[The use of oscillatory respiratory therapy with positive expiratory pressure (PEP-therapy) to restore the functional state of the lungs in patients after cardiac surgery].

Postoperative pulmonary complications in cardiac surgery patients occur in 10-35% of cases, depending on differences in their definition, patient characteristics and type of surgical intervention, most of them are associated with ineffective coughing and evacuation of bronchial secretions.

Objective: To determine the effectiveness of stimulating the evacuation of bronchial secretions with the help of oscillating PEP therapy carried out during the first three days.

Material and methods: A randomized prospective study of 60 adult patients after elective cardiac surgery was performed (Clinical Trials.gov. protocol number NCT05159401). Oscillatory PEP-therapy was performed in 30 patients using Acapella DHGreen device (SmithMedicalASD, USA) 10-12 hours after tracheal extubation 3 times a day for 3 days after surgery. The control group (30 patients). The inclusion criteria: age over 18 years, spontaneous breathing after tracheal extubation, clear consciousness and productive contact with the patient, the ability to maintain adequate gas exchange on the low-flow oxygen inhalation, adequate analgesia (<2 points of VAS). Exclusion criteria: the need for re-intubation and mechanical ventilation, non-invasive mask ventilation, high-flow oxygen therapy, acute cerebrovascular accident, ongoing bleeding, cardiac insufficiency (inotropic index >10), shocks syndrome of various etiologies, the use of any extracorporeal support, any neuromuscular disorders, pneumothorax, hydro-or hemothorax. Before each session and 20 minutes after its end, when breathing air, blood oxygen saturation was recorded using a pulse oximeter (SpO₂), the maximum inspiratory capacity (MIC) was measured using a Coach-2 incentive spirometer from SmithsMedical and spirometry with a portable ultrasonic spirometer Spiro Scout (Schiller, Switzerland). For the purposes of this work, the total index of the spirometry maximum inspiratory capacity (SMIC) was used - the sum of the respiratory volume and the reserve volume of inspiration in ml.

Results: Difficulties in evacuation of sputum were noted in 90% of patients. Three-day sessions of oscillating PEP- therapy are accompanied by a significant improvement in the passage of sputum, as evidenced by a 3-fold increase in the number of patients with productive cough. The increase in MIC in the main group was 46.9% and 21.3%, respectively (p=0.042), and the number of patients with values greater than MICo. 1500 ml increased from 23.3% to 7.6% (p<0.001). The effectiveness of oscillatory PEP-therapy is confirmed by a 7-fold decrease in the frequency of radiological changes in the lungs at the end of sessions (p<0.001), while in the control group the frequency of their occurrence practically did not change and remained at a high level. The total number of patients with respiratory insufficiency (SpO₂≤92%) decreased by 8.6 times after completion of all PEP- therapy sessions (p=0.001), however, without statistically significant difference with the control group.

Conclusions: Oscillatory PEP- therapy in cardiac surgery patients has a positive effect on sputum passage, ventilation parameters and oxygenating lung function. The procedure was well tolerated and there were no complications associated with it.