Meconium aspiration syndrome: current concepts

Aspiration of meconium causes considerable perinatal morbidity and mortality. Meconium-stained amniotic fluid (MSAF) is present in 7-22% of all deliveries. Gastrointestinal secretions, bile, bile acids, mucus, pancreatic juice, cellular debris, amniotic fluid, swallowed vernix caseosa, lanuge, and blood comprise meconium. Passage of meconium occurs most often in deliveries after 42 weeks gestation (30%) because of high levels of the hormone motilin. This hormone is responsible for bowel peristalsis, defecation, and maturation of the innervation of the intestinal tract associated with vagal stimulation. It tends to be a marker of pre/intrapartum asphyxia. MSAF is also a sign of fetal hypoxia or acidosis. It appears that meconium aspiration is predominantly an intrauterine event. The definition of meconium aspiration syndrome (MAS) is respiratory distress in a meconium-stained newborn, compatible radiographic findings (e.g., coarse, irregular pattern of increased density throughout the lung), and symptoms that can not otherwise be explained. MAS occurs in 1-4% of infants with MSAF and up to 10% of those with thick meconium. Mortality ranges from 6% to 40%. Initially, meconium particles mechanically obstruct the small airways. Later, chemical pneumonitis and interstitial edema are responsible for small airway obstruction. As many as 66% of persistent pulmonary hypertension of the newborn cases are associated with MAS. Clinical signs and symptoms of MAS include frothy, yellow-green secretions from the mouth; very rapid breathing; intercostal retractions; cyanosis; overinflated chest due to air trapping; rales; and rattling in the throat. Transcervical amnio-infusion of warmed normal saline may be an obstetric intervention in cases of MSAF. Intrapartum oropharyngeal suctioning and postpartum intratracheal suctioning has reduced the incidence of MAS. Routine care of MAS infants includes monitoring and correcting of the thermal environment and blood glucose and calcium levels. Chest physiotherapy, saline lavage, management of hypoxemia, surfactant therapy, and systemic steroid treatment are MAS therapies.     

Antenatal risk factors and neonatal outcome in meconium aspiration syndrome

Meconium staining of amniotic fluid, present in 10-22% of all live births, has been associated with the subsequent development of meconium aspiration syndrome (MAS). To learn more about the risk factors and outcomes associated with MAS, a retrospective comparison was made of the 187 newborns diagnosed with MAS at the Jawaharlal Institute of Postgraduate Medical Education and Research in Pondicherry, India, in 1989-90 and 400 control infants born on the same day with meconium-stained liquor but no MAS. During the 2-year study period, there were 7040 deliveries, of which 790 (11.2%) had meconium-stained liquor. The MAS group contained significantly more post-term babies, primipara and grand multipara, unbooked mothers, mothers with toxemia of pregnancy or prolonged rupture of the membranes, infants with moderate or severe birth asphyxia, and operative deliveries. 80.1% of the 37 neonatal deaths involving MAS infants had a 1-minute Apgar score of less than 3, indicating periods of antepartum and intrapartum asphyxia. Early detection of fetal hypoxia through adequate monitoring and timely delivery could substantially reduce neonatal morbidity and mortality from meconium aspiration.     

细胞因子与胎粪吸入综合征

胎粪吸入综合征是新生儿呼吸系统常见的严重疾病,细胞因子在该病的发生机制中起着极其重要的作用。胎粪吸入所致肺损伤与许多细胞因子有关。胎粪吸入后肿瘤坏死因子、白细胞介素- 1、2、6、8等多种细胞因子释放,引起并加重肺部的炎症反应。该文着重综述几种重要的细胞因子在胎粪吸入综合征发病中所起的作用和机制,并为胎粪吸入综合征的治疗提供一条新的思路。     

