Background

Multiple studies investigating the use of focused cardiac ultrasound (FCU) in lower and middle-income countries and in medically underserved areas of the United States have demonstrated utility in echocardiographic screening algorithms performed by a variety of operators at different levels of training. No study to date has employed previously untrained nurses in a medically underserved setting to identify older adults with cardiac disorders. The aim of this study was to assess the accuracy of nurse-performed FCU to screen adult subjects at a village health center in Vietnam.

Methods

Vietnamese nurses (N = 8) underwent structured training conducted by sonographers and physicians during an outreach event sponsored by the American Society of Echocardiography Education and Research Foundation. The nurses were trained to detect abnormalities from a single echocardiographic view (parasternal long-axis) with a laptop-sized device and underwent pre- and posttraining testing. Following training, cardiac ultrasound examinations were performed on subjects >50 years of age at a village health center. First, the nurses performed focused cardiac ultrasound using two-dimensional and color Doppler imaging in the parasternal long-axis view using the M7 device and recorded their assessments. Two-dimensional color and spectral Doppler echocardiography was thereafter performed using the same machine by a sonographer (n = 5) or a Vietnamese echocardiography-trained cardiologist (n = 1). Interviews and electrocardiography were performed at the time of FCU.

Results

Each nurse improved from pre- to posttraining (average improvement in correct answers, 21%; range, 2%–31%). During the scanning phase, nurses' sensitivity, specificity, and accuracy for identifying subjects with any abnormality were 51.5% (85 of 165), 78.1% (82 of 105) and 61.9%, respectively. There were 60 subjects with significant findings (22.2%); all of these subjects had significant abnormalities visible on parasternal long-axis images. Overall sensitivity, specificity, and accuracy for identifying subjects with major abnormalities were 83.3% (50 of 60), 78.1% (164 of 210), and 78.6%, respectively. Nurse-performed FCU demonstrated much higher sensitivity with lower specificity than electrocardiography alone. The combination of nurse-performed FCU plus ECG identified all of the significant findings on echocardiography and increased accuracy to 91.5%.

Conclusions

Nurses with no prior echocardiographic experience and with limited training can identify patients with significant cardiac abnormalities using FCU with acceptable accuracy. Screening strategies involving FCU may play a role in improving access to health care and triage in underserved areas.

中文翻译：

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越南农村地区护士进行的聚焦心脏超声检查

背景

多项调查在美国中低收入国家和医疗欠佳地区使用聚焦心脏超声（FCU）的多项研究表明，超声心动图筛查算法在各种培训水平下的各种操作者均能发挥效用。迄今为止，尚无研究在医学上服务不足的情况下雇用以前未经培训的护士来识别患有心脏病的老年人。这项研究的目的是评估由护士执行的FCU在越南乡村卫生中心筛查成人受试者的准确性。

方法

越南护士（N = 8）在由美国超声心动图教育与研究基金会协会举办的外展活动中，接受了由超声医师和医生进行的结构化培训。对护士进行了培训，以使用笔记本电脑大小的设备从单个超声心动图（胸骨旁长轴）观察异常，并进行了培训前和培训后的测试。训练后，在乡村保健中心对年龄大于50岁的受试者进行了心脏超声检查。首先，护士使用M7设备在胸骨旁长轴视图中使用二维和彩色多普勒成像技术进行了聚焦的心脏超声检查，并记录了他们的评估结果。此后，超声医师使用同一台机器进行二维彩色和频谱多普勒超声心动图检查（n = 5）或越南超声心动图培训的心脏病专家（n  = 1）。在FCU进行访谈和心电图检查。

结果

每位护士从培训前到培训后都有改善（正确答案的平均改善率为21％；范围为2％至31％）。在扫描阶段，护士识别异常对象的敏感性，特异性和准确性分别为51.5％（165个中的85），78.1％（105个中的82）和61.9％。有60名受试者有显着发现（22.2％）；所有这些对象在胸骨旁长轴图像上均可见明显异常。识别主要异常受试者的总体敏感性，特异性和准确性分别为83.3％（60分中的50％），78.1％（210分中的164位）和78.6％。与单独的心电图检查相比，由护士执行的FCU具有更高的灵敏度和更低的特异性。

结论

既往没有超声心动图检查经验且受过有限培训的护士可以使用FCU以可接受的准确度来识别出心脏异常的患者。涉及FCU的筛查策略可能在改善服务不足地区的卫生保健和分诊中发挥作用。