双水平正压通气和持续气道正压通气在早产儿呼吸窘迫综合征中应用的比较

目的：对患有新生儿呼吸窘迫综合征（RDS）的早产儿早期使用双水平正压通气（DuoPAP）和经鼻持续气道正压通气（NCPAP）模式在降低有创呼吸支持率和支气管肺发育不良（BPD）发生率方面进行比较分析。方法：该试验为单中心随机对照试验,将胎龄30~35 周患有RDS生后6 h内的早产儿随机分为早期使用DuoPAP组（n=34）和早期使用 NCPAP组（n=33）,若这两种方式不能维持则使用气管内插管、呼吸机辅助呼吸,肺表面活性物质作为急救药物。观察患儿生后24 h、48 h及72 h内的总插管有创呼吸支持率、支气管肺发育不良（BPD）发生率及使用无创呼吸支持后1、12、24、48、72 h 二氧化碳分压（PaCO2）、氧分压（PaO2）及氧合指数（OI）。结果：DuoPAP组48 h内、72 h内总插管有创呼吸支持率明显低于NCPAP组（P0.05）。DuoPAP组OI无创呼吸支持后1、12、24、48、72 h均高于NCPAP组（均P<0.05）。DuoPAP组PaCO2在无创呼吸支持后1、12、24 h明显小于NCPAP组（P<0.05）;DuoPAP组PaO2在无创呼吸支持后1、12 h 明显大于NCPAP组（P<0.05）。结论：早期使用DuoPAP与NCPAP相比,可明显降低RDS患儿插管有创呼吸支持率,值得推广。     

Early nasal intermittent positive pressure ventilation versus continuous positive airway pressure for respiratory distress syndrome

Aim:  To determine whether early nasal intermittent positive pressure ventilation (NIPPV), in comparison to early continuous positive airway pressure (CPAP), can reduce the need for intubation and mechanical ventilation in preterm neonates with suspected respiratory distress syndrome (RDS).
Methods:  In this stratified open-label randomized controlled trial, neonates (28–34 weeks gestation) with respiratory distress within 6 h of birth and Downe's score ≥ 4 were eligible. Subjects were randomly allocated to 'early-NIPPV' or 'early-CPAP' after stratifying for gestation (28–30 weeks, 31–34 weeks) and surfactant use. Primary outcome was failure of the allocated mode within 48 h.
Results:  Seventy-six neonates were enrolled (37 in 'early-NIPPV' and 39 in 'early-CPAP' groups). Failure rate was less with 'early-NIPPV' versus 'early-CPAP'[13.5% vs. 35.9%, respectively, RR 0.38 (95% CI 0.15–0.89), p = 0.024]. Similarly, need for intubation and mechanical ventilation by 7 days (18.9% vs. 41%, p = 0.036) was less with NIPPV. Failure rate with NIPPV was less in the subgroups of subjects born at 28–30 weeks (p = 0.023) and who did not receive surfactant (p = 0.018).
Conclusion:  Among preterm infants with suspected RDS, early use of NIPPV reduces the need for intubation and mechanical ventilation compared to CPAP.     

双水平正压通气和经鼻持续气道正压通气在早产儿呼吸窘迫综合征撤机后应用的比较

目的探讨重度新生儿呼吸窘迫综合征（RDS）早产儿撤机后使用双水平正压通气（DuoPAP）和持续气道正压通气（NCPAP）模式相比,是否可以降低撤机失败率。方法选择2012年1—12月入住本院早产儿重症监护病房、胎龄29—34周、需要有创呼吸、并且在生后4周内撤机的重度RDS早产儿,撤机后随机分为DuoPAP组和NCPAP组,若应用这两种方式不能维持则再次气管插管呼吸机辅助呼吸。主要观察指标为撤机失败率、失败原因以及使用无创呼吸支持后1、12、24、48、72h二氧化碳分压（PaCO2）、氧分压（PaO2）和氧合指数（OI）。结果共入选69例RDS早产儿,DuoPAP组35例,NCPAP组34例。DuoPAP组与NCPA组比较,撤机失败率降低（11．4％比35．3％）;12、24hOI升高[12h：（228．1±44．4）比（204．2±44．6）,24h：（254．6±39．5）比（230．4±44．4）],PaCO2（mmHg）降低[12h：（35．1±8．3）比（40．5士8．9）,24h：（36．8±8．4）比（42．1±8．8）];12hPaO2（mmHg）升高[（89．0±12．5）比（74．5±13．8）],P均〈0．05。两组总用氧时间、有创呼吸支持时间、气胸、坏死性小肠结肠炎和重度脑室内出血发生率差异均无统计学意义（P〉0．05）。结论与使用NCPAP相比,撤机后使用DuoPAP可明显降低重度RDS患儿撤机失败率,值得推广。     

