超早产儿生后72 h内低血压发生的危险因素及预后分析

目的 探讨超早产儿生后72 h内低血压的危险因素和预后。方法 回顾性分析2019年1月—2022年4月于浙江大学医学院附属儿童医院收治的超早产儿住院期间的临床资料。根据生后72 h内是否存在低血压，将入选患儿分为低血压组（41例）和正常血压组（82例），比较2组的临床特征、出生后72 h内的超声心动图参数和早期并发症，并采用多因素logistic回归分析探讨生后72 h内低血压的危险因素。采用受试者操作特征曲线分析评估相关指标预测超早产儿生后72 h内发生低血压的价值。结果 低血压组7 d内药物或手术关闭动脉导管未闭（patent ductus arteriosus, PDA）、≥Ⅲ度脑室内出血和严重肺出血的患儿比例及7 d内病死率显著高于正常血压组（P<0.05）。多因素logistic回归分析显示，出生体重较低、PDA直径较大及有血流动力学意义的PDA是超早产儿生后72 h内发生低血压的危险因素（P<0.05）。受试者操作特征曲线分析显示，出生体重、PDA直径、有血流动力学意义的PDA 3个指标联合预测超早产儿生后72 h内发生低血压的曲线下面积为0.873 (95%C...     

早期口服布洛芬治疗极低出生体重儿动脉导管未闭的临床研究

目的：探讨早期口服布洛芬治疗极低出生体重儿（VLBWI）动脉导管未闭（PDA）的临床效果和安全性。方法：生后24 h内经床边心脏彩超确诊的有临床症状的VLBWI PDA 64例,随机分为治疗组和对照组,每组32例。治疗组生后24 h内口服布洛芬,首剂10 mg/kg,第2、3剂5 mg/kg,每剂间隔24 h。对照组给予安慰剂生理盐水1 mL/kg,第2、3剂0. 5 mL/kg,每剂间隔24 h。观察两组患儿的治疗效果及不良反应。结果：第1疗程结束后治疗组动脉导管关闭率为84%,明显高于对照组的41%,两组比较差异有统计学意义（P＜0.01）。治疗组脑室周围白质软化和支气管肺发育不良的发生率明显低于对照组（P＜0.05）;机械通气时间和平均住院时间明显短于对照组（P＜0.05）。两组脑室内出血、早期肺出血、坏死性小肠结肠炎的发生率等差异无统计学意义（P＞0.05）,且均未发现明显不良反应。结论：早期口服布洛芬治疗VLBWI PDA可以减少部分近期并发症的发生率,缩短住院时间,且未发现明显不良反应。     

动脉导管未闭的药物治疗进展

正常足月儿生后24～48h动脉导管已呈功能性关闭，而早产儿的动脉导管常不能关闭，或功能性关闭后又重新开放。有呼吸窘迫综合征的极低出生体重儿，生后第3天动脉导管未闭(PDA)的发生率约为40％。PDA的临床结果取决于左向右分流的程度，可加重呼吸窘迫、促发充血性心力衰竭、支气管肺发育不良、肾脏低灌注及脑缺血、继发肠缺血。70％胎龄小于28周的早产儿需要药物或手术关闭动脉导管。     

布洛芬治疗极低出生体质量儿动脉导管未闭效果的相关因素北大核心CSCD

目的探讨布洛芬治疗早产儿动脉导管未闭（PDA）的相关影响因素。方法对2013年1月至2015年12月在河南省人民医院新生儿科住院且出生体质量〈1 500 g的1 236例早产儿进行分析。于出生7 d行床边超声心动图检查,对发生PDA的早产儿排除口服布洛芬的禁忌证者入组。实际进入调查376例。予口服/鼻饲布洛芬治疗后72 h再次床边超声心动图检查了解PDA的关闭率,分析引起布洛芬治疗PDA失败的高危因素。结果单因素分析显示,小胎龄、低出生体质量、宫内窘迫、出生窒息病史、呼吸窘迫综合征、感染、呼吸支持、导管直径、导管两端压差、导管水平峰值流速等是引起PDA药物治疗失败的高危因素（均P〈0.05）;Logistic回归分析显示,呼吸窘迫综合征、感染、呼吸支持、导管直径、导管两端压差、导管水平峰值流速等是PDA发生的独立高危因素,胎龄和出生体质量为保护性因素。结论关注引起早产儿PDA药物治疗失败的高危因素,早期防治PDA可提高早产儿的存活率和生存质量。     

