Ersdal H L, Eilevstjonn J, Perlman J, Gomo Ø, Moshiro R, Mdoe P, Kidanto H, Hooper S B, Linde J E
Critical Care and Anaesthesiology Research Group, Stavanger University Hospital, Norway; Faculty of Health Sciences, University of Stavanger, Norway.
Department of Research, Laerdal Medical/Laerdal Global Health, Tanke Svilands gate 30, 4002 Stavanger, Norway.
Resuscitation. 2020 Aug;153:71-78. doi: 10.1016/j.resuscitation.2020.05.033. Epub 2020 Jun 3.
Establishing functional residual capacity (FRC) during positive pressure ventilation (PPV) of apnoeic neonates is critical for survival. This may be difficult due to liquid-filled airways contributing to low lung compliance. The objectives were to describe initial PPV, changes in lung compliance and establishment of FRC in near-term/term neonates ≥36 weeks gestation at birth.
Observational study of all neonatal resuscitations between 01.07.13 and 30.06.18 in a Tanzanian referral hospital. Perinatal events and characteristics were observed and recorded by trained research assistants. PPV were performed using self-inflating bag-masks without positive end-expiratory pressure (PEEP). Ventilation signals (pressure/flow), expired CO (ECO) and heart rate were recorded by resuscitation monitors.
19,587 neonates were born, 1451 received PPV, of these 821 of median (p25, p75) birthweight 3180 (2844, 3500) grams and gestation 38 (37, 40) weeks had ≥20 ventilations and complete datasets. There was a significant increase in expired volume (from 3.3 to 6.0 ml/kg), ECO (0.3-2.4%), lung compliance (0.13-0.19 ml/kg/mbar) and heart rate (109-138 beats/min) over the first 20 PPVs. Inflation volume, time, and peak inflation pressure (PIP) were stable around 12-13 ml/kg, 0.45 s, and 36 mbar, respectively.
The combination of increasing expired volumes, ECO, and heart rate with decreasing inflation/expired volume ratios and constant PIP, suggests establishment of FRC during the first 20 PPVs in near-term/term neonates using a self-inflating bag-mask without PEEP, the most common device worldwide for ventilating non-breathing neonates. Initial lung compliance is low, and with short inflation times, higher than recommended PIP seem necessary to deliver adequate tidal volumes.
在呼吸暂停新生儿的正压通气（PPV）过程中建立功能残气量（FRC）对其存活至关重要。由于气道充满液体导致肺顺应性降低，这可能会很困难。本研究的目的是描述出生时孕周≥36周的近足月/足月新生儿的初始PPV、肺顺应性变化以及FRC的建立情况。
对坦桑尼亚一家转诊医院2013年7月1日至2018年6月30日期间所有新生儿复苏情况进行观察性研究。由经过培训的研究助理观察并记录围产期事件和特征。使用无呼气末正压（PEEP）的自动充气式面罩进行PPV。通过复苏监测仪记录通气信号（压力/流量）、呼出二氧化碳（ECO）和心率。
共出生19587例新生儿，1451例接受了PPV，其中821例出生体重中位数（第25百分位数，第75百分位数）为3180（2844，3500）克，孕周为38（37，40）周，接受了≥20次通气且有完整数据集。在最初的20次PPV过程中，呼出量（从3.3增加至6.0毫升/千克）、ECO（从0.3%增加至2.4%）、肺顺应性（从0.13增加至0.19毫升/千克/毫巴）和心率（从109次/分钟增加至138次/分钟）均有显著增加。充气量、时间和峰值充气压力（PIP）分别稳定在12 - 13毫升/千克、0.45秒和36毫巴左右。
呼出量、ECO和心率增加，同时充气/呼出量比值降低且PIP恒定，这表明在使用无PEEP自动充气式面罩对近足月/足月新生儿进行最初20次PPV期间建立了FRC，这是全球用于给无呼吸新生儿通气的最常用设备。初始肺顺应性较低，且由于充气时间较短，似乎需要高于推荐值的PIP才能输送足够的潮气量。
