic pulse wave velocity was increased in CDMs (3.2 ± 0.6 m/s vs 2.2 ± 0.4 m/s; P = 0.001), and correlated with IVSd z score (R 2 = 0.81; P = 0.001) and third trimester maternal A1c (R 2 = 0.65; P < 0.0001). Body surface area, height, weight, blood pressure, vascular reactivity, and physical activity scores did not differ between groups. Our longitudinal analysis showed that individuals with greater IVSd, and aortic stiffness in utero, early and late infancy also tended to have greater measures in early childhood (P < 0.001 and P < 0.0001, respectively). Conclusions: CDMs show persistently increased interventricular septal thickness and aortic stiffness in early childhood.

7.
Clin Auton Res ; 31(3): 443-451, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33560461

RESUMO

PURPOSE: Obstructive sleep apnea (OSA) is a common disorder (~ 4%) that augments sympathetic nerve activity (SNA) and elevates blood pressure. The relationship between sympathetic vasomotor outflow and vascular responsiveness, termed sympathetic neurovascular transduction (sNVT), has been sparsely characterized in patients with OSA. Therefore, we sought to quantify spontaneous sympathetic bursts and related changes in diastolic pressure. METHODS: Twelve participants with variable severities of OSA were recruited. We collected muscle sympathetic nerve activity (MSNA) (microneurography) and beat-by-beat diastolic pressure (finger photoplethysmography) during normoxia (FiO2 = 0.21) and hyperoxia (FiO2 = 1.0) to decrease MSNA burst frequency. MSNA burst sequences (i.e. singlets, doublets, triplets and quadruplets) were identified and coupled to changes in diastolic pressure over 15 cardiac cycles as an index of sNVT. sNVT slope for each individual was calculated from the slope of the relationship between peak responses in outcome plotted against normalized burst amplitude. RESULTS: sNVT slope was unchanged during hyperoxia compared to normoxia (normoxia 0.0024 ± 0.0011 Δ mmHg total activity [a.u.]-1 vs. hyperoxia 0.0029 ± 0.00098 Δ mmHg total activity [a.u.]-1; p = 0.14). sNVT slope was inversely associated with burst frequency during hyperoxia (r = -0.58; p = 0.04), but not normoxia (r = -0.11; p = 0.71). sNVT slope was inversely associated with the apnea-hypopnea index (AHI) (r = -0.62; p = 0.030), but not after age was considered. CONCLUSIONS: We have demonstrated that the prevailing MSNA frequency is unmatched to the level of sNVT, and this can be altered by acute hyperoxia.

8.
J Physiol ; 599(5): 1665-1683, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33428233

RESUMO

KEY POINTS: Patients with mild chronic obstructive pulmonary disease (COPD) have an elevated ventilatory equivalent to CO2 production ( V ̇ E / V ̇ C O 2 ) during exercise, secondary to increased dead space ventilation. The reason for the increased dead space is unclear, although pulmonary microvascular dysfunction and the corresponding capillary hypoperfusion is a potential mechanism. Despite emerging evidence that mild COPD is associated with pulmonary microvascular dysfunction, limited research has focused on experimentally modulating the pulmonary microvasculature during exercise in mild COPD. The present study sought to examine the effect of inhaled nitric oxide (iNO), a selective pulmonary vasodilator, on V ̇ E / V ̇ C O 2 , dyspnoea and exercise capacity in patients with mild COPD. Experimental iNO increased peak oxygen uptake in mild COPD, secondary to reduced V ̇ E / V ̇ C O 2 and dyspnoea. This is the first study to demonstrate that experimental manipulation of the pulmonary circulation alone, can positively impact dyspnoea and exercise capacity in mild COPD. ABSTRACT: Patients with mild chronic obstructive pulmonary disease (COPD) have an exaggerated ventilatory response to exercise, contributing to dyspnoea and exercise intolerance. Previous research in mild COPD has demonstrated an elevated ventilatory equivalent to CO2 production ( V ̇ E / V ̇ C O 2 ) during exercise, secondary to increased dead space ventilation. The reason for the increased dead space is unclear, although pulmonary microvascular dysfunction and the corresponding capillary hypoperfusion is a potential mechanism. The present study tested the hypothesis that inhaled nitric oxide (iNO), a selective pulmonary vasodilator, would lower V ̇ E / V ̇ C O 2 and dyspnoea, and improve exercise capacity in patients with mild COPD. In this multigroup randomized-control cross-over study, 15 patients with mild COPD (FEV1  =  89 ± 11% predicted) and 15 healthy controls completed symptom-limited cardiopulmonary exercise tests while breathing normoxic gas or 40 ppm iNO. Compared with placebo, iNO significantly increased peak oxygen uptake (1.80 ± 0.14 vs. 1.53 ± 0.10 L·min-1 , P < 0.001) in COPD, whereas no effect was observed in controls. At an equivalent work rate of 60 W, iNO reduced V ̇ E / V ̇ C O 2 by 3.8 ± 4.2 units (P = 0.002) and dyspnoea by 1.1 ± 1.2 Borg units (P < 0.001) in COPD, whereas no effect was observed in controls. Operating lung volumes and oxygen saturation were unaffected by iNO in both groups. iNO increased peak oxygen uptake in COPD, secondary to reduced V ̇ E / V ̇ C O 2 and dyspnoea. These data suggest that mild COPD patients demonstrate pulmonary microvascular dysfunction that contributes to increased V ̇ E / V ̇ C O 2 , dyspnoea and exercise intolerance. This is the first study to demonstrate that experimental manipulation of the pulmonary circulation alone, can positively impact dyspnoea and exercise capacity in mild COPD.