胎粪吸引管联用沐舒坦防治胎粪吸入综合征的探讨

目的探讨胎粪吸引管联用沐舒坦防治胎粪吸入综合征(MAS)的疗效。方法回顾性研究我院136例MAS患儿,分为A组76例和B组60例,A组指生后清理口腔和鼻腔黏液后,给予胎粪吸引管行气管内吸引,治疗中给予沐舒坦雾化吸入,保持呼吸道通畅;B组则常规给予清理口腔和鼻腔黏液(必要时气管内冲洗)等治疗措施。结果A组76例全部治愈,并发症明显减少,无1例死亡,治愈率100%;B组治愈52例,家属放弃4例,死亡4例,治愈率86.7%。A组明显优于B组(p<0.05);机械通气、氧疗时间、并发症发生率和住院时间A组明显优于B组(均p<0.05)。结论及时清吸气管内胎粪污染的羊水可以明显提高MAS患儿的治愈率,胎粪吸引管联用沐舒坦雾化吸入是抢救MAS的有效方法之一。     

足月妊娠羊水过少与妊娠结局的临床分析

目的 探讨足月妊娠羊水过少对母婴分娩结局及胎儿宫内发育情况的影响。方法:2012年1月至2014年1月选取本院妇产科收治的80例羊水过少的孕妇为观察组,另选取同期在本院分娩的80例正常孕妇为对照组,对比分析两组母婴并发症发生率及胎儿宫内发育情况。结果:观察组产妇剖宫产率、产程延长、胎盘钙化、产后出血、妊娠高血压、过期妊娠、胎粪II~III度污染发生率显著高于对照组,差异有统计学意义(P<0.05)。观察组胎儿宫内窘迫、羊水污染、吸入性肺炎、胎儿窘迫发生率显著高于对照组,差异有统计学意义(P<0.05)。观察组胎儿阿氏评分、出生体重、身长、头围均低于对照组,差异有统计学意义(P<0.05)。结论:羊水过少可增加母婴并发症发生率,威胁母婴生命安全。加强产妇产前检查,适时选择合适的分娩方式可降低羊水过少发生率,有利于确保母婴生命安全。     

胎粪吸入综合征的临床干预与治疗探讨

目的:探讨胎粪吸入综合征(MAS)的临床干预与治疗方法。方法:对75例MAS住院病例进行回顾性分析,所有病例均采用综合治疗,改善通气及供氧,尽早呼吸支持治疗。结果:轻度MAS无1例死亡,中、重度死亡6例,病死率为8.0%。结论:随着MAS病情加重病死率明显增高;胎儿娩出后及时彻底清除口咽、声门下及气管内的胎粪,可减少或减轻MAS的发生及病情的严重程度;新生儿科与产科应加强合作,放宽机械通气指征是重症MAS呼吸机治疗成功的关键。     

羊水胎粪污染与新生儿预后分析

目的：探讨羊水胎粪污染与新生儿预后的关系。方法：对本院323例足月儿头位分娩时羊水粪染对新生儿的影响进行实例讨论。323例中发生新生儿窒息59例,发生率为18.27％,其中发生胎粪吸入综合征（MAS）1例。结果：新生儿结局与羊水胎粪污染程度的关系为：Ⅲ度粪染者新生儿窒息率的发生率明显增高, I度与Ⅲ度、Ⅱ度与Ⅲ度粪污染新生儿出生窒息差异均有统计学意义（P〈0.05）,但I度与Ⅱ度粪污染新生儿出生窒息差异无统计学意义（P〉0.05）。结论：Ⅰ度与Ⅱ度粪染者应加强胎心电子监护,如果胎心监护正常,不需要进行特殊处理;如果胎心监护异常,应尽快终止妊娠或结束分娩,以免造成胎儿不良结局。     

妊娠期肝内胆汁淤积症对围产儿的影响

目的 :探讨妊娠期肝内胆汁淤积症 (Intrahepatic Cholestasis of Pregnancy,ICP)对围产儿的影响。方法 :对该院 2 0 0 0年 1月～ 2 0 0 2年 12月以剖宫产分娩结束妊娠的 ICP孕妇 72例 ,观察其羊水胎粪污染、胎儿窘迫、早产、新生儿窒息、新生儿吸入性肺炎的发病率 ,与同期行剖宫产分娩的 70例正常孕产妇的妊娠结局和新生儿结局进行对比分析。结果 :ICP组羊水胎粪污染率、胎儿窘迫率、早产率、新生儿窒息率、新生儿吸入性肺炎率分别为 3 0 .56%、 2 3 .61%、 16.67%、 5.56%、 16.67% ,与对照组相比有显著性差异 (P<0 .0 5～ 0 .0 1)。结论 :ICP可导致早产、胎儿窘迫、新生儿窒息、羊水胎粪污染、新生儿吸入性肺炎。     

