Supplementary Material for: Duration of Mechanical Ventilation and Extubation Success among Extremely Premature Infants

Objective: The objective of this study was to examine the duration of mechanical ventilation (MV) in days until the first successful extubation and the cumulative duration of MV until discharge of infants with gestational age (GA) Design and Setting: This population-based study analysed data reported to the Norwegian Neonatal Network on extremely premature infants admitted between January 1, 2013, and December 31, 2018. Results: A total of 406 infants were included, of which 293 (72%) survived to discharge. The proportion successfully extubated on their first attempt was 34% of the infants born at GA 22–23 weeks, 50% at GA 24 weeks, and 70% at GA 25 weeks. Median postmenstrual age (PMA) at the first successful extubation was 27 weeks. The median duration of MV was 35, 24, and 12 days for infants born at GA 22–23, 24, and 25 weeks, respectively. Male sex and low 5-min Apgar score were independent early predictors for prolonged MV duration adjusted for GA in regression analyses. Conclusions: Most of the infants born at GA 25 weeks were successfully extubated on the first attempt. However, half of the infants born <26 weeks experienced unsuccessful extubations, indicating a lack of useful clinical predictors of successful extubation. The median duration of MV in survivors was 4 weeks longer for infants at GA 22–23 weeks than for infants born at GA 25 weeks, while the difference in median PMA at the first successful extubation was 2 weeks.

研究目的：本研究旨在探讨不同胎龄（gestational age, GA）早产儿首次成功拔管前的有创机械通气（mechanical ventilation, MV）时长（以天计），以及直至出院前的累计有创机械通气时长。
研究设计与研究场景：本研究为基于人群的研究，分析了2013年1月1日至2018年12月31日期间入院的极早早产儿数据，相关数据已上报至挪威新生儿网络（Norwegian Neonatal Network）。
研究结果：本研究共纳入406例早产儿，其中293例（72%）存活至出院。胎龄22~23周的早产儿中，首次拔管尝试即成功的比例为34%；胎龄24周者为50%；胎龄25周者为70%。首次成功拔管时的校正胎龄（postmenstrual age, PMA）中位数为27周。胎龄22~23周、24周、25周早产儿的有创机械通气时长中位数分别为35天、24天、12天。经校正胎龄的回归分析显示，男性性别与5分钟阿普加（Apgar）评分偏低是有创机械通气时长延长的独立早期预测因素。
研究结论：胎龄25周的早产儿多数可首次拔管尝试成功。然而，胎龄小于26周的早产儿中，有半数出现拔管失败，提示目前尚缺乏可有效预测拔管成功的临床指标。存活早产儿的有创机械通气时长中位数，胎龄22~23周者较胎龄25周者长4周，而首次成功拔管时的校正胎龄中位数相差2周。