雾化吸入布地奈德混悬液治疗婴幼儿轻中度喘息性疾病的疗效

目的探讨雾化吸入布地奈德混悬液治疗婴幼儿轻中度喘息性疾病的疗效。方法将2006年1—12月收入重庆医科大学附属儿童医院呼吸中心病房的轻中度喘息性疾病婴幼儿120例作为研究对象。其中毛细支气管炎56例，喘息性支气管炎11例，婴幼儿哮喘53例。男64例，女56例；年龄1个月-3岁。按入院先后顺序随机分为治疗和对照组。治疗组患儿在常规综合治疗（解痉平喘、止咳化痰及病因治疗等）基础上，空气压缩泵雾化吸入布地奈德混悬液，1个月～1岁0．5mr／次，〉1—3岁1．0mg／次，2次／d。对照组采用空气压缩泵雾化吸入地塞米松，1个月～1岁5．0mg／次，〉1—3岁7．5mg／次，2次／d。二组患儿喘息症状缓解停药。对二组治疗前后症状、体征、病程及肺功能进行比较。采用SPSS12．0软件进行统计学分析。结果治疗组在喘息缓解、咳嗽缓解、哮鸣音消失及住院时间缩短方面均明显优于对照组（t=3．98，5．44，4．61，2．96Pa〈0．01）。治疗组治疗后（5～7d）的肺功能指标与对照组比较，潮气量（VT）和最大呼气流量（PEF）改善非常明显（t=5．57，2．96Pa〈0．01），呼吸频率（RR）、达峰时间比（％T-PF）、达峰容积比（％V—PF）也明显改善（t=2．26，2．29，2．41Pa〈0．05）。结论雾化吸入布地奈德混悬液治疗婴幼儿轻中度喘息性疾病临床疗效确切、安全性高，优于地塞米松雾化吸入。     

氧驱动雾化吸入控制婴幼儿哮喘急性发作临床观察

为评价氧驱动雾化吸入控制婴幼儿哮喘急性发作的临床效果及安全性，探讨婴幼儿哮喘急性发作时的最佳控制方案，将220例婴幼儿哮喘急性发作的病儿分治疗组(120例)，对照组(100例)。治疗组按顺序分配首选给予雾化吸入1，2，3号各40例。对照组首选给予静脉滴注糖皮质激素加短效β-受体激动剂吸入，后续治疗同治疗组。观察其用药后30min喘息改善情况、SaO2值、入院率、治疗l周经济费用等，并观察其安全性(雾化时是否有短暂缺氧)。结果：治疗组与对照组24小时哮喘分度、SaO2、l周疗效、入院率及安全性对比差异无显著性；而30min后肺部体征改善及l周内经济支出有明显差异；3组不同的雾化药液治疗结果也有一定差异。提示：控制婴幼儿哮喘急性发作，氧驱动雾化吸入较静脉用药有明显优越性；推荐糖皮质激质激素雾化液 短效β-受体激动剂作为雾化用药。     

硫酸镁和/或沙丁胺醇雾化吸入对哮喘患儿吸入乙酰胆碱激发后肺功能影响的随机对照研究

目的观察硫酸镁雾化能否改善哮喘患儿吸入乙酰胆碱激发后的肺功能,并与雾化吸入沙丁胺醇和硫酸镁＋沙丁胺醇进行比较。方法330例乙酰胆碱激发试验阳性的哮喘患儿随机分为3组,3组分别给予雾化吸入硫酸镁,沙丁胺醇,硫酸镁+沙丁胺醇,观察用药后2个时点（10 和20 min）第1秒用力呼气量（FEV1）、最大呼气流速(PEF）的肺功能指标。结果①3组患儿用药后2个时点的FEV1、PEF值均较激发值显著上升（P<0.05）,但3组2个时点的FEV1、PEF值两两比较差异无统计学意义（P>0.05）;②沙丁胺醇组及硫酸镁+沙丁胺醇组2个时点的FEV1、PEF值占预计值的百分比高于硫酸镁组（P<0.05）;③硫酸镁组和硫酸镁+沙丁胺醇组用药后20 min时点的FEV1及PEF值占预计值的百分比高于用药后10 min时点的百分比（P<0.05）。 结论硫酸镁雾化吸入能改善哮喘患儿吸入乙酰胆碱激发后的肺功能,但其效果不如单用沙丁胺醇;硫酸镁+沙丁胺醇联合应用不具有协同效应。     