两种无创呼吸支持治疗极低出生体重儿呼吸窘迫综合征疗效分析

目的 探讨早期应用经鼻间歇正压通气（NIPPV）与加温湿化经鼻导管高流量通气（HHHFNC）治疗极低出生体重呼吸窘迫综合征（RDS）早产儿的临床疗效。方法 89例极低出生体重RDS早产儿依据初始呼吸支持治疗方式随机分为NIPPV组（46例）和HHHFNC组（43例）。分析两组患儿初始治疗失败率、肺表面活性物质（PS）使用率、呼吸支持治疗相关数据及各种并发症的发生率。结果 NIPPV组治疗72 h内气管插管率、PS使用率、有创辅助通气时间、无创辅助通气时间及总用氧时间、严重呼吸暂停发生率、肺炎发生率与HHHFNC组的差异无统计学意义（P > 0.05）;NIPPV组支气管肺发育不良、颅内出血、早产儿视网膜病、坏死性小肠结肠炎、动脉导管未闭、气漏的发生率与HHHFNC组的差异均无统计学意义（P > 0.05）;NIPPV组鼻损伤的发生率高于HHHFNC组（P < 0.05）。结论 对于极低出生体重RDS早产儿的初始呼吸支持治疗,HHHFNC与NIPPV疗效相当,是可供临床选择的另一种安全和有效的无创辅助通气治疗方式。     

不同正压通气方式联合肺表面活性物质在早产儿呼吸窘迫综合征中的应用

目的比较双水平气道正压通气( BiPAP) 和鼻塞式持续气道正压通气( NCPAP) 联合肺表面活性物质( PS) 在早产儿呼吸窘迫综合征( RDS) 中的应用效果。方法选择本科 2009年2月至 2012年2月收治的 80 例 RDS 早产儿,常规使用 PS 进行替代治疗后,随机分入 BiPAP 通气模式组( BiPAP 组) 和 NCPAP 通气模式组( NCPAP 组) ,每组各 40 例。观察两组工作参数、氧动力学指标、正压通气时间、氧疗时间、治疗成功率及气胸、支气管肺发育不良、早产儿视网膜病等并发症的发生率。结果 ( 1) 两组通气模式工作参数: 吸入氧浓度( FiO2) 、呼气末正压/呼气相正压( PEEP/EPAP) 均随通气时间延长逐渐降低,0 h( 上机时) 差异无统计学意义( P > 0. 05) ,上机后6 h、12 h、24 h、48 h BiPAP 组 FiO2、PEEP/EPAP 均低于 NCPAP 组,差异有统计学意义( P <0. 05 或0. 01) 。( 2) 两组均能保持较好的氧分压( PaO2) 、动脉血氧分压/吸入氧浓度比值( P/F) 、动脉/肺泡氧分压比值( PaO2/ PAO2) ,且均有上升趋势,二氧化碳分压( PaCO2) 呈降低趋势,两组在0 h 时各指标差异均无统计学意义( P >0. 05) ,BiPAP 组上机后 6 h、12 h、24 h、48 h PaO2、P/F、PaO2/ PAO2均明显高于 NCPAP 组( P <0. 05 或 0. 01) ,PaCO2低于 NCPAP 组( P <0. 05) 。( 3) BiPAP 组通气时间、氧疗时间明显短于 NCPAP 组,治疗成功率高于 NCPAP 组( P <0. 05) 。( 4) 两组气胸、支气管肺发育不良、早产儿视网膜病发生率差异无统计学意义( P >0. 05) 。结论 BiPAP 联合 PS 治疗 RDS早产儿的疗效优于 NCPAP,其具有高效、安全等优点,值得推广。     