新生儿胎粪吸入综合征的临床X线分析(附81例报告)

目的:分析新生儿胎粪吸入综合征(简称MAS)的临床X线特征,进一步提高X线诊断水平。方法:回顾经X线平片和临床证实的8 l例胎粪吸入综合征并进行讨论。结果:X线征象因吸入量和胎粪羊水相对含量多少而异。其中65例X线表现程度相对较轻,表现为两肺纹理增强,轻度肺气肿征,部分可见小颗粒状影;16例较重显示两肺满布结节状和斑片状模糊影;5例并发气漏;合并肺内感染10例;合并ARDS 2例;死亡4例;2例放弃治疗。结论:胸部X线平片对MAS的诊断及其疗效评价具有重要价值。     

新法复苏推广后对胎粪吸入综合征发病率及发病情况的影响

目的:了解新法复苏推广后对胎粪吸入综合征(MAS)的影响。方法:调查2005年该院产科活产新生儿中MAS的发病率,分析2001～2005年住入新生儿病房MAS病儿的临床特点。结果:2005年该院高危新生儿中MAS发病率为0.87%,MAS的病情较轻,治愈率82.3%,合并症减少。结论:新法复苏推广后降低了MAS的发病率,由于病情减轻,提高了MAS的治愈率。     

Biparietal diameter/kidney length ratio in cases with chronic hypoxic state

AIMS: The object of this study was to investigate the fetal biparietal diameter/kidney length ratio in normal and hyperechogenic kidneys during the third trimester of gestation. MATERIAL AND METHODS: The selected cases were characterized by pregnancy-associated hypertension and/or proteinuria, which was associated with fetal hypoxia due to the depression of placental blood flow. Depending on the renal manifestation of intrauterine chronic hypoxia, cases were divided into two study groups. Group I was composed of 21 fetuses with pregnancy-associated hypertension and/or proteinuria and hyperechogenic renal medullae. Group II consisted of 162 fetuses with pregnancy-associated hypertension and/or proteinuria and normal echoic kidney. Both study groups included pregnant women from the third trimester. RESULTS: Fetal renal hyperechogenicity correlated with the pathological growth of fetal kidney. The fetal biparietal diameter/kidney length ratio was significantly lower in cases of hyperechogenicity. CONCLUSIONS: The fetal renal hyperechogenicity is a relevant indicator of diminution of fetal renal perfusion. This can lead to abnormal development of the affected kidney and can result in a pathological reduction of biparietal diameter/kidney length ratio, which may also be an in utero indicator of subsequent intrauterine and neonatal complications. Detailed ultrasound examinations of renal parenchyma and kidney length seem to be a useful method in the prenatal diagnosis of decreased renal perfusion and of intrauterine hypoxia and serve to detect pathological conditions in utero.     

Mineral Composition of Meconium

Objectives: We hypothesized that the concentration of major essential mineral elements in meconium correlate with gestational age (GA) or birth weight. To verify this premise we determined the concentration in meconium of calcium, magnesium, phosphorus, copper, zinc, iron, and manganese.

Methods: Thirty-four appropriate for age singleton infants without major congenital anomalies were divided into four GA groups (in weeks): 24 to 28; 29 to 33; 34 to 37; 38 to 42, or in birth weight groups (in g): <1500; 1500–1999; 2000–2499; ≥2500. Meconium was collected until the appearance of transitional stools and lyophilized for analysis.

Results: When adjusted for birth weight, the concentrations of calcium, copper, iron and phosphorus were higher in the meconium of 24 to 28 week GA infants than in those of the 38 to 42 week GA newborns. Birth weight adjusted copper concentration was highest in the 29 to 33 week GA group, while the remaining elements did not change across the range of GA. Meconium copper concentration in infants born with <2000 g was higher than in those born with a weight ≥2500 g.