布地奈德联合特布他林雾化吸入治疗毛细支气管炎

目的 观察布地奈德联合特布他林空气压缩泵雾化吸入治疗毛细支气管炎的疗效.方法 将80例毛细支气管炎患儿随机分为观察组和对照组,二组均予常规治疗.观察组加用布地奈德、特布他林空气压缩泵雾化吸入治疗.记录治疗5 d后喘息、哮鸣音有无减轻或消失及治疗后症状、体征消失的时间.并对治疗5 d后二组疗效进行比较.结果 治疗5 d后观察组显效率和有效率分别为50.0%和92.5%,明显高于对照组的25.0%和62.5%(Pa <0.001).观察组呼吸困难、咳嗽、喘息、哮鸣音、痰鸣青等消失时间与对照组比较均有显著性差异(P1 <0.05).结论 布地奈德联合特布他林空气压缩泵雾化吸入治疗毛细支气管炎能够迅速改善症状,缩短病程.     

布地奈德联合全乐宁雾化吸入治疗婴幼儿哮喘疗效分析

目的探讨布地奈德联合全乐宁雾化吸入治疗婴幼儿哮喘的疗效。方法将86例婴幼儿哮喘急性发作患儿分为治疗组（30例），对照组1组（26例），对照组2组（30例），3组病例在综合治疗基础上，治疗组给予布地奈德联合全乐宁雾化吸入治疗，对照1组给全乐宁雾化吸入，对照2组给氨茶碱片曰服。结果治疗组临床控制率明显高于对照1组及对照2组，差异有统计学意义（P〈0．05）。结论布地奈德联合全乐宁雾化吸入能有效控制婴幼儿哮喘急性发作，值得临床推广。     

经空气压缩泵吸入普米克令舒治疗婴幼儿急性喉炎50例疗效观察

目的探讨局部应用普米克令舒吸入治疗急性喉炎与全身大剂量应用激素的疗效对比。方法治疗组和对照组各随机选取50例婴幼儿急性喉炎患儿，传统治疗方案是在控制感染的基础上全身应用强的松和地塞米松，治疗组在控制感染的基础上利用空气压缩泵雾化吸入普米克令舒。结果治疗组在症状缓解时间上与对照组相比差异有显著性（P〈0．05），未发现任何毒副作用。结论利用空气压缩泵雾化吸入普米克令舒在治疗婴幼儿急性喉炎中效果肯定、疗效确切，可完全取代全身大剂量应用糖皮质激素，应在基层医院中大力推广。     

联合吸入布地奈德混悬液和特布他林雾化液治疗婴幼儿哮喘的疗效

目的探讨联合吸入布地奈德混悬液和特布他林雾化液治疗婴幼儿哮喘的疗效及安全性。方法对75例哮喘婴幼儿采用双盲对照随机抽样法,设单纯吸入特布他林雾化液（A组）及联合吸入布地奈德混悬液和特布他林雾化液（B组）、单纯吸入布地奈德混悬液（C组）3组分别进行治疗,每组25例。观察比较3组疗效及安全性。结果A组治愈16例,显效3例,无效6例,总有效率76%;B组治愈22例,显效2例,无效1例,总有效率96%;C组治愈14例,显效4例,无效7例,总有效率72%。A、B组总有效率比较有显著性差异（P〈0.05）;B、C组总有效率比较有显著性差异（P〈0.05）;A、C组总有效率比较差异无显著性（P〉0.05）。结论联合吸入布地奈德混悬液和特布他林雾化液治疗婴幼儿哮喘疗效优于单纯吸入特布他林雾化液和单纯吸入布地奈德混悬液,不良反应少,安全性好。     

