Intercostal and Quadriceps Femoris Muscles Oxygenation During Exercise in Patient With Fibrosing Interstitial Lung Diseases

Interstitial Lung Disease (ILD); It constitutes a heterogeneous group of approximately 200 diseases with acute or chronic course that affect the lung diffusely and cause varying degrees of inflammation, fibrosis and structural deterioration in the lung parenchyma. Clinical features of ILD include exercise-induced dyspnea, exercise-induced hypoxemia, progressive skeletal muscle weakness, and impaired exercise tolerance. The main symptoms of fibrosis are progressive decreases in forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO). Restriction of pulmonary ventilation leads to respiratory failure, which is exacerbated by capillary destruction and decreased alveolar blood flow resulting from hypoxic vasoconstriction.

Exercise intolerance is a key feature of ILD and is usually associated with significant dyspnea on exertion. Exercise limitation in ILD is related to altered respiratory mechanics, impaired gas exchange, and circulatory limitation. Evidence suggests that pulmonary rehabilitation can provide significant benefits in patients with ILD. Daily use of corticosteroids for >1 year significantly reduces muscle function in patients with chronic respiratory disease. Muscle size, strength, and functional outcomes were evaluated in ILD patients. Decreased quadriceps strength and endurance were seen in patients with fibrotic idiopathic interstitial pneumonia compared to healthy controls. Compared to the upper extremity, more atrophy and weakness were found in the lower extremity muscles. Therefore, exercise training is a critical component of pulmonary rehabilitation. The effect of exercise on blood oxygenation has been little studied in ILD patients, and the few data available in the literature are conflicting.

In the studies conducted, there are studies stating that there is a positive improvement in blood biochemistry as a result of an acute exercise, as well as a change with chronic exercises. An important goal of hemodynamic monitoring is the early detection of inadequate tissue perfusion and oxygenation. The use of simple, non-invasive monitoring techniques has the advantage of facilitating earlier initiation of therapy. Near-infrared spectroscopy (NIRS) is a noninvasive measurement instrument that does not impair skin integrity, allowing the measurement of muscle hemoglobin-oxygen saturation (StO2) during exercise. There are few studies in the literature where muscle oxygenation was measured with the NIRS device. According to the results of our literature review, our study will be the first study to examine muscle oxygenation in fibrosing lung patients.