Assuntos
Óxido Nítrico , Doença Pulmonar Obstrutiva Crônica , Estudos Cross-Over , Dispneia , Teste de Esforço , Tolerância ao Exercício , Humanos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico
9.
Ann Am Thorac Soc ; 18(3): 399-407, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33196294

RESUMO

To minimize transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus responsible for coronavirus disease (COVID-19), the U.S. Centers for Disease Control and Prevention and the World Health Organization recommend wearing face masks in public. Some have expressed concern that these may affect the cardiopulmonary system by increasing the work of breathing, altering pulmonary gas exchange and increasing dyspnea, especially during physical activity. These concerns have been derived largely from studies evaluating devices intentionally designed to severely affect respiratory mechanics and gas exchange. We review the literature on the effects of various face masks and respirators on the respiratory system during physical activity using data from several models: cloth face coverings and surgical masks, N95 respirators, industrial respirators, and applied highly resistive or high-dead space respiratory loads. Overall, the available data suggest that although dyspnea may be increased and alter perceived effort with activity, the effects on work of breathing, blood gases, and other physiological parameters imposed by face masks during physical activity are small, often too small to be detected, even during very heavy exercise. There is no current evidence to support sex-based or age-based differences in the physiological responses to exercise while wearing a face mask. Although the available data suggest that negative effects of using cloth or surgical face masks during physical activity in healthy individuals are negligible and unlikely to impact exercise tolerance significantly, for some individuals with severe cardiopulmonary disease, any added resistance and/or minor changes in blood gases may evoke considerably more dyspnea and, thus, affect exercise capacity.


Assuntos
COVID-19/epidemiologia , Transmissão de Doença Infecciosa/prevenção & controle , Exercício Físico/fisiologia , Máscaras , Pandemias , Equipamento de Proteção Individual , COVID-19/fisiopatologia , COVID-19/transmissão , Humanos , SARS-CoV-2 , Estados Unidos/epidemiologia
10.
Chest ; 159(5): 1922-1933, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33217419