支气管可逆性试验对哮喘儿童治疗的指导意义

目的：观察哮喘治疗期间不同临床症状患儿肺功能的变化,探讨支气管可逆性试验对儿童哮喘治疗的指导意义。方法：417例哮喘患儿通过吸入沙美特罗/氟替卡松治疗时间3个月以上。复诊时根据患儿症状分为无症状组（n=215）、单咳组（n=89）、阵咳组（n=72）和喘咳组（n=41）。34例正常儿童作为对照组。应用沙丁胺醇泵雾化进行支气管可逆性试验,试验前后行肺功能检测。结果：各个哮喘组沙丁胺醇雾化后肺功能异常率较雾化前均明显降低,FEV1%/预测值雾化后均较雾化前显著升高（P<0.05）。雾化前单咳组、阵咳组、喘咳组肺功能异常率均较对照组显著增高,FEV1%/预测值均较对照组显著降低（P<0.05）;雾化前各个不同症状哮喘组间肺功能异常率及FEV1%/预测值差异有统计学意义（P<0.05）。雾化后阵咳组、喘咳组肺功能异常率明显高于对照组（P<0.05）,其他各组与对照组比较差异无统计学意义;雾化后喘咳组FEV1%/预测值明显低于对照组,其他各组与对照组比较差异无统计学意义。不同症状的4个哮喘组支气管可逆性试验阳性率均高于对照组（P<0.05）;各个哮喘组间可逆性试验阳性率比较,除无症状组与单咳组差异无统计学意义外,其余各组间差异均有统计学意义（P<0.05）。结论：儿童哮喘治疗期间不同症状者肺功能存在差异;支气管可逆性试验结合肺功能检查有利于哮喘控制的评估和治疗指导。     

硫酸沙丁胺醇联合溴化异丙托品治疗婴幼儿喘息性支气管炎疗效观察

目的 观察硫酸沙丁胺醇联合溴化异丙托品治疗婴幼儿喘息性支气管炎的疗效.方法 74例喘息性支气管炎患儿分为2组,治疗组35例,对照组39例,两组患儿均应用0.5％硫酸沙丁胺醇,剂量为0.25 ml/次,加生理盐水至2～3ml,空气压缩泵雾化吸入,每日2次,每次10～15 min,疗程5～7d.治疗组在应用0.5％硫酸沙丁胺醇的同时加用0.025％溴化异丙托品,≤1岁1ml/次,～3岁2mL/次,每天2次经空气压缩泵雾化吸入,疗程5～7d.结果 治疗组有效率为94.3％ (33/35),对照组有效率为64.1％ (25/39),两组差异有统计学意义(x2=9.92,P＜0.01).结论 溴化异丙托品和硫酸沙丁胺醇联合雾化吸入具有更好的气管舒张效果,而且发生心悸、骨骼肌震颤、心律紊乱、低血钾等不良反应明显减少.     

雾化吸入硫酸镁对哮喘患儿肺功能影响的系统评价和Meta分析

目的 系统评价雾化吸入硫酸镁对儿童哮喘急性发作的疗效和安全性。方法 检索 PubMed、Medline、EMBASE、Cochrane图书馆、中国生物医学文献数据库、万方数据库、中国知网及维普中文科技期刊数据库,检索时间均从建库至 2014年7月31日,获得雾化吸入硫酸镁治疗儿童哮喘的RCT文献。根据 Cochrane系统评价员手册推荐的方法行文献质量评价。以吸入硫酸镁后10、20 min时点肺功能作为主要结局指标,住院率、哮喘严重程度评分和不良事件作为次要结局指标。效应量以SMD及其95%CI表示,采用RevMan 软件进行Meta 分析,并根据不同肺功能指标和硫酸镁用药方式（单用或合用）行亚组分析。结果 8 篇RCT文献（n=1 161）进入Meta分析。①吸入后10 、20 min时点总体肺功能指标,硫酸镁组与对照组差异无统计学意义（10 min：SMD＝-0.32,95%CI：-0.67~0.04,P=0.08;20 min：SMD＝-0.11,95%CI：-0.40~0.17,P=0.43）。②按不同肺功能指标和硫酸镁用药方式亚组分析结果显示,吸入后10、20 min,PEF较基线增加百分比硫酸镁组显著低于沙丁胺醇组（10 min：SMD=-0.75,95%CI: -1.29~-0.22,P=0.005;20 min：SMD=-0.46,95%CI: -0.72~-0.20,P=0.006）;FEV1占预计值百分比硫酸镁+沙丁胺醇组与对照组差异无统计学意义（10 min：SMD=-0.03,95%CI：-0.52~-0.46,P=0.89;20 min：SMD＝0.04,95%CI：-0.29~0.37,P=0.81）;PEF占预计值百分比硫酸镁+沙丁胺醇组与对照组差异无统计学意义（10 min：SMD=-0.02,95%CI ：-0.23~0.19,P=0.83;20 min：SMD=0.05,95%CI： -0.31~0.42,P=0.78）。③硫酸镁组和对照组在次要结局指标方面总体上没有表现出较大的差别。结论 硫酸镁雾化吸入相较于常规雾化治疗无明显优势,单用硫酸镁雾化吸入效果不如沙丁胺醇,硫酸镁与沙丁胺醇联合雾化吸入相较于单用沙丁胺醇无明显协同作用。     