早产儿呼吸窘迫综合征的呼吸支持策略及研究进展

新生儿呼吸窘迫综合征（respiratory distress syndrome,RDS）多见于早产儿,胎龄越小,发病率越高。近年的大规模随机对照研究突出了产房内开始的持续气道正压通气（continuous positive airway pressure,CPAP）在RDS防治中的重要作用,对于生后有自主呼吸的早产儿,产房内应用CPAP优于气管插管,而顶防性应用肺表面活性物质（pulmonary surfactant,PS）不再具有优势。2013版欧洲新生儿RDS防治指南推荐有患RDS风险的早产儿生后均应立即接受CPAP支持,初设呼气末正压至少6cmH2O（1cmn20=0．098kPa）;对于患RDS的早产儿,最理想的处理是生后CPAP以及早期解救性PS应用。而需要气管插管的早产儿应尽早接受PS替代治疗。不能耐受CPAP的患儿更换通气模式为无创正压通气可能降低拔管失败率。目前有多种策略来缩短机械通气时间并增加无创通气的成功率。患RDS的极早产儿应常规接受咖啡因治疗以提高撤机成功率,并降低支气管肺发育不良的发生率。生后1～2周后仍不能脱离呼吸机者,需接受小剂量递减地塞米松治疗,但应避免生后1周内应用地塞米松以及较大剂量应用。     

Variables associated with the early failure of nasal CPAP in very low birth weight infants

OBJECTIVE: To identify risk factors and neonatal outcomes associated with the early failure of "bubble" nasal continuous positive airway pressure (CPAP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS). STUDY DESIGN: Following resuscitation and stabilization at delivery, a cohort of 261 consecutively inborn infants (birth weight < or = 1250 g) was divided into three groups based on the initial respiratory support modality and outcome at 72 hours of age: "ventilator-started" group, "CPAP-failure" group, and "CPAP-success" group. RESULTS: CPAP was successful in 76% of infants < or = 1250 g birth weight and 50% of infants < or = 750 g birth weight. In analyses adjusted for postmenstrual age (PMA) and small for gestational age (SGA), CPAP failure was associated with need for positive pressure ventilation (PPV) at delivery, alveolar-arterial oxygen tension gradient (A-a DO2) >180 mmHg on the first arterial blood gas (ABG), and severe RDS on the initial chest x-ray (adjusted odds ratio [95% CI] = 2.37 [1.02, 5.52], 2.91 [1.30, 6.55] and 6.42 [2.75, 15.0], respectively). The positive predictive value of these variables ranged from 43% to 55%. In analyses adjusted for PMA and severe RDS, rates of mortality and common premature morbidities were higher in the CPAP-failure group than in the CPAP-success group. CONCLUSION: Although several variables available near birth were strongly associated with early CPAP failure, they proved weak predictors of failure. A prospective controlled trial is needed to determine if extremely premature spontaneously breathing infants are better served by initial management with CPAP or mechanical ventilation.     

Laryngeal mask airway used as a delivery conduit for the administration of surfactant to preterm infants with respiratory distress syndrome

BACKGROUND: The laryngeal mask airway (LMA(TM), Laryngeal Mask Co. Ltd, Jersey, UK) is a supraglottic device used to administer positive pressure ventilation (PPV) in adults, pediatric and neonatal patients. OBJECTIVES: To avoid endotracheal intubation, we evaluated the feasibility and practicality of administering surfactant via the LMA(TM) in preterm infants with respiratory distress syndrome (RDS). METHODS: Infants less than 72 h old with a gestational age of < or =35 weeks and a birth weight of >800 g, treated with nasal continuous positive airway pressure (CPAP, 5 cm H2O) for RDS were eligible for inclusion in the study if the arterial-to-alveolar oxygen tension ratio (a/APO2) was <0.20 over a period of >60 min. RESULTS: Eight preterm infants, median gestational age 31 (range 28-35) weeks; birth weight 1,700 (880-2,520) g, treated with nasal CPAP for RDS were enrolled. Three hours after surfactant instillation, the mean a/APO2 was significantly increased (0.13 +/- 0.04 to 0.34 +/- 0.11; p < 0.01) without complications. CONCLUSIONS: The LMA may be a useful and noninvasive conduit for the administration of surfactant therapy. A large randomized comparative clinical trial will be required to confirm the efficacy of this technique.     

