From the Division of Trauma and Surgical, Critical Care (J.J.G., T.M.S., S.B.M.), Department of Surgery, and Department of Anesthesiology (S.G.), University of Maryland School of Medicine, R Adams Cowley Shock Trauma Center, Baltimore; and Walter Reed National Military Medical Center (C.C.), Bethesda, Maryland.
J Trauma Acute Care Surg. 2016 Nov;81(5 Suppl 2 Proceedings of the 2015 Military Health System Research Symposium):S157-S161. doi: 10.1097/TA.0000000000001020.
Point-of-care ultrasound often includes cardiac ultrasound. It is commonly used to evaluate cardiac function in critically ill patients but lacks the specific quantitative anatomic assessment afforded by standard transthoracic echocardiography (TTE). We developed the Focused Rapid Echocardiographic Examination (FREE), a hybrid between a cardiac ultrasound and TTE that places an emphasis on cardiac function rather than anatomy. We hypothesized that data obtained from FREE correlate well with TTE while providing actionable information for clinical decision making.
FREE examinations evaluating cardiac function (left ventricular ejection fraction), diastolic dysfunction (including early mitral Doppler flow [E] and early mitral tissue Doppler [E']), right ventricular function, cardiac output, preload (left ventricular internal dimension end diastole), stroke volume, stroke volume variation, inferior vena cava diameter, and inferior vena cava collapse were performed. Patients who underwent both a TTE and FREE on the same day were identified as the cohort, and quantitative measurements were compared. Correlation analyses were performed to assess levels of agreement.
A total of 462 FREE examinations were performed, in which 69 patients had both a FREE and TTE. FREE ejection fraction was strongly correlated with TTE (r = 0.89, 95% confidence interval). Left ventricular outflow tract, left ventricular internal dimension end diastole, E, and lateral E' derived from FREE were also strongly correlated with TTE measurements (r = 0.83, r = 0.94, r = 0.77, and r = 0.88, respectively). In 82% of the patients, right ventricular function for FREE was the same as that reported for TTE; pericardial effusion was detected on both examinations in 94% of the cases. No significant valvular anatomy was missed with the FREE examination.
Functionally rather than anatomically based hybrid ultrasound examinations, like the FREE, facilitate decision making for critically ill patients. The FREE's functional assessment correlates well with TTE measurements and may be of significant clinical value in critically ill patients, especially when used in remote operating environments where resources are limited.
Diagnostic test, level III.
床边超声通常包括心脏超声。它常用于评估危重症患者的心功能，但缺乏标准经胸超声心动图（TTE）提供的特定定量解剖评估。我们开发了 Focused Rapid Echocardiographic Examination（FREE），它是心脏超声和 TTE 的混合体，侧重于心功能而非解剖结构。我们假设 FREE 获得的数据与 TTE 相关性良好，同时为临床决策提供可操作的信息。
进行了评估心脏功能（左心室射血分数）、舒张功能障碍（包括早期二尖瓣多普勒血流 [E]和早期二尖瓣组织多普勒 [E']）、右心室功能、心输出量、左心室舒张末期内径、每搏量、每搏量变异、下腔静脉直径和下腔静脉塌陷的 FREE 检查。确定了同一天接受 TTE 和 FREE 检查的患者为队列，并对定量测量结果进行了比较。进行了相关分析以评估一致性水平。
共进行了 462 次 FREE 检查，其中 69 名患者同时进行了 FREE 和 TTE。FREE 射血分数与 TTE 高度相关（r = 0.89，95%置信区间）。从 FREE 获得的左心室流出道、左心室舒张末期内径、E 和外侧 E'也与 TTE 测量值高度相关（r = 0.83，r = 0.94，r = 0.77 和 r = 0.88）。在 82%的患者中，FREE 的右心室功能与 TTE 报告的相同；两种检查均发现 94%的患者有心包积液。FREE 检查未漏诊任何显著的瓣膜解剖结构。
基于功能而非解剖的混合超声检查，如 FREE，为危重症患者的决策提供了便利。FREE 的功能评估与 TTE 测量值相关性良好，在危重症患者中可能具有重要的临床价值，尤其是在资源有限的远程操作环境中使用时。
诊断性测试，III 级。
