HIE subgroup posthoc analysis revealed improved survival and GOS-E at 6-mths.
A lot of discussion around treatment separation, secondary outcomes, and HIE post-hoc analyses.
要約だけ読んでも議論点がわからない論文となってる・・・良いのだろうか？
Conservative Oxygen Therapy during Mechanical Ventilation in the ICU
The ICU-ROX Investigators and the Australian and New Zealand Intensive Care Society Clinical Trials Group
Young P, et al
NEJM 2019;
DOI: 10.1015/NEJMoa1903297.
https://www.nejm.org/doi/full/10.1056/NEJMoa1903297
https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=369229
ICU収容後数日を超え人工呼吸必要な成人1000名患者を2群割り付け
翌日も人工換気継続可能と予測され、人工換気2時間内登録
オーストラリア・ニュージーランド 21 ICU
救急92％、急性脳障害 40%
Randomised to conservative vs usual oxygen
2群ともdefaultの酸素飽和度下限を SpO2 90%
- 保守的酸素群：SpO2上限アラームを音声にする：97％到達、許容下限までSpO2到達ならFiO2 0.21まで減少;Conservative 91-96%, could use FiO2 0.21
- 通常酸素群：FiO2、SpO2に特異的測定点を設定せず;no protocol defined upper limit, discourage use of FiO2 <0 .3="" li="">
Treatment separation- FIO2 0.21 received more in conservative arm (median 29 hours vs 1 hour), and less time with SpO2 of 97% or higher (median 27 hours vs 49 hours).
It is worth noting 1/3 of conservative patients had SpO2 >96%, and treatment separation dropped off by D5.
プライマリアウトカム：無人工換気日数：day 28までのランダム化からの日数
人工換気day 28で、保守的酸素投与群と通常酸素投与群で統計学的差を認めず
VFDs:人工換気不要日数 21.3 vs 22.1
保守的酸素投与群ではFiO2 0.21状態期間中央値 29時間 vs 通常酸素投与群 1時間
セカンダリアウトカム：
day 180での死亡率 保守的酸素投与群 33.7％、通常酸素投与群 34.5% ; HR 1.05 95% CI, 0.85 - 1.30
サブグループ解析：低酸素脳症(HIE)患者でのVFD増加有意に存在
HIEサブグループPost hoc解析、対死亡率 -43%、Kaplan-Meyer曲線にて 生存率改善示唆
6ヶ月GOS-E変化はアウトカム改善
FいO2 0.21のICU内の時間は保存的酸素療法群が通常酸素投与群より多く、中央値 29時間 (IQR 5−78時間)、と1時間(IQR 0-17時間)で絶対的時間差は 28時間; 95% CI< 22- 34時間
保存的酸素投与群では SpO2 96%超過時間短く時間 27時間 ( IQR, 11-63.5時間)、対し、通常酸素糖羊群 49時間 (IQR, 14 - 30時間)；絶対差 22時間, 95% CI, 14 -30時間
全体的には保守的酸素群はVFDs day 28の改善と相関せず
180日死亡率、保守的酸素群： 35.7% vs 通常酸素投与群: 34.5% 非補正オッズ比 1.05 (95% CI, 0.81 - 1.37)
研究者たちは有給被雇用労働、認知機能に関し2群間差認めず
低酸素性-虚血性脳症患者の2群差は明瞭にあり；day 28にて保守的酸素投与群での低酸素血症性-虚血性脳症症例は人工換気不要日数 21.1日間 vs 通常酸素群での低酸素血症性-虚血性脳症ではなし
通常酸素投与群は保守的酸素投与群に比べ180日間死亡率高い (43% vs. 59%)
低酸素血症性-虚血性脳症患者への保守的酸素療法のベネフィットの可能性を示唆
保守的酸素療法は心肺停止蘇生後の二次性脳障害頻度減少が生物学的に可能性有り、観察研究では、高酸素血症暴露は有害であることが示唆されている。
“Our data are suggestive of a possible benefit of conservative oxygen therapy in patients with suspected hypoxic-ischemic encephalopathy,” the authors wrote. “It is biologically plausible that conservative oxygen therapy reduces the incidence of secondary brain damage after resuscitation from cardiac arrest, and observational data suggest that exposure to hyperoxemia in such patients may be harmful.”
The authors noted that their trial did not rule out the possibility of benefit or harm had they used a more liberal oxygen regimen in their usual-care group, and that different conservative regimens might also have achieved different outcomes.
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).
