Jordi Vilaró

Physiological responses to the 6-min walk test in patients with chronic obstructive pulmonary disease

The 6-min walking test (6MWT) is frequently used to assess functional capacity in chronic cardiopulmonary disorders because of its simplicity. The study examines the physiological responses during encouraged 6MWT in patients with chronic obstructive pulmonary disease. Pulmonary oxygen (O2) uptake (V′O2) was measured in 20 male patients (age 66±6 yrs, forced expiratory volume in one second 45±14% predicted) during 6MWT and incremental cycling, in random order. O2 tension in arterial blood, carbon dioxide tension in arterial blood and arterial lactate concentration ([La]art) were obtained in the last 10 patients. During the 6MWT, V′O2 showed a plateau after the 3rd min (1.39±0.28, 1.42±0.31, and 1.40±0.30 L·min−1, 4th, 5th and 6th min, respectively), and minute ventilation (V′E) (42±8 L·min−1) was 91% maximal voluntary ventilation. No differences were shown between 6MWT (6th min) and peak cycling exercise in V′O2 (1.40±0.30 versus 1.41±0.28 L·min−1, respectively), cardiac frequency (126±13 versus 130±12 beats·min−1), or arterial respiratory blood gases. The two tests were significantly different in V′E (42±8 versus 47±8 L·min−1, 6MWT versus cycling, respectively), carbon dioxide production (1.30±0.31 versus 1.45±0.18 L·min−1) and [La]art (2.9±1.99 versus 5.9±1.51 M). The study demonstrates that an encouraged 6-min walking test generates a high but sustainable oxygen uptake. Since the oxygen uptake plateau reflects the integrated response of the system, it may explain the high prognostic value of the 6-min walking test.

Sildenafil to improve respiratory rehabilitation outcomes in COPD: a controlled trial

Pulmonary hypertension is a serious complication of chronic obstructive pulmonary disease (COPD) that currently has no established pharmacological treatment. This study aimed to assess whether concomitant treatment with sildenafil would enhance the results of pulmonary rehabilitation in patients with COPD and increased pulmonary arterial pressure (PAP). In this double-blind, randomised controlled trial patients received 20 mg sildenafil or placebo three times daily and underwent pulmonary rehabilitation for 3 months. The primary end-point was the gain in the cycle endurance time at a constant work-rate. Secondary end-points included performance in the incremental exercise test, 6-min walk distance and quality of life. 63 patients with severe COPD and moderately increased PAP were randomised. Cycle endurance time increased by 149 s (95% CI 26–518 s) in the sildenafil group and by 169 s (95% CI 0–768 s) in the placebo group (median change difference -7 s, 95% CI -540–244 s; p=0.77). Gains in the incremental exercise test, 6-min walk distance and quality of life at the end of the study did not differ between groups. Measurements of arterial oxygenation and adverse events were similar in both groups. In patients with severe COPD and moderately increased PAP, concomitant treatment with sildenafil does not improve the results of pulmonary rehabilitation in exercise tolerance. Sildenafil did not improve respiratory rehabilitation outcomes in patients with severe COPD and moderately increased PAP http://ow.ly/lh7cb

European Respiratory Society guidelines for the management of adult bronchiectasis

Bronchiectasis in adults is a chronic disorder associated with poor quality of life and frequent exacerbations in many patients. There have been no previous international guidelines. The European Respiratory Society guidelines for the management of adult bronchiectasis describe the appropriate investigation and treatment strategies determined by a systematic review of the literature. A multidisciplinary group representing respiratory medicine, microbiology, physiotherapy, thoracic surgery, primary care, methodology and patients considered the most relevant clinical questions (for both clinicians and patients) related to management of bronchiectasis. Nine key clinical questions were generated and a systematic review was conducted to identify published systematic reviews, randomised clinical trials and observational studies that answered these questions. We used the GRADE approach to define the quality of the evidence and the level of recommendations. The resulting guideline addresses the investigation of underlying causes of bronchiectasis, treatment of exacerbations, pathogen eradication, long term antibiotic treatment, anti-inflammatories, mucoactive drugs, bronchodilators, surgical treatment and respiratory physiotherapy. These recommendations can be used to benchmark quality of care for people with bronchiectasis across Europe and to improve outcomes. The publication of the first ERS guidelines for bronchiectasis http://ow.ly/wQSO30dU0nE

Training Depletes Muscle Glutathione in Patients with Chronic Obstructive Pulmonary Disease and Low Body Mass Index

