Vieillard-Baron Antoine, Jardin François
Medical Intensive Care Unit, University Hospital Ambroise Paré, 9 Avenue Charles-de-Gaulle, 92104 Boulogne Cedex, France.
Curr Opin Crit Care. 2003 Feb;9(1):15-21. doi: 10.1097/00075198-200302000-00004.
Even a slight increase in pulmonary vascular resistance can overload a normal right ventricle, which ejects blood through a low-pressure circuit. In a clinical setting, a persistent increase in pulmonary vascular resistance produces acute cor pulmonale. From an echocardiographic point of view, may be defined as the combination of a paradoxical septal motion, reflecting systolic overload, with right ventricular enlargement, reflecting diastolic overload. In patients with acute respiratory distress syndrome, this complication reflects the severity of the pulmonary disease involving the microvasculature but may also be caused or exacerbated by an aggressive ventilatory strategy. In the past, conventional respiratory support used in acute respiratory distress syndrome to obtain normocapnia was associated with a poor prognosis and a high frequency of acute cor pulmonale, suggesting some relation between the two findings. This prognosis has greatly improved with protective ventilation. At the same time, the incidence of acute cor pulmonale has diminished in acute respiratory distress syndrome, and the prognosis of this specific complication has also improved, suggesting that the right ventricle may develop some adaptation against persistent overload. Past lessons, however, have taught us that this potential may be limited and lead us to recommend right ventricular protection during mechanical ventilation.
即使肺血管阻力稍有增加，也可能使正常的右心室负担过重，因为右心室是通过低压循环射血的。在临床情况下，肺血管阻力持续增加会导致急性肺心病。从超声心动图的角度来看，其可被定义为反映收缩期负荷过重的矛盾性室间隔运动与反映舒张期负荷过重的右心室扩大的组合。在急性呼吸窘迫综合征患者中，这种并发症反映了累及微血管的肺部疾病的严重程度，但也可能由激进的通气策略引起或加重。过去，用于急性呼吸窘迫综合征以实现正常碳酸血症的传统呼吸支持与预后不良和急性肺心病的高发生率相关，这表明这两种情况之间存在某种关联。采用保护性通气后，这种预后有了很大改善。同时，急性呼吸窘迫综合征中急性肺心病的发生率有所降低，这种特定并发症的预后也有所改善，这表明右心室可能会对持续的负荷过重产生一些适应性变化。然而，过去的经验告诉我们，这种潜力可能是有限的，这促使我们建议在机械通气期间保护右心室。