Conclusions: These results could serve as normative data of a noninvasive examination of the mineral nutritional “history” of the fetus, and, eventually, to better evaluate possible neonatal deficiencies in infants with intrauterine growth retardation or other types of complicated intrauterine courses.     

Meconium staining of the liquor in a low-risk population

Summary. Although the significance of meconium-stained amniotic fluid as a sign of fetal distress remains controversial, its presence remains a concern to both obstetricians and neonatologists since signs of asphyxia and meconium staining are associated with an increase in perinatal morbidity and mortality. The aim of this study was to evaluate the role of meconium staining of the liquor in the low-risk obstetric population in terms of fetal distress and perinatal morbidity and mortality. In a prospective cohort study at a referral hospital and at one of two municipal clinics, women with a singleton pregnancy of 37 to 42 weeks gestation and with no pre-defined risk factor were recruited into the study. Study patients comprised those with meconium staining of the liquor and controls comprised similar women but with clear liquor. Meconium staining of the liquor was associated with poor outcome in all the outcome measures assessed. Fetal heart rate (FHR) abnormality was more closely associated with adverse outcome than meconium staining, and thin meconium alone was not associated with any adverse outcome except respiratory distress. Women with thin meconium in the presence of normal FHR can therefore be safely managed at the clinic level. Thick meconium itself was a risk factor for poor outcome, more so if associated with FHR abnormality, and should be an indicator for early referral.     

测定胎儿脑、脐血流速波预测胎儿缺氧与围产儿结局关系的临床分析

为预测胎儿宫内缺氧 ,应用彩色多普勒超声仪对 15 0例孕妇的胎儿进行血流测定。结果 :胎儿大脑中动脉 (MCA)血流 S/ D<4、PI<1.4、RI<0 .6 ;脐动脉 (UMA)血流 S/ D>3、PI>1.7、RI>0 .8、PI RI MCA/ PI RIUMA<1时 ,提示胎儿宫内缺氧 ;高危妊娠组胎儿缺氧发生率与正常组比较有明显差异性 (P<0 .0 0 1) ;两组围产儿不良结局 ,如低体重儿、胎儿窘迫、新生儿窒息、围产儿死亡率均有显著差异。产前监测胎儿大脑中动脉、脐动脉血流指标 ,可以了解胎儿颅脑循环及胎儿胎盘循环状态 ,预测胎儿宫内缺氧     

Neonatal screening for prenatal alcohol exposure: Assessment of voluntary maternal participation in an open meconium screening program

Meconium fatty acid ethyl esters (FAEEs) are validated biomarkers of fetal alcohol exposure. Meconium FAEE testing can potentially be used as a screen by health-care professionals to identify neonates at-risk for Fetal Alcohol Spectrum Disorder, thereby permitting diagnostic follow-up of these children and early intervention in those who develop disabilities. The purpose of this study was to assess whether women would willingly partake in a screening program of this nature. This was determined by launching a pilot screening program for prenatal alcohol exposure in a high-risk obstetric unit previously shown to have a high prevalence of FAEE-positive meconium via anonymous meconium testing. The program involved voluntary testing of meconium for FAEEs and long-term developmental follow-up of positive cases through an existing public health program. The participation rate in the screening program was significantly lower than when testing was conducted anonymously (78% vs. 95%, respectively; p < 0.05), and the positivity rate was 3% in contrast to 30% observed under anonymous conditions (p < 0.001). These low rates suggest that the majority of mothers who consumed alcohol in pregnancy refused to participate. We conclude that despite the potential benefits of such screening programs, maternal unwillingness to consent, likely due to fear, embarrassment, and guilt, may limit the effectiveness of meconium testing for population-based open screening, highlighting the need for public education and social marketing efforts for such programs to be of benefit.     

