We propose a novel method of evaluating right ventricular (RV) dysfunction in the emergency department (ED) using RV “bubble time”—the duration of time bubbles from a saline solution flush are visualized in the RV on echocardiography. The objective was to identify the optimal cutoff value for RV bubble time that differentiates patients with RV dysfunction and report on its diagnostic test characteristics. This prospective diagnostic accuracy study enrolled a convenience sample of hemodynamically stable patients in the ED. A sonographer administered a 10-mL saline solution flush into the patient’s intravenous catheter, performed a bedside echocardiogram, and measured RV bubble time. Subsequently, the patient underwent a comprehensive cardiologist-interpreted echocardiogram within 36 hours, which served as the gold standard. Patients with RV strain or enlargement of the latter found on an echocardiogram were considered to have RV dysfunction. Bubble time was evaluated by a second provider, blinded to the initial results, who reviewed the ultrasound clips. The primary outcome measure was the optimal cutoff value of RV bubble time that identifies patients with and without RV dysfunction. Of 196 patients, median age was 67 year, and half were women, with 69 (35.2%) having RV dysfunction. Median RV bubble time among patients with RV dysfunction was 62 seconds (interquartile range [IQR]: 52, 93) compared with 21 seconds (IQR: 12, 32) among patients without (<.0001). The optimal cutoff value of RV bubble time for identifying patients with RV dysfunction was 40 or more seconds, with a sensitivity of 0.97 (95% CI 0.93 to 1.00) and specificity of 0.87 (95% CI 0.82 to 0.93). In patients in the ED, an RV bubble time of 40 or more seconds had high sensitivity in identifying patients with RV dysfunction, whereas an RV bubble time of less than 40 seconds had good specificity in identifying patients without RV dysfunction. These findings warrant further investigation in undifferentiated patient populations and by emergency physicians without advanced ultrasound training.

中文翻译：

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右心室“泡沫时间”识别右心室功能障碍患者


我们提出了一种使用 RV“气泡时间”评估急诊科 (ED) 右心室 (RV) 功能障碍的新方法，即在超声心动图上在 RV 中观察到盐溶液冲洗产生的气泡的持续时间。目的是确定 RV 起泡时间的最佳截止值，以区分 RV 功能障碍患者并报告其诊断测试特征。这项前瞻性诊断准确性研究在急诊科招募了血流动力学稳定的患者作为方便样本。超声医师将 10 mL 生理盐水冲洗至患者的静脉导管中，进行床边超声心动图检查，并测量 RV 气泡时间。随后，患者在 36 小时内接受了全面的心脏病专家解释的超声心动图，这是金标准。超声心动图发现右心室应变或增大的患者被认为患有右心室功能障碍。气泡时间由第二位提供者评估，该提供者对初始结果不知情，但他审查了超声波剪辑。主要结果指标是右心室起泡时间的最佳截止值，用于识别有无右心室功能障碍的患者。 196 名患者中，中位年龄为 67 岁，其中一半为女性，其中 69 名（35.2%）患有右心室功能障碍。右心室功能障碍患者的中位右心室起泡时间为 62 秒（四分位数间距 [IQR]：52, 93），而没有右心室功能障碍的患者的中位右心室起泡时间为 21 秒（IQR：12, 32）（<.0001）。识别右心室功能障碍患者的右心室起泡时间的最佳截止值为 40 秒或更长，敏感性为 0.97（95% CI 0.93 至 1.00），特异性为 0.87（95% CI 0.82 至 0.93）。 在急诊科患者中，RV 起泡时间为 40 秒或以上，对于识别 RV 功能障碍患者具有较高的敏感性，而 RV 起泡时间小于 40 秒，对于识别没有 RV 功能障碍的患者具有良好的特异性。这些发现值得对未分化的患者群体以及未经高级超声培训的急诊医生进行进一步研究。