Bouhemad Bélaïd, Ferrari Fabio, Leleu Kris, Arbelot Charlotte, Lu Qin, Rouby Jean-Jacques
Department of Anesthesiology, Faculdade de Medicina da Universidade Estadual Paulista Julio de Mesquita Filho, Botucatu, Brazil.
Anesthesiology. 2008 Jan;108(1):55-62. doi: 10.1097/01.anes.0000296067.02462.34.
In spontaneously breathing cardiac patients, pulmonary artery pressure (PAP) can be accurately estimated from the transthoracic Doppler study of pulmonary artery and tricuspid regurgitation blood flows. In critically ill patients on mechanical ventilation for acute lung injury, the interposition of gas between the probe and the heart renders the transthoracic approach problematic. This study was aimed at determining whether the transesophageal approach could offer an alternative.
Fifty-one consecutive sedated and ventilated patients with severe hypoxemia (arterial oxygen tension/fraction of inspired oxygen < 300) were prospectively studied. Mean PAP measured from the pulmonary artery catheter was compared with several indices characterizing pulmonary artery blood flow assessed using transesophageal echocardiography: preejection time, acceleration time, ejection duration, preejection time on ejection duration ratio, and acceleration time on ejection duration ratio. In a subgroup of 20 patients, systolic PAP measured from the pulmonary artery catheter immediately before withdrawal was compared with Doppler study of regurgitation tricuspid flow performed immediately after pulmonary artery catheter withdrawal using either the transthoracic or the transesophageal approach.
Weak and clinically irrelevant correlations were found between mean PAP and indices of pulmonary artery flow. A statistically significant and clinically relevant correlation was found between systolic PAP and regurgitation tricuspid flow. In 3 patients (14%), pulmonary artery pressure could not be assessed echocardiographically.
In hypoxemic patients on mechanical ventilation, mean PAP cannot be reliably estimated from indices characterizing pulmonary artery blood flow. Systolic PAP can be estimated from regurgitation tricuspid flow using either transthoracic or transesophageal approach.
在自主呼吸的心脏病患者中，可通过经胸多普勒研究肺动脉和三尖瓣反流血流来准确估计肺动脉压（PAP）。在因急性肺损伤接受机械通气的重症患者中，探头与心脏之间存在气体，使得经胸途径存在问题。本研究旨在确定经食管途径是否能提供一种替代方法。
对51例连续的、接受镇静和通气治疗的严重低氧血症患者（动脉血氧分压/吸入氧分数<300）进行前瞻性研究。将通过肺动脉导管测得的平均PAP与使用经食管超声心动图评估的几个表征肺动脉血流的指标进行比较：射血前期时间、加速时间、射血持续时间、射血前期时间与射血持续时间之比以及加速时间与射血持续时间之比。在20例患者的亚组中，将肺动脉导管拔出前立即通过肺动脉导管测得的收缩期PAP与肺动脉导管拔出后立即使用经胸或经食管途径进行的三尖瓣反流血流多普勒研究结果进行比较。
发现平均PAP与肺动脉血流指标之间存在微弱且临床上无意义的相关性。发现收缩期PAP与三尖瓣反流血流之间存在具有统计学意义且临床上相关的相关性。在3例患者（14%）中，无法通过超声心动图评估肺动脉压。
在接受机械通气的低氧血症患者中，无法从表征肺动脉血流的指标可靠地估计平均PAP。使用经胸或经食管途径，可通过三尖瓣反流血流估计收缩期PAP。
