Overview

Title: The Impact of Pulmonary Rehabilitation Conducted in Therapeutic Salt Chambers on the Clinical Condition of Patients with Chronic Obstructive Pulmonary Disease

Background and Rationale:

Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory disorder that significantly reduces patients' quality of life and functional capacity. In the search for supportive therapeutic strategies, there is growing interest in unconventional therapeutic environments such as therapeutic salt chambers. The underground climate of the "Wieliczka" Salt Mine in Poland - characterized by humidity 60-75%, temperature 12.9-14.5°C, high air purity and ionization - has shown therapeutic potential. However, the clinical effects of pulmonary rehabilitation conducted in such an environment in COPD patients remain insufficiently documented.

Study Objective:

To evaluate the effect of pulmonary rehabilitation and climatic therapy conducted in underground salt chambers on the clinical condition of patients with stable COPD.

Research Question:

Does pulmonary rehabilitation conducted in a subterranean salt mine environment offer measurable clinical benefits compared to standard surface-based rehabilitation?

Study Design and Methods:

This is a randomized, controlled, four-arm interventional study including 80 adult patients with a confirmed diagnosis of COPD according to the GOLD 2025 criteria. Participants will be randomly assigned to one of four groups:

Group A: Pulmonary rehabilitation in underground therapeutic salt chambers (physical training + microclimate exposure).

Group B: Pulmonary rehabilitation in a surface-level gymnasium (physical training without microclimate exposure).

Group C: Passive stay in underground salt chambers (microclimate exposure without physical training).

Group D: Health education only (control group, surface level).

The intervention program consists of 16 consecutive working days of 3-hour daily sessions. The content of the rehabilitation varies depending on the assigned group and includes general conditioning exercises, respiratory exercises, relaxation training, and health education.

Outcome Measures and Assessment Tools:

Clinical assessments will be conducted at three time points: prior to the intervention (T0), immediately after the intervention (T1), and at a 3-month follow-up (T2 - for Groups A and B only). The monitored variables include:

Exercise Tolerance: Incremental Shuttle Walk Test (ISWT)

Health-Related Quality of Life: St. George's Respiratory Questionnaire

COPD Symptoms and Risk Indexes: COPD Assessment Test (CAT), BODE Index

Muscle Strength: Deadlift test, hand dynamometer, 30-second Chair Stand Test

Respiratory Muscle Strength: Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure (MEP)

Body Composition: Bioelectrical Impedance Analysis (BIA)

Dyspnea Scales: Borg Scale, modified Medical Research Council (mMRC) scale

Chest Mobility: Measuring tape assessment

The study is designed to evaluate both the immediate and long-term effects of different pulmonary rehabilitation models on clinical outcomes in COPD patients, with a focus on whether the underground environment enhances rehabilitation efficacy.

Eligibility

Inclusion Criteria:

• COPD diagnosis confirmed by a pulmonology specialist according to the 2025 GOLD guidelines.
• FEV1 ≥ 30% of the predicted value.
• FEV1/FVC \< 0.7 after bronchodilator administration in spirometry.
• Negative bronchodilator reversibility test.
• Voluntary written consent to participate in the study.

Exclusion Criteria:

• COPD exacerbation.
• Active cancer or a history of cancer within the past five years.
• Musculoskeletal disorders preventing independent movement and participation in exercise tests and training included in the study protocol.
• Recent (within six months) surgical procedure or trauma to the chest, abdomen, skull, brain, or eye area.
• Severe valvular heart disease.
• Implanted cardioverter-defibrillator.
• Diagnosed arrhythmias posing a risk of loss of consciousness.
• Acute coronary artery disease.
• Epilepsy.
• Uncontrolled arterial hypertension despite medication.
• Primary or secondary immunodeficiencies.
• Respiratory failure requiring chronic or intermittent oxygen therapy.
• Infectious diseases with fever during the experiment or within two weeks before the study.
• Claustrophobia.
• Pregnancy.
• Simultaneous participation in another rehabilitation program.
• Significant changes in pharmacological treatment during the study.