Progress in Clinical Application of Positive End-Expiratory Pressure

In the surgery patient under general anesthesia doesn’t breathe spontaneously, and lung movement is completely dependent on the mechanical ventilation of the anesthesia machine. In order to achieve effective and safe mechanical ventilation of the patient’s lungs during the operation, the concept of lung protective ventilation strategy (LPVS) was proposed, that is, the use of a low tidal volume and an appropriate level of positive end expiratory pressure (PEEP) to reduce alveolar overexpansion and prevent alveolar collapse. In the past, PEEP was an important measure to treat acute lung injury(ALI) or acute respiratory distress syndrome(ARDS) by improving oxygenation and reducing pulmonary edema. Subsequent studies found that PEEP not only be used to treat patients with ALI or ARDS, but also can reduce the incidence of postoperative pulmonary complications(PPCs) in some thoracoabdominal operations. Moreover, PEEP can prevent atelectasis during and after surgery in patients undergoing thoracic and abdominal surgery under general anesthesia, and decrease the incidence of postoperative infection. However, PEEP can affect venous return by increasing intrathoracic pressure, thereby causing changes in heart function and hemodynamics, and indirectly affecting intracranial pressure and renal function. Therefore, with the widespread clinical application of PEEP, more and more people are starting to focus on how to choose the appropriate PEEP. This article reviews the research progress of PEEP selection method, the influence of PEEP on physiological function and the clinical application of PEEP during mechanical ventilation.