支气管肺发育不良的研究进展

支气管肺发育不良是由于发育不成熟等多种因素共同作用下致肺泡和肺内血管发育受阻的一种慢性肺疾患,是由于早产、治疗损伤、感染和炎症等多种因素共同作用的结果。该病需采用综合的方法来预防和治疗,包括产前糖皮质激素的应用、合适的呼吸及营养支持、防治感染、抗炎及抗氧化治疗等。要想找到更有效的防治方法,需加强基础和临床研究,特别是对肺发育和该病发生机制的研究。     

支气管肺发育不良的研究进展

支气管肺发育不良(BPD)是早产儿最常见的严重呼吸系统疾病。随着产前糖皮质激素的应用、呼吸支持的改善、肺表面活性物质(PS)的应用,经典型BPD发病率有所降低,新型BPD发生率有所增多,其发病机制主要是在基因易感性的基础上,宫内和出生后的多重打击引起促炎、抗炎因子的级联反应,对发育不成熟的肺引起损伤,以及损伤后血管化失调和肺组织异常修复。在治疗上无满意的治疗策略,目前常采用的方法包括保持适当的血氧含量,允许性高碳酸血症,早期使用无创呼吸支持,使用气管内插管-PS使用-尽早拔管改用无创呼吸支持模式,常用药物为咖啡因、类固醇、外源性PS等,但具体效果仍存在争议。     

Fibronectin Expression in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic fibrotic lung disease of neonates. Fibronectin (FN), a component of the extracellular matrix, is increased in the tracheobronchial effluent of neonates destined to develop BPD. Pulmonary FN is derived from plasma and local cellular synthesis. In order to identify which pulmonary cells synthesize FN and to test the hypothesis that FN is more abundant in lungs with BPD, we examined the distribution of pulmonary FN by in situ hybridization (for mRNA) and immunohistochemistry (for protein) in neonatal autopsy lung specimens, comparing lungs with BPD to those without. We used a staging system in which BPD is characterized by disruption of alveolar architecture, severe vascular changes, airway epithelial necrosis, smooth muscle hypertrophy, and peribronchial fibrosis. FN mRNA and protein were found in vascular endothelium, macrophages, fibroblasts, vascular and airway smooth muscle, and chondrocytes as well as in the pulmonary parenchyma in neonates with and without BPD. Hyaline membranes, when present, immunostained intensely for FN protein. FN mRNA was not seen in airway epithelial cells of either group. FN mRNA and protein were first increased in early acute BPD with their levels appearing greatest during the chronic reparative stage of BPD. In long-standing “healed” BPD, lower levels of FN mRNA and protein were seen. These findings are consistent with the association of increased FN with adult fibrotic lung disease and the previously reported increase in FN tracheal effluent levels in infants with BPD. Our results suggest an important role for pulmonary cell-derived FN in the early inflammatory and later proliferative stages of BPD. Received September 29, 1997; accepted January 13, 1998.     

Postasphyxiai Encephalopathy in Preterm Neonates

Objective : Perinatal asphyxia is an important determinant of infant neurological outcome. There are very few studies looking exclusively at postasphyxial encephalopathy in preterm neonates.Methods : We studied the neurologic and sonographic abnormalities in 40 preterm babies with severe birth asphyxia during their hospital stay and till 3 months corrected age.Result : 87.5 % of the asphyxiated preterm babies had neonatal neurologic abnormality, compared to only 17% of the control babies (p < 0.0001). Generalised hypotonia and reduced activity were the commonest abnormalities (observed in 85% of asphyxiated babies) while depressed sensorium (60%) and seizures (35%) were seen in more severe cases. White matter disease (WMD-including periventricular flare, cerebral edema and periventricular leucomalacia) was significantly more frequent in the study cases (34.5% in study casesvs 7.5% in controls, p < 0.0001) as was grade 3/4 intraventricular hemorrhage(IVH) (25% in study cases vs 2.5% in controls, p < 0.0001). There was 11 fold higher mortality among the asphyxiated babies (23 deaths in study casesvs 2 in controls, p < 0.0001).Conclusion :The survivors had a significantly higher incidence of both mild and severe neurological abnormalities at corrected age of 3 months among the asphyxiated babies. There was a good correlation between the severity of the neonatal encephalopathy as well as the sonographic findings and the outcome.     

Dexamethasone in the Treatment of Bronchopulmonary Dysplasia

Benini, F., Rubaltelli, F. F., Griffith, P., Sala, M. and Zorzi, C. (Department of Paediatrics, University of Padova, Italy). Dexamethasone in the treatment of bronchopulmonary dysplasia. Acta Paediatr Scand Suppl 360: 108, 1989.
Sixteen chronically ventilator-dependent newborns with BPD were treated with one or more cycles of dexamethasone (0.5 mg/kg/day). In 11 cases extubation was possible during the therapy period. Ventilatory parameters were lowered in 3 other newborns. FIO₂, respiratory rate, PIP, and PEEP, assessed before and after dexamethasone administration, decreased in a statistically significant way. Our data confirm the utility of dexamethasone in the extubation in chronically ventilated infants with BPD.     

IgG Subclass Concentrations in Preterm Neonates

Serum IgG subclass concentrations were measured in 158 sera from preterm, appropriate for gestational age, infants born between 27 and 37 weeks of gestation, pregnancy, delivery and neonatal period being uncomplicated in all cases. At birth the IgG subclass concentrations were inversely correlated to the degree of prematurity. The IgG subclass concentrations decreased mainly proportionately during the neonatal period. The most immature infants born before the 30th week of gestation had critically low concentrations of all IgG subclasses. All immature infants, already in the first week after birth, showed capacity for IgGl and IgG3 synthesis.     

