Surfactant with and without bronchoalveolar lavage in an experimental model of meconium aspiration syndrome.

OBJECTIVES: To assess the effect of surfactant administration, preceded or not by bronchoalveolar lavage (BAL) with dilute surfactant, on pulmonary function in experimental severe meconium aspiration syndrome. METHODS: Twenty-one newborn pigs received 20% meconium in saline intratracheally and were randomly allocated to one of three groups: I, control; II, surfactant only (poractant alfa, 200 mg/kg); or III, dilute surfactant BAL followed by 125 mg/kg surfactant. Arterial blood gases (ABGs), lung compliance, and resistance were assessed. RESULTS: Thirty minutes after treatment, mean PaO2 (mm Hg) increased to 72 in group I, to 106 in group II and to 172 in group III (P=0.01). After 3 h, mean PaO2 (mm Hg) was 70 in group I, 95 in group II and 198 in group III (P<0.01). After 6 h, it was 79 in group I, 110 in group II, and 217 in group III (P=0.01). From the 30-min point onward, there were significant differences among treatment groups in all other parameters and at every point of assessment, except for compliance and resistance 3 h after treatment. CONCLUSIONS: BAL with dilute surfactant, followed by an additional dose of surfactant, produced significant improvements in ABGs and pulmonary mechanics as compared with a single dose of surfactant.

Immunoglobulin G and subclasses placental transfer in fetuses and preterm newborns: a systematic review.

Immunoglobulin G (IgG) and subclasses are the only class of antibodies capable of crossing placenta and providing protection against neonatal infectious diseases, especially in premature infants. This systematic review aimed to review the literature concerning the transplacental transfer of IgG and its subclasses in fetuses and preterm newborns and compare the results with data from term neonates. Eleven studies were included in the final review. Most studies demonstrated a lower transplacental passage of IgG2 than other subclasses in term and preterm newborns and a more efficient passage of total IgG and IgG1 after 37 weeks of gestational age. These results elucidate the physiology of IgG subclass transfer during pregnancy and may explain one of the reasons preterm newborns are especially susceptible to specific pathogens, such as encapsulated bacteria.

Neonatal diseases and oxidative stress in premature infants: an integrative review.

OBJECTIVE: To describe the relationship of oxidative stress and antioxidant biomarkers in cord blood of premature newborns and the prognosis of diseases in the neonatal period. SOURCES: This study consists of an integrative review. Searches were conducted in electronic databases Scopus, PubMed, Web of Science, and Medline/Lilacs through the Virtual Library on Health Issues, using the descriptors: "premature infants", "preterm infants", "preterm birth", "preterm", "oxidative stress", "antioxidants", "infant, premature, diseases" and "cord blood". Original articles published between 2016 and 2021 in Portuguese, English, or Spanish, which analyzed oxidative stress and/or antioxidant levels through cord blood of premature newborns and evaluated clinical outcomes, were included. SUMMARY OF THE FINDINGS: Of the 1,003 studies reviewed, after exclusion of duplicate articles, analysis of titles, abstracts, and full texts, 18 articles were included. 72.2% (n = 13) of analyzed studies reported a positive association between oxidative stress and the development of prematurity-related diseases; 27.7% (n = 5) showed no significant relation. Outcomes that showed a positive association were: intrauterine growth restriction, necrotizing enterocolitis, bronchopulmonary dysplasia, intraventricular hemorrhage, fetal inflammatory response syndrome, early-onset neonatal sepsis, retinopathy of prematurity, morbidity, and mortality. CONCLUSION: The analysis of oxidative stress and antioxidants in cord blood of premature newborns may be useful in the prognosis of some pathologies. The consequences of oxidative damage are known to be associated with increased morbidity in the short and long term. Further investigation is needed in this population in order to define normality parameters of biomarkers, clinical manifestations, diagnosis and treatment of these conditions.

