OBJECTIVES: 

ICUs have had to deal with a large number of patients with acute respiratory distress syndrome COVID-19, a significant number of whom received prone ventilation, which is a substantial consumer of care time. The selection of patients that we have to ventilate in prone position seems interesting. We evaluate the correlation between the percentage of collapsed dependent lung areas in the supine position, monitoring by electrical impedance tomography and the oxygenation response (change in Pao₂/Fio₂ ratio) to prone position.

DESIGN: 

An observational prospective study.

SETTING: 

From October 21, 2020, to 30 March 30, 2021. At the Sainte Anne military teaching Hospital and the Timone University Hospital.

PATIENTS: 

Fifty consecutive patients admitted in our ICUs, with COVID-19 acute respiratory distress syndrome and required mechanical, were included. Twenty-four (48%) received prone ventilation. Fifty-eight prone sessions were investigated.

INTERVENTIONS: 

An electrical impedance tomography recording was made in supine position, daily and repeated just before and just after the prone session. The daily dependent area collapse was calculated in relation to the previous electrical impedance tomography recording. Prone ventilation response was defined as a Pao₂/Fio₂ ratio improvement greater than 20%.

MEASUREMENT AND MAIN RESULTS: 

The main outcome was the correlation between dependent area collapse and the oxygenation response to prone ventilation. Dependent area collapse was correlated with oxygenation response to prone ventilation (R² = 0.49) and had a satisfactory prediction accuracy of prone response with an area under the curve of 0.94 (95% CI, 0.87–1.00; p < 0.001). Best Youden index was obtained for a dependent area collapse greater than 13.5 %. Sensitivity of 92% (95% CI, 78–97), a specificity of 91% (95% CI, 72–97), a positive predictive value of 94% (95% CI, 88–100), a negative predictive value of 87% (95% CI, 78–96), and a diagnostic accuracy of 91% (95% CI, 84–98).

CONCLUSIONS: 

Dependent lung areas collapse (> 13.5%), monitored by electrical impedance tomography, has an excellent positive predictive value (94%) of improved oxygenation during prone ventilation.

中文翻译：

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通过电阻抗断层扫描监测的肺相关区域塌陷可预测 COVID-19 急性呼吸窘迫综合征中俯卧通气的氧合反应

目标： 

ICU 必须处理大量患有急性呼吸窘迫综合征 (COVID-19) 的患者，其中相当多的患者接受俯卧位通气，这耗费了大量的护理时间。我们选择俯卧位通气的患者似乎很有趣。我们评估了仰卧位塌陷依赖性肺区域的百分比（通过电阻抗断层扫描监测）与俯卧位的氧合反应（Pa o ₂ /F io ₂比率的变化）之间的相关性。

设计： 

一项观察性前瞻性研究。

环境： 

2020年10月21日至2021年3月30日。在圣安妮军事教学医院和蒂莫大学医院。

患者： 

我们的 ICU 连续收治 50 名患有 COVID-19 急性呼吸窘迫综合征且需要机械治疗的患者。二十四 (48%) 接受俯卧位通气。对五十八次俯卧训练进行了调查。

干预措施： 

每天在仰卧位进行电阻抗断层扫描记录，并在俯卧训练之前和之后重复记录。每日相关面积塌陷是根据之前的电阻抗断层扫描记录来计算的。俯卧位通气反应定义为 Pa o ₂ /F io ₂比率改善大于 20%。

测量和主要结果： 

主要结果是依赖区塌陷与俯卧位通气的氧合反应之间的相关性。依赖区塌陷与俯卧位通气的氧合反应相关（R ² = 0.49），并且对俯卧位反应具有令人满意的预测准确性，曲线下面积为0.94（95% CI，0.87-1.00；p < 0.001）。最佳约登指数是针对大于 13.5% 的相关区域塌陷而获得的。敏感性为 92% (95% CI, 78–97)，特异性为 91% (95% CI, 72–97)，阳性预测值为 94% (95% CI, 88–100)，阴性预测值87% (95% CI, 78–96)，诊断准确率为 91% (95% CI, 84–98)。

结论： 

通过电阻抗断层扫描监测，依赖性肺区域塌陷（> 13.5%）对于俯卧通气期间氧合改善具有极好的阳性预测值（94%）。