RESUMO
BACKGROUND AND OBJECTIVES: With the intensive study of lung protective ventilation strategies, people begin to advocate the individualized application of positive end-expiratory pressure (PEEP). This study investigated the optimal PEEP in patients during one-lung ventilation (OLV) and its effects on pulmonary mechanics and oxygenation. METHODS: Fifty-eight patients who underwent elective thoracoscopic lobectomy were randomly divided into two groups. Both groups received an alveolar recruitment maneuver (ARM) after OLV. Patients in Group A received optimal PEEP followed by PEEP decremental titration, while Group B received standard 5 cmH2O PEEP until the end of OLV. Relevant indexes of respiratory mechanics, pulmonary oxygenation and hemodynamics were recorded after entering the operating room (T0), 10 minutes after intubation (T1), pre-ARM (T2), 20 minutes after the application of optimal PEEP (T3), at the end of OLV (T4) and at the end of surgery (T5). Postoperative outcomes were also assessed. RESULTS: The optimal PEEP obtained in Group A was 8.8 ± 2.4 cmH2O, which positively correlated with BMI and forced vital capacity (FVC). Group A had a higher CPAT than Group B at T3, T4, T5 (p < 0.05) and a smaller ΔP than Group B at T3, T4 (p < 0.01). At T4, PaO2 was significantly higher in Group A (p < 0.01). At T3, stroke volume variation was higher in Group A (p < 0.01). Postoperative outcomes did not differ between the two groups. CONCLUSIONS: Our findings suggest that the individualized PEEP can increase lung compliance, reduce driving pressure, and improve pulmonary oxygenation in patients undergoing thoracoscopic lobectomy, with little effect on hemodynamics.