Current methods of non-invasive ventilatory support for neonates

Non-invasive ventilatory support can reduce the adverse effects associated with intubation and mechanical ventilation, such as bronchopulmonary dysplasia, sepsis, and trauma to the upper airways. In the last 4 decades, nasal continuous positive airway pressure (CPAP) has been used to wean preterm infants off mechanical ventilation and, more recently, as a primary mode of respiratory support for preterm infants with respiratory insufficiency. Moreover, new methods of respiratory support have been developed, and the devices used to provide non-invasive ventilation (NIV) have improved technically. Use of NIV is increasing, and a variety of equipment is available in different clinical settings. There is evidence that NIV improves gas exchange and reduces extubation failure after mechanical ventilation in infants. However, more research is needed to identify the most suitable devices for particular conditions; the NIV settings that should be used; and whether to employ synchronized or non-synchronized NIV. Furthermore, the optimal treatment strategy and the best time for initiation of NIV remain to be identified. This article provides an overview of the use of non-invasive ventilation (NIV) in newborn infants, and the clinical applications of NIV.     

无创通气在早产儿呼吸窘迫综合征中的应用进展

为了减少有创通气所带来的严重并发症,临床医生越来越多地在早产儿呼吸窘迫综合征(RDS)的初始治疗中采用无创通气(NIV)技术.在过去的40 年中,经鼻持续气道正压通气(NCPAP)一直是治疗RDS 的主要模式,甚至是唯一的NIV 模式.近十年来,随着传感器和人机连接界面的改进,产生了不少新的NIV 模式,如经鼻间歇正压通气(NIPPV)、双水平气道正压通气(BiPAP)等.随后的研究表明,有些新的模式在RDS 的治疗上可能较NCPAP 更为优越.为了让临床医生了解NIV 在早产儿RDS 初始治疗中应用的新进展,更好的运用NIV 技术,该文复习了近年来相关文献并作简要综述.     

肺表面活性物质对不同胎龄呼吸窘迫综合征新生儿的疗效

目的 探讨肺表面活性物质(PS)对不同胎龄儿呼吸窘迫综合征(RDS)的疗效差异.方法 选择胎龄28～39周,出生体质量760～3 240 g,经PS治疗的RDS患儿67例.早期组:胎龄28～30周的早期早产儿18例;中期组:胎龄31～33周的中期早产儿28例;晚期组:胎龄34周以上的晚期早产儿和足月儿21例.比较3组PS治疗时RDS的重症程度、PS开始使用时间、第1次使用剂量、总剂量、重复使用例数、氧疗时间、最高吸氧体积分数(FiO2)、机械通气时间等指标.结果 PS治疗时早期组和中期组轻度RDS例数明显多于晚期组(Pa＜0.05).中期组和晚期组重度RDS例数明显多于早期组(Pa＜0.05),PS开始使用时间晚期组明显晚于早、中期组(Pa＜0.05).第1次使用剂量早期组明显多于中、晚期组(Pa＜0.05).使用总剂量和重复使用例数各组间均无统计学差异(Pa＞0.05).机械通气时间早、晚期组明显多于中期组(P=0.040);最高FiO2以晚期组最高(P=0.006).结论 早期早产儿RDS病情轻、开始PS治疗时间早、剂量足,但需氧疗和机械通气时间长;晚期早产儿和足月儿RDS病情危重、开始PS治疗时间晚、剂量不足、需氧疗和机械通气时间长.对晚期早产儿和足月儿RDS治疗应尽早、足量使用PS.     

