Farrell Olivia, Perkins Elizabeth J, Black Don, Miedema Martijn, Paul Joel Don, Pereira-Fantini Prue M, Tingay David Gerald
Neonatal Research, Murdoch Children's Research Institute, Melbourne, Australia.
Department of Paediatrics, University of Melbourne, Melbourne, Australia.
Arch Dis Child Fetal Neonatal Ed. 2018 Mar;103(2):F120-F125. doi: 10.1136/archdischild-2017-312640. Epub 2017 Jun 28.
Volume-targeted ventilation (VTV) is widely used and may reduce lung injury, but this assumes the clinically set tidal volume (V) is accurately delivered. This prospective observational study aimed to determine the relationship between V, expiratory V (V) and endotracheal tube leak in a modern neonatal -volume-targeted ventilator (VTV) and the resultant partial arterial pressure of carbon dioxide (PaCO) relationship with and without VTV.
Continuous inflations were recorded for 24 hours in 100 infants, mean (SD) 34 (4) weeks gestation and 2483 (985) g birth weight, receiving synchronised mechanical ventilation (SLE5000, SLE, UK) with or without VTV and either the manufacturer's V4 (n=50) or newer V5 (n=50) VTV algorithm. The V, V and leak were determined for each inflation (maximum 90 000/infant). If PaCO was sampled (maximum of 2 per infant), this was compared with the average V data from the preceding 15 min.
A total of 7 497 137 inflations were analysed. With VTV enabled (77 infants), the V-V bias (95% CI) was 0.03 (-0.12 to 0.19) mL/kg, with a median of 80% of V being ±1.0 mL/kg of V. Endotracheal tube leak up to 30% influenced V-V bias with the V4 (r=-0.64, p<0.0001; linear regression) but not V5 algorithm (r=0.04, p=0.21). There was an inverse linear relationship between V and PaCO without VTV (r=0.26, p=0.004), but not with VTV (r=0.04, p=0.10), and less PaCO within 40-60 mm Hg, 53% versus 72%, relative risk (95% CI) 1.7 (1.0 to 2.9).
VTV was accurate and reliable even with moderate leak and PaCO more stable. VTV algorithm differences may exist in other devices.
容量目标通气（VTV）被广泛应用，可能会减少肺损伤，但这是假设临床设定的潮气量（V）能准确输送。这项前瞻性观察性研究旨在确定在现代新生儿容量目标通气机中V、呼气末V（V）与气管插管漏气之间的关系，以及在有和没有VTV的情况下由此产生的二氧化碳分压（PaCO）关系。
对100名婴儿进行了24小时的持续充气记录，这些婴儿平均（标准差）孕周为34（4）周，出生体重为2483（985）克，接受有或没有VTV的同步机械通气（SLE5000，SLE，英国），以及制造商的V4（n = 50）或更新的V5（n = 50）VTV算法。确定每次充气（每个婴儿最多90000次）的V、V和漏气情况。如果采集了PaCO（每个婴儿最多2次），则将其与前15分钟的平均V数据进行比较。
共分析了7497137次充气。启用VTV（77名婴儿）时，V - V偏差（95%CI）为0.03（-0.12至0.19）mL/kg，V的中位数为V的80%±1.0 mL/kg。高达30%的气管插管漏气会影响V4的V - V偏差（r = -0.64，p < 0.0001；线性回归），但不影响V5算法（r = 0.04，p = 0.21）。在没有VTV的情况下，V与PaCO之间存在负线性关系（r = 0.26，p = 0.004），但在有VTV的情况下不存在（r = 0.04，p = 0.10），并且在40 - 60 mmHg范围内PaCO更低，分别为53%和72%，相对风险（95%CI）为1.7（1.0至2.9）。
即使存在中度漏气且PaCO更稳定，VTV也是准确可靠的。其他设备可能存在VTV算法差异。
