胎鼠宫内窘迫复苏：空气与高浓度氧复苏的效果比较

比较窒息时空气与纯氧复苏的效果 ,为窒息复苏方案的选择提供依据 ,应用方法将 35只胎龄为 2 0天的SD大鼠胎鼠随机分为 3组 ,即假手术组 (对照组 ,C组 ) 1 1只 ,制成宫内窘迫模型而给予空气复苏者作为空气复苏组 (A组 ) 1 0只 ,给予92 8%浓度氧复苏者为高氧复苏组 (Ox 组 ) 1 4只。监测各组胎鼠脑细胞内外钙、钠、钾含量的变化。结果显示 ,空气复苏组与高氧复苏组的脑细胞内游离钙离子浓度 (分别为 552 0 8± 93 50和 52 0 6 1± 79 0 8nmol L)基本一样 ,均明显高于对照组 ( 31 5 2 7± 86 88nmol L) (P <0 0 0 1 )。各组脑组织总钙、钠、钾含量无显著差异 (P >0 0 5)。因此 ,应用空气或 92 8%浓度氧进行窒息复苏时 ,复苏效果相似 ,揭示临床上可考虑应用空气代替纯氧对窒息新生儿进行复苏。     

不同复苏氧浓度对宫内窘迫胎鼠脑细胞内外钙的影响

目的：探讨窒息时复苏氧浓度与复苏效果的关系,找出较佳复苏氧浓度,改善窒息新生儿预后。方法：将56只胎龄为20 d的SD大鼠胎鼠随机分为5组,即假手术组(对照组)11只,空气复苏组(复苏组)10只,给予不同浓度氧和在不同时间内复苏的Ox1组14只,Ox2组11只和Ox3组10只。监测各组胎鼠脑细胞内外钙、钠、钾含量的变化。结果：复苏组与Ox1组(氧浓度92.8%)的脑细胞内游离钙离子浓度分别为(552.08±93.50) nmol/L和(520.61±79.08) nmol/L,两者相近(P>0.05),但均明显高于对照组(315.27±86.88) nmol/L(P0.05)。结论：不同氧浓度复苏,其效果不一样：应用 92.8% 氧或空气复苏,其复苏效果相似,提示临床上可考虑应用空气代替纯氧对窒息新生儿进行复苏;采用65% 氧复苏, 其复苏效果可能较纯氧或空气复苏更佳。     

碱性成纤维细胞生长因子与宫内窘迫胎鼠神经元增殖

目的　观察碱性成纤维细胞生长因子 (bFGF)干预窘迫胎鼠后脑神经元增殖情况。方法　将 32只怀孕 15dWistar大鼠随机分为A正常对照、B窘迫对照、C窘迫干预及D预防组 (窘迫前 3d预防 ) 4组 ,采用神经营养因子bFGF干预。用免疫双标记法标记增殖的脑神经元细胞。结果　A、B、C、D各组增殖神经元计数每高倍视野分别为 4.5 0± 2 .49个 ,5 .82± 3.17个 ,17.2 5± 5 .48个 ,18.18± 5 .83个 ,F =12 8.18　P <0 .0 0 1。均有显著统计学意义。结论　bFGF能够促进受损脑组织神经元增殖     

宫内窘迫胎鼠肾组织环氧化酶-2表达的实验研究(英文)

目的　缺血缺氧性肾损伤是一个复杂的病理生理过程,炎症反应在其中占有重要的作用。该文 旨在观察宫内窘迫后胎鼠肾组织炎症介质环氧化酶 2(COX 2)蛋白和基因表达及其代谢产物前列环素I2(PGI2), 前列腺素E2(PGE2)和血栓素(TXA2)的动态变化,初步探讨COX 2在宫内窘迫胎鼠肾损伤发病机制中的作用。方 法　制备胎鼠宫内缺血缺氧再灌注模型(缺血缺氧组:缺血缺氧30min;再灌注组:缺血缺氧30min后,分别再灌注 0.5h,2h,6h,12h,24hand30h)。各时间点分别取胎鼠20只,假手术组胎鼠22只,将肾组织匀浆后采用 RT PCR,Western印迹杂交和放免法进行检测。同时苏木精 伊红染色观察肾组织病理学改变。结果　宫内窘迫 后胎肾组织COX 2蛋白和基因表达上调,PGI2的稳定代谢产物6 keto PGF1α及PGE2均于再灌注2h开始增高(P <0.05)。其中6 keto PGF1α增加迅速,于再灌注12h达高峰(P<0.01),PGE2于再灌注24h达最高水平(P< 0.01),而TXB2增加幅度不大。结论　宫内缺血再灌注从转录水平诱导胎肾COX 2蛋白表达增强,COX 2的主要 代谢产物是PGI2和PGE2。COX 2可能通过PGI2和PGE2对缺血性胎肾损伤具有保护作用,因此,在围产期肾损 伤不宜应用COX 2抑制剂。     

