Individualized positive end-expiratory pressure in patients undergoing thoracoscopic lobectomy: a randomized controlled trial

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 cmH(2)O PEEP until the end of OLV. Relevant indexes of respiratory mechanics, pulmonary oxygenation and hemodynamics were recorded after entering the operating room (T(0)), 10 minutes after intubation (T(1)), pre-ARM (T(2)), 20 minutes after the application of optimal PEEP (T(3)), at the end of OLV (T(4)) and at the end of surgery (T(5)). Postoperative outcomes were also assessed. RESULTS: The optimal PEEP obtained in Group A was 8.8 ± 2.4 cmH(2)O, which positively correlated with BMI and forced vital capacity (FVC). Group A had a higher C(PAT) than Group B at T(3), T(4), T(5) (p < 0.05) and a smaller ΔP than Group B at T(3), T(4) (p < 0.01). At T(4), PaO(2) was significantly higher in Group A (p < 0.01). At T(3), 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.