Background: A physiological increase in muscle glutathione after training is not seen in patients with chronic obstructive pulmonary disease (COPD), indicating abnormal peripheral muscle adaptations to exercise. Objective: We hypothesized that oxidative stress is primarily associated with low body mass index (BMI). Methods: Eleven patients with preserved BMI (BMIN: 28.2 ± 1.2 kg·m–2), 9 patients with low BMI (BMIL: 19.7 ± 0.60 kg·m–2) and 5 age-matched controls (26.5 ± 0.9 kg·m–2) were studied before and after 8 weeks of high-intensity endurance training. Reduced glutathione (GSH) and γ-glutamyl cysteine synthase heavy-subunit chain mRNA expression (γGCS-HS mRNA) were measured in the vastus lateralis. Results: After training, exercise capacity increased (ΔVO2PEAK, 13 ± 5.2%; 10 ± 5.6% and 15 ± 4.3% in BMIL, BMIN and controls, respectively; p < 0.05 each). GSH levels decreased in BMIL (from 5.2 ± 0.7 to 3.7 ± 0.8 nmol/mg protein, ΔGSH –1.5 ± 0.7 nmol/mg protein, p < 0.05); no changes were seen in BMIN (from 5.4 ± 0.7 to 6.7 ± 0.9 nmol/mg protein, ΔGSH 1.3 ± 0.9 nmol/mg protein), whereas GSH markedly increased in controls (from 4.6 ± 1 to 8.7 ± 0.4 nmol/mg protein, ΔGSH 4.1 ± 1 nmol/mg protein, p < 0.01). ΔGSH in BMIL was different from ΔGSH in BMIN and controls (p < 0.05, each). Consistent changes were observed in γGCS-HS mRNA expression. Conclusions: GSH depletion after training in BMIL may suggest that oxidative stress plays a key role in muscle wasting in COPD patients.

Clinical assessment of peripheral muscle function in patients with chronic obstructive pulmonary disease.

Vilaro J, Rabinovich R, Gonzalez-deSuso JM, Troosters T, Rodríguez D, Barberà JA, and Roca J: Clinical assessment of peripheral muscle function in patients with chronic obstructive pulmonary disease. Am J Phys Med Rehabil 2009;88:39–46. Objective:Correlation of muscle function, muscle mass and endurance, and exercise tolerance in chronic obstructive pulmonary disease (COPD). Design:Sixteen COPD patients (forced expiratory volume during the first second 38 ± 15% predicted) and 6 controls underwent magnetic resonance imaging of the thigh, muscle strength and endurance, and exercise tolerance assessments. Results:Thigh mass distribution was bimodal (cutoff 19.0 kg m−2). Six COPD patients (16 ± 2.5 kg m−2) (P < 0.05) presented reduced thigh mass (COPDLQ), whereas 10 patients with normal quadriceps mass (COPDNQ) and all controls had identical mass distribution (22 ± 2.4 kg m−2). COPDLQ patients had lower muscle function and lower exercise tolerance than both COPDNQ and controls (P < 0.05 each), but muscle strength corrected by mass was similar between COPD patients (COPDLQ 0.59 ± 0.12 and COPDNQ 0.55 ± 0.10 Nm kg−1 m−2) and controls (0.62 ± 0.04 Nm Kg−1 m−2). In contrast, endurance to muscle mass ratio was lower in COPD (COPDLQ and COPDNQ 0.91 ± 0.15 and 0.89 ± 0.15 J kg−1 m−2) than in controls (1.07 ± 0.11 J kg−1 m−2) (P < 0.05). Half-time phosphocreatine recovery (COPDLQ 66 ± 14 and COPDNQ 55 ± 9 secs, not significant) was also slower than in controls (43 ± 10 secs) (P < 0.01). Conclusions:Impaired muscle strength was explained by reduced muscle mass, but it did not account for abnormal muscle endurance. The latter seems associated to impaired O2 transport/O2 utilization, resulting in altered muscle bioenergetics.

Evaluación de la tolerancia al ejercicio en pacientes con EPOC. Prueba de marcha de 6 minutos

