This study evaluates enhanced external counterpulsation as a non-pharmacological therapy for patients with severe and moderate ventilation disorders due to chronic lung diseases (chronic obstructive pulmonary disease, bronchial asthma and interstitial lung diseases). The study will include 80 patients with severe (30% < forced expiratory volume in 1 second < 49% or lung diffusion capacity < 40%) and moderate (50% < forced expiratory volume in 1 second < 59% or lung diffusion capacity 40-60%) ventilation disorders, who will be divided into 2 groups (the main group and the comparison group). In addition to optimal pharmacological therapy according to the current clinical guidelines of the Russian Ministry of Health, the main group will receive a course of enhanced external counterpulsation. The comparison group will receive only optimal pharmacological therapy (according to the current clinical guidelines of the Russian Ministry of Health). At the time of inclusion in the study and after 1 month, spirometry, bodyplethysmography, lung diffusion capacity, a 6-minute walk test and an assessment of quality of life according to the SF-36 questionnaire will be conducted.

Chronic lung diseases represent a significant medical and social burden, leading to reduced quality of life and high disability rates. Despite advances in pharmacotherapy, a subset of patients remains inadequately responsive to pharmacological treatments. Enhanced external counterpulsation, initially developed for cardiology, shows potential for improving pulmonary and respiratory muscle perfusion. This method based on counterpulsation by special cuffs on the legs in the phase of diastole of the heart. The operation of the enhanced external counterpulsation device is synchronized with the patient's electrocardiogram. In the phase of diastole of the heart, there is a rapid sequential inflation of air into the cuffs in the direction from the calves to the buttocks with subsequent compression of arterial vessels and retrograde direction of blood flow in the opposite direction - to the coronary vessels. The cuffs deflate before the next systole. However, its efficacy in pulmonology patients remains understudied. An open-label controlled trial involving 80 patients (n=40 main group, n=40 control group) age 35-74 years with severe (30% < forced expiratory volume in 1 second < 49% or lung diffusion capacity < 40%) and moderate (50% < forced expiratory volume in 1 second < 59% or lung diffusion capacity 40-60%) ventilation disorders, stable condition on optimal therapy (in accordance with the current clinical guidelines of the Russian Ministry of Health (extended-release beta2-agonists, extended-release m-cholinolytics, inhaled glucocorticosteroids, systemic glucocorticosteroids). The main group will receive 20 (5 days a week for 4 weeks) one-hour procedures (compression pressure 220-280 mmHg) of enhanced external counterpulsation (device: LUMENAIR EECP, Vasomedical Inc., USA, registration certificate №2018/6915 dated 15.03.2018) in addition to optimal pharmacological therapy. The comparison group will receive only optimal pharmacological therapy. At the time of inclusion in the study and after 1 month, spirometry (device MIR Spirolab I, bronchodilator 400 mcg of salbutamol - Salbutamol was registered on October 14, 2011, registration number: 001925), bodyplethysmography (Jager Master Screen Body), lung diffusion capacity (Jager Master Screen Body), a 6-minute walk test and an assessment of quality of life according to the SF-36 questionnaire will be conducted. Statistical data processing will be carried out using the StatTech program.

Inclusion Criteria:

• Verified severe (30% < forced expiratory volume in 1 second < 49% or lung diffusion capacity < 40%) and moderate (50% < forced expiratory volume in 1 second < 59% or lung diffusion capacity 40-60%) ventilation disorders in patients with different chronic lung diseases who are on optimal basic therapy (according to current clinical guidelines) and are in a stable state of respiratory disease (1 month without exacerbations)
• Signed informed voluntary consent to participate in the study

Exclusion Criteria:

• A history of thrombophlebitis and/or phlebitis
• Thoracic or abdominal aortic aneurysm
• Severe pathology of the valvular heart (Area of orifice in stenoses: Aortic and tricuspid valves: < 1.0 cm²; Mitral valve: < 1.5 cm². Pulmonary valve: pressure gradient between right ventricle and pulmonary artery > 50 mmHg; In case of insufficiency, regurgitation of grade 3-4 according to echocardiography)
• Pregnancy
• High pulmonary hypertension (grade 2-3; >45 mmHg)
• Catheterization cardiac arrest performed within 2-4 weeks before the study
• Tachyarrhythmias (device Myocard-12)
• Uncontrolled arterial hypertension (>180/110 mmHg when treated with 3 drugs, one of which is a diuretic)
• Hemorrhagic conditions critical arterial ischemia of the lower extremities (Stages 3 and 4 of chronic arterial insufficiency of the lower extremities according to the Pokrovsky-Fontaine classification are patients with pain at rest and with trophic or infectious-inflammatory changes in the tissues of the extremities
• Dilatation of the heart cavities (device Philips iU22 Ultrasound)
• Ejection fraction <50% (device Philips iU22 Ultrasound)
• Level of NT-pro BNP > 125 pg/ml
• A history of myocardial infarction
• Severe renal (glomerular filtration rate <30 ml/min/1,73 m2) failure
• Hepatic failure (B and C on the Child-Pugh scale)
• Poor tolerance of the procedure (side effects that disrupt the patient's condition and prevent the continuation of procedures (local: hyperemia, pain, and itching in the area of the cuff application; systemic: hypertensive reaction, dizziness)
• Low patient compliance (skipping more than 3 procedures), refusal to participate in the study
• Exacerbation of the underlying disease during the study

The investigators can't share the research materials because the local ethics committee doesn't allow it.