宫内窘迫胎鼠肾组织COX-2基因表达

探讨宫内窘迫胎鼠肾组织COX-2基因表达的动态变化及其与病理改变的关系.建立胎鼠宫内缺血/再灌注动物模型、应用HE染色及RT-PCR方法,观察不同程度、不同时间胎鼠宫内缺血/再灌注后胎肾组织的病理改变及COX-2mRNA表达的变化.结果显示宫内缺血10分钟不同时间再灌注后,胎肾组织仅表现肾浊肿,COX-2mRNA表达无显著变化.而宫内缺血30分钟,再灌注6小时,胎肾近曲小管出现片状坏死,COX-2mRNA表达以6～12小时达高峰,与病理改变趋于一致.提示前列腺素代谢在宫内窘迫胎鼠肾损伤发病过程中具有重要作用,COX-2可能作为重要介质参与新生儿肾损伤的发病过程.     

宫内缺血缺氧胎鼠胃肠组织神经降压素的变化

目的：探讨宫内缺血缺氧胎鼠胃肠组织神经降压素（ＮＴ）的变化及对消化系统的影响。方法：采用放免方法,检测３４只宫内缺血缺氧胎鼠和１３只假手术组胎鼠的ＮＴ含理。结果：假手术组小肠组织ＮＴ含量比胃组织ＮＴ含量明显增高,宫内缺血缺氧组与假手术组相比,胃肠组织ＮＴ含量均有降低,以缺血２０分钟降低最为明显。结论：宫内缺血氧能造成胎鼠胃肠组织ＮＴ的降低。     

宫内窘迫胎鼠肾组织COX—2基因表达

探讨宫内窘达迫胎鼠肾组织COX-2基因表达的动态变化及其与病理改变的关系。建立胎鼠宫内缺血/再灌注动物模型、应用HE染色及RT-PCR方法，观察不同程度、不同时间胎鼠宫内缺血/再灌注后胎肾组织的病理改革及COX-2mRNA表达的变化。结果显示：宫内缺血10分钟不同时间灌注后，胎肾组织仅表现肾浊肿，COX-2mRNA表达无显著变化。而宫内缺血30分钟，再灌注6小时，胎肾近曲小管出现片状坏死，COX-2mRNA表达以6-12小时达高峰，与病理改变趋于一致。提示：前列腺素代谢在宫内窘迫胎鼠肾损伤发病过程中具有重要作用，COX-2可能作为重要介质参与新生儿肾损伤的发病过程。     

宫内缺血缺氧胎鼠胃肠组织神经降压素的变化

目的探讨宫内缺血缺氧胎鼠胃肠组织神经降压素(NT)的变化及对消化系统的影响.方法采用放免方法,检测34只宫内缺血缺氧胎鼠和13只假手术组胎鼠的NT含量.结果假手术组小肠组织NT含量比胃组织NT含量明显增高(P<0.01).宫内缺血缺氧组与假手术组相比,胃肠组织NT含量均有降低,以缺血20分钟降低最为明显(P<0.01).结论宫内缺血缺氧能造成胎鼠胃肠组织NT的降低.     

盐酸氨溴索和地塞米松对胎鼠肺表面活性蛋白基因表达的影响

目的　探讨盐酸氨溴索和地塞米松对发育期胎鼠肺表面活性蛋白 (SPs)基因表达的影响。方法　将胎鼠 4 2只随机分为生理盐水对照组和盐酸氨溴索、地塞米松两个干预组 ,剖宫取孕19d的胎鼠肺组织作为早产鼠肺模型 ,用原位杂交研究胎鼠肺泡Ⅱ型上皮细胞内SP B基因的表达 ,逆转录PCR(RT PCR)观察分析各组肺表面活性蛋白SP A、SP B和SP CmRNA表达变化 ,用 β actinmRNA扩增产物为内参照密度扫描半定量分析。结果　 (1)发育 19d的胎鼠肺泡Ⅱ型上皮细胞内SP BmRNA表达阳性 ;(2 )鼠胚胎发育后期 ,支气管周围也分布着肺泡Ⅱ型上皮细胞 ;(3)生理盐水对照组SP A、SP B、SP CmRNA表达与 β actinmRNA比值分别为 0 81± 0 2 6、0 97± 0 2 0、0 88± 0 11。盐酸氨溴索干预SP A、SP B、SP CmRNA表达比值分别为 1 0 4± 0 16、1 2 8± 0 2 9、1 0 9± 0 2 5 ,与对照组比较显著性增加 (P <0 0 5 )。地塞米松干预后的胎鼠肺SP A、SP B、SP CmRNA表达比值分别为 1 0 8±0 2 5、1 2 3± 0 35、1 2 1± 0 2 5 ,与对照组比较显著性增加 (P <0 0 5 )。 (4 )对比盐酸氨溴索与地塞米松在促进SP A、SP B、SP C基因表达上 ,两者差异没有显著意义 (P >0 0 5 )。结论　盐酸氨溴索和地塞米松产前用药对发育期的胎鼠SPs基     

