Physical Activity in COPD Post Pulmonary Rehabilitation - Literature review Example

1. INTRODUCTION Physical activity (PA) is defined as ‘any bodily movement produced by skeletal muscles that result in energy expenditure beyond resting energy expenditure’ (Thompson et al., 2003). The American College of Sports Medicine (2010) recommends that every adult should perform 30 minutes of moderate intensity PA on most days of the week to be active, and those not meeting this standard are considered inactive. In chronic obstructive pulmonary disease (COPD), the reduction in PA, such as walking time and standing time, starts from stage 2 (moderate) and stage 3 (severe) COPD as defined by Global initiative for obstructive lung disease compared to normal subjects with chronic bronchitis (Pitta et al., 2005; Waltz et al., 2009). Two distinct obstructive lung disorders, emphysema and chronic bronchitis often occur in overlapping fashion and are clinically grouped together as COPD. The common exacerbating factor for both the conditions being cigarette smoking is implicated in vast majority of cases ( Kumar et al. 2005).With its ever-increasing mortality rate, which is now rising 16%, COPD ranks as the 4th leading cause of death in United States (http://www.copd-international.com/library/statistics.htm). COPD is also a major cause of emergency department visits and hospitalizations, as well as disability. The focus of this literature review is to examine the impact of pulmonary rehabilitation on levels of physical activity in COPD patients. 1.1 PHYSICAL DISABILITY IN COPD The disability sequel of COPD most often includes dyspnea (shortness of breath) if the disease pattern is predominantly emphysema or in other cases, productive cough with thick sputum when the disease pattern is majorly chronic bronchitis (Schiffman, George. www.Medicinenet.com). The disease is diagnosed by lung function tests, which reflect the degree of severity of COPD. The disease is progressive in nature, i.e. the symptoms worsen over the time as the dyspnea on exertion advances to dyspnea at rest. American Lung Association (ALA) demonstrates the disability associated with COPD. Their recent survey reported that 51 percentage of patients suffering from COPD experience disability in terms of daily routine activities i.e. normal exertion (70%), household chores (56%), social activities (53%), sleeping (50%), and family activities (46%). It is likely that these patients will hugely benefit from pulmonary rehabilitation (PR) that incorporates a focus on PA and the importance of PA. 1.2 TREATMENT- PULMONARY REHABILITATION The treatment options for COPD aim at reducing the disability incurred by the disease and preventing further deterioration of the lung function. The proposed rehabilitation plans focus upon the following areas: 1. Smoking cessation. 2. Bronchodilators and anti-inflammatory drugs 3. Oxygen supplementation 4. Vaccination 5. Pulmonary rehabilitation (PR). PR has been gaining wide acceptance and appreciation worldwide. The aim of PR is to help the patients gain control over their condition through patient education, i.e. physical therapy (Celli BR.,1995). It works by educating the patients about normal and abnormal lung function and ways in which to counter the malfunctioning mechanism through proper breathing techniques, systematically increasing the body’s exercise capacity to counter the declining respiratory function, increasing muscle strength as well as increasing the threshold for breathlessness (Bourjeily et al., 2000; Spruit et al., 2008). In addition to this, pulmonary rehabilitation aims to boost the patients with a new confidence on a psychological level by introducing a sense of control over their illness (Fischer et al 2009), (Hatch, C. A. 2009). 2. METHODOLOGY The methodology selected for this research is qualitative as case studies are reviewed in order to come to conclusion on physical activity in COPD post pulmonary rehabilitation. The purpose of this literature review is to summarize and synthesize the available research in such an area. Pub Med and EMBASE are the two main database employed to search the articles relevant to this review. The keywords used in searching these databases were ‘COPD and Physical activity’, ‘COPD post pulmonary rehabilitation’ and ‘physical activity in COPD’. A number of research studies were found from the mentioned databases, which were nearly ninety-five in number out of which eight were opted for reviewing that were more pertinent to this review topic. The studies that are chosen for inclusion in the review deal with the issue of physical activity in subjects with COPD post pulmonary rehabilitation due to which, they are chosen for inclusion in this research. Research studies reviewing the Impact of PR on Levels of PA in COPD Salman et al (2003) conducted a randomized control trial investigating the role of rehabilitation in patients with COPD. The aim of the study was to analyze the effect of rehabilitation on exercise capacity and shortness of breath. Exercise capacity was assessed using the walking test while shortness of breath was measured based on the dyspnea domain of Chronic Respiratory Disease Questionnaire (CRDQ). The rehabilitation program included different kinds of exercises such as flexibility exercises, endurance exercises and breathing exercises. Along with these exercises, lower extremity training and respiratory muscle training was also provided to the PR group. The PR group have to attend at least four weeks of rehabilitation program while there were no rehabilitation programs for the control group. The PR groups and the control groups were compared for the differences in results on walking tests. PR group did significantly better than the control groups. Similarly in the results for the comparison of shortness of breath, again, the PR group showed better results than the control group as they were significantly less short of breath. The PR group showed a result in P > 0.005 while control group had P > 0.001 in