de la Matta M, Delgado-Sánchez J M, Gutiérrez G M, López Romero J L, Martínez Gómez M M, Domínguez Blanco A
Servicio de Anestesiología y Reanimación, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
Departamento de Matemática Aplicada I, Escuela Técnica Superior de Arquitectura, Universidad de Sevilla, Sevilla, Spain.
Rev Esp Anestesiol Reanim (Engl Ed). 2021 Jun-Jul;68(6):346-352. doi: 10.1016/j.redare.2020.10.002. Epub 2021 Jun 9.
Due to its high transmissibility, measures aimed at reducing the spread of SARS CoV2 have become mandatory. Different organizations have recommended performing polymerase chain reaction tests (PCR) as part of the preoperative screening of surgical patients. We aimed to determine the performance of PCR testing to detect asymptomatic carriers.
Observational study carried out at a tertiary care center. We compared the results of preoperative real-time reverse-transcription-PCR test (RT-PCR) performed on a cohort of patients pending surgery with the results we would have expected assuming the epidemiological data released by government offices.
We registered no positives in the 2,722 preoperative RT-PCR tests performed in our health care area between epidemiological Weeks 18 to 21, meaning a cumulative incidence trending to zero. Assuming public epidemiological data, the probabilistic projection of potential asymptomatic individuals ranged from 0.27 × 10e (according to official data of new cases diagnosed by PCR) to 4.69 × 10e if we assumed cases confirmed by IgG test in our province. Assuming a RT-PCR sensitivity of 95%, to obtain a positive result we should perform 38,461 and 2,028 tests respectively.
In scenarios of very low prevalence and despite high sensitivity scores, indiscriminate preoperative RT-PCR screening is of a questionable effectiveness for detecting asymptomatic carriers. Our findings evidence the difficulty of establishing reliable predictive models for the episodic and rapidly evolving incidence of infections such as has characterized the SARS CoV2 pandemic.
由于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的高传播性，旨在减少其传播的措施已成为强制性要求。不同组织建议将聚合酶链反应检测（PCR）作为外科手术患者术前筛查的一部分。我们旨在确定PCR检测在检测无症状携带者方面的性能。
在一家三级医疗中心进行观察性研究。我们将对一组等待手术的患者进行的术前实时逆转录PCR检测（RT-PCR）结果与假设政府部门公布的流行病学数据时我们预期的结果进行了比较。
在我们医疗区域第18至21个流行病学周期间进行的2722次术前RT-PCR检测中，我们未记录到阳性结果，这意味着累积发病率趋于零。假设公共流行病学数据，潜在无症状个体的概率预测范围为0.27×10e（根据PCR诊断的新病例官方数据）至4.69×10e（如果我们假设根据我省IgG检测确诊的病例）。假设RT-PCR敏感性为95%，要获得阳性结果我们应分别进行38461次和2028次检测。
在患病率极低的情况下，尽管敏感性得分很高，但术前不加区分地进行RT-PCR筛查在检测无症状携带者方面的有效性值得怀疑。我们的研究结果证明了为像SARS-CoV-2大流行这样具有突发性和快速演变特征的感染发病率建立可靠预测模型的难度。