La disnea desencadenada por el ejercicio es uno de los síntomas fundamentales en los pacientes con enfermedad pulmonar obstructiva crónica (EPOC). Se presenta en las fases iniciales de la enfermedad, afecta al desarrollo de las actividades de la vida diaria1 y determina en gran medida el grado de percepción de enfermedad y la magnitud del deterioro de la calidad de vida. La tolerancia al ejercicio en estos pacientes es un marcador de gravedad independiente del volumen espiratorio forzado en el primer segundo2-4. En realidad, la evaluación conjunta de ambos factores –gravedad de la alteración ventilatoria obstructiva (volumen espiratorio forzado en el primer segundo) y de la limitación de la tolerancia al ejercicio– resulta clave para el control evolutivo de la EPOC. Entre las pruebas simples para evaluar la tolerancia al ejercicio, la distancia recorrida en la prueba de marcha de 6 min (6MWD; 6 min walking distance) ha demostrado ser un predictor de supervivencia independiente de otras variables5 y, a su vez, permite discriminar a los pacientes con una mayor tasa de ingresos hospitalarios debidos a exacerbaciones6. Esto adquiere especial relevancia si se tiene en cuenta que la evolución de la enfermedad está muy influida por la frecuencia de dichos episodios que, a su vez, llevan una mortalidad asociada del 3 al 10%, o mayor si el paciente es tributario de cuidados intensivos7. En otro orden de cosas, la 6MWD ha demostrado un alto valor predictivo de la evolución postoperatoria en pacientes candidatos a cirugía de reducción de volumen al permitir identificar a los individuos con una evolución desfavorable8. Entre los pacientes que presentan mejoría funcional posquirúrgica, se ha observado que el incremento de la tolerancia al ejercicio es más duradero que los cambios observados en el volumen espiratorio forzado en el primer segundo9. Esta disociación entre la función pulmonar en reposo y las pruebas de evaluación de tolerancia al ejercicio se explicaría porque estas últimas reflejan, además de los cambios pulmonares, las interacciones con otros sistemas del organismo involucrados en la respuesta al ejercicio, como los sistemas cardiovascular y muscular. De esta forma, el alto valor predictivo de la tolerancia al ejercicio es atribuible al origen multifactorial de ésta: a) limitación ventilatoria por disfunción mecánica; b) alteración del intercambio de gases; c) incremento inadecuado del débito cardíaco durante el ejercicio, y d) disfunción muscular periférica. Este carácter multifactorial, junto con las limitaciones de la función pulmonar medida en condiciones de reposo, plantea el interés de incluir la evaluación de la tolerancia al ejercicio en la caracterización de los pacientes con EPOC10. Sin embargo, las consideraciones relativas a la aplicabilidad clínica de los protocolos de ejercicio fuera del laboratorio de función pulmonar constituyen un aspecto de carácter práctico a tener en cuenta.

Effects and barriers to deployment of telehealth wellness programs for chronic patients across 3 European countries

BACKGROUND Benefits of cardiopulmonary rehabilitation (CPR) in patients with chronic obstructive pulmonary disease (COPD) are well established, but long-term sustainability of training-induced effects and its translation into healthy lifestyles are unsolved issues. It is hypothesized that Integrated Care Services supported by Information and Communication Technologies (ICS-ICT) can overcome such limitations. In the current study, we explored 3 ICS-ICT deployment experiences conducted in Barcelona, Trondheim and Athens. METHODS In the 3 sites, a total of 154 patients completed an 8-week supervised CPR program. Thereafter, they were allocated either to an ICS-ICT group or to usual care (CPR + UC) during a follow-up period of at least 12 months with assessment of 6-min walking test (6MWT) as main outcome variable at all time points in the 3 sites. Because real deployment was prioritized, the interventions were adapted to site heterogeneities. RESULTS In the ICS-ICT group from Barcelona (n = 77), the use of the personal health folder (PHF) was the cornerstone technological tool to empower COPD patients for self-management showing high applicability and user-acceptance. Long-term sustainability of training-induced increase in exercise capacity was observed in ICS-ICT compared to the control group (p = 0.01). Likewise, ICS-ICT enhanced the activities domain of the SGRQ (p < 0.01) and daily physical activity (p = 0.03), not seen in controls. No effects of ICS-ICT were observed in Trondheim (n = 37), nor in Athens (n = 40), due to technological and/or organizational limitations. CONCLUSIONS The study results suggest the potential of the ICS-ICT Barcelonas approach to enhance COPD management. Moreover, it allowed identification of the factors limiting transferability to the other sites. The research prompts the need for large multicenter trials specifically designed to assess effectiveness, efficiencies and transferability of this type of intervention.

