Department of Surgery, UCSF East Bay, Alameda County Medical Center, Oakland, California 94602, USA.
J Surg Res. 2011 Oct;170(2):291-6. doi: 10.1016/j.jss.2011.03.057. Epub 2011 Apr 19.
End points of resuscitation in trauma patients are difficult to define. The size of the inferior vena cava (IVC) on CT scan may accurately indicate volume status and guide resuscitation efforts. Our hypothesis was that IVC "flatness" on CT scan reflects volume status in hemodynamically normal trauma patients.
The study population was drawn from a database of trauma patients who had abdominal CT scans and lactate levels drawn on arrival. Lactate was chosen as a marker of volume status since hypotensive patients were unlikely to undergo CT. Anteroposterior (AP) and transverse (TV) diameters of the IVC were measured at the suprarenal and infrarenal locations. A flatness index was calculated for each location (TV ÷ AP) and this value was correlated with heart rate, blood pressure, and lactate.
There was no difference in IVC flatness at the suprarenal or infrarenal position for patients with an elevated lactate compared with those with a normal lactate: 1.54 ± 0.18 versus 1.43 ± 0.08 (P = 0.2) suprarenal and 1.54 ± 0.46 versus 1.68 ± 0.58 (P = 0.4) infrarenal. IVC flatness at the suprarenal location weakly correlated with blood pressure (r = -0.29). IVC flatness did not correlate with blood pressure at the infrarenal location (r = -0.1). IVC flatness did not correlate with heart rate (P > 0.3) or age (P > 0.2).
These results did not demonstrate a correlation between IVC flatness and the markers of intravascular volume of heart rate, blood pressure, or lactate. IVC flatness on CT scan is not a valid indicator of volume status in hemodynamically normal trauma patients.
创伤患者的复苏终点难以定义。CT 扫描下下腔静脉（IVC）的大小可能准确反映容量状态并指导复苏努力。我们的假设是，CT 扫描下 IVC“变平”反映了血流动力学正常的创伤患者的容量状态。
该研究人群来自腹部 CT 扫描和入院时乳酸水平检测的创伤患者数据库。选择乳酸作为容量状态的标志物，因为低血压患者不太可能进行 CT 检查。测量肾上和肾下 IVC 的前后（AP）和横径（TV）。计算每个部位的平坦指数（TV/AP），并将该值与心率、血压和乳酸相关联。
与乳酸正常的患者相比，乳酸升高的患者肾上和肾下 IVC 平坦度没有差异：1.54±0.18 与 1.43±0.08（P=0.2）肾上，1.54±0.46 与 1.68±0.58（P=0.4）肾下。肾上 IVC 平坦度与血压呈弱相关（r=-0.29）。肾下 IVC 平坦度与血压不相关（r=-0.1）。IVC 平坦度与心率（P>0.3）或年龄（P>0.2）无关。
这些结果表明 IVC 平坦度与心率、血压或乳酸等血管内容量标志物之间没有相关性。CT 扫描下 IVC 平坦度不是血流动力学正常创伤患者容量状态的有效指标。