breathing exercises. The study also analysed variations in severity of COPD and the changes that occurred with type and duration of rehabilitation plan. The PR that included the regimen of lower extremity training proved far better than those that were focused on respiratory muscle training only. There was no difference between these groups; the improvement was evident on the walking tests as well as on CRDQ. As for the duration of rehabilitation, 6 months or longer rehabilitation plans proved better and showed more consistent improvements for severe COPD. Interestingly for mild to moderate disease, it has been shown that long and short term plans worked effectively (Gulrajani R. 2010; Puhan et al 2008). Indeed, there is evidence that that PR is effective in all stages of COPD at improving physical activity (Gerald et al 2001). These findings analyze the physiologic changes after PR. It has been suggested that PR increases exercise tolerance by improving neuromuscular synchronization and blunting dyspnoea perception, this leads to enhanced ability to carry out daily deeds (Gerald et al., 2001; Gulrajani R., 2010; Puhan et al 2008). Pitta et al (2008) conducted a study involving 29 patients with moderate to severe COPD. This study aimed at proving that rehabilitation programs are very crucial in enabling patients with moderate to severe COPD to improve their PA. The patients underwent a 6-month outpatient multidisciplinary PR programme, with 3 sessions per week for the first 3 months and 2 sessions per week for the last 3 months. A number of variables were first measured at the start of the programme and then periodically at 3 months and then 6 months after the rehabilitation program. The measured variables were daily activities of the patients, their pulmonary function, exercise capacity, muscle force and quality of life. The daily physical activity before and after rehabilitation program was assessed in the following main areas. Walking Time: As measured through 6MWD test, the mean walking time was measured as 55 ± 26 min/day at the start of the program. This increased to 59 ± 27 min/day following 3 months of rehabilitation training, and 65 ± 29 min/day immediately post 6 months of rehabilitation. The mean improvement was 7% and 20% after 3 months and 6 months of rehabilitation training respectively. The changes in walking time were correlated with dyspnea realm of Chronic Respiratory Disease Questionnaire and the total number of sessions that the patient accomplished. Longer duration rehabilitation programmes were effective for more severe COPD patients in improving physical activity levels (Pitta et al., 2008). Mean Movement Intensity during Walking: This measured parameter increased significantly during 3 months from that measured at the time of entry i.e. 1.81 ± 0.24 m/s2 to 1.88 ± 0.30 m/s2 while after 6 months, it was 1.94 ± 0.30 m/s2 even though, the pre and post pulmonary rehab did not have significant difference on the number of blocks walked uninterruptedly by the patients. No significant pattern changes were found between baseline and after 6 months of rehabilitation. Standing, Sitting and Lying: At the start of the rehab program, the mean duration of time that the patients spent in these positions were recorded as standing 227 ± 92 min/day, sitting 355 ± 121 min/day, and lying down 77 ± 87 min/day. No significant changes were observed in these values in 6 months. Inverse Correlation between Walking Time and Lying Time: An interesting observation was the inverse relationship between the time spent walking and the time spent lying down. Though significant improvements were noticed in exercise tolerance, muscle force and quality of life in the 6 months period, it was debated whether these improvements really did help the patients attain a regular active lifestyle especially after the rehabilitation program ended (Spencer et al 2007). Nevertheless, an important point raised by this study was that an active lifestyle should be a therapeutic priority for patients of COPD (Laviolette L. et al 2008). The study concluded that long-term rehabilitation plan i.e. at least 6 months are necessary to effectively help patients with moderate to severe COPD achieve an active lifestyle. The improvements over short period are very short lived. Thus, an active lifestyle as a therapeutic priority for patients with COPD must be given a major consideration. Another study by Cote and Citelli (2005) highlighted the BODE index as a consistent marker to measure mortality in COPD. A BODE score evaluates the systemic components of COPD on a 10-point scale with higher score suggestive of higher symptom severity. Its components are body mass index, respiratory function (forced expiratory volume (FEV1) in one sec), dyspnoea, and exercise tolerance (6MWD). Cote and Citelli (2005) used changes in bode index to measure the effect of PR on BODE index. The independent predictors of survival in COPD, measured as BODE are: B: Body mass index (BMI) (comprising dyspnoea and exercise capacity) O: Obstruction degree D: Dyspnoea E: Exercise capacity A total of 246 patients with severe COPD were considered. 130 refused PR, 116 completed PR, and Bode index was compared between the two groups at the start of the program, at the end of it and after 1 and 2 years. The study also considered the rates of hospitalization, length of hospital stay (LOS), and the mortality rates. The PR program included exercise training and education related to COPD and physical activity. The participants were provided with exercising schedules that included walking, standing, sitting, lying and other exercises related to breathing and lung support. Improvement in the BODE is shown by a decrease in the index score, whereas an increase in the score implies a worsening in the prognosis. Over 70% of the patients had an improvement of at least one unit in the BODE index (Cote & Citelli, 2005). Patients participating in PR showed a survival advantage compared with patients who declined participation in PR (p Read More