西地那非治疗新生儿持续肺动脉高压的临床疗效观察

目的评价西地那非治疗新生儿持续肺动脉高压(PPHN)的有效性和安全性。方法对确诊PPHN的23例患儿给予西地那非0.25～0.5 mg.kg-1.次-1,6～8 h 1次。观察治疗前和服药3 d后,利用超声心动图仪检测平均肺动脉压等。结果治疗3 d后,除病情恶化2例死亡外,平均肺动脉压、PaCO2均有下降(P<0.01),SaO2、PaO2显著升高(P<0.01)。治愈14例,好转5例,无效4例,总有效率82.6%。结论西地那非对新生儿持续肺动脉高压有肯定的疗效,且安全性较高。     

米力农联合机械通气治疗新生儿持续肺动脉高压的疗效及护理

目的：探讨米力农联合机械通气治疗新生儿持续肺动脉高压(PPHN)的疗效及有效护理措施。方法选择2013年1月至2016年2月期间我院新生儿科收治的56例新生儿持续肺动脉高压患儿,根据随机数字表法随机分为对照组和观察组,每组28例,对照组予常频机械通气治疗,观察组在此基础上联合米力农治疗,疗程3 d。比较两组患儿治疗前后的肺动脉收缩压(PASP)的变化、机械通气时间及临床疗效,总结有效护理措施。结果治疗后观察组与对照组患儿PASP分别为(30.5±12.3) mmHg和(39.2±14.2) mmHg,均较治疗前的(65.3±19.6) mmHg和(66.5±18.7) mmHg明显降低,且观察组低于对照组,差异均有统计学意义(P<0.05);观察组患儿机械通气时间为(88.7±22.8) h,明显短于对照组的(101.6±24.1) h,差异有统计学意义(P<0.05);观察组患儿治疗总有效率为85.71%,明显高于对照组的64.29%,差异有统计学意义(P<0.05)。结论米力农联合机械通气治疗PPHN可进一步降低PASP、缩短机械通气治疗时间进而提高临床疗效;有效的护理措施则可保证治疗顺利、有效地进行,减少治疗相关并发症,对改善患儿的预后有利。     

Surfactant phosphatidylcholine metabolism in neonates with meconium aspiration syndrome

OBJECTIVE: Because meconium directly inhibits surfactant function, we sought to determine the effect of meconium on endogenous surfactant synthesis and clearance. STUDY DESIGN: We studied surfactant phosphatidylcholine kinetics with the use of stable isotopes in 11 newborn infants with meconium aspiration syndrome (MAS) who required extracorporeal membrane oxygenation (ECMO). For comparison we studied 6 neonates with persistent pulmonary hypertension (PPHN) on ECMO and 10 term neonates ventilated for non-pulmonary indications and not on ECMO. All patients received a 24-hour [U- 13C]glucose infusion as precursor for the palmitic acid in surfactant phosphatidylcholine. RESULTS: In the meconium group, the maximal 13C-incorporation in phosphatidylcholine (PC) was half of that in controls (0.09 +/- 0.01 vs 0.18 +/- 0.03 atom percent excess [APE], P = .027). There was a trend toward lower surfactant synthesis in the MAS group (3.3 +/- 0.7%/day) and PPHN group (2.6 +/- 0.3%/day) compared with controls 8.0 +/- 2.4%/day, P = .058). Significantly lower PC concentrations in tracheal aspirates were found in the MAS group (4.4 +/- 2.6 mg/mL) and PPHN group (3.6 +/- 2.0 mg/mL) compared with controls (12.8 +/- 2.6 mg/mL, P = .01). Endogenously synthesized surfactant had a similar half-life in all groups, ranging from 63 to 98 hours. CONCLUSION: We conclude that surfactant synthesis is disturbed and that surfactant PC concentrations are low in infants with MAS on ECMO.     

Foetal to neonatal transition — what can go wrong?

Failure of the foetus to make a successful transition from the intrauterine environment can be life threatening. Prompt recognition of problems can enable critical, life-saving interventions to take place. Whilst there are numerous adaptations of the newborn at birth, this article focuses on those which are the most common and/or clinically urgent, and describes not only the conventional treatments but also emerging therapies. The article therefore covers maladaptive processes in the normal newborn, not those with genetic or other congenital problems which cause maladaptation due to the underlying disease. Likewise, it is outside the scope of this article to discuss neonatal jaundice, as it is arguably not a maladaptation, and may also not be the ‘design flaw’ that it has previously been considered to be, as bilirubin may have a physiological role as the main antioxidant in the newborn in the first week of postnatal life. I have described five neonatal conditions: transient tachypnoea of the newborn, respiratory distress syndrome, persistent pulmonary hypertension, which can all cause significant hypoxaemia, patent ductus arteriosus which is usually not clinically significant but is common and often causes considerable parental anxiety, and transient hyperinsulinaemia which can cause profound hypoglycaemia.     

