Prone positioning is recommended for patients with moderate-to-severe acute respiratory distress syndrome (ARDS) receiving mechanical ventilation. While the debate continues as to whether COVID-19 ARDS is clinically different from non-COVID ARDS, there is little data on whether the physiological effects of prone positioning differ between the two conditions. We aimed to compare the physiological effect of prone positioning between patients with COVID-19 ARDS and those with non-COVID ARDS. We retrospectively compared 23 patients with COVID-19 ARDS and 145 patients with non-COVID ARDS treated using prone positioning while on mechanical ventilation. Changes in PaO2/FiO2 ratio and static respiratory system compliance (Crs) after the first session of prone positioning were compared between the two groups: first, using all patients with non-COVID ARDS, and second, using subgroups of patients with non-COVID ARDS matched 1:1 with patients with COVID-19 ARDS for baseline PaO2/FiO2 ratio and static Crs. We also evaluated whether the response to the first prone positioning session was associated with the clinical outcome. When compared with the entire group of patients with non-COVID ARDS, patients with COVID-19 ARDS showed more pronounced improvement in PaO2/FiO2 ratio [adjusted difference 39.3 (95% CI 5.2–73.5) mmHg] and static Crs [adjusted difference 3.4 (95% CI 1.1–5.6) mL/cmH2O]. However, these between-group differences were not significant when the matched samples (either PaO2/FiO2-matched or compliance-matched) were analyzed. Patients who successfully discontinued mechanical ventilation showed more remarkable improvement in PaO2/FiO2 ratio [median 112 (IQR 85–144) vs. 35 (IQR 6–52) mmHg, P = 0.003] and static compliance [median 5.7 (IQR 3.3–7.7) vs. − 1.0 (IQR − 3.7–3.0) mL/cmH2O, P = 0.006] after prone positioning compared with patients who did not. The association between oxygenation and Crs responses to prone positioning and clinical outcome was also evident in the adjusted competing risk regression. In patients with COVID-19 ARDS, prone positioning was as effective in improving respiratory physiology as in patients with non-COVID ARDS. Thus, it should be actively considered as a therapeutic option. The physiological response to the first session of prone positioning was predictive of the clinical outcome of patients with COVID-19 ARDS.

中文翻译：

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俯卧位对 COVID-19 ARDS 与非 COVID ARDS 氧合和静态呼吸系统顺应性的影响

对于接受机械通气的中重度急性呼吸窘迫综合征 (ARDS) 患者，建议采用俯卧位。尽管关于 COVID-19 ARDS 在临床上是否与非 COVID ARDS 不同的争论仍在继续，但关于俯卧位的生理效应在这两种情况下是否不同的数据很少。我们旨在比较 COVID-19 ARDS 患者和非 COVID ARDS 患者俯卧位的生理效应。我们回顾性比较了机械通气时使用俯卧位治疗的 23 名 COVID-19 ARDS 患者和 145 名非 COVID ARDS 患者。比较两组首次俯卧位后 PaO2/FiO2 比值和静态呼吸系统顺应性 (Crs) 的变化：首先，使用所有非 COVID ARDS 患者，其次，使用非 COVID ARDS 患者亚组与 COVID-19 ARDS 患者 1:1 匹配基线 PaO2/FiO2 比值和静态 Crs。我们还评估了对第一次俯卧位的反应是否与临床结果相关。与整个非 COVID ARDS 患者组相比，COVID-19 ARDS 患者的 PaO2/FiO2 比值 [调整后差异 39.3 (95% CI 5.2–73.5) mmHg] 和静态 Crs [调整后差异 3.4 (95% CI 1.1–5.6) mL/cmH2O]。然而，当分析匹配的样本（PaO2/FiO2 匹配或依从性匹配）时，这些组间差异并不显着。成功停止机械通气的患者在 PaO2/FiO2 比值 [中位数 112 (IQR 85–144) 对 35 (IQR 6–52) mmHg 方面表现出更显着的改善，P = 0.003] 和静态顺应性 [中位数 5.7 (IQR 3.3–7.7) vs. − 1.0 (IQR − 3.7–3.0) mL/cmH2O，P = 0.006] 俯卧位后与未卧位的患者相比。在调整后的竞争风险回归中，氧合和 Crs 对俯卧位和临床结果的反应之间的关联也很明显。在 COVID-19 ARDS 患者中，俯卧位在改善呼吸生理机能方面与非 COVID ARDS 患者一样有效。因此，应积极考虑将其作为一种治疗选择。对第一次俯卧位的生理反应可以预测 COVID-19 ARDS 患者的临床结果。在调整后的竞争风险回归中，氧合和 Crs 对俯卧位和临床结果的反应之间的关联也很明显。在 COVID-19 ARDS 患者中，俯卧位在改善呼吸生理机能方面与非 COVID ARDS 患者一样有效。因此，应积极考虑将其作为一种治疗选择。对第一次俯卧位的生理反应可以预测 COVID-19 ARDS 患者的临床结果。在调整后的竞争风险回归中，氧合和 Crs 对俯卧位和临床结果的反应之间的关联也很明显。在 COVID-19 ARDS 患者中，俯卧位在改善呼吸生理机能方面与非 COVID ARDS 患者一样有效。因此，应积极考虑将其作为一种治疗选择。对第一次俯卧位的生理反应可以预测 COVID-19 ARDS 患者的临床结果。