Resuscitation of newborn infants with room air or oxygen

Oxygen is a toxic agent and a critical approach regarding its use during resuscitation at birth is developing. Animal data indicate that room air is efficient for newborn resuscitation. Three clinical studies have established that normal ventilation is delayed after oxygen resuscitation. Oxidative stress is augmented for several weeks in infants exposed to oxygen at birth – the long-term implications of these observations remain unclear. There are limited data regarding the use of room air during complicated resuscitations, i.e. in meconium aspiration, the severely asphyxiated infant and in the preterm infant. Thus, it is necessary to continue ongoing rigorous examination of the long-accepted practice of oxygen administration during neonatal resuscitation.     

不同浓度氧气复苏窒息极早产儿的系统评价

目的探讨不同浓度氧气复苏窒息极早产儿的临床效果。方法通过文献检索收集不同浓度氧气复苏窒息极早产儿的随机对照试验,采用RevMan 5.0分析软件,首先进行异质性检验,当结果不存在异质性,以固定效应模型描述,存在异质性时,以随机效应模型表达,将资料进行定量综合,采用比值比(OR)及其95%可信区间(95%CI)表示。结果共6篇文献符合条件纳入研究,其中4篇文献为B级,2篇文献为C级。累计低浓度氧(21%~50%)复苏组157例,高浓度氧(90%~100%)复苏组168例。不同氧浓度复苏对极早产儿复苏失败率(OR=2.03,95%CI:0.87~4.71)和病死率(OR=1.23,95%CI:0.53~2.86)无影响,对支气管肺发育不良(OR=1.07,95%CI:0.55~2.10)、颅内出血(OR=1.99,95%CI:0.76~5.23)、败血症(OR=1.00,95%CI:0.46~2.17)、早产儿视网膜病(OR=0.71,95%CI:0.18~2.73)、气胸(OR=0.28,95%CI:0.04~1.82)、动脉导管未闭(OR=0.74,95%CI:0.34~1.64)的发生率均无影响(P均<0.05)。结论不同浓度氧气复苏窒息极早产儿的效果无差异,但由于纳入文献质量有限,对于复苏开始的氧浓度、如何调整氧浓度、安全的血氧饱和度范围等问题仍需进一步大样本随机对照试验进行评价。     

新生儿窒息复苏气体的临床应用研究

愈来愈多的证据表明，新生儿窒息复苏时使用100％氧气可能对新生儿造成损害。部分研究结果归纳总结如下。     

Resuscitation of asphyxiated newborns with room air or 100% oxygen at birth: a multicentric clinical trial

OBJECTIVE: To compare the short-term efficacy of room air versus 100% oxygen for resuscitation of asphyxic newborns at birth. DESIGN: Multicentric quasi randomized controlled trial. SETTING: Teaching hospitals. INCLUSION CRITERIA: Asphyxiated babies weighing greater than 1000 grams, with heart rate less than 100 per min and/or apnea, unresponsive to nasopharyngeal suction and tactile stimuli and having no lethal abnormalities. INTERVENTION: Asphyxiated neonates born on odd dates were given oxygen and those on even dates room air for resuscitation. OUTCOME MEASURES: Primary: Apgar score at 5 minutes; Secondary: Mortality and Hypoxic ischaemic encephalopathy (HIE) during first 7 days of life. RESULTS: A total of 431 asphyxiated babies, 210 in the room air and 221 in 100% oxygen group were enrolled for the study. Both the groups were comparable for maternal, intrapartum and neonatal characteristics. The heart rates in room air and 100% oxygen groups were comparable at 1 minute (94 bpm and 88 bpm), 5 minutes (131 bpm and 131 bpm) and 10 minutes (135 bpm and 136 bpm). Median apgar scores at 5 min [7 versus 7] and 10 minutes [8 versus 8 ], in the room air and oxygen groups respectively, were found to be comparable. Median time to first breath (1.5 versus 1.5 minutes) was similar in the room air and oxygen group. Median time to first cry (2.0 versus 3.0 minutes) and median duration of resuscitation (2.0 versus 3 minutes) were significantly shorter in the room air group. The number of babies with HIE during first seven days of life in the two treatment groups (35.7% babies in room air and 37.1% in the 100% oxygen group) were similar. There was also no statistically significant difference in the overall and asphyxia related mortality in the two treatment groups (12.4% and 10.0% in room air versus 18.1% and 13.6% in oxygen group). CONCLUSION: Room air appears as good as 100% oxygen for resuscitation of asphyxic newborn babies at birth.     