RESUMO

BACKGROUND: Physiologic and symptom responses at the ventilatory threshold (Tvent) during incremental cardiopulmonary exercise testing (CPET) can provide important prognostic information. RESEARCH QUESTION: This study aimed to develop an updated normative reference set for physiologic and symptom responses at Tvent during cycle CPET (primary aim) and to evaluate previously recommended reference equations from a 1985 study for predicting Tvent responses (secondary aim). STUDY DESIGN AND METHODS: Participants were adults 40 to 80 years of age who were free of clinically relevant disease from the Canadian Cohort Obstructive Lung Disease. Rate of oxygen consumption (V˙O2) at Tvent was identified by two independent raters; physiologic and symptom responses corresponding to V˙O2 at Tvent were identified by linear interpolation. Reference ranges (5th-95th percentiles) for responses at Tvent were calculated according to participant sex and age for 29 and eight variables, respectively. Prediction models were developed for nine variables (oxygen pulse, V˙O2, rate of CO2 production, minute ventilation, tidal volume, inspiratory capacity, end-inspiratory lung volume [in liters and as percentage of total lung capacity], and end-expiratory lung volume) using quantile regression, estimating the 5th (lower limit of normal), 50th (normal), and 95th (upper limit of normal) percentiles based on readily available participant characteristics. The two one-sided test of equivalence for paired samples evaluated the measured and 1985-predicted V˙O2 at Tvent for equivalence. RESULTS: Reference ranges and equations were developed based on 96 participants (49% men) with a mean ± SD age of 63 ± 9 years. Mean V˙O2 at Tvent was 50% of measured V˙O2 peak; the normal range was 33% to 66%. The 1985 reference equations overpredicted V˙O2 at Tvent: mean difference in men, -0.17 L/min (95% CI, -0.25 to -0.09 L/min); mean difference in women, -0.19 L/min (95% CI, -0.27 to -0.12 L/min). INTERPRETATION: A contemporary reference set of CPET responses at Tvent from Canadian adults 40 to 80 years of age is presented that differs from the previously recommended and often used reference set from 1985. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00920348; URL: www.clinicaltrials.gov.

12.
J Appl Physiol (1985) ; 130(1): 139-148, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33211599

RESUMO

To determine whether increased chemoreflex tonic activity is associated with augmented muscle sympathetic nervous system activity (MSNA) in women diagnosed with preeclampsia. Women with preeclampsia (n = 19; 32 ± 5 yr old, 31 ± 3 wk of gestation) were matched by age and gestational age with pregnant women (controls, n = 38, 32 ± 4 yr old, 31 ± 4 wk gestation; 2:1 ratio). MSNA (n = 9 preeclampsia) was assessed during baseline, peripheral chemoreflex deactivation (hyperoxia), and a cold pressor test (CPT). Baroreflex gain and diastolic blood pressure at which there is a 50% likelihood of MSNA occurring (T50) and plasma noradrenaline concentrations were measured. Baseline mean arterial pressure (MAP: 106 ± 11 vs. 87 ± 10 mmHg, P < 0.0001), noradrenaline concentrations (498 ± 152 pg/mL vs. 326 ± 147, P = 0.001), and T50 (79 ± 7 vs. 71 ± 9 mmHg, P = 0.02) were greater in women with preeclampsia than in controls. However, baseline MSNA (burst incidence [BI]: 41 ± 16 vs. 45 ± 13 bursts/100 hb, P = 0.4) was not different between groups. Responses to hyperoxia (ΔBI -5 ± 7 vs. -1 ± 8 bursts/100 hb, P = 0.1; ΔMAP -1 ± 3 vs. -2 ± 3 mmHg, P = 0.7) and CPT (ΔBI 15 ± 7 vs. 12 ± 11 bursts/100 hb, P = 0.6; ΔMAP 10 ± 4 vs. 12 ± 11 mmHg, P = 0.6) were not different between groups. Our findings question the assumption that increased MSNA contributes to hypertension in women with preeclampsia. The chemoreflex does not appear to contribute to an increase in MSNA in women with preeclampsia.NEW & NOTEWORTHY We wanted to determine whether increased chemoreflex tonic activity is associated with augmented muscle sympathetic nervous system activity (MSNA) in women diagnosed with preeclampsia. The chemoreflex does not contribute to increased MSNA in women with preeclampsia. Our data also challenge the belief that preeclampsia is associated with sympathetic neural hyperactivity. Thus, targeting sympathetic neural hyperactivity as therapeutic strategy is unlikely to be the most efficacious approach to treatment and management.