系统评价胎龄小于32周早产儿预防性经鼻持续气道正压通气的作用

目的 评价早产儿早期应用经鼻持续气道正压通气（NCPAP）预防呼吸窘迫综合征（RDS）,减少呼吸机应用、病死率和并发症的发生。方法 以（prophylactic nasal CPAP OR early nasal CPAP）AND （preterm infants OR low birth weight infants） ,经鼻持续气道正压通气AND（早产儿OR低出生体重儿）为英中文关键词,检索PubMed、EMBASE、Cochrane临床对照试验库、维普中文科技期刊数据库、中国知网和万方数据库,检索时间均从建库至2011年12月,并辅以手工检索。应用RevMan 5.0软件进行Meta分析,根据异质性结果选择相应的效应模型分析;无法进行Meta分析时采用描述性分析。结果 8篇RCT文献进入分析。Meta分析结果显示： NCPAP组未能显著降低早产儿气管插管呼吸机应用率（RR＝-0.09,95%CI：-0.19~0.02,P=0.09）、RDS发生率（RR＝0.81,95%CI：0.59~1.1, P =0.18）和病死率（RR＝0.88,95%CI：0.72~1.09,P=0.25）;NCPAP组能显著减少早产儿肺表面活性物质应用率（RR＝0.72,95%CI：0.64~0.80,P﹤0.000 01）。NCPAP组未能显著减少气管插管呼吸机通气时间（MD= -1.91 d,95%CI：-6.47~4.45 d,P= 0.72）及氧气应用时间(MD=-0.46 d,95%CI：-6.55~5.63 d,P= 0.88）。NCPAP组除增加气胸的发生率外,并未明显增加支气管肺发育不良、颅内出血、早产儿视网膜病、败血症、新生儿坏死性小肠结肠炎和动脉导管未闭等并发症的发生率。结论 目前的证据表明早期应用NCPAP可减少肺表面活性物质应用,但增加了气胸的发生率;未能减少早产儿呼吸机应用、RDS发生率和病死率,未增加除气胸外的其他并发症发生率。     

Mechanical ventilation of very low birth weight infants: is volume or pressure a better target variable?

OBJECTIVE: To compare the efficacy and safety of volume-controlled (VC) ventilation to time-cycled pressure-limited (TCPL) ventilation in very low birth weight infants with respiratory distress syndrome (RDS). STUDY DESIGN: Newborns weighing between 600 and 1500 g and with a gestational age of 24 to 31 weeks who had RDS were randomized to receive either VC or TCPL ventilation and treated with a standardized protocol. The 2 modalities were compared by determining the time required to achieve a predetermined success criterion, on the basis of either the alveolar-arterial oxygen gradient <100 mm Hg or the mean airway pressure <8 cm H(2)O. Secondary outcomes included mortality, duration of mechanical ventilation, and complications commonly associated with ventilation. RESULTS: The mean time to reach the success criterion was 23 hours in the VC group versus 33 hours in the TCPL group (P = .15). This difference was more striking in babies weighing <1000g (21 versus 58 hours; P = .03). Mean duration of ventilation with VC was 255 hours versus 327 hours with TCPL (P = .60). There were 5 deaths in the VC group and 10 deaths in the TCPL group (P = .10). The incidence of other complications was similar. CONCLUSION: VC ventilation is safe and efficacious in very low birth weight infants and may have advantages when compared with TCPL, especially in smaller infants.     

Early nasal continuous positive airway pressure and low threshold for intubation in very preterm infants

AIM: To determine if selective intubation, use of early nasal continuous positive airway pressure (NCPAP) at birth with a low threshold for early surfactant treatment, reduces the need for intubation in very preterm infants in the first days after birth. METHODS: Two cohorts of very preterm infants < or = 32 weeks, born at the Leiden University Medical Center in the Netherlands, were compared retrospectively before (1996-1997) and after (2003-2004) introducing selective intubation and use of early NCPAP. A FiO(2)> or = 0.40 was used as criterion for intubation. Primary outcome measure was intubation < 72 h of age. Bronchopulmonary dysplasia (BPD) was a secondary outcome. RESULTS: The rate of intubation in the delivery room (69% vs. 46%, p < 0.001) and within 72 h of age (73% vs. 57%, p < 0.001) was lower following the change in policy. Early NCPAP was, in 2003-2004, increasingly used as primary treatment (10% vs. 33%, p < 0.001) with higher maximum NCPAP levels (4.0 (0.9) vs. 5.8 (1.5), p < 0.001). There was no change in BPD (14.3% vs. 15.2%, p = 0.82). CONCLUSION: Avoiding intubation by using early NCPAP while maintaining a low-threshold for surfactant treatment decreased the need for intubation.     