早产儿动脉导管未闭的临床研究

目的　观察早产儿动脉导管未闭 (PDA)发生率、影响因素及血流动力学的变化 ,提供监测及干预治疗的建议。方法　 86例胎龄 2 8～ 3 6周、无呼吸机治疗 (未用或已停用 )的早产儿 ,出生 2～ 5d行首次超声心动图检查。对诊断为PDA的早产儿动态超声心动图监测。结果　生后 3～ 4d超声心动图诊断PDA 2 2例 ,胎龄 (3 3 .1± 2 .0 )周。生后 8.5d 2 0例复查 ,16例动脉导管自行关闭 ;4例PDA早产儿经治疗 ,动脉导管关闭 2例 (1例吲哚美辛 ;1例动脉导管再开放 )。最终遗留PDA 3例。单因素及多因素Logistic回归分析发现 ,出生体质量越低 ,PDA发生机率越高 (χ2 =2 .890 7　P =0 .0 891) ;生后窒息及严重疾病增加PDA发生的危险性 (χ2 =4.3 72 9　P =0 .0 3 65 ;χ2 =11.65 90　P =0 .0 0 0 6)。PDA存在使早产儿左心房 /主动脉根内径比值增高 (1.0 8± 0 .18vs 1.0 0± 0 .0 7　P =0 .0 48) ,心功能良好。结论　平均胎龄 3 3周、平均日龄 3d、一般状况较好的早产儿超声心动图诊断PDA机率 2 5 .6% ,85 %早产儿PDA可自行关闭。低出生体质量、出生窒息、严重疾病及症状性PDA发生或持续均是高危因素。     

早产儿有创机械通气初次撤机失败相关危险因素分析

目的 研究早产儿有创机械通气初次撤机失败相关危险因素及不良预后。方法 回顾性纳入北京大学第三医院新生儿重症监护室收治的生后72 h内有创机械通气的早产儿,根据初次撤机后72 h内是否需要再插管分为撤机成功组和撤机失败组,分析初次撤机失败相关危险因素及不良预后。结果 共纳入282例早产儿,其中撤机失败组43例（15.2%）。撤机失败组胎龄、出生体重均低于撤机成功组（P < 0.05）,撤机失败组产房内插管率、动脉导管未闭（patent ductus arteriosus,PDA;内径≥2.5 mm）比例高于撤机成功组（P < 0.05）。撤机前应用≥2种血管活性药物（OR=2.48,95%CI：1.22~5.03）、PDA（≥2.5 mm）（OR=4.54,95%CI：2.02~10.24）为撤机失败的危险因素（P < 0.05）。撤机失败组患儿呼吸机相关性肺炎、中-重度支气管肺发育不良、败血症的发生率均高于撤机成功组（P < 0.05）,撤机失败组吸氧时间、住院时间长于撤机成功组（P < 0.05）。结论 撤机前使用≥2种血管活性药物、PDA（≥2.5 mm）是撤机失败的主要危险因素,撤机失败可能与住院早产儿不良结局有关。     