Neonatal diseases and oxidative stress in premature infants: an integrative review

Abstract Objective To describe the relationship of oxidative stress and antioxidant biomarkers in cord blood of premature newborns and the prognosis of diseases in the neonatal period. Sources This study consists of an integrative review. Searches were conducted in electronic databases Scopus, PubMed, Web of Science, and Medline/Lilacs through the Virtual Library on Health Issues, using the descriptors: "premature infants", "preterm infants", "preterm birth", "preterm", "oxidative stress", "antioxidants", "infant, premature, diseases" and "cord blood". Original articles published between 2016 and 2021 in Portuguese, English, or Spanish, which analyzed oxidative stress and/or antioxidant levels through cord blood of premature newborns and evaluated clinical outcomes, were included. Summary of the findings Of the 1,003 studies reviewed, after exclusion of duplicate articles, analysis of titles, abstracts, and full texts, 18 articles were included. 72.2% (n = 13) of analyzed studies reported a positive association between oxidative stress and the development of prematurity-related diseases; 27.7% (n = 5) showed no significant relation. Outcomes that showed a positive association were: intrauterine growth restriction, necrotizing enterocolitis, bronchopulmonary dysplasia, intraventricular hemorrhage, fetal inflammatory response syndrome, early-onset neonatal sepsis, retinopathy of prematurity, morbidity, and mortality. Conclusion The analysis of oxidative stress and antioxidants in cord blood of premature newborns may be useful in the prognosis of some pathologies. The consequences of oxidative damage are known to be associated with increased morbidity in the short and long term. Further investigation is needed in this population in order to define normality parameters of biomarkers, clinical manifestations, diagnosis and treatment of these conditions.

Bronchoalveolar lavage plus surfactant in a piglet model of meconium aspiration syndrome.

INTRODUCTION: Meconium aspiration produces airway obstruction and surfactant inhibition. Bronchoalveolar lavage (BAL) and surfactant replacement have been proposed as treatments for the syndrome. OBJECTIVE: To evaluate the effect of BAL with normal saline followed by a supplementary dose of surfactant in a piglet model of meconium aspiration syndrome. METHODS: 15 newborn piglets were used in the study. The animals were ventilated with fixed settings. After inhalation of 4 ml/kg of diluted meconium, the piglets were randomized into three groups: group I (n = 5) - tracheal aspiration without BAL; group II (n = 5) - BAL with normal saline (15 ml/kg), and group III (n = 5) - BAL with normal saline (15 ml/kg) followed by a supplementary dose of surfactant (Curosurf(R) 100 mg/kg). Arterial blood gas samples were obtained 30 min and 6 h after the inhalation of meconium. RESULTS: A significant increase of PaO(2 )values at 6 h after treatment was only observed in group III (from 51 +/- 13 to 189 +/- 115 mm Hg; p = 0.04). At this time, PaO(2) in group III was significantly higher compared to group II (189 +/- 115 and 37 +/- 11 mm Hg, respectively; p = 0.023) and showed a borderline significance when compared to group I (p = 0.066). CONCLUSION: BAL with normal saline followed by a supplementary dose of surfactant may improve oxygenation in an experimental piglet model of meconium aspiration syndrome.

Novas opções terapêuticas na síndrome de aspiração de mecônio / New therapeutic options in meconium aspiration syndrome

OBJETIVOS: revisar a literatura sobre a síndrome de aspiração de mecônio (SAM), enfocando aspectos clínicos, fisiopatológicos e abordagem terapêutica, com destaque ao uso do surfactante e lavado broncoalveolar. MÉTODOS: revisão baseada em artigos publicados na MEDLINE, SCIELO e resumos de congressos internacionais de 1988 a 2004, incluindo ensaios randomizados ou quasi-randomizados, estudos caso-controle e metanálises. RESULTADOS: devido à comprovação da inibição do surfactante na SAM, houve modificações em sua abordagem terapêutica. O manejo atual consiste na aspiração das vias aéreas na sala de parto, seguida de suporte ventilatório necessário para manter a oxigenação arterial adequada, e tratamento das complicações. Tendo em vista a obstrução mecânica do mecônio e seu efeito inibitório sobre o surfactante, a reposição e lavado broncoalveolar com surfactante estão sendo estudados atualmente. CONCLUSÕES: estudos em animais e em recém-nascidos apresentam resultados controversos quanto aos benefícios do uso de surfactante e lavado broncoalveolar na SAM. Torna-se importante a realização de mais estudos para avaliar novas estratégias ventilatórias e se existem vantagens no uso do surfactante e lavado broncoalveolar com surfactante na SAM.