支气管肺发育不良分子遗传学研究进展

支气管肺发育不良(BPD)的发病率在我国呈逐年上升趋势,但其病因及发病机制尚不十分清楚,研究表明,BPD的发生不仅与早产及氧体积分数等外源性因素有关,且有较大的遗传易感性。现就肺表面活性物质、基质金属蛋白酶、血管内皮生长因子、TNF、转化生长因子-β和结缔组织生长因子等在BPD发生发展中的调节作用的研究进展进行综述。     

Disodium Cromoglycate in the Treatment of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) has become the most common form of chronic lung disease in the neonate. Recently, we have experienced a severe case of BPD and examined the effect of disodium cromoglycate (DSCG) on BPD. The gestational age and birth weight of the patient were 27 weeks and 1,000 g, respectively. Although RDS subsided after surfactant replacement therapy, the arterial-alveolar oxygen tension ratio (a/AP_O2) gradually decreased and Fi_O2 increased with age, respectively, and pure oxygen supplementation was eventually required after 67 days of life. The DSCG treatment was commenced at 80 days of life. After 6 days of the inhalation therapy, a/AP_O2 gradually increased. After 10 days of the treatment, the baby was extubated. While the baby was intubated, intratracheal lavage fluid samples were obtained. Eosinophilic cationic protein (ECP) and polymorphonuclear (PMN) elastase concentrations were determined. ECP and PMN elastase concentrations of intratracheal lavage fluids gradually decreased with the DSCG treatment. These results may indicate that DSCG has led to an improvement of pulmonary function and facilitated weaning from mechanical ventilation in an infant with BPD.     

早产儿支气管肺发育不良25例

目的 探讨早产儿支气管肺发育不良(BID)的危险因素及早期诊断和治疗.方法 回顾性分析本院2003年9月-2007年12月住院BPD患儿25例的临床资料,对患儿的原发病、合并症、临床诊断和治疗进行分析,并对患儿出院12个月内进行随访,分析BPD发生的重要因素及早期诊治的效果.结果 25例中胎龄26～27周2例,28～30周17例,31～32周5例,35周1例;出生体质量700～1 000 g9例,1 001～1 500 g 12例,1 501～2 000 g4例.诊断BPD前并感染15例、动脉导管未闭10例.最早拟诊时间出生13 d.20例接受地塞米松治疗,经治疗24例好转出院,1例放弃治疗后死亡.结论 早产、极低出生体质量、并感染、机械通气、动脉导管未闭等是BPD发生的重要因素,对易感患儿进行严密监测、早期诊断、防治感染、及时关闭导管、及时应用利尿剂和地塞米松是预防和治疗BPD的重要措施.     

新生儿发育性髋关节异常筛查结果分析

目的 探讨新生儿发育性髋关节异常(DDH)的发病情况.方法 选取2008年6月-2009年7月在本院住院和门诊就诊的762例足月新生儿(男382例,女380例).患儿均采用Graf法和Morin法相结合的超声检查手段进行髋关节测量.参照Graf分类方法将髋关节发育不良、髋关节半脱位和髋关节全脱位者定为DDH.对髋关节发育不良患儿采取随访观察,而对髋关节半脱位和髋关节全脱位的DDH患儿行早期Pavlik吊带治疗,同时采用超声跟踪随访6个月,以进一步决定治疗方案.结果 1.143例DDH新生儿中髋关节脱位的发病率为0.52%,髋关节发育不良的发病率为18.25%;2.健康新生儿619例髋关节超声测量指标α角、β角、股骨头覆盖率的正常值分别为(60.19±6.92)度、(45.25±7.29)度、(62.85±6.38)%,DDH患儿分别为(44.52±7.53)度、(58.45±10.36)度、(37.65±7.74)%,二组超声测量指标比较差异均有统计学意义(Pa<0.05);3.性别、胎位、分娩产式、左侧等均为髋关节脱位的高危因素.结论 1.超声检查是新生儿DDH筛查的首选方法.2.明确新生儿髋关节发育的指标、DDH的发病率及相关高危因素,有利于减少DDH发生,同时早期发现DDH、尽早治疗,可改善患儿预后.     

Echocardiographic Measurements in Normal Preterm and Term Neonates

ABSTRACT. To the purpose of better defining normative data on intracardiac dimensions and systolic time intervals in very low birth weight infants, we collected M-mode echocardiograms from 210 healthy preterm and term neonates with birth weights between 780 and 5350 g and gestational ages ranging from 26 to 43 weeks. Fifty-nine neonates were less than 24 h, 62 were 25-48 h, and 89 were 48-144 h of age. Diastolic and systolic left ventricular dimensions increased gradually with advancing birth weight ( r =+0.84 and 0.78). Left atrial and aortic root dimensions tended to show a parabolic relationship with birth weight, increments were reduced at higher birth weights ( r =+0.92 and 0.85). The shortening fraction of the left ventricle (mean + SD 33.8 ± 4.9%) and the left atrial/aortic ratio (1.16 ± 0.10) were constant throughout all weight subgroups. Pre-ejection periods and ejection times of both ventricles were reduced in preterm infants due to their higher heart rates, but left and right ventricular PEP/ ET ratios in preterm and term infants were comparable. Septal thickness in diastole and in systole tended to increase slowly with advancing birth weight, but correlation coefficients were low. This information is currently used as data base for a computer program to interpret M-mode echocardiograms performed in our nursery.