Assuntos
Pré-Eclâmpsia , Pressão Arterial , Barorreflexo , Pressão Sanguínea , Feminino , Frequência Cardíaca , Humanos , Músculo Esquelético , Gravidez , Sistema Nervoso Simpático
14.
Pilot Feasibility Stud ; 6: 162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33117559

RESUMO

Background: Pulmonary rehabilitation is an important component of chronic disease management in chronic obstructive pulmonary disease (COPD) and has been shown to improve shortness of breath, exercise capacity, quality of life, and decrease hospitalizations. However, pulmonary rehabilitation capacity is low. Primary care may be an effective method for delivering disease management services to this population. The objective of this feasibility pragmatic clinical trial was to evaluate enrollment and completion of a primary care network exercise and education program for people with COPD. Methods: COPD patients (N = 23; mean age = 65 ± 9 years; FEV1 = 68 ± 20% predicted) were recruited after referral to a primary care network exercise program in Edmonton, Alberta. Participants self-selected either an 8-week 16-session supervised exercise program or an 8-week unsupervised exercise program where they received three visits with an exercise specialist. Both groups self-selected education sessions with clinicians for disease management support. Referrals, completion, and program outcomes (physical activity, exercise capacity and health status) were measured before (T1), immediately after (T2), and 8 weeks following the program (T3). Results: Forty-three referrals were received in 10 months, where a minimum of 50 was required in order for the program to be considered feasible. Twenty-three participants provided baseline data, and twenty participants started the exercise program (10 in each exercise group), 16 of which completed the exercise program (80%). On average, 48% of the recommended education sessions were completed by participants. Conclusions: Enrollment into a COPD exercise and education program in a primary care network was low indicating the need for improved referral processes from physicians. Completion rates by participants were adequate for exercise but not education. The low referral rate and the lack of enrollment in COPD education by the patients indicate that a large-scale trial of the program as designed is not feasible.

15.
Artigo em Inglês | MEDLINE | ID: mdl-32924018

RESUMO

Background: Chronic obstructive pulmonary disease (COPD) is one of the most common causes of mortality and morbidity in high-income countries. In addition to the high costs of initial hospitalization, COPD patients frequently return to the emergency department (ED) and are readmitted to hospital within 30 days of discharge. A COPD acute care discharge care bundle focused on optimizing care for patients with an acute exacerbation of COPD has been shown to reduce ED revisits and hospital readmissions. The aim of this study was to explore and understand factors influencing implementation and uptake of COPD discharge care bundle items in acute care facilities from the perspective of health care providers and patients. Methods: Qualitative methodology was adopted. Nine focus groups were conducted using a semi-structured guide: seven with acute and primary/community health care providers and two with patients/family members. Focus groups were audiotaped, transcribed verbatim, and coded and analyzed using a thematic approach. Results: Forty-six health care providers and 14 patients/family members participated in the focus groups. Health care providers and patients identified four factors that can challenge the implementation of COPD discharge care bundles: process of care complexities, human capacity in care settings, communication and engagement, and attitudes and perceptions towards change. Both health care providers and patients recognized process of care complexity as the most important determinant of the COPD discharge bundle uptake. Processes of care complexity include patient activities in seeking and receiving care, as well as practitioner activities in making a diagnosis and recommending or implementing treatment. Important issues linked to human capacity in care settings included time constraints, high patient volume, and limited staffing. Communication during transitions in care across settings and patient engagement were also broadly discussed. Other important issues were linked to patients', providers', and system attitudes towards change and level of involvement in COPD discharge bundle implementation. Conclusions: Complexities in the process of care were perceived as the most important determinant of COPD discharge bundle implementation. Early engagement of health providers and patients in the uptake of COPD discharge bundle items as well as clear communication between acute and post-acute settings can contribute positively to bundle uptake and implementation success.

16.
Front Physiol ; 11: 659, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32714201

RESUMO

Cardiopulmonary exercise testing (CPET) is a method for evaluating pulmonary and cardiocirculatory abnormalities, dyspnea, and exercise tolerance in healthy individuals and patients with chronic conditions. During exercise, ventilation (V˙ E) increases in proportion to metabolic demand [i.e., carbon dioxide production (V˙CO2)] to maintain arterial blood gas and acid-base balance. The response of V˙ E relative to V˙CO2 (V˙ E/V˙CO2) is commonly termed ventilatory efficiency and is becoming a common physiological tool, in conjunction with other key variables such as operating lung volumes, to evaluate exercise responses in patients with chronic conditions. A growing body of research has shown that the V˙ E/V˙CO2 response to exercise is elevated in conditions such as chronic heart failure (CHF), pulmonary hypertension (PH), interstitial lung disease (ILD), and chronic obstructive pulmonary disease (COPD). Importantly, this potentiated V˙ E/V˙CO2 response contributes to dyspnea and exercise intolerance. The clinical significance of ventilatory inefficiency is demonstrated by findings showing that the elevated V˙ E/V˙CO2 response to exercise is an independent predictor of mortality in patients with CHF, PH, and COPD. In this article, the underlying physiology, measurement, and interpretation of exercise ventilatory efficiency during CPET are reviewed. Additionally, exercise ventilatory efficiency in varying disease states is briefly discussed.

