Mechanical Ventilation in the Healthy Lung: OR and ICU

Abstract

Mechanical ventilation with a lower tidal volume (VT) and a higher positive end-expiratory pressure (PEEP) benefits patients with acute respiratory distress syndrome (ARDS). This chapter deals with the question whether a lower VT and a higher PEEP also benefits patients with healthy lungs. Findings In patients under general anesthesia for surgery, intraoperative ventilation with a lower VT decreases the risk of postoperative pulmonary complications. Intraoperative ventilation with a higher PEEP does not affect postoperative outcomes, but has a strong potential to induce intraoperative hemodynamic instability. There is also no benefit from intraoperative higher PEEP in obese surgery patients. In critically ill patients without ARDS, ventilation with a high VT is associated with worse outcomes. It is uncertain, however, whether VT should be as low as in patients with ARDS. A higher PEEP does not affect duration of ventilation in critically ill patients without ARDS, and it may be wise to use PEEP only if necessary. Recommendations During intraoperative ventilation, a lower VT but not a higher PEEP should be used. In critically ill patients without ARDS, VT should be kept low, but probably VT can be higher than advised for in patients with ARDS. PEEP should not be high, also not as a preventive measure. The lowest possible PEEP is probably best in patients without ARDS.