Assessing Exercise Techniques in Pulmonary Rehabilitation for COPD

Pulmonary rehabilitation programs represent a key component in the management of patients with chronic obstructive pulmonary disease (COPD), with a substantial body of research supporting its numerous benefits in this population.

In a 2018 meta-analysis of 13 randomized trials including 801 patients, pulmonary rehabilitation initiated during or within 4 weeks of hospitalization for an acute COPD exacerbation was associated with reductions in mortality (relative risk [RR], 0.58; 95% CI, 0.35-0.98), number of days in the hospital (4.27 days; 95% CI, -6.85 to -1.69 days), and hospital readmissions (RR, 0.47; 95% CI, 0.29-0.75), as well as improvements in walking distance and health-related quality of life compared with usual care.¹ Similar improvements have also been noted in patients with stable COPD who participated in pulmonary rehabilitation programs.

Experts increasingly emphasize the need to personalize this intervention based on a thorough assessment of each patient’s clinical picture, current circumstances, and other individual considerations.² “Offering a patient-tailored, individualized, comprehensive intervention targeting complex needs to improve physiological, psychological and social outcomes and to promote long-term adherence to health-enhancing behaviors must be the cornerstone of every rehabilitation program,” wrote Wouters et al in a paper published in Expert Review of Respiratory Medicine.³ “The multifaceted manifestation of COPD and the individual patient characteristics make [pulmonary rehabilitation] a complex health-care intervention, adaptable to the patient needs.”

Specific assessment approaches and exercise techniques for use in pulmonary rehabilitation in COPD have been evaluated in research, including cardiopulmonary testing (CPET), personality assessments, eccentric cycling training, and novel exercise programming.

Cardiopulmonary Exercise Testing

CPET is underused in patients with COPD, most likely because of its greater cost and requirements compared with other techniques such as the 6-minute walk test; however, research findings support its utility in tailoring exercise interventions to each patient.^3,4 In a 2017 study, 69% of patients who underwent CPET achieved positive outcomes after exercise training compared with 31% of those who did not undergo CPET (P =.014).⁵

“Such assessment of the integrated response cardiopulmonary response to exercise can be very helpful in the personalized assessment and management of COPD patients with exercise limitation and breathlessness and to select appropriate rehabilitative strategies in particular in the group of symptomatic patients with severe cardiorespiratory constraints,” explained Wouters et al.³ For example, the “…presence of impaired aerobic function, indicated by a low Δ V̇O₂/Δ Work rate during incremental cardiopulmonary exercise testing, discriminates a subgroup of patients with COPD-[heart failure] who are particularly symptomatic and disabled” and are more likely to experience greater breathlessness and leg discomfort at rest and on exertion.

Personality Assessment

Results of a 2020 study published in Respiratory Medicine and Research suggest that personality type, as assessed with the Dominance-Influence-Steadiness-Conscientiousness (DISC) behavioral profile, may influence adherence to pulmonary rehabilitation programs.⁶ However, all personality types demonstrated similar improvement in outcomes after the intervention. “Further integration of the personality type into the program design might also improve patient adherence to the program,” as stated in the article.

Eccentric Cycle Training

Investigators of a randomized trial published in February 2020 noted the need for “alternative and/or adjunct exercise training strategies that sufficiently overload the skeletal muscle without also increasing the perception of dyspnea, in symptomatic patients with severe COPD.”⁷ To that end, they compared the effects of concentric vs eccentric cycle training (in which muscle shortens or lengthens, respectively, while producing force) in 24 patients with severe COPD. The 10-week intervention consisted of 3 weekly 30-minute sessions.

