INTRODUCTION
Chronic obstructive pulmonary disease (COPD) is the third major cause of death worldwide, characterized by airflow limitation, persistent respiratory symptoms, and high morbidity (1). Acute exacerbations of COPD and hospitalizations are observed frequently as the disease severity increases. Exercise-induced dyspnea is a common symptom among patients with COPD and emphysema. Loss of elasticity in the lungs is the primary cause of dyspnea on emphysema. Due to the early closing in small airways on expiration, air trapping occurs, and consequently, inspiratory capacity decreases. Decreased inspiratory capacity is the spirometric manifestation of reduced exercise capacity. Intrathoracic pressure rises with the increased air trapping, so cardiac functions are affected negatively, and mortality increases. Despite the medication, exercise intolerance is the least improvable symptom in patients with emphysema. Pulmonary rehabilitation (PR) is a multidisciplinary approach for improving exercise capacity and quality of life. With the help of a PR program, exercise tolerance, daily physical activity, self confidence can improve, while anxiety and depression diminish. Due to such alterations, healthcare costs can be reduced (2,3). In this study, the effectiveness of PR on patients with COPD and emphysema is investigated.
METHODS
This retrospective, cross-sectional, analytical study was performed between January 01, 2017 and December 31, 2019. This study was conducted following the amended Declaration of Helsinki. The parameters were recorded after obtaining Gülhane Research and Training Hospital’s non-interventional ethics board approval.
Fifty-eight patients with severe and very severe emphysema dominant-COPD were referred to the PR program by the outpatient clinic. All of them had been using long-term oxygen therapy. It is planned 3 times a week for 8-week duration. The exclusion criteria were inability to complete the 8 week-PR program, suspicion of infection by the referral time, acute coronary syndrome, congestive heart failure (ejection fraction <40%), cardiac or thoracic surgery within the 3 months by referral time. After these exclusion criteria, 34 patients were included in the analysis for this study (Table 1). Pre and post-PR spirometric measurements, modified Medical Research Council (mMRC) dyspnea scores, and 6-minute walking test (6-MWT) results were recorded.
Statistical Analysis
R software was used for the statistical analysis. Variables were analyzed with the Kolmogorov-Smirnov test to evaluate the distribution. Results for descriptive statistics are expressed as mean ± standard deviation. Continuous variables of pre and post-PR change were analyzed with paired t-test or Wilcoxon Signed-rank test. Statistical significance was accepted as p<0.05.
RESULTS
Fifty-eight patients with severe and very severe emphysema dominant COPD attended the PR program in Pulmonary Rehabilitation Unite of Pulmonary Diseases Clinic from January 01, 2017 to December 31, 2019. For this study, the patient files were examined. 34 patients have met the inclusion criteria (Figure 1). Mean age was 63.4±3.5 years of all study population, it was 64.6±3.2 years for men and 63.3±3.6 years for women. Only 3 of 34 patients were women. All spirometric parameters except forced vital capacity (FVC) were improved significantly after PR. In addition, a significant increase in mMRC dyspnea scores and distance of 6-MWT were noted. The results of the study are summarized in Table 1.
DISCUSSION
This study shows patients with emphysema dominant-COPD benefit from PR. Respiratory function test parameters, exercise capacity, and dyspnea improve significantly with PR.
The major goal of COPD treatment is diminishing symptoms and increasing quality of life. Many patients with COPD have a limitation of activity due to dyspnea. PR is an essential treatment option for this group of patients. Physiotherapy reduces work of breathing and oxygen consumption, thus diminishes dyspnea. Many studies use PR for lung cancer, idiopathic pulmonary fibrosis, and chronic respiratory diseases (4). However, unfortunately, many patients do not have access to PR.
Thirty-four patients constitute this study population, completed the 3 times a week, 8 week-PR programs. Pre-PR predicted % FEV1 mean was 33.2±7.1. Lower FEV1 means lower exercise capacity and quality of life for patients with COPD. Post-PR predicted % FEV1 mean rose to 37.5±7.6 in this study. Although it may be seen as a slight increase, this change of FEV1 increases exercises capacity. It can be understood from the increased distance of 6-MWT pre and post PR. This statistically significant change in predicted FEV1% was + 4.3. Notably, three major PR studies show no significant increase in FEV1 % pre and post PR (5-7).
The 6MWT is a safe, inexpensive, widely used tool to assess the functional status of patients with COPD. The difference in 6MWT is 54 mt for patients with COPD to notice an improvement (8). In this study 6MWT was 73.2±63.4 m, substantially higher than the threshold.
Our study population distinguishes this study from others. Only patients with severe and very severe emphysema dominant-COPD were included in this study. In patients with chronic bronchitis dominant-COPD, it is not expected that significant improvement on overserved spirometric parameters. Pre-PR mean mMRC dyspnea score was 3.14±0.74, post-PR, it declined to 2.26±0.66. This shows that PR improves not only spirometric measurements also the sense of dyspnea. Although decreasing dyspnea and increasing exercise capacity with PR can be associated with life expectancy, the literature shows no clear connection (9). A study by Bowen et al. showed that after PR, 3-year life expectancy is 69%-85% for patients with COPD (10). Nevertheless, it is known that PR diminishes dyspnea in patients with COPD (11,12).
PR program was planned for 8 weeks for patients with COPD in our daily practice. Only patients who completed 8 week-program have been included in the study. Based on the current literature, it is recommended to apply the PR program for at least 8 weeks, and for the optimum effect of the treatment, more than 8 weeks is required (13).
The study has some limitations. First, its retrospective methodology was a significant limitation. The study population was minimal, and there is no information about their comorbidities and pharmacological treatments. We believe that a prospective study with a large study population will overcome these limitations.
CONCLUSION
Our comprehensive, outpatient, 8 week-PR programs are effective for patients with severe and very severe COPD and emphysema component. Besides spirometric parameters, dyspnea scores and exercise capacity were all improved.
ETHICS
Ethics Committee Approval: Approval of the Local Research Ethics Committee of our tertiary hospital was obtained before initiating the study (University of Medical Sciences Turkey, Gülhane Training and Research Hospital, project no: 2020-13, date: 07.01.2020).
Informed Consent: Is a retrospective study.
Authorship Contributions: Surgical and Medical Practices: D.D., C.T., Y.A., Concept: D.D., C.T., N.Ö., Design: D.D., N.Ö., Data Collection or Processing: D.D.M., Y.A., Analysis or Interpretation: D.D., D.D.M., Y.A., Literature Search: D.D.M., C.T., N.Ö., Writing: D.D., D.D.M, C.T.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study received no financial support.