Objective To determine the diagnostic accuracy of point-of-care ultrasound in suspected pulmonary embolism. Design Systematic review and meta-analysis. Data sources MEDLINE, Embase, CINAHL and Cochrane library were searched on 2 July 2020 with no restrictions on the date of publication. Subject headings or subheadings combined with text words for the concepts of pulmonary embolism, ultrasound and diagnosis were used. Eligibility criteria and data analysis Eligible studies reported sensitivity and specificity of deep venous, lung, cardiac or multiorgan ultrasound in patients with suspected pulmonary embolism, using an adequate reference-test. Prospective, cross-sectional and retrospective studies were considered for eligibility. No restrictions were made on language. Studies were excluded if a control group consisted of healthy volunteers or if transesophageal or endobronchial ultrasound was used. Risk of bias was assessed using quality assessment of diagnostic accuracy studies-2. Meta-analysis of sensitivity and specificity was performed by construction of hierarchical summary receiver operator curves. I2 was used to assess the study heterogeneity. Main outcome measures The primary outcome was overall sensitivity and specificity of reported ultrasound signs, stratified by organ approach (deep venous, lung, cardiac and multiorgan). Secondary outcomes were stratum-specific sensitivity and specificity within subgroups defined by pretest probability of pulmonary embolism. Results 6378 references were identified, and 70 studies included. The study population comprised 9664 patients with a prevalence of pulmonary embolism of 39.9% (3852/9664). Risk of bias in at least one domain was found in 98.6% (69/70) of included studies. Most frequently, 72.8% (51/70) of studies reported >24 hours between ultrasound examination and reference test or did not disclose time interval at all. Level of heterogeneity ranged from 0% to 100%. Most notable ultrasound signs were bilateral compression of femoral and popliteal veins (22 studies; 4708 patients; sensitivity 43.7% (36.3% to 51.4%); specificity 96.7% (95.4% to 97.6%)), presence of at least one hypoechoic pleural-based lesion (19 studies; 2134 patients; sensitivity 81.4% (73.2% to 87.5%); specificity 87.4% (80.9% to 91.9%)), D-sign (13 studies; 1579 patients; sensitivity 29.7% (24.6% to 35.4%); specificity 96.2% (93.1% to 98.0%)), visible right ventricular thrombus (5 studies; 995 patients; sensitivity 4.7% (2.7% to 8.1%); specificity 100% (99.0% to 100%)) and McConnell’s sign (11 studies; 1480 patients; sensitivity 29.1% (20.0% to 40.1%); specificity 98.6% (96.7% to 99.4%)). Conclusion Several ultrasound signs exhibit a high specificity for pulmonary embolism, suggesting that implementation of ultrasound in the initial assessment of patients with suspected pulmonary embolism may improve the selection of patients for radiation imaging. PROSPERO registration number CRD42020184313. All data relevant to the study are included in the article or uploaded as supplementary information. Data can also be requested from the corresponding author. The study guarantors (CF, NJ and CBL) affirms that this manuscript is an honest, accurate and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

中文翻译：

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聚焦深静脉、肺、心脏和多器官超声在疑似肺栓塞中的诊断准确性：系统评价和荟萃分析

目的确定床旁超声诊断疑似肺栓塞的准确性。设计系统回顾和荟萃分析。数据源 MEDLINE、Embase、CINAHL 和 Cochrane 图书馆于 2020 年 7 月 2 日进行了检索，出版日期没有限制。肺栓塞、超声和诊断等概念的主题词或副标题与文本词相结合。合格标准和数据分析合格的研究报告了深静脉、肺、心脏或多器官超声对疑似肺栓塞患者的敏感性和特异性，并使用了充分的参考测试。前瞻性、横断面和回顾性研究被认为是合格的。对语言没有任何限制。如果对照组由健康志愿者组成，或者如果使用经食道或支气管内超声，则排除研究。使用诊断准确性研究的质量评估来评估偏倚风险-2。通过构建分层汇总接收器操作曲线进行敏感性和特异性的荟萃分析。I2 用于评估研究的异质性。主要结果测量 主要结果是报告的超声体征的总体敏感性和特异性，按器官方法（深静脉、肺、心脏和多器官）分层。次要结果是由肺栓塞的预测概率定义的亚组内的分层特异性敏感性和特异性。结果 确定了 6378 篇参考文献，纳入了 70 项研究。研究人群包括 9664 名患者，肺栓塞的患病率为 39.9% (3852/9664)。在 98.6% (69/70) 的纳入研究中发现了至少一个领域的偏倚风险。最常见的是，72.8% (51/70) 的研究报告超声检查和参考测试之间 > 24 小时或根本没有透露时间间隔。异质性水平在 0% 到 100% 之间。最显着的超声体征是双侧股静脉和腘静脉受压（22 项研究；4708 名患者；敏感性 43.7%（36.3% 至 51.4%）；特异性 96.7%（95.4% 至 97.6%）），存在至少一个低回声胸膜基于病变（19 项研究；2134 名患者；敏感性 81.4%（73.2% 至 87.5%）；特异性 87.4%（80.9% 至 91.9%）），D 征（13 项研究；1579 名患者；敏感性 29.7%（24.6% 至 35.4） %)；特异性 96.2% (93.1% 至 98.0%))，可见右心室血栓（5 项研究；995 名患者；敏感性 4.7%（2.7% 至 8.1%）；特异性 100%（99.0% 至 100%））和麦康奈尔征（11 项研究；1480 名患者；敏感性 29.1%（20.0% 至40.1%）；特异性 98.6%（96.7% 至 99.4%））。结论 几种超声体征对肺栓塞表现出较高的特异性，提示在疑似肺栓塞患者的初步评估中实施超声可改善放射成像患者的选择。PROSPERO 注册号 CRD42020184313。所有与研究相关的数据都包含在文章中或作为补充信息上传。也可向通讯作者索取资料。研究担保人（CF、NJ 和 CBL）确认这份手稿是诚实的，对所报告的研究进行准确和透明的说明；没有遗漏研究的重要方面；并且已经解释了与计划中的研究（以及，如果相关，已注册）的任何差异。