The results revealed improvements in peak cycling power and endurance time in both groups, as well as several improvements in the eccentric training group compared with the concentric training group: isometric peak muscle force, dyspnea at peak cycling power, and sensory intensity ratings of dyspnea and leg fatigue (all P <.05). The investigators concluded that eccentric training “could be an effective alternative and/or adjunct modality to pulmonary rehabilitation in severely ventilatory limited COPD patients.”⁷

Novel Exercise Program

In other research examining exercise techniques for patients with severe COPD, Lu et al explored the use of a novel approach called Zheng’s Supine Rehabilitation Exercise (ZSRE) in 82 elderly patients with acute exacerbation of COPD.⁸

ZSRE is a low-intensity program consisting of 3 exercises that can be performed in bed: pull-ups performed by gripping the edges of the bed and pulling oneself to an upright sitting position; bridging, which involves raising the buttocks while keeping feet flat on the bed and knees bent; and air-stepping, in which the patient starts in a supine position with knees bent, then alternates cycling motions with the legs while keeping the upper body still.

According to the authors, advantages of ZSRE include strengthening of various muscle groups (upper and lower limbs, abdominal and back muscles, and diaphragm); ease of tailoring the intensity, frequency, and duration to each patient’s needs; the option for patients to rest when tired; and the ability to perform the exercises nearly anywhere and without the need for equipment.

Patients in the rehabilitation group started the intervention on the second day of hospitalization and continued until 8 weeks postdischarge. Compared with the control group, the ZSRE group demonstrated significantly better scores on the COPD Assessment Test, 6MWD, and Modified Medical Research Council Dyspnea Scale (P <.01; P <.01; and P <.05, respectively) in the ninth week after discharge.

All patients in the ZSRE group were able to complete the program while hospitalized, and 36 of the 41 patients continued the program at home. The intervention did not result in hypoxemia, arrhythmia, or other sudden events at any point during the program, further supporting the safety and feasibility of ZSRE for patients with Global Initiative for Chronic Lung Disease (GOLD) III or GOLD IV COPD.

Ultimately, the “type of training most suitable for COPD patients depends on their physiologic requirements and individual demands,” wrote Zeng et al in a 2018 review.⁴

Ongoing research to elucidate the specific traits and needs of various subgroups of patients with COPD will facilitate continued progress toward the realization of personalized medicine for this heterogenous population.

References

1. Ryrsø CK, Godtfredsen NS, Kofod LM, et al. Lower mortality after early supervised pulmonary rehabilitation following COPD-exacerbations: a systematic review and meta-analysis. BMC Pulm Med. 2018;18(1):154.

2. Wouters EFM, Wouters BBREF, Augustin IML, Houben-Wilke S, Vanfleteren LEGW, Franssen FME. Personalised pulmonary rehabilitation in COPD. Eur Respir Rev. 2018;27(147):170125.

3. Wouters EF, Posthuma R, Koopman M, et al. An update on pulmonary rehabilitation techniques for patients with chronic obstructive pulmonary disease. Expert Rev Respir Med. 2020;14(2):149-161.

4. Zeng Y, Jiang F, Chen Y, Chen P, Cai S. Exercise assessments and trainings of pulmonary rehabilitation in COPD: a literature review. Int J Chron Obstruct Pulmon Dis. 2018;13:2013-2023.

5. Choi CM, Choo KL, Lamb WK, et al. Clinical use of cardiopulmonary exercise testing in patients with chronic obstructive pulmonary disease undergoing a pulmonary rehabilitation programme: A retrospective cohort study. Respir Med. 2017;132:P273.

6. Grosbois JM, Charlet Deffontaines L, Caron A, et al. Influence of DISC behavioral profile on the short- and long-term outcomes of home-based pulmonary rehabilitation in patients with chronic obstructive pulmonary disease. Respir Med Res. 2020;77:24-30.

7. Bourbeau J, De Sousa Sena R, Taivassalo T, et al. Eccentric versus conventional cycle training to improve muscle strength in advanced COPD: A randomized clinical trial. Respir Physiol Neurobiol. 2020;276:103414.

8. Lu H, Liu N, Hu J, et al. The effectiveness, safety and compliance of Zheng’s Supine Rehabilitation Exercise as a rehabilitation program among elderly patients with AECOPD [published online February 11, 2020]. Clin Respir J. doi:10.1111/crj.13164