Background

Although an RT-PCR test is the “gold standard” tool for diagnosing an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), chest imaging can be used to support a diagnosis of coronavirus disease 2019 (COVID-19) – albeit with fairly low specificity. However, if the chest imaging findings do not faithfully reflect the patient's clinical course, one can question the rationale for relying on these imaging data in the diagnosis of COVID-19.

Aims

To compare clinical courses with changes over time in chest imaging findings among patients admitted to an ICU for severe COVID-19 pneumonia.

Methods

We retrospectively reviewed the medical charts of all adult patients admitted to our intensive care unit (ICU) between March 1, 2020, and April 15, 2020, for a severe COVID-19 lung infection and who had a positive RT-PCR test. Changes in clinical, laboratory and radiological variables were compared, and patients with discordant changes over time (e.g. a clinical improvement with stable or worse radiological findings) were analyzed further.

Results

Of the 46 included patients, 5 showed an improvement in their clinical status but not in their chest imaging findings. On admission to the ICU, three of the five were mechanically ventilated and the two others received high-flow oxygen therapy or a non-rebreather mask. Even though the five patients’ radiological findings worsened or remained stable, the mean ± standard deviation partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO₂:FiO₂) ratio increased significantly in all cases (from 113.2 ± 59.7 mmHg at admission to 259.8 ± 59.7 mmHg at a follow-up evaluation; p=0.043).

Interpretation

Our results suggest that in cases of clinical improvement with worsened or stable chest imaging variables, the PaO2:FiO2 ratio might be a good marker of the resolution of COVID-19-specific pulmonary vascular insult.

中文翻译：

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重症 COVID-19 肺炎临床病程与胸部影像学的分离：一系列 5 例病例

背景

尽管 RT-PCR 检测是诊断严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 感染的“金标准”工具，但胸部成像可用于支持 2019 冠状病毒病 (COVID-19) 的诊断– 尽管特异性相当低。然而，如果胸部影像学检查结果不能如实反映患者的临床病程，人们可能会质疑依赖这些影像学数据诊断 COVID-19 的基本原理。

宗旨

比较因重症 COVID-19 肺炎入住 ICU 的患者的临床病程与胸部影像学检查结果随时间的变化。

方法

我们回顾性地审查了 2020 年 3 月 1 日至 2020 年 4 月 15 日期间入住我们重症监护病房 (ICU) 的所有成年患者的病历，这些患者因严重 COVID-19 肺部感染且 RT-PCR 检测呈阳性。比较临床、实验室和放射学变量的变化，并进一步分析随时间变化不一致的患者（例如，临床改善但放射学结果稳定或更差）。

结果

在纳入的 46 名患者中，5 名的临床状况有所改善，但胸部影像学检查结果没有改善。在进入 ICU 时，五人中的三人接受了机械通气，另外两人接受了高流量氧疗或非循环呼吸面罩。尽管 5 名患者的放射学检查结果恶化或保持稳定，但所有病例的动脉氧分压与吸入氧分压 (PaO ₂ : FiO ₂ ) 比率的平均值±标准差均显着增加（从入院时的 113.2 ± 59.7 mmHg 开始）在后续评估中降至 259.8 ± 59.7 mmHg；p=0.043）。

解释

我们的结果表明，在临床改善且胸部影像学变量恶化或稳定的情况下，PaO2:FiO2 比率可能是 COVID-19 特异性肺血管损伤消退的良好标志。