Study to assess exercise capacity in patients with copd on pulmonary rehabilitation through six minute walk test

Background: To evaluate the efficacy of 6 minute walk test as an assessment tool in COPD patients after pulmonary rehabilitation and to correlate 6 minute walk test [6MWT] with spirometry indices. COPD [Chronic obstructive pulmonary disease] is the one of the leading cause of morbidity and mortality throughout the world. Pulmonary rehabilitation reduces the distress in patients. Spirometry and 6MWT are the tools used to assese the effect of pulmonary rehabilitation. Methodology: The study was conducted at Rajarajeswari Medical College, Bengaluru, from April 2018 to March 2019 with 82 patients. Consent of patient and ethical committee clearance was taken. Patients were followed up for a period of 12 months with intervals of every 3 months with FEV1 and 6MWT(6 minute walk test). Results: Out of the total 82 patients studied 46 patients continued till the end of 12 months, 3 people died. Female patients showed less improvement in 6MWT distance than male. Out of 10 cases of very severe COPD, 4(40%) cases showed significant improvement in 6MWTD(6 minute walk test distance) and out of 46 people studied 8[9.8%] were severe COPD, out of 8 severe COPD cases, 6[75%] showed improvement and 33[42%] people with moderate copd completed the study and showed improvement in 6MWT. The FEV1 and 6MWT were correlated significantly. Conclusions: 6MWT was observed to be the best tool in evaluating the pulmonary rehabilitation and also a cost effective tool as compared to that of spirometry. Introduction Chronic obstructive pulmonary disease (COPD) is preventable and a treatable disease which is characterised by persistent respiratory symptoms and limitation of airflow due to airway and alveolar abnormalities usually caused by exposure to noxious particles or gases. The main risk factors for COPD are tobacco smoking, biomass fuel exposure and air pollution. Chronic obstructive pulmonary disease (COPD) is one of the leading cause of death in the world, prevalence and consequent morbidity and mortality of the disease is expected to increase in the near future [1,2]. This is one of the most common reasons for hospitalization in India [3]. The disease is progressive, distressing and debilitating. It is difficult to predict the mortality and trajectory of disease [4]. Exercise testing and composite indexes such as the BODE index, have been used to predict mortality, but as it is time consuming, its often not utilized clinically [5-7]. The 6MWT is used to evaluate exercise capacity. 6MWT is easy to perform by the patient, it requires no special traning or special equipments.The test results correlates well with sophisticated tests requiring a treadmill or cycle ergometer [8,10]. Hence the distance walked in 6 minutes (6MWD) is frequently used as an outcome measure in evaluating the benefit of pulmonary rehabilitation (PR) [11-13]. Pulmonary rehabilitation is widely used to treat COPD patients with different degree of severity, thus bringing them benefits in terms of improvement in exercise capacity, symptoms and quality of life. Materials and Methods The study is a prospective and observational study conducted in the respiratory medicine department of Rajarajeswari Medical College, Bengaluru. The study period April 2018March 2019. A total of 82 patients who were diagnosed as COPD through spirometry with FEV1/FVC<_70 and FEV1<80(GOLD-2-4-moderate-very severe COPD)-who were willing to give written consent and who were willing to undergo pulmonary rehabilitation were taken for the study. The ethical committee clearance was obtained. The patients were given pulmonary rehabilitation over a period of 3 months, 6months and 12 months. The rehabilitation consisted of endurance exercises, resistance exercises, counselling and cessation of smoking, optimal treatment and other encouraging psychotherapy. For all the patients, six minute Article Info Received: 27th July, 2019 Accepted: 17th August, 2019 Published Online: 18th September, 2019