Capper S J, Ross J J, Sandström E, Braidley P C, Morgan-Hughes N J
South Yorkshire Cardiothoracic Centre, UK.
Br J Anaesth. 2007 Apr;98(4):442-6. doi: 10.1093/bja/aem010. Epub 2007 Mar 8.
Transoesophageal echocardiography (TOE) can image pleural fluid. Left pleural collections may be easier to detect than right, as the thoracic aorta serves as an acoustic window. Attempts to quantify pleural fluid using TOE are restricted to a case report in which volume was predicted by multiplying maximal cross-sectional area (CSA(max)) by axial length (AL). A computed tomography (CT) derived formula for quantifying pleural effusions is maximal effusion depth squared (d2) multiplied by maximal effusion length.
Eight patients were studied before chest closure following coronary bypass surgery. Fifty millilitre saline aliquots were instilled into the pleural space until detected by TOE. Saline was then instilled up to the next 200 ml increment and further 200 ml aliquots added until it spilled from the pleural space. CSA(max), d and AL were measured for each stage and used to calculate pleural fluid volume.
Median detection volume (range) was 125 ml (50-200) on the left and 225 ml (150-300) on the right (P = 0.016). Volume calculated by CSA(max) x AL correlated strongly with actual volume (r2 = 0.93 left and 0.92 right) as did volume calculated by d2 x AL (r2 = 0.86 left and 0.89 right). Mean difference between volume calculated by CSA(max) x AL and actual volume was - 51 ml on the left and 45 ml on the right vs - 253 ml on the left and - 212 ml on the right for volume calculated by d2 x AL.
TOE detects small volumes of pleural fluid on both sides of the chest. CSA(max) x AL provides a reasonably accurate measure of pleural fluid volume.
经食管超声心动图（TOE）能够对胸腔积液进行成像。由于胸主动脉可作为声学窗口，左侧胸腔积液可能比右侧更容易被检测到。使用TOE对胸腔积液进行定量的尝试仅限于一份病例报告，该报告中通过将最大横截面积（CSA(max)）乘以轴向长度（AL）来预测积液量。一种通过计算机断层扫描（CT）得出的用于定量胸腔积液的公式是最大积液深度的平方（d2）乘以最大积液长度。
对8例冠状动脉搭桥手术后关胸之前的患者进行研究。将50毫升生理盐水等分试样注入胸腔，直至通过TOE检测到。然后再注入生理盐水直至增加到下一个200毫升增量，并继续添加200毫升等分试样，直至其从胸腔溢出。对每个阶段测量CSA(max)、d和AL，并用于计算胸腔积液量。
左侧的中位检测量（范围）为125毫升（50 - 200），右侧为225毫升（150 - 300）（P = 0.016）。通过CSA(max)×AL计算得出的积液量与实际积液量密切相关（左侧r2 = 0.93，右侧r2 = （此处原文有误，应为0.92）），通过d2×AL计算得出的积液量也是如此（左侧r2 = 0.86，右侧r2 = 0.89）。通过CSA(max)×AL计算得出的积液量与实际积液量的平均差值在左侧为 - 51毫升，右侧为45毫升；而通过d2×AL计算得出的积液量与实际积液量的平均差值在左侧为 - 253毫升，右侧为 - 212毫升。
TOE能够检测双侧胸腔的少量胸腔积液。CSA(max)×AL可提供较为准确的胸腔积液量测量方法。
