ICU-ROX研究人员联合澳大利亚-新西兰重症监护学会临床试验组，研究了重症监护病房采用保守氧疗进行机械通气的效果。相关论文2019年10月14日在线发表于《新英格兰医学杂志》。

据悉，在重症监护病房（ICU）进行机械通气的患者通常会获得较高的吸入氧浓度（FiO₂）和高动脉血氧张力。氧气的保守使用可减少患者的氧暴露，减少肺及全身的氧化损伤，从而增加无呼吸机的天数。

研究组招募了1000名成人患者，他们预计在ICU接受机械通气治疗，脉搏血氧饱和度（SpO₂）监测下限默认为90%。将其随机分为两组，保守氧疗组中，当SpO₂达到上限97%时便会鸣响报警，当SpO₂高于可接受的下限时，FiO₂降低到0.21；常规氧疗组中，没有限制FiO₂或SpO₂的具体措施。

保守氧疗组和常规氧疗组的平均无呼吸机天数分别为21.3天和22.1天，差异不显著。保守氧疗组在ICU时FiO₂为0.21的中位持续时间为29小时，常规氧疗组为1小时。保守氧疗组SpO₂超过96%的平均持续时间为27小时，常规氧疗组为49小时。180天时，保守氧疗组和常规氧疗组的死亡率分别为35.7%和34.5%，未校正的比值比为1.05。

综上，在ICU进行机械通气的成年人中，与常规氧疗相比，保守氧疗并未显著增加无呼吸机天数。

附：英文原文

Title: Conservative Oxygen Therapy during Mechanical Ventilation in the ICU

Author: The ICU-ROX Investigators and the Australian and New Zealand Intensive Care Society Clinical Trials Group

Issue&Volume: 14 October 2019

Abstract: 

BACKGROUND
Patients who are undergoing mechanical ventilation in the intensive care unit (ICU) often receive a high fraction of inspired oxygen (Fio2) and have a high arterial oxygen tension. The conservative use of oxygen may reduce oxygen exposure, diminish lung and systemic oxidative injury, and thereby increase the number of ventilator-free days (days alive and free from mechanical ventilation).

METHODS
We randomly assigned 1000 adult patients who were anticipated to require mechanical ventilation beyond the day after recruitment in the ICU to receive conservative or usual oxygen therapy. In the two groups, the default lower limit for oxygen saturation as measured by pulse oximetry (Spo2) was 90%. In the conservative-oxygen group, the upper limit of the Spo2 alarm was set to sound when the level reached 97%, and the Fio2 was decreased to 0.21 if the Spo2 was above the acceptable lower limit. In the usual-oxygen group, there were no specific measures limiting the Fio2 or the Spo2. The primary outcome was the number of ventilator-free days from randomization until day 28.

RESULTS
The number of ventilator-free days did not differ significantly between the conservative-oxygen group and the usual-oxygen group, with a median duration of 21.3 days (interquartile range, 0 to 26.3) and 22.1 days (interquartile range, 0 to 26.2), respectively, for an absolute difference of −0.3 days (95% confidence interval [CI], −2.1 to 1.6; P=0.80). The conservative-oxygen group spent more time in the ICU with an Fio2 of 0.21 than the usual-oxygen group, with a median duration of 29 hours (interquartile range, 5 to 78) and 1 hour (interquartile range, 0 to 17), respectively (absolute difference, 28 hours; 95% CI, 22 to 34); the conservative-oxygen group spent less time with an Spo2 exceeding 96%, with a duration of 27 hours (interquartile range, 11 to 63.5) and 49 hours (interquartile range, 22 to 112), respectively (absolute difference, 22 hours; 95% CI, 14 to 30). At 180 days, mortality was 35.7% in the conservative-oxygen group and 34.5% in the usual-oxygen group, for an unadjusted odds ratio of 1.05 (95% CI, 0.81 to 1.37).

CONCLUSIONS
In adults undergoing mechanical ventilation in the ICU, the use of conservative oxygen therapy, as compared with usual oxygen therapy, did not significantly affect the number of ventilator-free days.

DOI: 10.1056/NEJMoa1903297

Source: https://www.nejm.org/doi/full/10.1056/NEJMoa1903297