早产儿支气管肺发育不良危险因素及2岁时随访结局

目的探讨早产儿发生支气管肺发育不良（BPD）的危险因素及远期随访结局。方法 以2012年1月至2013年12月在复旦大学附属儿科医院新生儿科病房住院的胎龄≤32周、出生体重≤1 500 g及生后7 d内入院的BPD早产儿为BPD组,同期入住我院的非BPD早产儿中选取与BPD组等同样本量的病例为对照组。采集与BPD发生的母亲和新生儿因素行单因素分析和多因素分析。同时统计BPD早产儿生后1岁内和~2岁的支气管炎、肺炎、喘息发作次数和住院次数等指标。结果 BPD组和对照组均纳入了156例早产儿。单因素分析显示,BPD组母亲年龄（P=0.046）、先兆子（P=0.025）和阴道产（P<0.001）比例显著高于对照组;BPD组出生胎龄、出生体重显著低于对照组 (P均<0.001 )。BPD组1 和5 min Apgar 评分,败血症 ≥72 h、动脉导管未闭（PDA）、早产儿视网膜病变、应用肺表面活性物质、呼吸机相关性肺炎、机械通气≥7 d的比例均与对照组差异有统计学意义。多因素Logistic回归分析显示胎龄(OR= 0.46,95%CI:0.37~0.58)、机械通气≥7 d(OR=9.47,95%CI：3.70~24.27)、PDA(OR=2.21,95%CI：1.18~4.12)、先兆子(OR=4.91,95%CI：1.26~19.15 )是发生BPD的危险因素。BPD组1岁以内支气管炎、喘息的发生率高于对照组,再入院率两组差异无统计学意义;BPD组生后~2岁较生后1岁以内肺炎的发生率显著下降,支气管炎、喘息的发生率及再入院率差异无统计学意义。结论 低出生胎龄、机械通气≥7 d、PDA、先兆子是发生BPD的危险因素;BPD早产儿在生后1年以内下呼吸道感染的发生率增高。     

新型冠状病毒肺炎疫情对极低出生体重儿亲母母乳喂养的影响

目的 分析新型冠状病毒肺炎疫情防控期间住院的极低出生体重儿（very low birth weight infants,VLBWI）亲母母乳喂养率和喂养量的特征变化。 方法 回顾性分析2019年1月至2020年12月出生并收治于南京市妇幼保健院新生儿重症监护病房的胎龄<32周VLBWI的临床资料,比较并分析疫情期间VLBWI亲母母乳喂养率和喂养量的变化。 结果 共纳入301名VLBWI,根据疫情暴发时间分为疫情前组（n=205）和疫情后组（n=96）,疫情后组VLBWI在生后0~28 d及住院期间亲母母乳喂养率均低于疫情前组（P<0.05）。疫情后组VLBWI在生后0~7 d、0~14 d、0~28 d内的亲母母乳喂养量均低于疫情前组（P<0.05）;疫情后组VLBWI中-重度支气管肺发育不良和喂养不耐受的发生率高于疫情前组（P<0.05）。 结论 新型冠状病毒肺炎疫情对VLBWI的亲母母乳喂养有明显的影响,VLBWI生后28 d内的亲母母乳喂养率和喂养量明显下降,在整个住院期间亲母母乳喂养率也有明显下降。     

极低出生体重儿动脉导管未闭转归的影响因素分析

目的分析极低出生体重儿动脉导管未闭(PDA)转归的影响因素。方法以2012年1月至2014年12月收治的194例极低出生体重儿为研究对象,根据心脏超声检查及治疗转归情况分为无PDA组,PDA自然关闭组、药物关闭组、手术关闭组,分析其临床及超声心动图特征。结果 PDA自然关闭率58.7%。自然关闭组的出生胎龄、出生体重、小于胎龄儿比例均大于药物和手术关闭组,药物及手术关闭组的新生儿呼吸窘迫综合征发生率及肺表面活性物质(PS)应用比例高于自然关闭组(P0.05)。不同时间段自然关闭组的动脉导管直径均明显小于药物和手术关闭组(P0.05)。多因素logistic回归分析示出生胎龄、PS应用及48 h动脉导管直径与PDA转归显著相关。自然关闭组PDA分流类型均以关闭型为主,而药物及手术关闭组在48 h以肺高压型及进展型为主,在4 d、7 d时均以进展型为主。结论极低出生体重儿PDA自然关闭率较高,出生胎龄越小以及应用PS的患儿自然关闭率越低;动脉导管直径越大且分流类型为进展型或脉冲型的PDA不易自然关闭。     