Resuscitation of depressed newborn infants with ambient air or pure oxygen: a meta-analysis

BACKGROUND: It is discussed whether depressed newborn infants should be resuscitated with room air or 100% O2. OBJECTIVE: To perform a systematic review and meta-analysis including studies that report resuscitation of depressed newly born infants with 21 or 100% O2. METHODS: Inclusion criterion was randomized or pseudo-randomized, blinded or not, studies of depressed newborn infants resuscitated with either 21 or 100% O2. The literature was searched in Medline/Pubmed/EMBASE and The Cochrane library databases. All identified studies were included. RESULTS: Five studies fulfilled the inclusion criterion in which 881 infants were resuscitated with 21% O2 and 856 with 100% O2. Neonatal mortality was 8.0 vs. 13.0% in the 21 and 100% O2 groups respectively, OR 0.57, 95% CI 0.42-0.78. In term infants neonatal mortality was 5.9% in the 21% O2 group and 9.8% in the 100% O2 group, OR 0.59, 95% CI 0.40-0.87. The figures for the premature infants were very similar. In infants with 1-min Apgar score <4, OR for neonatal mortality was 0.81 (95% CI 0.54-1.21). Apgar score at 5 min and heart rate at 90 s were significantly higher, and time to first breath significantly earlier in infants given 21% O2 compared with 100% O2. CONCLUSIONS: A systematic review and meta-analysis demonstrated that neonatal mortality is significantly reduced when depressed newly born infants are resuscitated with ambient air instead of pure oxygen. For infants with low 1-min Apgar score (<4), no significant difference in neonatal mortality was found. Recovery was faster in infants resuscitated with 21% O2 than 100% O2.     

Newborn piglets with meconium aspiration resuscitated with room air or 100% oxygen

We investigated whether newborn piglets exposed to hypoxemia and severe meconium aspiration could be reoxygenated with room air as efficiently as with 100% O(2). Twenty-one 2- to 5-d-old piglets were randomly divided into three groups: 1) the room air group: hypoxemia, meconium aspiration, and reoxygenation with room air (n = 8); 2) the O(2) group: hypoxemia, meconium aspiration, and reoxygenation with 100% O(2) (n = 8); and 3) the control group: meconium aspiration, and reoxygenation with room air (n = 5). Hypoxemia was induced by ventilation with 8% O(2) until the mean blood pressure reached <20 mm Hg or the base excess reached <-20 mM. At this point, reoxygenation was started with either room air or 100% O(2). Three milliliters per kilogram of meconium 110 mg/mL was instilled into the trachea immediately before the start of reoxygenation. The O(2) tension in arterial blood was significantly lower in the room air group; at 5 min of reoxygenation it was 9.1 +/- 0.5 kPa versus 43.5 +/- 6 kPa in the O(2) group (p < 0.05). At 5 min of reoxygenation the tidal volume per kilogram was 12.1 +/- 0.7 mL/kg in the room air group and 13.1 +/- 0.9 mL/kg in the O(2) group (NS). There were no significant differences between the room air and the O(2) groups during 120 min of reoxygenation in mean arterial blood pressure, pulmonary arterial pressure, cardiac index, base excess, or plasma hypoxanthine. In conclusion, hypoxic newborn piglets with meconium aspiration were found to be reoxygenated as efficiently with room air as with 100% O(2).     

Reventilation with room air or 100% oxygen after asphyxia differentially affects cerebral neuropathology in newborn pigs

AIM: To test if reventilation with room air (RA) or 100% oxygen (O2) after asphyxia would differentially affect neuronal damage in different brain areas of newborn pigs. METHODS: Anaesthetized piglets were subjected to 10 min asphyxia (n=27) or served as time controls (n=7). Reventilation started with either RA or O2 for 1 h, and was continued with RA for an additional 1-3 h. Cortical or cerebellar blood flow was assessed with laser-Doppler flowmetry (LDF). Haematoxylin/eosin-stained sections from six brain regions were prepared for blinded neuropathological examination and scoring. RESULTS: Asphyxia resulted in significant neuronal damage compared to time controls in all areas examined except the pons. O2 ventilation elicited greater neuronal lesions in the hippocampus and the cerebellum but smaller damage in the basal ganglia compared to RA. The assessed physiological parameters including the LDF signals were similar in both ventilation groups, except for PaO2 in the first hour of reventilation (RA 75+/-5 mmHg, O2 348+/-57 mmHg; p<0.05). Interestingly, however, reactive hyperaemia was much higher in the O2-sensitive cerebellum as compared with the cortex (1101+/-227 vs 571+/-73; p<0.05, area under the curve). CONCLUSION: O2 toxicity after asphyxia was demonstrated in the piglet hippocampus and cerebellum but not in the cerebral cortex or basal ganglia. The observed regional differences may be associated with local haemodynamic factors.