Brunnella Alcantara Chagas de Freitas

NICeSim: An open-source simulator based on machine learning techniques to support medical research on prenatal and perinatal care decision making

OBJECTIVE This paper describes NICeSim, an open-source simulator that uses machine learning (ML) techniques to aid health professionals to better understand the treatment and prognosis of premature newborns. METHODS The application was developed and tested using data collected in a Brazilian hospital. The available data were used to feed an ML pipeline that was designed to create a simulator capable of predicting the outcome (death probability) for newborns admitted to neonatal intensive care units. However, unlike previous scoring systems, our computational tool is not intended to be used at the patients bedside, although it is possible. Our primary goal is to deliver a computational system to aid medical research in understanding the correlation of key variables with the studied outcome so that new standards can be established for future clinical decisions. In the implemented simulation environment, the values of key attributes can be changed using a user-friendly interface, where the impact of each change on the outcome is immediately reported, allowing a quantitative analysis, in addition to a qualitative investigation, and delivering a totally interactive computational tool that facilitates hypothesis construction and testing. RESULTS Our statistical experiments showed that the resulting model for death prediction could achieve an accuracy of 86.7% and an area under the receiver operating characteristic curve of 0.84 for the positive class. Using this model, three physicians and a neonatal nutritionist performed simulations with key variables correlated with chance of death. The results indicated important tendencies for the effect of each variable and the combination of variables on prognosis. We could also observe values of gestational age and birth weight for which a low Apgar score and the occurrence of respiratory distress syndrome (RDS) could be less or more severe. For instance, we have noticed that for a newborn with 2000 g or more the occurrence of RDS is far less problematic than for neonates weighing less. CONCLUSIONS The significant accuracy demonstrated by our predictive model shows that NICeSim might be used for hypothesis testing to minimize in vivo experiments. We observed that the model delivers predictions that are in very good agreement with the literature, demonstrating that NICeSim might be an important tool for supporting decision making in medical practice. Other very important characteristics of NICeSim are its flexibility and dynamism. NICeSim is flexible because it allows the inclusion and deletion of variables according to the requirements of a particular study. It is also dynamic because it trains a just-in-time model. Therefore, the system is improved as data from new patients become available. Finally, NICeSim can be extended in a cooperative manner because it is an open-source system.

Sepse tardia em pré-termos de uma unidade de terapia intensiva neonatal: análise de três anos

OBJECTIVE To evaluate the prevalence factors and etiologies associated with late neonatal sepsis in preterm neonates in a neonatal intensive care unit. METHODS This was a cross-sectional study of secondary data pertaining to preterm neonates admitted to the neonatal intensive care unit between 2008 and 2010 and was gathered from medical charts. The outcome variable, late neonatal sepsis, was characterized using the Brazilian national health surveillance agency criteria. Pearsons Chi-squared test, Fishers exact test and the linear trend Chi-squared test were used to assess the qualitative variables for linear trends. The statistical significance level was set at p < 0.05. Bivariate and multivariate analyses of the independent and dependent variables were conducted to obtain a measure of the effect and prevalence ratios, considering a p-value of less than 0.20 to indicate statistical significance. RESULTS This study included 267 preterm neonates. Of the participants, 28.5% were characterized as having late-onset sepsis. Positive blood cultures were recorded for 17.1% of the neonates. Death occurred in 8.2% of the total cases, and of these deaths, 68.2% occurred within the sepsis group. Three deaths were associated with positive blood cultures, all of which grew Gram-negative bacteria. The bivariate analysis demonstrated that as the gestational age and birth weight decreased, the prevalence of late-onset sepsis trended upward. Ten or more days on mechanical ventilation was associated with late-onset neonatal sepsis in 80.8% of cases. Peripherally inserted central catheters left in place for 11 or more days were associated with late-onset neonatal sepsis in 76.2% of cases. The multivariate analysis demonstrated that a peripherally inserted catheter left in place for less than 11 days was associated with late-onset neonatal sepsis. Gram-negative bacteria, including Klebsiella pneumoniae and Escherichia coli, were the most frequent causative agents. CONCLUSIONS Late sepsis remains a concern because of its prevalence in intensive care units and because it increases the number of invasive procedures that preterm children usually undergo in these units. The authors emphasize the expanding role of Gram-negative bacteria in late-onset neonatal sepsis and the need for more efficient methods to identify confirmed sepsis.

Terapia nutricional e sepse neonatal

This article reviews the current understanding of enteral and parenteral nutrition therapy in preterm infants, with an emphasis on very low birth weight babies. The protective effects of nutrition therapy against neonatal sepsis and necrotizing enterocolitis are discussed. Different methods of feeding preterm infants are evaluated. Special attention is given to the problems of very low birth weight babies and the protective effects of nutrition to counteract complications, especially infection. The preferential use of breast milk for enteral nutrition, the management of protein and energy offers, the use of early and minimal enteral nutrition, the early introduction of parenteral nutrition (within the first 24 hours of life) and the use of immunonutrients that are appropriately supported by a sufficient number of studies can provide good adjuvant therapy guidelines to prevent neonatal sepsis and necrotizing enterocolitis. However, we conclude that additional multicenter, randomized controlled studies are necessary to clarify the protective role of nutrition in preterm infants. Appropriate nutrition is not only effective in treating and preventing infective complications, but it also promotes neurodevelopment and prevents future harmful consequences.

