Wheeler Kevin, Klingenberg Claus, McCallion Naomi, Morley Colin J, Davis Peter G
Department of Paediatrics, Royal Women's Hospital, Locked Bag 300, 20 Flemington Rd, Parkville, Victoria, Australia, 3052.
Cochrane Database Syst Rev. 2010 Nov 10(11):CD003666. doi: 10.1002/14651858.CD003666.pub3.
Damage caused by lung overdistension (volutrauma) has been implicated in the development bronchopulmonary dysplasia (BPD). Modern neonatal ventilation modes can target a set tidal volume as an alternative to traditional pressure-limited ventilation using a fixed inflation pressure. Volume targeting aims to produce a more stable tidal volume in order to reduce lung damage and stabilise pCO(2)
To determine whether volume-targeted ventilation (VTV) compared with pressure-limited ventilation (PLV) leads to reduced rates of death and BPD in newborn infants. Secondary objectives were to determine whether use of VTV affected outcomes including air leak, cranial ultrasound findings and neurodevelopment.
The search strategy comprised searches of the Cochrane Central Register of Controlled Trials, MEDLINE PubMed 1966 to January 2010, and hand searches of reference lists of relevant articles and conference proceedings.
All randomised and quasi-randomised trials comparing the use of volume-targeted versus pressure-limited ventilation in infants of less than 28 days corrected age.
Two review authors assessed the methodological quality of eligible trials and extracted data independently. When appropriate, meta-analysis was conducted to provide a pooled estimate of effect. For categorical data the relative risk (RR) and risk difference (RD) were calculated with 95% confidence intervals. Number needed to treat was calculated when RD was statistically significant. Continuous data were analysed using weighted mean difference.
Twelve randomised trials met our inclusion criteria; nine parallel trials (629 infants) and three crossover trials (64 infants).The use of VTV modes resulted in a reduction in the combined outcome of death or bronchopulmonary dysplasia [typical RR 0.73 (95% CI 0.57 to 0.93), NNT8 (95% CI 5 to 33)]. VTV modes also resulted in reductions in pneumothorax [typical RR 0.46 (95% CI 0.25 to 0.84), NNT 17 (95% CI 10 to 100)], days of ventilation [MD -2.36 (95% CI -3.9 to -0.8)], hypocarbia [typical RR 0.56 (95%CI 0.33 to 0.96), NNT 4 (95% CI 2 to 25)] and the combined outcome of periventricular leukomalacia or grade 3-4 intraventricular haemorrhage [typical RR 0.48 (95% CI 0.28 to 0.84), NNT 11 (95% CI 7 to 50)].
AUTHORS' CONCLUSIONS: Infants ventilated using VTV modes had reduced death and chronic lung disease compared with infants ventilated using PLV modes. Further studies are needed to identify whether VTV modes improve neurodevelopmental outcomes and to compare and refine VTV strategies.
肺过度扩张（容积伤）所造成的损害被认为与支气管肺发育不良（BPD）的发生有关。现代新生儿通气模式可以设定目标潮气量，以此替代使用固定充气压力的传统压力限制通气。容积目标通气旨在产生更稳定的潮气量，以减少肺损伤并稳定pCO₂。
确定与压力限制通气（PLV）相比，容积目标通气（VTV）是否能降低新生儿的死亡率和BPD发生率。次要目的是确定使用VTV是否会影响包括气漏、头颅超声检查结果和神经发育等结局。
检索策略包括检索Cochrane对照试验中心注册库、1966年至2010年1月的MEDLINE PubMed，以及手工检索相关文章的参考文献列表和会议论文集。
所有比较使用容积目标通气与压力限制通气对矫正年龄小于28天婴儿影响的随机和半随机试验。
两名综述作者评估了符合条件试验的方法学质量并独立提取数据。在适当情况下，进行荟萃分析以提供合并效应估计值。对于分类数据，计算相对风险（RR）和风险差（RD）及其95%置信区间。当RD具有统计学意义时计算所需治疗人数。连续数据使用加权均数差进行分析。
12项随机试验符合我们的纳入标准；9项平行试验（629名婴儿）和3项交叉试验（64名婴儿）。使用VTV模式可降低死亡或支气管肺发育不良的合并结局[典型RR 0.73（95%CI 0.57至0.93），NNT 8（95%CI 5至33）]。VTV模式还可降低气胸发生率[典型RR 0.46（95%CI 0.25至0.84），NNT 17（95%CI 10至100）]、通气天数[MD -2.36（95%CI -3.9至-0.8）]、低碳酸血症[典型RR 0.56（95%CI 0.33至0.96），NNT 4（95%CI 2至25）]以及脑室周围白质软化或3-4级脑室内出血的合并结局[典型RR 0.48（95%CI 0.28至0.84），NNT 11（95%CI 7至50）]。
与使用PLV模式通气的婴儿相比，使用VTV模式通气的婴儿死亡率和慢性肺病发生率更低。需要进一步研究以确定VTV模式是否能改善神经发育结局，并比较和完善VTV策略。