17.
Cardiol Young ; 30(10): 1409-1416, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32716280

RESUMO

INTRODUCTION: We evaluated the safety and feasibility of high-intensity interval training via a novel telemedicine ergometer (MedBIKE™) in children with Fontan physiology. METHODS: The MedBIKE™ is a custom telemedicine ergometer, incorporating a video game platform and live feed of patient video/audio, electrocardiography, pulse oximetry, and power output, for remote medical supervision and modulation of work. There were three study phases: (I) exercise workload comparison between the MedBIKE™ and a standard cardiopulmonary exercise ergometer in 10 healthy adults. (II) In-hospital safety, feasibility, and user experience (via questionnaire) assessment of a MedBIKE™ high-intensity interval training protocol in children with Fontan physiology. (III) Eight-week home-based high-intensity interval trial programme in two participants with Fontan physiology. RESULTS: There was good agreement in oxygen consumption during graded exercise at matched work rates between the cardiopulmonary exercise ergometer and MedBIKE™ (1.1 ± 0.5 L/minute versus 1.1 ± 0.5 L/minute, p = 0.44). Ten youth with Fontan physiology (11.5 ± 1.8 years old) completed a MedBIKE™ high-intensity interval training session with no adverse events. The participants found the MedBIKE™ to be enjoyable and easy to navigate. In two participants, the 8-week home-based protocol was tolerated well with completion of 23/24 (96%) and 24/24 (100%) of sessions, respectively, and no adverse events across the 47 sessions in total. CONCLUSION: The MedBIKE™ resulted in similar physiological responses as compared to a cardiopulmonary exercise test ergometer and the high-intensity interval training protocol was safe, feasible, and enjoyable in youth with Fontan physiology. A randomised-controlled trial of a home-based high-intensity interval training exercise intervention using the MedBIKE™ will next be undertaken.


Assuntos
Reabilitação Cardíaca , Treinamento Intervalado de Alta Intensidade , Adolescente , Adulto , Criança , Exercício Físico , Terapia por Exercício , Tolerância ao Exercício , Humanos
18.
Chest ; 158(6): 2532-2545, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32679236

RESUMO

BACKGROUND: Up-to-date normative reference sets for cardiopulmonary exercise testing (CPET) are important to aid in the accurate interpretation of CPET in clinical or research settings. RESEARCH QUESTION: This study aimed to (1) develop and externally validate a contemporary reference set for peak CPET responses in Canadian adults identified with population-based sampling; and (2) evaluate previously recommended reference equations for predicting peak CPET responses. STUDY DESIGN AND METHODS: Participants were healthy adults who were ≥40 years old from the Canadian Cohort Obstructive Lung Disease who completed an incremental cycle CPET. Prediction models for peak CPET responses were estimated from readily available participant characteristics (age, sex, height, body mass) with the use of quantile regression. External validation was performed with a second convenience sample of healthy adults. Peak CPET parameters that were measured and predicted in the validation cohort were assessed for equivalence (two one-sided tests of equivalence for paired-samples and level of agreement (Bland-Altman analyses). Two one-sided tests of equivalence for paired samples assessed differences between responses in the derivation cohort using previously recommended reference equations. RESULTS: Normative reference ranges (5th-95th percentiles) for 28 peak CPET parameters and prediction models for 8 peak CPET parameters were based on 173 participants (47% male) who were 64 ± 10 years old. In the validation cohort (n = 84), peak CPET responses that were predicted with the newly generated models were equivalent to the measured values. Peak cardiac parameters predicted by the previously recommended reference equations by Jones and colleagues and Hansen and colleagues were significantly higher. INTERPRETATION: This study provides reference ranges and prediction models for peak cardiac, ventilatory, operating lung volume, gas exchange, and symptom responses to incremental CPET and presents the most comprehensive reference set to date in Canadian adults who were ≥40 years old to be identified with population-based sampling.