Evaluation Exercise Tolerance in COPD Patients: the 6-Minute Walking Test

Dyspnea brought on by exercise is one of the basic symptoms of patients with chronic obstructive pulmonary disease (COPD). It appears in the initial phases of the disease, affects activities of daily living, and determines, to a large extent, the perception of the degree of illness and extent of deterioration in quality of life. Tolerance to exercise in these patients is an indicator of severity, regardless of forced expiratory volume in the first second. In fact, the evaluation of both factors—severity of obstructive ventilation (forced expiratory volume in 1 second) and the limitation of tolerance to exercise—are vital in controlling the progression of COPD. Among the simple tests used to evaluate tolerance to exercise, the 6-minute walking (6MW) distance has proved to be a predictor of survival independent of other variables and, at the same time, indicates frequency of hospitalizations from exacerbations. This is important considering that the progression of the disease is influenced by the frequency of these episodes which signify an associated mortality of from 3% to 10%, or more if the patient is admitted to intensive care. The 6MW distance has also been shown to predict postoperative outcome in candidates for volume reduction surgery by identifying patients with a potentially unfavorable outcome. Among patients that present postoperative functional improvement, an improvement in tolerance to exercise has a longer duration than changes in forced expiratory volume in 1 second. This discrepancy can be explained by the fact that exercise tests reflect not only lung changes but also interactions with other systems that respond to exercise such as the cardiovascular and muscular systems. Thus, the high predictive value of exercise tolerance lies in its multifaceted nature, being affected by: a) airflow limitation from mechanical dysfunction; b) impaired gas exchange; c) insufficient increase in heart rate during exercise, and d) peripheral muscle dysfunction. This multifaceted nature together with lung function limitations measured at rest makes exercise tolerance valuable in characterizing COPD patients. However, exercise protocols that can be clinically applied outside lung function laboratories are a practical consideration.

Physiological response during activity programs using Wii-based video games in patients with cystic fibrosis (CF)

UNLABELLED Patients with cystic fibrosis (CF) are characterized by an abnormal ventilation response that limits the exercise capacity. Exercise training increases exercise capacity, decreases dyspnea and improves health-related quality of life in CF. Adherence to pulmonary rehabilitation programs is a key factor to guarantee optimal benefits and a difficult goal in this population. The aim of this study was to determine the physiological response during three Nintendo Wii™ video game activities (VGA) candidates to be used as training modalities in patients with CF. METHOD 24 CF patients (age 12.6±3.7 years; BMI 18.8±2.9kgm(-2); FEV1 93.8±18.8%pred) were included. All participants performed, on two separate days, 3 different VGA: 1) Wii Fit Plus (Wii-Fit); 2) Wii Active (Wii-Acti), and 3) Wii Family Trainer (Wii-Train), in random order during 5min. The obtained results were compared with the 6-min walk test (6MWT). The physiological variables [oxygen uptake (VO2), minute ventilation (VE), and heart rate (HR)] were recorded using a portable metabolic analyzer. RESULTS During all VGA and 6MWT, VO2 reached a plateau from the 3rd min. Compared with the 6MWT (1024.2±282.2mLm(-1)), Wii-Acti (1232.2±427.2mLm(-1)) and Wii-Train (1252.6±360.2mLm(-1)) reached higher VO2 levels during the last 3min (p<0.0001 in both cases), while Wii-Fit (553.8±113.2mLm(-1)) reached significantly lower levels of VO2 (p<0.001). Similar effects were seen for the ventilatory volume (VE). No differences in dyspnea and oxygen saturation were seen between the different modalities. All patients were compliant with all three Wii™ modalities. CONCLUSION Active video game are well tolerated by patients with CF. All the modalities evaluated imposed a constant load but were associated with different physiological responses reflecting the different intensities imposed. Wii-Acti and Wii-Train impose a significantly high metabolic demand comparable to the 6MWT. Further research is needed to evaluate the effects of VGA as a training program to increase exercise capacity for CF patients.

Endurance Exercise Training Improves Heart Rate Recovery in Patients with COPD

Abstract Background: Abnormalities of autonomic function have been reported in patients with chronic obstructive pulmonary disease. The effect of the exercise training in heart rate recovery (HRR) has not been established in patients with COPD. Objective: To assess the effects of 8-weeks’ endurance training program on parasympathetic nervous system response measured as heart rate recovery in a sample of moderate-to-severe COPD patients. Methods: We recruited a consecutive sample of patients with COPD candidates to participate in a pulmonary rehabilitation program from respiratory outpatient clinics of a tertiary hospital. HRR was calculated, before and after training, as the difference in heart rate between end-exercise and one minute thereafter (HRR1) in a constant-work rate protocol. Results: A total of 73 COPD patients were included: mean (SD) age 66 (8) years, median (P25-P75) post-bronchodilator FEV1 39 (29–53)%. The prevalence of slow HRR1 (≤12 beats) at baseline was 63%, and was associated with spirometric severity (mean FEV1 35% in slow HRR1 vs 53 in normal HRR1, p < 0.001). After 8-weeks training, HRR1 improved from mean (SD) 10 (7) to 12 (7) beats (p = 0.0127). Multivariate linear regression models showed that the only variable related to post-training HRR1 was pre-training HRR1 (p < 0.001). Conclusions: These results suggest that training enhances HRR in patients with moderate-to-severe COPD. HRR is an easy tool to evaluate ANS such that it may be a useful clinical marker of parasympathetic nervous system response in patients with COPD.