PROtective ventilation with high versus low PEEP during one-lung ventilation for THORacic surgery

One-lung ventilation (OLV) with resting of the contralateral lung may be required to allow or facilitate thoracic surgery. However, OLV can result in severe hypoxemia, requiring a mechanical ventilation approach that is able to maintain adequate gas exchange, while protecting the lungs against postoperative pulmonary complications (PPCs). During OLV, the use of lower tidal volumes (V_T) is helpful to avoid over-distension, but can result in increased atelectasis and repetitive collapse-and-reopening of lung units, particularly at low levels of positive end-expiratory pressure (PEEP). Nevertheless, it is not known if, during OLV with low V_T, high levels of PEEP combined with lung recruitment maneuvers are superior to low to moderate PEEP for protection against PPCs.

The objective is to compare a strategy using high PEEP (10 cmH₂O) with recruitment maneuvers versus low PEEP (5 cmH₂O) without recruitment maneuvers, during thoracic surgery under standardized one lung ventilation with low V_T (5 mL/kg predicted body weight - PBW) in adults.