BACKGROUND Improving oxygen systems may improve clinical outcomes for hospitalised children with acute lower respiratory infection (ALRI). This paper reports the effects of an improved oxygen system on mortality and clinical practices in 12 general, paediatric, and maternity hospitals in southwest Nigeria. METHODS AND FINDINGS We conducted an unblinded stepped-wedge cluster-randomised trial comparing three study periods: baseline (usual care), pulse oximetry introduction, and stepped introduction of a multifaceted oxygen system. We collected data from clinical records of all admitted neonates (<28 days old) and children (28 days to 14 years old). Primary analysis compared the full oxygen system period to the pulse oximetry period and evaluated odds of death for children, children with ALRI, neonates, and preterm neonates using mixed-effects logistic regression. Secondary analyses included the baseline period (enabling evaluation of pulse oximetry introduction) and evaluated mortality and practice outcomes on additional subgroups. Three hospitals received the oxygen system intervention at 4-month intervals. Primary analysis included 7,716 neonates and 17,143 children admitted during the 2-year stepped crossover period (November 2015 to October 2017). Compared to the pulse oximetry period, the full oxygen system had no association with death for children (adjusted odds ratio [aOR] 1.06; 95% confidence interval [CI] 0.77-1.46; p = 0.721) or children with ALRI (aOR 1.09; 95% CI 0.50-2.41; p = 0.824) and was associated with an increased risk of death for neonates overall (aOR 1.45; 95% CI 1.04-2.00; p = 0.026) but not preterm/low-birth-weight neonates (aOR 1.30; 95% CI 0.76-2.23; p = 0.366). Secondary analyses suggested that the introduction of pulse oximetry improved oxygen practices prior to implementation of the full oxygen system and was associated with lower odds of death for children with ALRI (aOR 0.33; 95% CI 0.12-0.92; p = 0.035) but not for children, preterm neonates, or neonates overall (aOR 0.97, 95% CI 0.60-1.58, p = 0.913; aOR 1.12, 95% CI 0.56-2.26, p = 0.762; aOR 0.90, 95% CI 0.57-1.43, p = 0.651). Limitations of our study are a lower-than-anticipated power to detect change in mortality outcomes (low event rates, low participant numbers, high intracluster correlation) and major contextual changes related to the 2016-2017 Nigerian economic recession that influenced care-seeking and hospital function during the study period, potentially confounding mortality outcomes. CONCLUSIONS We observed no mortality benefit for children and a possible higher risk of neonatal death following the introduction of a multifaceted oxygen system compared to introducing pulse oximetry alone. Where some oxygen is available, pulse oximetry may improve oxygen usage and clinical outcomes for children with ALRI. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry: ACTRN12617000341325.

中文翻译：

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用于改善儿童和新生儿临床护理和结果的氧气系统：尼日利亚的一项阶梯楔形整群随机试验。

背景技术改善氧气系统可以改善患有急性下呼吸道感染（ALRI）的住院儿童的临床结果。本文报告了改进的氧气系统对尼日利亚西南部 12 家综合医院、儿科医院和妇产医院的死亡率和临床实践的影响。方法和结果我们进行了一项非盲阶梯楔形整群随机试验，比较了三个研究阶段：基线（常规护理）、脉搏血氧饱和度介绍和多方面氧气系统的逐步介绍。我们收集了所有入院新生儿（<28 天）和儿童（28 天至 14 岁）的临床记录数据。主要分析将全氧系统周期与脉搏血氧测定周期进行比较，并使用混合效应逻辑回归评估儿童、患有 ALRI 的儿童、新生儿和早产新生儿的死亡几率。二次分析包括基线期（能够评估脉搏血氧仪的引入）并评估其他亚组的死亡率和实践结果。3家医院每隔4个月接受一次氧气系统干预。主要分析包括 2 年阶梯交叉期间（2015 年 11 月至 2017 年 10 月）入院的 7,716 名新生儿和 17,143 名儿童。与脉搏血氧饱和度周期相比，全氧系统与儿童（调整后比值比 [aOR] 1.06；95% 置信区间 [CI] 0.77-1.46；p = 0.721）或 ALRI 儿童（aOR 1.09；p = 0.721）的死亡没有关联。 95% CI 0.50-2.41；p = 0.824），并且与新生儿总体死亡风险增加相关（aOR 1.45；95% CI 1.04-2.00；p = 0.026），但与早产/低出生体重新生儿无关（aOR 1.30；95% CI 0.76-2.23；p = 0.366）。二次分析表明，在实施全氧系统之前，脉搏血氧仪的引入改善了吸氧实践，并且与 ALRI 儿童较低的死亡几率相关（aOR 0.33；95% CI 0.12-0.92；p = 0.035），但对于儿童、早产新生儿或新生儿（aOR 0.97，95% CI 0.60-1.58，p = 0.913；aOR 1.12，95% CI 0.56-2.26，p = 0.762；aOR 0.90，95% CI 0.57-1.43，p = 0.651 ）。我们研究的局限性是检测死亡率结果变化的能力低于预期（低事件发生率、低参与者数量、高集群内相关性）以及与 2016-2017 年尼日利亚经济衰退相关的重大背景变化，这些变化影响了就医和医疗服务研究期间的医院功能，可能会混淆死亡率结果。结论 我们观察到，与单独引入脉搏血氧仪相比，引入多层面供氧系统后，儿童死亡没有任何益处，而且新生儿死亡风险可能更高。在有氧气可用的情况下，脉搏血氧测定法可以改善 ALRI 儿童的氧气使用量和临床结果。试验注册澳大利亚新西兰临床试验注册处：ACTRN12617000341325。