The safety and efficacy of nitric oxide therapy in premature infants

OBJECTIVES: To assess the safety-efficacy balance of low-dose inhaled nitric oxide (iNO) in hypoxemic premature infants because no sustained beneficial effect has been demonstrated clearly and there are concerns about side effects. STUDY DESIGN: Eight hundred and sixty infants <32 weeks were randomized at birth to receive 5 ppm iNO or placebo when they presented with hypoxemic respiratory failure (HRF) defined by a requirement for mechanical ventilation, fraction of inspired oxygen (FIO 2 ) >40%, and arterio-alveolar ratio in oxygen (aAO 2 ) <0.22. The primary end point was intact survival at 28 days of age. RESULTS: Sixty-one of 415 infants presented with HRF and were compared with 84 of 445 controls who presented with HRF. There was no difference in the primary end point (61.4% in infants [23% with HRF who were treated with iNO] vs 61.1% in controls [21.4% in controls with HRF]; P = .943). For the infants with HRF who were treated with iNO, there was no significant difference from controls for intraventricular hemorrhage (IVH) (6% vs 7%), necrotizing enterocolitis (8% vs 6 %), or patent ductus arteriosus (PDA) (34% vs 37%). Compared with nonhypoxemic infants, the risk of bronchopulmonary displasia (BPD) increased significantly in HRF controls (OR = 3.264 [CI 1.461-7.292]) but not in infants with HRF who were treated with iNO (OR = 1.626 [CI 0.633-4.178]). CONCLUSIONS: iNO appears to be safe in premature infants but did not lead to a significant improvement in intact survival on day 28.     

Expanding the phenotype of alveolar capillary dysplasia (ACD)

OBJECTIVES: To define the phenotype of congenital alveolar capillary dysplasia (ACD) as a first step toward mapping the responsible gene(s). STUDY DESIGN: Analysis of pathology reports and microscopic slides of 23 subjects with ACD and sequence analysis of two candidate genes. RESULTS: Our review of the pre- and postmortem records delineates both the natural history of this condition and the associated anomalies. Our collection of families corroborates the likely autosomal recessive nature of this condition in some families and provides additional data for genetic and prenatal counseling. Anomalies of many organ systems were detected either in the prenatal period or during the hospital course. However, some major anomalies were not detected until postmortem examination. Left-right asymmetry and gastrointestinal malrotation emerge as important, previously recognized but underappreciated phenotypic features of ACD. Finally, we used sequence analysis to exclude mutations in the coding region of two candidate genes, bone morphogenetic protein type II receptor (BMPR2) and endothelial monocyte-activating polypeptide II (EMAP II), as candidates for ACD. CONCLUSIONS: Understanding the clinical spectrum of ACD and the cloning of an "ACD gene" both have implications for counseling, for prenatal testing, and for understanding the molecular pathophysiology of ACD and other organ malformations that are associated with this condition.     

Incidence of alveolar capillary dysplasia in severe idiopathic persistent pulmonary hypertension of the newborn

OBJECTIVE: To determine the incidence and outcome and to review the management of alveolar capillary dysplasia (ACD) among newborns with severe idiopathic persistent pulmonary hypertension (PPHN). METHODS: A retrospective review of medical records of infants admitted to a paediatric intensive care unit from 1982 to 2000 with a diagnosis of severe PPHN, and re-examination of lung histological sections was carried out. Results: Thirteen new-born infants with pulmonary hypertension not associated with any known cause were identified. All were treated with conventional mechanical ventilation or high-frequency oscillatory ventilation with high inspired-oxygen and non-specific pulmonary vasodilators. Nine infants were also treated with inhaled nitric oxide therapy and eight with extracorporeal membrane oxygenation (ECMO). Seven infants died and six survived. At autopsies, the histological features of ACD were seen in the six who had died in the newborn period. All these had been treated with ECMO. In two of these six infants, lung biopsies had been performed showing similar features, suggesting the possibility of diagnosis during life. In the remaining infant, who died at 3 months of age, there was only marked hypertrophy of the muscle coat in the small pulmonary arteries. CONCLUSIONS: Alveolar capillary dysplasia is probably not as rare a condition as previously suggested in sporadic case reports from literature on the subject. It should be entertained as a cause of otherwise severe idiopathic PPHN of the newborn, particularly if ECMO is required. Diagnosis during life is possible by lung biopsy. It is uncertain if survival occurs with milder forms of the condition.     

Neonatal extracorporeal life support: impact of new therapies on survival

OBJECTIVE: To evaluate the effects of pre-extracorporeal life support (ECLS) management with nitric oxide (NO), high frequency ventilation (HFV), and surfactant on mortality among neonates supported with ECLS. STUDY DESIGN: Extracorporeal Life Support Organization (ELSO) data on 7017 neonates cannulated for respiratory reasons between 1996 and 2003 were analyzed using chi2, analysis of variance, and logistic regression. RESULTS: The use of ECLS declined by 26.6% over the study period with no significant change in mortality. Unadjusted ECLS mortality for NO-treated patients was lower than for infants not treated with NO (25.1% vs 28.6%, P = .0012) and for infants treated with surfactant than for infants not treated with surfactant (18.7% vs 30.3%, p <.0001.) Unadjusted mortality for HFV-treated patients was no different than for non-HFV-treated patients (26.0% vs 26.6%, P = .56). After adjusting for confounders (primary diagnosis, age at cannulation, ECMO year 1996-1999 vs 2000-2003), surfactant use was associated with decreased mortality. NO-treated neonates were less likely to have a pre-ECLS cardiopulmonary arrest than infants not treated with NO. NO, HFV, and surfactant were not associated with prolongation of ECLS or mechanical ventilation. CONCLUSIONS: NO, HFV, and surfactant were not associated with increased mortality in neonates who require ECLS for hypoxic respiratory failure.