Duration of breastfeeding in preterm infants followed at a secondary referral service

Abstract Objective: Identify and analyze variables associated with shorter duration of breastfeeding in preterm infants. Methods: Retrospective cohort of premature infants followed up at secondary referral service in the period of 2010-2015. Inclusion: first appointment in the first month of corrected age and have undergone three or more consultations. Exclusion: diseases that impaired oral feeding. Outcome: duration of breastfeeding. A total of 103 preterm infants were evaluated, accounting for 28.8% of the preterm infants born in the municipality in that period, with a power of study of 80%. Descriptive analysis, t-test, chi-square test, Kaplan-Meier curves and Cox regression were used. p-values <0.05 were considered significant. Results: The median duration of breastfeeding among preterm infants was 5.0 months. The risk of breastfeeding discontinuation among preterm infants with gestational age <32 weeks was 2.6-fold higher than for those born at 32 weeks or more and the risk of breastfeeding interruption in preterm infants who were receiving breastfeeding supplementation in the first outpatient visit was 3-fold higher when compared to those who were exclusively breastfed in the first consultation. Conclusions: The median duration of breastfeeding in preterm infants was below the recommended one and discontinuation was associated with gestational <32 weeks and the fact that the infant was no longer receiving exclusive breastfeeding in the first outpatient visit. When these two variables were associated, their negative effect on the median duration of breastfeeding was potentiated.

Fatores associados à transfusão de concentrado de hemácias em prematuros de uma unidade de terapia intensiva

OBJECTIVE This study analyzed the factors that are associated with the need for packed red blood cell transfusions in premature infants in a neonatal intensive care unit. METHODS This study is a cross-sectional study of secondary data from premature infants who were admitted to a neonatal intensive care unit between 2008 and 2010. Premature infants with low birth weight were included. Packed red blood cell transfusion was the dependent variable. Pearsons Chi-square or Fishers exact tests were used for data analysis, and the median, minimum, and maximum values were calculated. Prevalence ratios were calculated using the Poisson regression and Pearson correlation coefficient. Linear regression analyses were performed. P < 0.05 was considered to be significant. RESULTS We examined 254 premature infants, and 39.4% of this sample received packed red blood cells. Transfusions were 70% less prevalent in premature infants who were born at >32 weeks of gestation, and 191% more prevalent in infants who exhibited late-onset neonatal sepsis. The number of transfusions per patient was negatively correlated with gestational age and positively correlated with late-onset neonatal sepsis. A gestational age <32 weeks and late-onset neonatal sepsis explained 45% of the transfusions (p<0.0001). CONCLUSIONS Premature infants with a gestational age <32 weeks and who developed late-onset neonatal sepsis exhibited a greater need for packed red blood cell transfusions.

Infecção por Clostridium tetani no recém-nascido: revisão sobre o tétano neonatorum

Although tetanus is a preventable disease by vaccination, it continues to claim lives around the world. Whereas cases of accidental origin reflect insufficient population immunization, tetanus neonatorum reveals a double-nature fault-poor vaccination coverage of adults coupled with difficulties accessing appropriate prenatal care; this situation is aggravated by the extreme severity of tetanus in this age group in which the mortality rate can reach up to 80%. The early detection of tetanus in neonates is essential for immediately initiating the proper therapy. Therefore, although reaching an early diagnosis of tetanus is important, the most relevant aspect is related to the appropriate management and prophylaxis of this disease. Consequently, the aim of this article is to review neonatorum tetanus with an emphasis on its therapy and prevention.

Extrauterine growth restriction: Universal problem among premature infants

Objective: To analyze the growth rate of premature infants in the first weeks of life and factors associated with extrauterine growth restriction. Methods: This is a cross-sectional study of 254 premature infants in a neonatal intensive care unit conducted from January 1, 2008 to December 31, 2010. Infants who died or had malformations incompatible with life were excluded. Median weight curves according to gestational age were constructed for the first four weeks of life. The Fenton growth chart calculations provided the weight Z-scores. Extrauterine growth restriction was defined as corrected weight-for-age Z-score ≤-2. Perinatal, morbidity, and health care variables were analyzed. The Poisson regression model yielded the prevalenceratios . Associations between extrauterine growth restriction and the perinatal, morbidity, and care variables were investigated. Poisson regression controlled possible confounding factors. Results: The frequency of extrauterine growth restriction was 24.0%. Most (85.0%) small-for-gestational-age infants developed extrauterine growth restriction; 55.3% of extrauterine growth restriction cases involved small-for-gestational-age infants. Premature infants with gestational age >32 weeks did not recover the median birth weight until the third week of life and had a higher frequency of small-for-gestational-age. The Z-scores of non-small-for-gestational-age infants decreased more after birth than those of small-for-gestational-age infants. extrauterine growth restriction was associated with small-for-gestational-age (PR=6.14; 95%CI=3.33-11.33;p <0.001) and time without enteral diet (PR=1.08; 95%CI=1.04-1.13; p =0.010). Conclusion: Extrauterine growth restriction occurs in premature infants of all gestational age. The participation of small-for-gestational-age and nutritional practices in its genesis is noteworthy. We suggest prospective studies of all premature infants. The implementation of best care practices, individualized for small-for-gestational-age infants, to improve nutrient supply can minimize the problem.

