Purpose

The optimal physiologic parameters to monitor after a session of awake prone positioning in patients with acute respiratory failure are not well understood. This study aimed to identify which early physiologic changes after the first session of awake prone positioning are linked to the need for invasive mechanical ventilation or death in patients with acute respiratory failure.

Methods

We performed a secondary analysis of a prospective cohort study of adult patients with acute respiratory failure related to coronavirus disease 2019 (COVID-19) treated with awake prone positioning. We assessed the association between relative changes in physiological variables (oxygenation, respiratory rate, pCO₂ and respiratory rate-oxygenation [ROX] index) within the first 6 h of the first awake prone positioning session with treatment failure, defined as endotracheal intubation and/or death within 7 days.

Results

244 patients [70 female (29%), mean age 60 (standard deviation [SD] 13) years] were included. Seventy-one (29%) patients experienced awake prone positioning failure. ROX index was the main physiologic predictor. Patients with treatment failure had lower mean [SD] ROX index at baseline [5 (1.4) versus 6.6 (2.2), p < 0.0001] and within 6 h of prone positioning [5.6 (1.7) versus 8.7 (2.8), p < 0.0001]. After adjusting for baseline characteristics and severity, a relative increase of the ROX index compared to baseline was associated with lower odds of failure [odds ratio (OR) 0.37; 95% confidence interval (CI) 0.25–0.54 every 25% increase].

Conclusion

Relative changes in the ROX index within 6 h of the first awake prone positioning session along with other known predictive factors are associated with intubation and mortality at day 7.

中文翻译：

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清醒俯卧位后的早期生理变化可预测急性低氧性呼吸衰竭患者的临床结局

 目的

对于急性呼吸衰竭患者，在清醒俯卧位后监测的最佳生理参数尚不清楚。本研究旨在确定第一次清醒俯卧位后哪些早期生理变化与急性呼吸衰竭患者需要有创机械通气或死亡有关。

 方法

我们对一项前瞻性队列研究进行了二次分析，该研究纳入了接受清醒俯卧位治疗的 2019 冠状病毒病 （COVID-19） 相关急性呼吸衰竭成年患者。我们评估了第一次清醒俯卧位前6 h内生理变量（氧合、呼吸频率、pCO₂和呼吸频率-氧合[ROX]指数）的相对变化与治疗失败（定义为气管插管和/或7天内死亡）之间的关联。

 结果

包括 244 名患者 [70 名女性 （29%），平均年龄 60 （标准差 [SD] 13） 岁]。71 例 （29%） 患者出现清醒俯卧位失败。ROX 指数是主要的生理预测因子。治疗失败患者在基线时的平均 [SD] ROX 指数较低 [5 （1.4） 比 6.6 （2.2），p < 0.0001] 和俯卧位 6 小时内 [5.6 （1.7） 比 8.7 （2.8），p < 0.0001]。在调整基线特征和严重程度后，ROX 指数相对于基线的相对增加与较低的失败几率相关 [比值比 （OR） 0.37;95% 置信区间 （CI） 0.25-0.54，每增加 25%。

 结论

第一次清醒俯卧位后 6 小时内 ROX 指数的相对变化以及其他已知的预测因素与第 7 天的插管和死亡率相关。