小儿先天性心脏病介入治疗后心肌损伤和炎症反应的研究

目的：研究先天性心脏病（CHD）介入治疗后7 d心肌损伤和炎症反应。方法：选择77例CHD患儿,其中室间隔缺损（VSD）12例,肺动脉瓣狭窄(PS)14例,房间隔缺损（ASD）14例,动脉导管未闭（PDA）37例。检测术后即刻、术毕、术后6 h、24 h、72 h及7 d 的血清心肌酶（AST、CK、CKMB）、肌钙蛋白I(cTnI)和CRP值的变化。结果：VSD组AST水平于术后即刻,术后6 h和术后24 h明显高于其他3种类型CHD组（P<0.05）;术后即刻及术后6 h各组间CK及CKMB水平差异有统计学意义,以VSD组最高;术后72 h和术后7 d PDA组CRP水平明显高于其他3种类型CHD组（P<0.05）。与术前相比,术后6 h和24 h,4种类型CHD组AST均明显升高（P<0.05）;术后即刻和术后6 h,VSD组CK和CKMB水平较术前明显升高（P<0.05）;术后即刻和术后6 h,VSD、PDA和PS组cTnI水平较术前明显升高（P<0.05）;PDA组CRP水平术后24 h、72 h和7 d较术前明显升高（P<0.05）。结论：介入治疗CHD 7 d内可引起轻微心肌损伤,以VSD明显,主要集中在术毕至术后24 h较短时间内,未引起明显炎症反应。     

近红外光谱技术对有血流动力学意义的动脉导管未闭早产儿肠道组织氧饱和度监测价值的前瞻性研究

目的 使用近红外光谱技术研究有血流动力学意义的动脉导管未闭（hemodynamically significant patent ductus arteriosus,hsPDA）早产儿肠道组织氧饱和度（regional oxygen saturation,rSO₂）的变化及规律,初步探索hsPDA早产儿肠道组织血氧水平变化的临床意义。 方法 前瞻性选取2017年10月至2020年10月深圳市龙岗中心医院新生儿科收治的胎龄<32周和/或出生体重<1 500 g的动脉导管未闭（patent ductus arteriosus,PDA）早产儿。按照hsPDA的诊断标准分为hsPDA组和无血流动力学意义的动脉导管未闭（non-hemodynamically significant patent ductus arteriosus,nhsPDA）组,将hsPDA组早产儿根据口服布洛芬后动脉导管关闭情况分为hsPDA关闭亚组和hsPDA未闭亚组。分别在诊断PDA时及治疗后测定血流动力学指标,持续监测患儿肠道组织rSO₂水平,分析其变化规律。 结果 共有241例PDA早产儿纳入研究,其中hsPDA组55例（22.8%）,nhsPDA组186例（77.2%）;hsPDA关闭亚组36例（65%）,hsPDA未闭亚组19例（35%）。hsPDA组左心房内径/主动脉根部内径值大于nhsPDA组,左室射血分数和短轴缩短率均低于nhsPDA组（P<0.05）。hsPDA组患儿肠道组织rSO₂在诊断后6 h内各时间点（1、2、4、6 h）均低于nhsPDA组（P<0.05）;hsPDA组早产儿肠道组织rSO₂随时间呈下降趋势（P<0.05）,至6 h时达最低值（0.448±0.014）。hsPDA关闭亚组左心房内径/主动脉根部内径值低于hsPDA未闭亚组,左室射血分数和短轴缩短率高于hsPDA未闭亚组（P<0.05）。hsPDA关闭亚组患儿肠道组织rSO₂在治疗后48~96 h内各时间点（48、72、96 h）均高于hsPDA未闭亚组（P<0.05）;hsPDA关闭亚组早产儿肠道组织rSO₂从治疗24 h后随时间呈上升趋势（P<0.05）,至96 h达最高值（0.578±0.031）。 结论 hsPDA对早产儿肠道组织氧合有影响,可通过近红外光谱技术持续监测hsPDA早产儿肠道组织rSO₂变化趋势指导临床管理。     