Micronutrient supplementation adherence and influence on the prevalences of anemia and iron, zinc and vitamin A deficiencies in preemies with a corrected age of six months

OBJECTIVE: To analyze adherence to the recommended iron, zinc and multivitamin supplementation guidelines for preemies, the factors associated with this adherence, and the influence of adherence on the occurrence of anemia and iron, zinc and vitamin A deficiencies. METHODS: This prospective cohort study followed 58 preemies born in 2014 until they reached six months corrected age. The preemies were followed at a referral secondary health service and represented 63.7% of the preterm infants born that year. Outcomes of interest included high or low adherence to iron, zinc and multivitamin supplementation guidelines; prevalence of anemia; and prevalences of iron, zinc, and vitamin A deficiencies. The prevalence ratios were calculated by Poisson regression. RESULTS: Thirty-eight (65.5%) preemies presented high adherence to micronutrient supplementation guidelines. At six months of corrected age, no preemie had vitamin A deficiency. The prevalences of anemia, iron deficiency and zinc deficiency were higher in the low-adherence group but also concerning in the high-adherence group. Preemies with low adherence to micronutrient supplementation guidelines were 2.5 times more likely to develop anemia and 3.1 times more likely to develop zinc deficiency. Low maternal education level increased the likelihood of nonadherence to all three supplements by 2.2 times. CONCLUSIONS: Low maternal education level was independently associated with low adherence to iron, zinc and vitamin A supplementation guidelines in preemies, which impacted the prevalences of anemia and iron and zinc deficiencies at six months of corrected age.

Prevalência e fatores associados à displasia broncopulmonar em hospital de referência para microrregião de Minas Gerais

OBJECTIVE The aim of the present study was to evaluate the prevalence and factors associated with bronchopulmonary dysplasia at a neonatal intensive care unit. METHODS The study was a cross-sectional study that used secondary data from premature infants who were born with less than 32 weeks of gestational age and were admitted to a neonatal intensive care unit. Chi-square, Mann-Whitney and multivariate tests were used. Significance was set at p<0.05. RESULTS A total of 88 premature infants were included in the study. Bronchopulmonary dysplasia occurred in 27.3% of the infants and was related to having a gestational age below 28 weeks (OR: 4.80; 95% CI: 1.50-15.34; p=0.008) and a patent ductus arteriosus (OR: 3.44; 95% CI: 1.10-10.76; p=0.034). The group with bronchopulmonary dysplasia used mechanical ventilation for a longer duration, with a median of 24.5 days (p<0.0001). At discharge, the corrected and chronological ages were higher in the group with bronchopulmonary dysplasia (p<0.0001), with respective medians of 38.4 weeks and 70.5 days. CONCLUSIONS In this study, the prevalence of bronchopulmonary dysplasia was high; the high prevalence was related to extreme prematurity, patent ductus arteriosus, a longer period under mechanical ventilation and prolonged hospitalization. The increased survival of infants with low gestational age makes this disorder a public health issue.

Comparação entre duas curvas de crescimento para detectar recém-nascidos pequenos para a idade gestacional

Objetivos: comparar duas curvas de crescimento, Lubchenco e Fenton e Kim, na deteccao de recem-nascidos (RN) pequenos para idade gestacional (PIG) segundo sexo. Metodos: estudo transversal de dados de RN, de 01/01/2010 a 31/12/2012 Definiu-se PIG o peso ao nascer (PN) inferior ao percentil 10 para idade gestacional (IG) segundo as curvas Lubchenco e Fenton & Kim. Mensurou-se a concordância entre as curvas pelo Metodo de Kappa para o diagnostico de PIG segundo sexo e IG. Construiram-se curvas dos percentis 10 de PN e referenciais, por sexo, utilizando funcao polinomial de terceiro grau. Para comparar e medir associacoes entre as variaveis sexo, IG e PIG foram utilizados o teste do qui-quadrado de Pearson e regressao logistica bivariada, respectivamente. Significância: p<0,05. Resultados: foram incluidos 2364 recem-nascidos no estudo. As curvas Fenton e Kim detectaram mais RN PIG, cuja taxa foi 16,2%, enquanto as Lubchenco detectaram 3,3% (p<0,001; k=0,292). A discordância foi maior com o aumento da IG. O sexo masculino se associou a maior chance de nascer PIG 1,6 vezes em relacao ao feminino (OR= 1,59; IC95%= 1,28-2,00; p<0,001). Conclusoes: as curvas Fenton e Kim detectaram mais RN PIG. O nascimento PIG foi mais frequente no sexo masculino. Os achados contribuem para adocao de estrategias visando melhorias no diagnostico, cuidados e prognostico.