OBJECTIVES: to review the literature on meconium aspiration syndrome (MAS) focusing on clinical aspects, pathophysiology, and treatment with emphasis on surfactant and bronchoalveolar lavage. METHODS: review including articles from MEDLINE, SCIELO and abstracts published in the national and international literature, from 1988 to 2004 using the keywords meconium aspiration syndrome, surfactant and bronchoalveolar lavage. Randomized and quasi-randomized trials, case control studies, meta-analyses and recently published reviews were selected. Other articles were included for their valuable contribution to the subject. RESULTS: the discovery of new pathophysiological mechanisms ensued new therapeutic options availability. MAS management is initiated with airway aspiration in the delivery room, followed by the ventilatory management required to maintain optimal arterial oxygenation, as well as complications treatment. Considering evidences showing that meconium mechanical airway obstruction and its inhibitory effect on the surfactant system, the use of surfactant replacement and bronchoalveolar lavage with surfactant suspension are under study. CONCLUSIONS: experimental studies and studies focused on newborn using different surfactant suspensions have demonstrated controversial results. Therefore, it is very important to identify new ventilatory strategies and evaluate whether there are advantages in using surfactant and bronchoalveolar lavage with surfactant suspension in MAS.

Manejo da síndrome de aspiração de mecônio / Handling of the meconium aspiration syndrome

A síndrome de aspiração de mecônio (SAM) é uma importante causa de insuficiência respiratória em recém-nascidos a termo. A aspiração de mecônio inibe a função do surfactante endógeno e causa uma importante resposta inflamatória pulmonar. O efeito do surfactante e do lavado broncoalveolar (LBA) com surfactante em recém-nascidos com SAM tem sido estudado por diversos grupos. Este artigo tem como objetivo apresentar uma revisão bibliográfica sobre SAM com ênfase no tratamento.

Módulo de ensino fototerapia / Modulus of teaching phototherapy

A icterícia é um dos achados de exame físico mais comuns em recém-nascidos (RNs) saudáveis ou enfermos. Estima-se que aproximadamente 60% dos RNs desenvolvem níveis séricos de bilirrubina superiores a 5 mg%, ou seja, detectáveis no exame clínico. As causas são diversas, e o tipo de tratamento dependerá do nível sérico de bilirrubina, presença de incompatibilidade sangüínea, peso, idade cronológica e comorbidades associadas. Uma história perinatal completa é essencial para o entendimento da causa da icterícia. O uso materno de medicações como o diazepam e a ocitocina aumenta o risco de hiperbilirrubinemia. Um parto traumático (pélvico, fórceps), com céfalo-hematoma ou outros sangramentos, aumenta de bilirrubina. A presença de policitemia, incompatibilidade sangüínea, teste de Coombs direto (no recém-nascido) ou indireto (na mãe) positivos são outros fatores que norteiam a necessidade de tratamento da hiperbilirrubinemia. O principal do tratamento da hiperbilirrubinemia é a prevenção da impregnação cerebral pelo pigmento amarelo e suas complicações neurológicas graves, como o Kernicterus. A fototerapia constitui-se na modalidade terapêutica mais utilizada mundialmente no tratamento da hiperbilirrubinemia neonatal causada pelo aumento dos níveis de bilirrubina indireta (lipossolúvel, não conjugada). A eficácia da fototerapia é dependente da absroção de fótons de luz pelas moléculas de bilirrubina. Nas últimas décadas houve um aprimoramento das técnicas de fototerapia, aumentando muito sua eficácia e reduzindo o número de indicações de exsangüineotransfusão.

Rastreamento de anormalidades cardíacas fetais durante a ecografia obstétrica / Identification of congenital heart disease by means of fetal echocardiography

O exame do coraçäo através do corte ecocardiográfico de 4-câmaras, realizado durante a ultra-sonografia obstétrica de rotina, permite a identificaçäo de um número significativo de casos de cardiopatias congênitas. A detecçäo precoce permite o encaminhamento adequado e o planejamento da conduta perinatal, alterando significativamente o prognóstico desses fetos. Com o objetivo de avaliar a prevalência de diagnóstico pré-natal de cardiopatias congênitas em fetos submetidos à ecocardiografia obstétrica, foi planejado este estudo, tendo sido avaliados, de forma consecutiva e näo intencional 80 recem-nascidos internados no Setor de Cardiologia Pediátrica do Instituto de Cardiologia do Rio Grande do Sul(FUC)...