Pinsky M R
Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh, Pennsylvania.
Crit Care Clin. 1990 Jul;6(3):663-78.
Positive-pressure ventilation may improve gas exchange, decrease the work-cost of breathing, and rest respiratory muscles, but it also will alter cardiac output and may modify blood flow distribution. Ventilation may induce these hemodynamic changes by altering systemic venous return to the RV (RV preload), pulmonary arterial pressure (RV afterload), ventricular interdependence (LV preload), or transmural LV ejection pressure (LV afterload). These interactions are magnified when the changes in lung volume and intrathoracic pressure are increased or under conditions associated with a reduced effective circulating blood volume or cardiac contractility. An understanding of these interactions is central to the effective management of the ventilator-dependent patient.
正压通气可改善气体交换、降低呼吸功并使呼吸肌得到休息，但它也会改变心输出量并可能改变血流分布。通气可通过改变体循环静脉回流至右心室（右心室前负荷）、肺动脉压（右心室后负荷）、心室相互依赖（左心室前负荷）或左心室跨壁射血压力（左心室后负荷）来诱发这些血流动力学变化。当肺容积和胸内压变化增加时，或在有效循环血容量减少或心脏收缩力降低的情况下，这些相互作用会被放大。了解这些相互作用对于有效管理依赖呼吸机的患者至关重要。