喘乐宁空气压缩雾化治疗婴儿毛细支气管炎疗效判定

目的　应用 β2 受体激动剂治疗的急性毛细支气管炎效果一直有争议。该研究观察毛细支气管炎患儿喘乐宁雾化吸入治疗前后肺功能的变化 ,并探讨其临床意义。方法　 30例急性毛细支气管炎患儿随机分为治疗组 1 6例 (喘乐宁雾化吸入 )和对照组 1 4例 (生理盐水雾化吸入 ) ,在雾化吸入前、吸入后即刻、1 5min和 30min分别测定潮气呼吸流速容量环 (TBFV)、呼吸系统静态顺应性及阻力的变化。结果　治疗组到达潮气呼气峰流速时呼出气量 /潮气量 (%V PF)在吸入后 30min与吸入前比较 ,差异有显著性 (P <0 .0 5 )。两组雾化后即刻 2 5 /PF、吸气时间 (Ti)差异有显著性 (P <0 .0 5 )。结论　喘乐宁雾化吸入后 30min可明显降低小气道阻力 ,改善通气。     

Co-administration of salbutamol and fluticasone for emergency treatment of children with moderate acute asthma.

This study aimed to compare the efficacy of nebulized therapy with salbutamol alone or in combination with fluticasone. In a randomized, double-blind clinical trial, 150 children with moderate acute asthma were randomly assigned to receive by nebulizations either (i) three doses of salbutamol 30 microl/kg per dose, each dose administered every 15 min, (ii) three doses of salbutamol plus two doses of fluticasone 500 microg/dose at 15 and 30 min after first dose of salbutamol, or (iii) three doses of salbutamol/fluticasone 500 microg/dose, each combined dose administered every 15 min. Pulse oxymetry (SaO2), peak expiratory flow (PEF) and Wood et al. (Am J Dis Child, 123, 1972, 123) clinical scale were evaluated at baseline, 15, 30, 45, 60, 90 and 120 min after the first nebulization. Patients in the three groups significantly improved since 15 min after the first nebulization. We did not observe differences in the recovery of SaO2 and PEF among the three groups of treatment (p > 0.10). In group 3, children showed better clinical response at 120 min than the other two groups (p < 0.05). No significant adverse effects were observed with any treatment. To summarize, in children with acute moderate asthma, nebulized salbutamol at an accumulated dose of 90 mul/kg plus fluticasone at an accumulated dose of 1500 microg produced better clinical relief after 2 h. However, similar PEF and SaO2 responses were observed with salbutamol alone or in combination with different doses of fluticasone.     

Oxygen desaturation during sleep in infants and young children with congenital heart disease.

Oxygen saturation (SaO2) during sleep and pulmonary functions were evaluated in 19 infants with congenital heart disease, aged 6 +/- 4 months, and in 11 normal infants, aged 8 +/- 5 months, to determine whether infants with congenital heart disease have more frequent oxygen desaturation during sleep and, if so, its relationship to underlying pulmonary function. Infants with congenital heart disease were classified as acyanotic (n = 11) or cyanotic (n = 8) on the basis of their aortic SaO2 at the time of cardiac catheterization (greater or less than 90% SaO2). Pulmonary function tests included respiratory rate, functional residual capacity, total respiratory system compliance, and maximal flows at functional residual capacity. Significant differences were found in the values for the lowest SaO2 of each 5-minute epoch (SaO2L) averaged during the entire sleep time (normal 94% +/- 2%, acyanotic 90% +/- 3%, and cyanotic 74% +/- 4%; p less than 0.01). The three groups also differed significantly in frequency distributions of percentage of total sleep time with SaO2L less than 90% (SaO2%T) (normal 10% +/- 17%, acyanotic 36% +/- 34%, and cyanotic 97% +/- 4%; p less than 0.05). Compared with the control group, the acyanotic group had a higher respiratory rate (66 +/- 19 breaths/min vs 35 +/- 6 breaths/min; p less than 0.01), a lower tidal volume (65% +/- 29% predicted vs 105% +/- 18% predicted; p less than 0.01), and a lower total respiratory compliance (59% +/- 18% predicted vs 106% +/- 30% predicted; p less than 0.01). A negative correlation existed between SaO2%T and aortic SaO2 (R2 = 0.64; p less than 0.01). We conclude that oxygen desaturation occurs during sleep in infants with congenital heart disease; the presence of desaturation appears to be related to the initial degree of hypoxemia and the presence of abnormal pulmonary function.     

