Division of Asthma, Allergy & Lung Biology, MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, UK.
Arch Dis Child Fetal Neonatal Ed. 2012 Jul;97(4):F264-6. doi: 10.1136/archdischild-2011-301041. Epub 2011 Dec 22.
To determine the impact of different volume-targeted (VT) levels during volume-targeted ventilation (VTV) on the work of breathing (WOB) of infants born at or near term and to investigate whether a level of VT reduced the WOB below that experienced on respiratory support without VT.
Prospective crossover study.
Sixteen infants, median gestational age of 38 (range 34-41) weeks, birth weight of 3.1 (range 1.5-4.1) kg and postnatal age of 5 (range 2-17) days were studied. The infants were receiving time-cycled, pressure-limited ventilation in a continuous mandatory or in a triggered mode.
The infants were studied first without VT (baseline) and then at VT levels of 4, 5 and 6 ml/kg delivered in a random order. After each VT level, the infants were returned to baseline.
The WOB was assessed by measuring the transdiaphragmatic pressure-time product (PTPdi).
One infant became apnoeic at VT of 6 ml/kg. At a VT level of 4 ml/kg, four infants were making such vigorous respiratory efforts that no inflations were delivered. The median PTPdi was higher at a VT level of 4 ml/kg than at 5 ml/kg (p<0.01) or 6 ml/kg (p<0.001). Only at a VT level of 6 ml/kg was the median PTPdi lower than that at baseline (p<0.01).
Low VT levels (4 ml/kg) during VTV increase the WOB in ventilated infants born at term or near term. The results suggest that a VT level of 6 ml/kg could be used to reduce the WOB.
确定不同容量目标（VT）水平在容量目标通气（VTV）期间对接近足月或足月出生婴儿呼吸功（WOB）的影响，并研究是否存在降低 WOB 的 VT 水平低于无 VT 时的呼吸支持水平。
前瞻性交叉研究。
16 名婴儿，中位胎龄为 38 周（范围 34-41 周），出生体重为 3.1kg（范围 1.5-4.1kg），出生后年龄为 5 天（范围 2-17 天）。婴儿接受定时、压力限制通气，采用持续强制或触发模式。
婴儿首先在无 VT（基线）的情况下进行研究，然后以随机顺序分别在 4、5 和 6ml/kg 的 VT 水平下进行研究。在每个 VT 水平后，婴儿恢复到基线。
通过测量膈神经压力-时间乘积（PTPdi）来评估 WOB。
一名婴儿在 VT 为 6ml/kg 时出现呼吸暂停。在 4ml/kg 的 VT 水平下，有 4 名婴儿进行了如此剧烈的呼吸努力，以至于没有进行通气。4ml/kg 的 VT 水平下的中位 PTPdi 高于 5ml/kg（p<0.01）或 6ml/kg（p<0.001）。只有在 6ml/kg 的 VT 水平下，中位 PTPdi 低于基线（p<0.01）。
VTV 期间的低 VT 水平（4ml/kg）会增加接近足月或足月出生婴儿的 WOB。结果表明，6ml/kg 的 VT 水平可用于降低 WOB。