Surgical closure of patent ductus arteriosus in very-low-birth-weight infants

 In many very-low-birth-weight (VLBW) infants the ductus arteriosus fails to close spontaneously, and they subsequently develop signs and symptoms of poor tissue perfusion and heart failure. This study evalutes the results of early surgical closure of patent ductus arteriosus (PDA). We retrospectively reviewed the records of all 101 VLBW infants who weighed 1,500 g or less when their PDA was surgically ligated in Turku University Hospital between 1988 and 1998. The mean gestational age at birth was 27.2 weeks and mean birth weight 963±239 g. The operation was performed at 12±8 days of age; the infants' weight at operation was 969±231 g and they were tracheally extubated 11±14 days after the operation. The surgery-related mortality was 3% (3/101) and overall mortality 10% (10/101). We conclude that surgical closure of PDA is safe and effective in VLBW infants. Accepted: 19 June 2000     

Necrotizing enterocolitis after red blood cell transfusion in preterm infants with patent ductus arteriosus: a case series

Aim: Both patent ductus arteriosus (PDA) and packed red blood cell (PRBC) transfusion are risk factors for necrotizing enterocolitis (NEC). The combination of PDA and PRBC transfusion may have a synergistic effect on the intestinal circulation. Methods: We present four cases of NEC in very low birth weight (VLBW) infants within 14 h after PRBC transfusion. Results: All infants were growing on full enteral feeding, and they all had a PDA. Conclusion: We are concerned that the simultaneous presence of a PDA and PRBC transfusion in VLBW infants may place the infant at even greater risk of NEC than each of these factors alone.     

氨基末端脑钠肽前体预测早产儿症状性动脉导管未闭的价值

目的 探讨氨基末端脑钠肽前体(NT-proBNP)预测早产儿症状性动脉导管未闭(sPDA)的价值。方法 选择2014年6月至2015年4月出生、胎龄≤32周、48 h内超声心动图确定存在动脉导管的早产儿为研究对象,监测其临床表现,于生后3 d及5 d检测血清NT-proBNP水平并行超声心动图检查,根据患儿临床表现、超声心动图结果分为sPDA组及非症状性动脉导管未闭(asPDA)组,分析血清NT-proBNP水平与超声指标的关系,比较两组间相同日龄血清NT-proBNP水平,ROC曲线确定血清NT-proBNP水平预测sPDA的敏感性、特异性。结果 共69例早产儿纳入研究,其中sPDA组13例,asPDA组56例。血清NT-proBNP水平与动脉导管管径、左房内径与主动脉根部内径比值(LA/AO)呈正相关关系(分别r=0.856、0.713,均 PPCI:0.892~1.000,PCI:0.848~1.000,P结论 NT-proBNP可能是动脉导管分流量的量化指标;生后3 d 及5 d血清NT-proBNP水平的检测均有助于早期预测sPDA。     

Timing of surgical ligation of patent ductus arteriosus in very low birth weight infants北大核心CSCD