鼻塞式同步间歇指令通气和持续气道正压通气在早产儿呼吸窘迫综合征中的应用比较

目的：比较鼻塞式同步间歇指令通气(nSIMV)和鼻塞式持续气道正压通气（nCPAP）在早产儿呼吸窘迫综合征（RDS）中的临床应用效果。方法：50例RDS早产儿,常规使用肺表面活性物质进行替代治疗后,随机分入nSIMV组或nCPAP组,观察治疗后临床症状和血气指标的变化。结果：nSIMV组需气管插管行呼吸机通气比率明显低于nCPAP组（24% vs 60%, P<0.05）;nSIMV组CO2潴留和低氧血症的比率分别为12%和24%,明显低于nCPAP组的40%和36%（P<0.05）。结论：nSIMV能更有效地对RDS早产儿进行呼吸支持治疗。［中国当代儿科杂志,2010,12（7）：524-526］     

Stable microbubble test on tracheal aspirate for the diagnosis of respiratory distress syndrome

BACKGROUND: Exogenous surfactant should be used as early as possible in the presence of respiratory distress syndrome (RDS), but diagnosis may only become clear late in the course of the disease. The stable microbubble test (SMT) in the tracheal aspirates could help in the decision to give early surfactant to preterm babies with respiratory distress. OBJECTIVES: The objective of this study was to evaluate the accuracy of the SMT on tracheal aspirate for the diagnosis of RDS in newborns requiring mechanical ventilation. METHODS: The test was performed on specimens obtained from 74 infants requiring mechanical ventilation, through routine suctioning. RESULTS: Patients with RDS and meconium aspiration syndrome (MAS) had a significantly lower stable microbubble count than non-RDS and non-MAS patients. Preterm infants without RDS had a significantly higher microbubble count than preterm babies with RDS and a similar count to that of term babies. Considering a cutoff point of 120 microbubbles/mm(2) for the diagnosis of RDS, the sensitivity of the microbubble test was 96.3% (95% CI: 79.1-99.8) and the specificity 97.6% (95% CI: 85.9-99.9). CONCLUSIONS: The SMT on tracheal aspirates is accurate for RDS diagnosis and may be useful to support the decision to give surfactant to newborns on mechanical ventilation.     

经鼻间歇正压通气辅助呼吸治疗早产儿呼吸窘迫综合征

目的 探讨经鼻间歇正压通气(NIPPy)治疗早产儿呼吸窘迫综合征(RDS)的疗效及安全性.方法 将2010年1-12月本院收治的胎龄小于34周RDS早产儿30例设为NIPPV组,并将2009年3月-2010年11月随机抽取的胎龄小于34周RDS早产儿30例作为经鼻持续正压通气(NCPAP)组,2组患儿胎龄、出生体质量比较差异均无统计学意义.诊断RDSⅢ～Ⅳ级,无严重并发症,均接受肺表面活性物质治疗.结果 NIPPV组辅助通气时间较NCPAP组明显缩短(P＜0.05).机械通气率NIPPV组明显低于NCPAP组,且病死率及肺气漏无增加.2h时,2组呼吸机工作参数比较无统计学差异(P＞0.05),12h、24h和36h时比较差异均有统计学意义(Pa＜0.05),12h、24h和36h时吸氧体积分数比较差异均有统计学意义(Pa＜0.05).呼气末正压12h、24h和36h时比较差异均有统计学意义(Pa＜0.05).2组2h时pH比较无统计学差异(P＞0.05),而12h、24h和36h时pH的差异均有统计学意义.12h时动脉血氧分压比较无统计学差异(P＞0.05),而24h和36h均有统计学差异(Pa＜0.05).NIPPV组极低体质量儿及超极低出生体质量儿12例,NCPAP组10例,均未发生支气管肺发育不全.结论 与NCPAP比较,NIPPV治疗RDS有较好疗效,且可减少RDS患儿的气管再插管和机械通气.     

