Acute Exacerbation Chronic Obstructive Pulmonary Disease, COPD (Chronic Obstructive Pulmonary Disease), Muscle Oxygenation
Conditions
Brief summary
Chronic obstructive pulmonary disease (COPD) is often complicated by acute exacerbations, which lead to functional impairments, increased dyspnea, and a rapid decline in lung function. During an exacerbation, impaired pulmonary gas exchange, systemic inflammation, and increased work of breathing significantly alter oxygen availability and metabolic demand in skeletal muscles. The aim of this study is to evaluate and compare respiratory and peripheral muscle oxygenation in patients with acute exacerbation of COPD (AECOPD) and patients with clinically stable COPD. By examining these physiological changes, the study seeks to determine the impact of exacerbations on muscle function and oxygenation efficiency
Detailed description
Chronic obstructive pulmonary disease (COPD) is characterized by recurrent acute exacerbations that negatively affect patients' quality of life and accelerate lung function decline. Severe exacerbations requiring hospitalization pose a significant mortality risk both during admission and in the following year. During acute exacerbations, maximal pressure generation by respiratory muscles declines, and respiratory muscle efficiency-particularly of the diaphragm-is significantly reduced. Acute dynamic hyperinflation further shortens the inspiratory muscles, leading to functional muscle weakness. Consequently, accessory respiratory muscles are recruited maximally, often causing notable alterations in chest-wall and abdominal kinematics. Due to the requirement of spending a higher proportion of their maximum capacity with each breath, these patients face an elevated risk of developing respiratory muscle fatigue. Exacerbations lead to severe hypoxemia caused by impaired pulmonary gas exchange, driven primarily by ventilation-perfusion mismatch and increased tissue oxygen consumption. Acute hypoxemia exacerbates muscle weakness and impairs skeletal muscle function. Even after discharge from respiratory intensive care units following severe exacerbations, persistent respiratory muscle dysfunction is observed in more than a third of patients, requiring additional care and rehabilitation. Physiological factors such as impaired gas exchange, reduced perfusion, and systemic inflammation during exacerbations substantially impact muscle oxygenation. Reduced arterial oxygen content diminishes oxygen availability to peripheral tissues and muscles. Simultaneously, the metabolic demands of both respiratory and peripheral muscles increase due to the heightened work of breathing and systemic stress. This study aims to investigate respiratory and peripheral muscle oxygenation in patients with AECOPD and stable COPD, evaluating underlying physiological changes and assessing the impact of exacerbations on muscle function and oxygenation dynamics. The aim of study is to investigate respiratory and peripheral muscle oxygenation in patients with AECOPD.
Interventions
None listed
Sponsors
Hacettepe University
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Acute Exacerbation Group: 1. Diagnosis of Chronic Obstructive Pulmonary Disease (COPD) 2. Hospital admission or presentation due to an acute exacerbation of COPD 3. Age 40 years or older 4. Voluntary agreement to participate with signed written informed consent Clinically Stable Group: 1. Diagnosis of COPD (GOLD Stage 1, 2, 3, or 4) 2. Age 40 years or older 3. Clinically stable condition for at least the past 4 weeks without acute exacerbations 4. Voluntary agreement to participate with signed written informed consent
Exclusion criteria
Acute Exacerbation Group: 1. Active participation in a formal pulmonary rehabilitation program 2. Co-existing neurological disorders 3. Heart failure classified as New York Heart Association (NYHA) Class III or IV 4. Unstable mental or cognitive status (Mini-Mental State Examination \[MMSE\] score ≤24) 5. History of surgical intervention within the past three months 6. Presence of malignant conditions . Clinically Stable Group: 1. History of lung cancer, sarcoidosis, tuberculosis, and/or prior lung surgery 2. Known mental or cognitive impairment.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Muscle Oxygen Saturation | baseline (1 day) | Muscle oxygen saturation (SmO\_2) will be measured continuously using Near-Infrared Spectroscopy (NIRS) (Train.Red FYER) on the intercostal, deltoid, and dominant quadriceps muscles. The primary parameter ΔSmO\_2 max represents the difference between the peak SmO\_2 during functional tasks (30-second sit-to-stand test, 4-meter gait speed test, and upper extremity assessment) and the baseline resting |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| functional capacity | baseline (1 day) | 30-Second Sit-to-Stand Test: Assesses functional lower-limb muscle strength and exercise capacity. The total number of completed full stand-ups from a chair (height 43.2 cm) within 30 seconds will be recorded. |
| Gait speed | baseline (1 day) | 4-Meter Gait Speed Test: Gait speed will be evaluated over a 4-meter course at normal walking pace. Gait speed is calculated in meters per second (m/s) by dividing 4 meters by the time taken |
| Peripheral Muscle Strength | baseline (1 day) | Maximal isometric handgrip strength will be measured in kilograms (kg) using a digital hand dynamometer (Baseline BIMS). The highest value of three trials for both dominant and non-dominant hands will be recorded |
| pulmonary functions | baseline (1 day) | Spirometry will be performed according to ATS/ERS guidelines. Values will be recorded. |
| Dyspnea and Fatigue Perception | baseline (1 day) | Dyspnea will be evaluated using the Modified Medical Research Council (mMRC) scale (grades 0-4) and Visual Analog Scale (VAS, 0-10 cm). Fatigue perception will be assessed using the Modified Borg Scale (0-10) before and after functional tests. |
| Activities of Daily Living | baseline (1 day) | Activities of daily living will be assessed using the London Chest Activity of Daily Living (LCADL) scale (score range 0-75). |
Countries
Turkey (Türkiye)
Contacts
CONTACTAynur Demirel, PT, PhD, Assoc. Prof.
CONTACTAlper kemal Gurbuz, PT, MSc.
STUDY_DIRECTORAynur Demirel
Hacettepe University
Outcome results
None listed