Assuntos
Teste de Esforço , Adulto , Canadá/epidemiologia , Estudos de Coortes , Teste de Esforço/métodos , Teste de Esforço/normas , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Valores de Referência , Reprodutibilidade dos Testes
19.
Front Physiol ; 11: 195, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226392

RESUMO

Purpose: Chronic heart failure (CHF) is characterized by heightened sympathetic nervous activity, carotid chemoreceptor (CC) sensitivity, marked exercise intolerance and an exaggerated ventilatory response to exercise. The purpose of this study was to determine the effect of CC inhibition on exercise cardiovascular and ventilatory function, and exercise tolerance in health and CHF. Methods: Twelve clinically stable, optimally treated patients with CHF (mean ejection fraction: 43 ± 2.5%) and 12 age- and sex-matched healthy controls were recruited. Participants completed two time-to-symptom-limitation (TLIM) constant load cycling exercise tests at 75% peak power output with either intravenous saline or low-dose dopamine (2 µg⋅kg-1⋅min-1; order randomized). Ventilation was measured using expired gas data and operating lung volume data were determined during exercise by inspiratory capacity maneuvers. Cardiac output was estimated using impedance cardiography, and vascular conductance was calculated as cardiac output/mean arterial pressure. Results: There was no change in TLIM in either group with dopamine (CHF: saline 13.1 ± 2.4 vs. dopamine 13.5 ± 1.6 min, p = 0.78; Control: saline 10.3 ± 1.2 vs. dopamine 11.5 ± 1.3 min, p = 0.16). In CHF patients, dopamine increased cardiac output (p = 0.03), vascular conductance (p = 0.01) and oxygen delivery (p = 0.04) at TLIM, while ventilatory parameters were unaffected (p = 0.76). In controls, dopamine improved vascular conductance at TLIM (p = 0.03), but no other effects were observed. Conclusion: Our findings suggest that the CC contributes to cardiovascular regulation during full-body exercise in patients with CHF, however, CC inhibition does not improve exercise tolerance.

20.
J Appl Physiol (1985) ; 128(4): 925-933, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32163328

RESUMO

Patients with mild chronic obstructive pulmonary disease (COPD) demonstrate resting pulmonary vascular dysfunction as well as a blunted pulmonary diffusing capacity (DLCO) and pulmonary capillary blood volume (VC) response to exercise. The transition from the upright to supine position increases central blood volume and perfusion pressure, which may overcome microvascular dysfunction in an otherwise intact alveolar-capillary interface. The present study examined whether the supine position normalized DLCO and VC responses to exercise in mild COPD. Sixteen mild COPD participants and 13 age-, gender-, and height-matched controls completed DLCO maneuvers at rest and during exercise in the upright and supine position. The multiple FIO2-DLCO method was used to determine DLCO, VC, and membrane diffusion capacity (DM). All three variables were adjusted for alveolar volume (DLCOAdj, VCAdj, and DMAdj). The supine position reduced alveolar volume similarly in both groups, but oxygen consumption and cardiac output were unaffected. DLCOAdj, DMAdj, and VCAdj were all lower in COPD. These same variables all increased with upright and supine exercise in both groups. DLCOAdj was unaffected by the supine position. VCAdj increased in the supine position similarly in both groups. DMAdj was reduced in the supine position in both groups. While the supine position increased exercise VCAdj in COPD, the increase was of similar magnitude to healthy controls; therefore, exercise VC remained blunted in COPD. The persistent reduction in exercise DLCO and VC when supine suggests that pulmonary vascular destruction is a contributing factor to the blunted DLCO and VC response to exercise in mild COPD.NEW & NOTEWORTHY Patients with mild chronic obstructive pulmonary disease demonstrate a combination of reversible pulmonary microvascular dysfunction and irreversible pulmonary microvascular destruction.


Assuntos
Capacidade de Difusão Pulmonar , Doença Pulmonar Obstrutiva Crônica , Volume Sanguíneo , Capilares , Exercício Físico , Humanos , Decúbito Dorsal
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