BACKGROUND Patients not mechanically ventilated often fail to achieve the recommended duration of awake prone positioning due to treatment interruption and discomfort. Few studies have investigated the link between treatment outcome and prone-positioning duration, the inability to accurately guide patients to perform awake prone positioning. OBJECTIVES The aim of this study was to characterise and explore the relationship between awake prone-positioning duration with the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2 [P/F]) changes and the risk of disease aggravation. METHODS A prospective cohort study; dose-response relationship was used. Awake prone positioning was performed on patients with severe Corona Virus Disease 2019 (COVID-19) for 5 consecutive days from 1 February to 21 March 2023. Linear and logistic regression models were utilised to assess the association between prone-positioning duration with P/F changes and risk of disease aggravation, respectively. Meanwhile, the restricted cubic spline was used to evaluate the dose-response relationships. RESULTS A total of 408 patients with severe COVID-19 were analysed. The daily prone positioning duration was 4.57 ± 2.74 h/d, and the changes in P/F were 67.63 ± 69.17 mmHg. On the sixth day of hospitalisation, the condition of 52 (12.8%) patients deteriorated. There was a positive, nonlinear dose-response relationship (Poverall < 0.001, Pnonlinearity = 0.041) and a strong, significant positive correlation (β = 29.286, t = 4.302, P < 0.001) between the prone-positioning duration and P/F changes. The risk of disease aggravation gradually decreases with the increase of prone-positioning duration. Nonetheless, the prone-positioning duration was not statistically associated with disease aggravation (odds ratio = 0.986, 95% confidence interval: 0.514-1.895). CONCLUSIONS Awake prone positioning for ≥4 h/d is effective on oxygenation (not mortality/intubation) and is achievable for patients with severe COVID-19. Prolonged prone positioning is promising in improving patients' oxygenation but does not alleviate their risk of disease aggravation.

中文翻译：

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重症 COVID-19 患者清醒俯卧位持续时间与 PaO2/FiO2 变化以及疾病恶化风险之间的剂量反应关系：一项前瞻性队列研究。


背景技术由于治疗中断和不适，未进行机械通气的患者常常无法达到推荐的清醒俯卧位持续时间。很少有研究调查治疗结果与俯卧位持续时间之间的联系，无法准确指导患者进行清醒的俯卧位。目的 本研究的目的是表征和探讨清醒俯卧位持续时间与动脉氧分压与吸入氧分数之比 (PaO2/FiO2 [P/F]) 变化之间的关系以及发生以下疾病的风险：病情加重。方法 前瞻性队列研究；使用剂量-反应关系。从2023年2月1日至3月21日，对2019年重症冠状病毒病（COVID-19）患者连续5天进行清醒俯卧位。利用线性和逻辑回归模型评估俯卧位持续时间与P/F之间的关联分别是变化和疾病恶化的风险。同时，利用限制三次样条来评估剂量反应关系。结果 总共分析了 408 名重症 COVID-19 患者。每日俯卧位持续时间为4.57±2.74 h/d，P/F变化为67.63±69.17 mmHg。入院第六天，52名患者（12.8%）病情恶化。俯卧位持续时间与 P/ 之间存在正的非线性剂量反应关系（Poverall < 0.001，Pnonlinearity = 0.041），并且存在强且显着的正相关性（β = 29.286，t = 4.302，P < 0.001）。 F改变。随着俯卧位时间的增加，病情加重的风险逐渐降低。 尽管如此，俯卧位持续时间与疾病恶化没有统计学相关性（比值比 = 0.986，95% 置信区间：0.514-1.895）。结论 每天≥4 小时的清醒俯卧位对于氧合（而非死亡率/插管）有效，并且对于重症 COVID-19 患者来说是可以实现的。长时间俯卧位有望改善患者的氧合，但并不能降低疾病恶化的风险。