The goal of this observational study is to evaluate the effectiveness and safety of vibro-acoustic pulmonary therapy (VAPT) in complex therapy for the acute respiratory failure of mixed type I-II stages in comparison with percussion massage in cardiac surgical patients in the early postoperative period.

Inclusion Criteria:

• Age from 18 years to 80 years inclusive

• Body mass index from 18.5 to 35

• Physical status according to ASA II to ASA III (inclusive)

• Performed planned cardiac surgery (CS) under general anaesthesia with tracheal intubation and mechanical ventilation lasting more than 3 hours using a heart-lung machine (no more than 120 minutes)

• Left ventricular injection fraction before surgical treatment is above 40%

• Development of postoperative mixed ARF grade 1-2 (clinical criteria). SpO2 less than 95% with FiO2 21%.

• Stable-severe condition of the patient according to vital signs:

  1. stable hemodynamics (norepinephrine and/or adrenaline less than 0.15 mcg/kg/min, and/or dobutamine less than 10 mcg/kg/min, and/or no need for vasopressin (ADH) for 6 hours or more)
  2. absence of acute kidney injury (urine output more than 500 ml/day)
  3. stable respiratory dynamics.P/F more than 150 units, SpO2 more than 70% with FiO2 21%.Tracheal extubation within 8 hours of completion of surgery
  4. absence of critical coagulopathy (platelets more than 50 units/l)
  5. absence of acute cerebral insufficiency (GCS more than 12 points)
  6. absence of acute liver failure (bilirubin less than 30 units/l)

• Relieved postoperative pain syndrome and delirium (NRS less than 5 points, BPS less than 6 points, CAM-ICU (-), RASS -3-0 points).

Exclusion Criteria:

• The presence of implanted or external medical electronic-mechanical devices in the impact projection (pacemaker, circulatory support devices, etc.);
• Severe hypocoagulation, risk of hematoma formation or bleeding in the projection of exposure;
• Severe hypercoagulation, risk of formation and/or migration of blood clots or emboli along the great vessels in the projection of exposure;
• Acute cerebrovascular accident (ACB), first 1-3 days;
• Cerebral Edema;
• High intracranial pressure;
• The presence of many purulent or burn wound surfaces in the projection of exposure;
• Presence of an unstable rib fracture;
• Pneumohemomediastinum and/or subcutaneous emphysema of the chest;
• Risk of development of hemo-pneumothorax;
• Osteomyelitis of the ribs and/or thoracic spine;
• Spinal fracture without orthopedic fixation;
• Trauma to the chest or abdomen with bleeding;
• High risk of seizures (CNS pathologies);
• The presence of an oncological process in the projection of exposure with destruction of tumor tissue and the risk of bleeding and/or metastasis;
• The presence of endothoracic and/or large endovascular implants (aortic stents, intra-aortic balloon pumps, endocardial catheters, mechanical heart valves, vena cava filters, subcutaneous venous ports, permanent hemodialysis devices);
• Heart rhythm disturbances (ventricular fibrillation, ventricular tachycardia);
• Hypovolemia;
• Disturbances of water-electrolyte balance and acid-base balance;
• Meningoencephalitis;
• Destructive purulent pneumonia;
• High risk of pulmonary hemorrhage;
• Hiatal hernia;
• Risk of dislocation of implanted drainage tubes and catheters;
• The presence of multiple wound surfaces in the projection of exposure;
• Severe bullous deformation of the lungs;
• Severe kyphoscoliosis;
• Spontaneous pneumothorax within the last year;
• Estimated systolic pressure over the pulmonary artery more than 50 mm Hg. Art.

Patients of both sexes from 18 to 80 years old who are undergoing planned hospitalization for cardiac surgery (CABG, Mammary Coronary Bypass Surgery, Plastic and Replacement of Valves, Atrial Septal Defect, Ventricular Septal Defect)