Background and Goal of Study: Thoracic surgery often requires one lung ventilation (OLV). To continue the double lung ventilation (DLV), the recruitment maneuver (RM) is one of the methods for restoring gas exchange in the collapsed lung. This paper aims to assess the effect of two different RM methods on oxygenation parameters, respiratory mechanics and hemodynamics in patients operated with OLV.

Materials and Methods: The study included two groups of 20 patients, who underwent thoracoscopy and OLV. The RM method “40x40” (CPAP 35-45 cmH2O for 35-45 sec, FiO2=1,0) was applied for the patients of the 1st group, whereas a “slow” RM (VCV, Vt 8-10 ml/kg, PEEP 10-15 cmH2O for 10-15 min) was applied for the patients of the 2nd group. The efficacy of the procedure was assessed visually, as well as the oxygenation indices (PaO2, ScvO2), respiratory mechanics (PIP, Ppl, Pdr, Cdyn, Raw) and hemodynamics (MAP, CVP, HR) before and after its carrying out.

Results and Discussion: RM was successfully completed for the patients of both groups and this was confirmed by the expansion of the operated lung, as well as an improvement in oxygenation (an increase in PaO2 and ScvO2) and respiratory mechanics (an increase in Cdyn with a decrease in Raw). There were no significant differences between these indices in patients of the both groups before and after the RM. The essential difference was revealed in relation to the RM influence on the pressure in the airways (AW) and hemodynamics. Therefore, after the completion of the RM, the values of PIP (46.8±6.2 cmH2O), Ppl (40.5±4.3 cmH2O) and Pdr (22.6±4.8 cmH2O) in the 1st group were significantly higher than those in the 2nd one (28.2±4.5 cmH2O, 25.4±3.8 cmH2O and 13.6±4.3 cmH2O). Further, at the current stage, the HR (113.7±11.5 per min) and CVP (132.5±17.8 mmH2O) values in the 1st group also significantly exceeded those in the 2nd group (85.7±8.3 per min and 103.6±13.4 mmH2O), and on the contrary, the MAP level was much lower (62.4±12.3 mmHg and 78.6±10.1 mmHg). It is obvious that the method “40x40” significantly increases pressure in the AW, which leads to the rise in ITP and the CVP, a reduction of venous return with a decrease in cardiac output and the level of MAP. The tachycardia is compensatory nature.

Conclusion: Thus, both methods of performing RM demonstrate similar efficacy, improving oxygenation and respiratory mechanics. At the same time, the “40x40” method has a more evident negative effect on hemodynamics.

02 / EFFICACY AND SAFETY EVALUATION OF TWO TYPES OF RECRUITMENT MANEUVER AFTER ONE LUNG VENTILATION IN THORACIC SURGERY