Expiratory flow-limitation in mechanically ventilated patients:A risk for ventilator-induced lung injury?

• 作者: Antonia Koutsoukou Matteo Pecchiari
• 来源期刊: 世界重症医学杂志
• 学科: 医学
• 关键词: Expiratory flow-limitation Mechanical ventilation Ventilator-induced lung injury Acute respiratory distress syndrome POSITIVE end-expiratory PRESSURE Intrinsic POSITIVE end-expiratory PRESSURE
• 年，卷（期）: 2019,（1）
• 页码范围: 1-8
• 页数: 8页
• 分类号: R

摘要

Expiratory flow limitation(EFL),that is the inability of expiratory flow to increase in spite of an increase of the driving pressure,is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions.Recent evidence suggests that the presence of EFL is associated with an increase in mortality,at least in acute respiratory distress syndrome(ARDS)patients,and in pulmonary complications in patients undergoing surgery.EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi),which in ARDS patients is heterogeneously distributed,with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation.Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation,abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa,possibly generating the small airways abnormalities detected at autopsy in ARDS.Finally,the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury,but this possibility is still unproven.PEEP application can abolish EFL,decrease PEEPi heterogeneity,and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.