In vitro evaluation of bronchodilator drug delivery by jet nebulization during pediatric mechanical ventilation.

OBJECTIVE: To determine the influence of jet nebulizer brands and nebulization mode on albuterol delivery in a mechanically ventilated pediatric lung model. DESIGN: In vitro, laboratory study. SETTING: Research laboratory of a university hospital. INTERVENTIONS: Using albuterol as a marker, six jet nebulizers (Microneb NA420, Sidestream, Acorn II, Cirrus, Upmist, Micro Mist) were tested in four nebulization modes in a bench model mimicking the ventilatory pattern of a 10-kg infant (Galileo ventilator, Hamilton Medical). The amounts of albuterol deposited on the inspiratory filters at the end of the endotracheal tube were determined, as well as the pressure, flow profiles, and particle size distribution of the jet nebulizers. MEASUREMENTS AND MAIN RESULTS: Pooling the data of the six jet nebulizer brands (n = 30) indicated that intermittent nebulization during the expiratory phase was more efficient (6.5 +/- 2.5% of the initial dose, p < .001) than intermittent nebulization during the inspiratory phase (1.9 +/- 1.2%) and continuous nebulization with air from the ventilator (4.0 +/- 1.5%) or from an external source (4.2 +/- 1.4%). The particle size distribution at 6 L x min(-1) was between 2.81 and 3.30 microm. CONCLUSIONS: In our in vitro pediatric lung model, the quantity of inhaled drug was low. Jet nebulizer brands and nebulization modes significantly affected drug delivery, and in vitro models designed for adults cannot be extrapolated to infants.     

支气管哮喘患儿外周血辅助性T淋巴细胞17、白细胞介素-17、白细胞介素-21水平变化

目的 检测辅助性T淋巴细胞17(Th17)及细胞因子IL-17、IL-21在支气管哮喘(哮喘)患儿外周血中的表达,探讨其在儿童哮喘发病机制中的作用.方法 以哮喘患儿60例(哮喘组)为研究对象,根据病情分为哮喘发作期(发作期组,n=30)、哮喘缓解期(缓解期组,n=30);以健康儿童30例作为健康对照组.分离外周血单个核细胞,采用流式细胞术检测其Th17细胞百分率.采用ELISA法检测各组IL-17、IL-21表达水平.采用SPSS 13.0软件进行统计学分析.结果 哮喘发作期组患儿外周血中Th17及 IL-17 水平明显高于缓解期组和健康对照组(Pa<0.05);哮喘发作期组患儿血清IL-21表达水平明显低于缓解期组和健康对照组(Pa<0.05);哮喘缓解期组与健康对照组外周血Th17、IL-17、IL-21水平比较,差异均无统计学意义(Pa>0.05).结论 Th17、IL-17通过全身系统性炎症反应参与儿童哮喘的发病,IL-21可作为儿童哮喘的控制指标,亦有望为哮喘的治疗提供新的靶点.     

Efficacy and safety of a home-made non-valved spacer for bronchodilator therapy in acute asthma

The aim of this study was to assess the efficacy and safety of an alternative spacer to deliver salbutamol in acute asthma. A prospective randomized study was performed with 196 patients with acute asthma, aged 4-15 y. The clinical features, oxygen saturation (SaO2) and the best of three peak expiratory flow rate (PEFR) measurements were recorded in a standardized questionnaire. Each patient received up to three conventional doses of salbutamol through an alternative home-made non-valved spacer (NVS) (500 ml mineral water plastic bottle) or an oxygen-driven nebulizer (ODN). The clinical and functional respiratory parameters (PEFR and SaO2) were assessed 15 min after each administration of the bronchodilator. In the ODN (n = 99) and NVS (n = 97) groups, PEFR (p > 0.05) and SaO2 (p > 0.05) measurements improved in all stages of the treatment. During the asthma attacks, the ODN group needed a prolonged observation in the emergency room (p = 0.000000). Side effects of salbutamol, e.g. increased heart rate, were observed in 17.2% of the patients in the ODN group and 4.1% in the NVS group (p = 0.003). CONCLUSION: Both devices showed comparable efficacy in mild and moderate acute attacks, but the use of the alternative NVS resulted in a shorter observation period in the emergency room. The frequency of side effects was significantly higher in the ODN group than in the NVS group.     

