Physiological effects of two driving pressure-based methods to set positive end-expiratory pressure during one lung ventilation

Abstract

During one-lung ventilation (OLV), titrating the positive end-expiratory pressure (PEEP) to target a low driving pressure (∆P) could reduce postoperative pulmonary complications. However, it is unclear how to conduct PEEP titration: by stepwise increase starting from zero PEEP (PEEP INCREMENTAL) or by stepwise decrease after a lung recruiting manoeuvre (PEEP DECREMENTAL). In this randomized trial, we compared the physiological effects of these two PEEP titration strategies on respiratory mechanics, ventilation/perfusion mismatch and gas exchange. Patients undergoing video-assisted thoracoscopic surgery in OLV were randomly assigned to a PEEP INCREMENTAL or PEEP DECREMENTAL strategy to match the lowest ∆P. In the PEEP INCREMENTAL group, PEEP was stepwise titrated from ZEEP up to 16 cm H 2 O, whereas in the PEEP DECREMENTAL group PEEP was decrementally titrated, starting from 16 cm H 2 O, immediately after a lung recruiting manoeuvre. Respiratory mechanics, ventilation/perfusion mismatch and blood gas analyses were recorded at baseline, after PEEP titration and at the end of surgery. Sixty patients were included in the study. After PEEP titration, shunt decreased similarly in both groups, from 50 [39-55]% to 35 [28-42]% in the PEEP INCREMENTAL and from 45 [37-58]% to 33 [25-45]% in the PEEP DECREMENTAL group (both p < 0.001 vs baseline). The resulting ∆P, however, was lower in the PEEP DECREMENTAL than in the PEEP INCREMENTAL group (8 [7-11] vs 10 [9-11] cm H 2 O; p = 0.03). In the PEEP DECREMENTAL group the PaO 2 / FIO 2 ratio increased significantly after intervention (from 140 [99-176] to 186 [152-243], p < 0.001). Both the PEEP INCREMENTAL and the PEEP DECREMENTAL strategies were able to decrease intraoperative shunt, but only PEEP DECREMENTAL improved oxygenation and lowered intraoperative ΔP. Clinical trial number NCT03635281; August 2018; "retrospectively registered"

Effect of pressure-controlled ventilation-volume guaranteed mode combined with individualized positive end-expiratory pressure on respiratory mechanics, oxygenation and lung injury in patients undergoing laparoscopic surgery in Trendelenburg position

“…At present, the PEEP titration based on lung compliance has two methods: incremental titration and decremental titration. Previous study shown that both the incremental titration and decremental titration were able to decrease intraoperative shunt, but only the decremental titration improved oxygenation and lowered driving pressure [14]. Our previous study suggested that the decremental PEEP titration can improve respiratory mechanics, oxygenation parameters, and the inflammatory reaction during one-lung ventilation [10].…”

“…The PBW was calculated according to a predefined formula:50 + 0.91 × (centimeters of height-152.4) for men and 45.5 + 0.91 × (centimeters of height-152.4) for women. The incremental PEEP titration [14] was performed two times in VI and PI group. In both groups, the first incremental PEEP titration was performed immediately after intubation, and the individualized PEEP level was set and maintained until the establishment of pneumoperitoneum.…”

“…Additionally, numerous studies also showed that lung mechanics and gas exchange can be improved by the application of PEEP [10][11][12][13]. However, it was unreasonable to apply a fixed PEEP for all patients, and it is critical to determine individualized PEEP by the "titration method" to stabilize the lung function and minimize lung injury, thereby contributing to preferable physiologic and lung-protective effects [10,14]. The optimal PEEP titration determined by Cdyn is relatively simple and practical, which has been proven to reduce the incidence of postoperative respiratory complications (PPCs) in patients with abdominal surgery [13].…”

What is new in respiratory monitoring?

“…In a more nuanced approach to setting optimal PEEP during ventilation of only one lung while monitoring lung mechanics and oxygenation, Spadaro et al [ 18 ] investigated whether it is better to titrate by increasing PEEP incrementally from a pressure of zero up to 16 cmH 2 O, or by decreasing it decrementally from 16 cmH 2 O after recruiting the lungs with a deep inflation. Both approaches proved beneficial, but only the decremental titration strategy improved oxygenation and reduced the swings in airway pressure needed to ventilate the lungs.…”

Relationship between Driving Pressure and Mortality in Ventilated Patients with Heart Failure: A Cohort Study

“…Relevant studies have shown that lower driving pressure could decrease lung overstress and was associated with lower mortality in patients with ARDS [ 14 – 17 ]. However, the increased risk of poor prognosis associated with high drive pressure has been observed not only in patients with ARDS but also in ventilated patients, which includes patients with severe pneumonia without ARDS [ 18 ] and surgical patients with healthy lungs during the perioperative period [ 19 – 21 ]. Even so, studies on driving pressure and patients with HF are limited.…”