Objective To study the effect of timing of surgical ligation of patent ductus arteriosus (PDA) on the prognosis of very low birth weight infants (VLBWI). Methods The medical data of VLBWI who underwent transthoracic ligation for PDA from June 2018 to May 2021 were reviewed retrospectively. The infants were divided into early ligation group (≤21 days of age) and late ligation group (>21 days of age) based on the age of ligation. The two groups were compared in terms of perioperative clinical features, complications, and mortality. The risk factors for early surgical ligation were analyzed. Results A total of 72 VLBWI were enrolled, with 19 infants (26%) in the early ligation group and 53 infants (74%) in the late ligation group. There were significant differences in birth weight, gestational age, weight at operation, days of age at operation, rates of preoperative invasive and noninvasive mechanical ventilation, incidence rate of pulmonary hemorrhage, incidence rate of hypotension, preoperative PDA internal diameter (mm/kg), intraoperative PDA external diameter (mm/kg), incidence rate of post-ligation cardiac syndrome, and duration of postoperative invasive mechanical ventilation between the two groups (P<0.05). A binary logistic regression analysis showed that pulmonary hemorrhage was an indication of early surgical ligation of PDA (P<0.05). There were no significant differences in the incidence rates of post-operative complications and the mortality rate between the early ligation and late ligation groups. Conclusions Early surgical ligation may be performed for VLBWI who are experiencing pulmonary hemorrhage and hemodynamically significant PDA confirmed by cardiac ultrasound after birth. However, post-ligation cardiac syndrome should attract enough attention. In addition, early surgical ligation of PDA does not increase the risk of surgery-related and long-term complications or death, indicating that it is a safe and feasible treatment option. © 2022 Central South University. All right reserved.     

血N端脑钠肽前体在早产儿症状性动脉导管未闭诊治中的应用价值

目的探讨血浆N端脑钠肽前体(NT-pro BNP)在早产儿症状性动脉导管未闭(s PDA)诊治中的临床应用价值。方法选取2013年10月—2014年9月入住新生儿重症监护病房、胎龄28~32周、出生体质量??1 500 g的早产儿107例,分别于生后第4、7天检测NT-pro BNP,采血后30 min内行超声心动图检查。根据生后第4天超声心动图检查结果分PDA组(39例)与对照组(68例);PDA组根据有无超声血流动力学显著改变及临床表现分为症状性PDA(s PDA组,20例)和无症状性PDA(as PDA组,19例);s PDA组再根据是否服用布洛芬分为治疗组(13例)与非治疗组(7例)。结果生后第4天,s PDA组患儿血浆NT-pro BNP水平高于as PDA组,as PDA组高于对照组,差异均有统计学意义(P??0.05);生后第7天,s PDA组患儿血浆NT-pro BNP水平高于as PDA组和对照组,差异有统计学意义(P??0.05),as PDA组与对照组的差异则无统计学意义(P??0.05)。治疗组生后第7天血浆NT-pro BNP水平较第4天显著下降,差异有统计学意义(P??0.05);非治疗组生后第7天与第4天血浆NT-pro BNP水平的差异无统计学意义(P??0.05)。PDA患儿生后第4天血浆NT-pro BNP水平与动脉导管(DA)直径、左心房/主动脉根部内径比值(LA/AO)及DA直径与左肺动脉内径比值(TDD/LPA)呈正相关(r=0.498~0.670,P均??0.05)。生后第4天血浆NT-pro BNP水平预测s PDA的ROC曲线下面积(AUC)为0.969(95%CI:0.938~1.000),NT-pro BNP水平在13 964 pg/m L时,诊断s PDA的灵敏度为95%,特异度为95.4%。结论 s PDA早产儿血浆NT-pro BNP水平明显增高,治疗后下降。第4天血浆NT-pro BNP是预测s PDA的敏感指标,动态监测血浆NT-pro BNP水平变化对指导早产儿PDA治疗策略的选择有重要临床价值。     

A preliminary study of the application of the transductal velocity ratio for assessing persistent ductus arteriosus