Clara细胞分泌蛋白10基因G38A多态性与5岁以下喘息患儿的相关性

目的探讨5岁以下喘息患儿Clara细胞分泌蛋白10(CC10)基因G38A位点多态性与喘息发病机制的关系。方法随机选取于本院就诊的5岁以下反复喘息患儿120例,分为有特应质高危因素的喘息Ⅰ组(n=67)(湿疹45例,父母或父母一方有哮喘病史13例,变应性鼻炎5例,变应性皮炎4例)和无特应质高危因素的喘息Ⅱ组(n=53);对照组为本院外科近期无感染疾病史、择期进行手术的术前患儿(n=55)。采用PCR-限制性片段长度多态性分析对喘息组和对照组患儿CC10 G38A位点基因型频率和等位基因频率进行检测,比较3组间CC10 G38A位点基因型频率和等位基因频率。结果喘息Ⅰ组、喘息Ⅱ组和对照组3种基因型AA、GA、GG分布频率分别为20.9%、44.8%、34.3%,9.4%、32.1%、58.5%、9.1%、31.0%、60.0%;喘息Ⅰ组和喘息Ⅱ组CC10基因G38A位点基因型频率比较差异有统计学意义(P<0.05);喘息Ⅰ组和对照组CC10基因G38A位点基因型频率比较差异亦具有统计学意义(P<0.05)。喘息Ⅰ组、喘息Ⅱ组和对照组38A和38G等位基因频率分别为43.3%、56.7%,25.5%、74.5%,24.5%、75.5%;喘息Ⅰ组和喘息Ⅱ组、喘息Ⅰ组和对照组比较差异均有统计学意义(Pa<0.05)。结论喘息患儿与哮喘存在相同的基因分布频率,发生哮喘的危险性高;对于CC10基因具有A等位基因的喘息患儿应密切关注。     

Treatment of asthma crises in children with nebulized salbutamol

Thirty-two children were treated with nebulized salbutamol for acute asthma. Seventy-five per cent of the treatments were efficient, either after a first nebulization at 0.15 mg/kg (47% = group I), or after a second nebulization 45 min later, at 0.05 mg/kg (27% = group II). Twenty-five per cent of the treatments (group III) were inefficient or only partly efficient. The clinical tolerance was good except in two children. Group I and II presented differences only for the auscultation score. Children from group I and II were older and had less severe asthma than those from group III. On the basis of this study, nebulized salbutamol appears to be an affective and safe treatment for acute asthma. The repeated administration of low doses, shortly after the first nebulization increases the quality of the response.     

Randomized trial of high-frequency oscillatory ventilation versus conventional ventilation: effect on systemic blood flow in very preterm infants

OBJECTIVE: Low superior vena cava (SVC) flow is common in very preterm infants in the first day and strongly associated with periventricular hemorrhage and disability. We examined the effect of high-frequency oscillatory ventilation (HFOV) compared with conventional ventilation (CV) on SVC flow and right ventricular output. METHODS: Forty-five infants <29 weeks were randomized before 1 hour of age to HFOV or CV. Echocardiography was performed on 43 infants at 3, 10, and 24 hours of age. Infants with low SVC flow (<50 mL/kg/min) or hypotension (mean blood pressure < or =20) were treated with volume and inotrope. RESULTS: Infants allocated to HFOV (n=23) and to CV (n=20) were well matched. There was a nonsignificant trend toward more infants on HFOV having SVC flow <50 mL/kg/min (48% vs 20%) and receiving volume and inotropes (61% vs 40%). There were no significant differences in mean SVC flow or right ventricular output at 3, 10, or 24 hours. Infants on HFOV had a significantly higher calculated upper body vascular resistance at 10 hours and mean blood pressure at 24 hours. CONCLUSIONS: There were no significant adverse effects of HFOV on systemic blood flow in very preterm infants during the first 24 hours of life.