The role of surfactant and non-invasive mechanical ventilation in early management of respiratory distress syndrome in premature infants

Background

Surfactant replacement therapy has been used for few decades for the treatment of respiratory distress syndrome (RDS) and has significantly improved morbidity and mortality in premature infants. Non-invasive respiratory support has recently emerged as a strategy in the early management of RDS. In this review, we discuss the different strategies of early management of RDS.

Data sources

A literature search of PubMed database was conducted to review the subject. The quality of evidence of key clinical studies was graded according to a modified grading system of the international GRADE group.

Results

Continuous positive airway pressure (CPAP) with selective surfactant is a safe alternative to routine intubation, surfactant and mechanical ventilation in preterm infants with spontaneous breathing, and such an approach has been associated with decreased risk of death and bronchopulmonary dysplasia. There is a risk of pneumothorax when using a high pressure of CPAP (≥8 cm of H₂O), a high partial pressure of carbon dioxide (PCO₂ >75 mm of Hg), and a high fraction of inspired oxygen (FiO₂ >0.6) as a threshold for intubation while on CPAP.

Conclusion

Not all preterm infants need surfactant treatment, and non-invasive respiratory support is a safe and effective approach.     

Disturbed surface properties in preterm infants with pneumonia

Congenital pneumonia in preterm infants is often associated with respiratory insufficiency requiring mechanical ventilation. This study was performed to show whether pneumonia in these infants is associated with an inhibition or deficiency of surfactant. The ratio of lecithin and sphingomyelin (L/S ratio) and minimal surface tension were determined in pharyngeal aspirates from 90 term born infants (healthy) and in tracheal aspirates from preterm infants with wet lung (n = 13), congenital pneumonia (n = 21) and respiratory distress syndrome (RDS) (n = 90). The L/S ratio was lower (p < 0.0001) in the RDS group (8.6) when compared with healthy (48.6), wet lung (42.9) and pneumonia (28.9). Surface tension was higher (p < 0.001) in RDS (37 mN/m) and pneumonia (33.7) when compared with healthy (22.9) or wet lung (21.2). For infants with RDS, L/S ratio <16.5 detects surfactant deficiency with 96% specificity and 70% sensitivity, surface tension >29 mN/m represents surfactant inhibition (specificity 97%, sensitivity 92%). Using these cut-off values in infants with pneumonia, 81% had a sufficient amount of surfactant but only 21% of infants with pneumonia had appropriate surface tension. Our study shows that lung effluent of respiratory insufficient infants with pneumonia, who need mechanical ventilation, has disturbed surface properties despite a sufficient amount of surfactant. In these infants, surfactant substitution could be beneficial.     

不同时间给予肺表面活性物质治疗对呼吸窘迫综合征早产儿的影响

目的探讨早期或晚期给予肺表面活性物质(PS)治疗对呼吸窘迫综合征(RDS)早产儿的影响。方法本院新生儿科2009—2010年收治的RDS早产儿,按照PS的给予时间分为早期组(出生2 h内给药)和晚期组(出生2～12 h给药),比较两组机械通气时间、氧疗时间、病死率以及并发症发生率方面的差异。结果早期组48例,晚期组51例,早期给予PS能显著减少机械通气时间和氧疗时间[机械通气时间:(4.1±1.9)天比(5.4±2.2)天,氧疗时间:(5.8±3.4)天比(8.1±5.5)天,P<0.05]。但未影响气漏、肺出血、动脉导管未闭、坏死性小肠结肠炎、严重脑室内出血和支气管肺发育不良的发生率以及RDS早产儿的病死率。结论早期给予PS治疗能显著减少RDS早产儿的机械通气时间和氧疗时间。