新生儿胎粪吸入综合征血液中淋巴细胞ICAM-1的研究

目的:了解新生儿胎粪吸入综合征(MAS)血液中淋巴细胞ICAM水平的变化,探讨其在MAS的意义。方法:采用流式细胞仪检测21例MAS患儿生后第1 d及25例足月健康新生儿脐血淋巴细胞表面ICAM的水平。结果:MAS患儿生后第1 d血液淋巴细胞ICAM-1水平为4.99％±2.60％,与对照组比较无显著性差异。MAS患儿淋巴细胞ICAM-1水平与血白细胞总数、中性粒细胞绝对值、淋巴细胞绝对值的相关系数分别为0.241、0.215、0.205。MAS患儿ICAM-1与生后1 h血PH值的相关系数为0.134。结论:MAS患儿生后第1 d淋巴细胞ICAM-1与对照组比较无差异,与血白细胞、PH值均无关。     

妊娠期肝内胆汁淤积早产及胎儿窘迫的发病机理

妊娠期肝内胆汁淤积对母亲的危害轻微 ,但其患者的胎儿围生期并发症较多 ,易发生早产和羊水胎粪污染、胎儿窘迫、围生儿死亡。现就妊娠期肝内胆汁淤积早产、胎儿窘迫发病机理的研究状况做一综述     

珂立苏联合鼻塞式持续气道正压通气治疗重症胎粪吸入综合征的临床观察

目的:探讨肺泡表面活性物质(珂立苏)联合鼻塞式持续气道正压通气(NCPAP)治疗重症胎粪吸入综合征的临床疗效。方法:将58例胎粪吸入综合征患儿随机分成两组。治疗组28例,采用NCPAP及常规治疗的同时气道注入珂立苏;观察组30例,给予NCPAP及常规治疗。观察两组患儿血气数值、氧合功能,NCPAP参数和临床疗效。结果:治疗后的不同时期,治疗组患儿的PO2和氧合指数明显高于对照组,PCO2明显低于对照组,差异有统计学意义;治疗组NCPAP参数PEEP和FiO2能及早下调,上机时间、用氧时间及改机械通气病例数均显著少于对照组。结论:珂立苏联合NCPAP治疗重症胎粪吸入综合征疗效显著、方法简单、安全性好,值得临床推广应用。     

联合监测IL-8、TNF-α及血气在新生儿胎粪吸入综合征中的临床意义探讨

目的:探讨胎粪吸入综合征(MAS)新生儿血中白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)及血气分析的临床价值,为疾病诊治提供参考.方法:选取2019年7月～2020年5月在本院治疗的MAS新生儿62例为观察组,包括轻症34例、重症28例,同时选择非感染新生儿40例为对照组,比较IL-8、TNF-α水平,以...     

新生儿呼吸窘迫综合征高危因素893例分析

目的 探讨新生儿呼吸窘迫综合征(respiratory distress syndrome,RDS)发病的高危因素,为临床治疗提供参考依据。方法 对2007年1月-2012年10月在八一儿童医院新生儿监护病房住院确诊为RDS的893例新生儿进行回顾性研究。根据胎龄分为足月儿组(148例)和早产儿组(745例),将两组的性别、胎龄、出生体重、分娩方式、窒息、胎盘异常、胎膜早破、宫内感染、胎粪吸入综合征、孕母糖尿病、孕母高血压指各标进行组内及组间比较。采用SPSS 19.0对数据进行统计分析。结果 单因素方差分析显示男性、剖官产、宫内感染、宫内窘迫是足月儿RDS发生的高危因素,早产、胎膜早破、孕母高血压、出生窒息是早产儿RDS发病的高危因素,多因素Logistic回归分析提示,胎龄、分娩方式、出生体重、胎膜早破、出生窒息、孕母糖尿病、孕母高血压、宫内感染为RDS发病危险因素(P<0.05),各因素在RDS发生中作用的大小顺序依次为:剖宫产＞孕母高血压＞宫内感染＞出生体重＞孕母糖尿病＞出生窒息(OR值分别为71.136、66.117、65.824、38.565、4.935、1.940)。结论 RDS的发生是多因素的,早产、剖宫产、宫内感染、窒息缺氧、孕母高血压、孕母糖尿病等与新生儿呼吸窘迫综合征的发生密切相关,临床应予以重视。