OBJECTIVE: To compare the transductal velocity ratio (TVR) of the persistent ductus arteriosus (PDA) with other echocardiographic criteria for haemodynamic significance of a PDA. METHODS: This was a prospective study (from January 1997 to August 1998) in the nurseries of the Royal Women's Hospital, Melbourne. Infants with a clinically suspected PDA were eligible and included if the echocardiogram showed a PDA with a structurally normal heart and the TVR had been measured. The PDA was assessed for evidence of left heart dilatation, the presence of reverse or absent diastolic flow in the descending aorta, the pattern of Doppler flow velocity waveform in the ductus arteriosus, and subjective assessment of ductal diameter on the real time image. The peak systolic velocity (PSV) was obtained from the pulmonary and aortic ends of the PDA, and the TVR calculated by dividing the PSV at the pulmonary end by the PSV at the aortic end. RESULTS: Forty two infants had 59 echocardiographs with their TVR calculated. Mean (SD) birth weight was 1008 (362) g. Mean (SD) gestational age at birth was 27.4 (2.2) weeks with a mean (SD) corrected gestational age of 28.7 (2.7) weeks. The mean TVR was decreased in those infants with a high left atrial diameter/aortic diameter (LA/Ao) ratio (1.9 v 2.8, p = 0.0032) or reverse/absent diastolic flow in the descending aorta (2.1 v 3.0, p = 0.02). This difference was greater if those two criteria were combined (1.7 v 3.4, p = 0.0027). The mean TVR was decreased in infants with a wide open duct seen on two dimensional imaging (1.5 v 3.0, p < 0.0001) or pulsatile flow seen on pulsed Doppler in the PDA (1.9 v 3.4, p = 0.0001). The LA/Ao and left ventricle internal diameter/aortic diameter (LVIDd/Ao) ratios were higher in the group with a TVR < 1.8 than in the other two groups; these differences were statistically significant. CONCLUSIONS: The TVR as a measure of the degree of constriction of a PDA is associated with other echocardiographic criteria for a haemodynamically significant PDA. A low TVR (signifying a poorly constricted duct) is associated with echocardiographic features of a significant left to right shunt, and vice versa. Further research is required to determine the usefulness of the TVR in predicting closure or likely continuing patency of a PDA and the need for treatment.     

Cardiac output and ductal reopening during phototherapy in preterm infants

Left ventricular output (LVO), left pulmonary artery blood flow (LPA) and patency of the ductus arteriosus (PDA) were studied with 2D/pulsed Doppler ultrasound before, during and after phototherapy treatment in 27 preterm infants (gestational age < or =32 wk), who were exposed for a minimum of 12 h to phototherapy for non-haemolytic hyperbilirubinemia. In 14 infants (52%) the ductus arteriosus reopened during phototherapy, but ductal patency was not of haemodynamic importance. LVO initially decreased in preterm infants in whom the ductus did not reopen. From 12 h until discontinuation of phototherapy, LVO and LPA were higher than before phototherapy in all infants. After withdrawal of phototherapy, LVO and LPA returned to pre-phototherapy values.     

Closure of the ductus arteriosus and development of pulmonary branch stenosis in babies of less than 32 weeks gestation

AIMS: To define how often transient pulmonary branch stenosis (PBS) develops after closure of a patent ductus arteriosus (PDA) in babies born at less than 32 weeks gestation; to describe the natural history of PBS and the relation between PBS and a cardiac murmur. METHODS: Fifty three preterm infants born at a gestational age less than 32 weeks and who had PDA diagnosed on echocardiography were recruited. An echocardiogram was performed on alternate days until the ductus arteriosus closed. If PBS was diagnosed, the baby was followed up until PBS resolved. RESULTS: In 59%, PBS developed in one or both branches after closure of the PDA. In 21%, both pulmonary branches were affected. In 79%, the left pulmonary artery alone was involved but the right side was never affected alone. PBS had resolved in 74% by the time the infants reached 40 weeks, in 95% at a corrected age of 6 weeks, and in 100% at a corrected age of 3 months. There is a better correlation between a cardiac murmur and PBS than between a murmur and PDA. CONCLUSIONS: PBS in preterm infants is usually not present at birth but develops after closure of a PDA. PBS resolves by a corrected age of 3 months. The presence of a murmur after closure of a PDA is usually related to PBS and not to reopening of the ductus arteriosus.