Jorge Hecker Luz

Perinatal factors associated with early deaths of preterm infants born in Brazilian Network on Neonatal Research centers

OBJECTIVE To evaluate perinatal factors associated with early neonatal death in preterm infants with birth weights (BW) of 400-1,500 g. METHODS A multicenter prospective cohort study of all infants with BW of 400-1,500 g and 23-33 weeks of gestational age (GA), without malformations, who were born alive at eight public university tertiary hospitals in Brazil between June of 2004 and May of 2005. Infants who died within their first 6 days of life were compared with those who did not regarding maternal and neonatal characteristics and morbidity during the first 72 hours of life. Variables associated with the early deaths were identified by stepwise logistic regression. RESULTS A total of 579 live births met the inclusion criteria. Early deaths occurred in 92 (16%) cases, varying between centers from 5 to 31%, and these differences persisted after controlling for newborn illness severity and mortality risk score (SNAPPE-II). According to the multivariate analysis, the following factors were associated with early intrahospital neonatal deaths: gestational age of 23-27 weeks (odds ratio - OR = 5.0; 95%CI 2.7-9.4), absence of maternal hypertension (OR = 1.9; 95%CI 1.0-3.7), 5th minute Apgar 0-6 (OR = 2.8; 95%CI 1.4-5.4), presence of respiratory distress syndrome (OR = 3.1; 95%CI 1.4-6.6), and network center of birth. CONCLUSION Important perinatal factors that are associated with early neonatal deaths in very low birth weight preterm infants can be modified by interventions such as improving fetal vitality at birth and reducing the incidence and severity of respiratory distress syndrome. The heterogeneity of early neonatal rates across the different centers studied indicates that best clinical practices should be identified and disseminated throughout the country.

Variability on red blood cell transfusion practices among Brazilian neonatal intensive care units

BACKGROUND: Guidelines for red blood cell (RBC) transfusions exist; however, transfusion practices vary among centers. This study aimed to analyze transfusion practices and the impact of patients and institutional characteristics on the indications of RBC transfusions in preterm infants.

Proactive management of extreme prematurity: disagreement between obstetricians and neonatologists.

Objective:To verify, in extremely preterm infants, if disagreement between obstetricians and neonatologists regarding proactive management is associated with early death.Study Design:Prospective cohort of 484 infants with 230/7 to 266/7 weeks, without malformations, born from January 2006 to December 2009 in eight Brazilian hospitals. Pro-active management was defined as indication of ⩾1 dose of antenatal steroid or cesarean section (obstetrician) and resuscitation at birth according to the international guidelines (neonatologist). Main outcome was neonatal death in the first 24 h of life.Result:Obstetricians and neonatologists disagreed in 115 (24%) patients: only neonatologists were proactive in 107 of them. Disagreement between professionals increased 2.39 times the chance of death in the first day (95% confidence interval 1.40 to 4.09), adjusted for center and maternal/neonatal clinical conditions.Conclusion:In infants with 23 to 26 weeks of gestation, disagreement between obstetricians and neonatologists, translated as lack of antenatal steroids and/or vaginal delivery, despite resuscitation procedures, increases the odds of death in the first day.

Stable Microbubble Test on Tracheal Aspirate for the Diagnosis of Respiratory Distress Syndrome

Background: Exogenous surfactant should be used as early as possible in the presence of respiratory distress syndrome (RDS), but diagnosis may only become clear late in the course of the disease. The stable microbubble test (SMT) in the tracheal aspirates could help in the decision to give early surfactant to preterm babies with respiratory distress. Objectives: The objective of this study was to evaluate the accuracy of the SMT on tracheal aspirate for the diagnosis of RDS in newborns requiring mechanical ventilation. Methods: The test was performed on specimens obtained from 74 infants requiring mechanical ventilation, through routine suctioning. Results: Patients with RDS and meconium aspiration syndrome (MAS) had a significantly lower stable microbubble count than non-RDS and non-MAS patients. Preterm infants without RDS had a significantly higher microbubble count than preterm babies with RDS and a similar count to that of term babies. Considering a cutoff point of 120 microbubbles/mm2 for the diagnosis of RDS, the sensitivity of the microbubble test was 96.3% (95% CI: 79.1–99.8) and the specificity 97.6% (95% CI: 85.9–99.9). Conclusions: The SMT on tracheal aspirates is accurate for RDS diagnosis and may be useful to support the decision to give surfactant to newborns on mechanical ventilation.

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® 100 mg/kg). Arterial blood gas samples were obtained 30 min and 6 h after the inhalation of meconium. Results: A significant increase of PaO2 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, PaO2 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.

Uso antenatal de corticosteróide e condições de nascimento de pré-termos nos hospitais da Rede Brasileira de Pesquisas Neonatais

PURPOSE: to assess the use of antenatal corticosteroid (AC) by mothers and its repercussion on the birth conditions of preterm babies at the eight university neonatal units belonging to the Brazilian Network of Neonatal Research. METHODS: an observational prospective cohort study. All 463 pregnant women with a gestational age (GA) of 23 to 34 weeks and their 514 newborn babies were evaluated during the period from August 1 to December 31, 2001. The data were obtained by maternal interview, by the analysis of the medical records and by the follow-up of the newborn infants, and analyzed statistically using c2, Mann-Whitney and ANOVA tests and multiple logistic regression, with the level of significance set at 0.05. RESULTS: 60.1% (282/463) of the pregnant women (a variation from 12.5 to 87.3% among units) received at least one AC dose. The AC use was directly associated with the number of prenatal visits, with maternal hypertension and with the antenatal use of tocolytic agents. Babies from treated pregnant women presented higher birth weight (1,379±421 vs 1,244±543 g), longer gestational age (30.9±2.0 vs 29.5±3.5 weeks), better Apgar scores at the 1st and 5th minute, and a reduced need for intervention in the delivery room. The use of AC, the GA and a baby small for GA independently improved the birth conditions. CONCLUSIONS: at most centers, AC was administered at frequencies below the desired ones, and in 50% of cases in an inadequate manner. Treatment was applied more to mothers who received appropriate prenatal care and was associated with better birth conditions.

T-piece versus self-inflating bag ventilation in preterm neonates at birth

Objective To verify whether the use of the T-piece resuscitator compared with the self-inflating bag in preterm infants ventilated at birth modifies survival to hospital discharge without major morbidities. Design Pragmatic prospective cohort study. Setting 20 Brazilian university hospitals of Brazilian Network on Neonatal Research. Patients were 1962 inborn infants in 2014–2015 ventilated at birth with 23–33’ weeks gestation and birth weight 400–1499 g without malformations. Patients transferred until the 27th day after birth were excluded. Interventions Positive pressure ventilation at birth with T-piece resuscitator or self-inflating bag without positive end expiratory pressure valve. Intervention with ventilation followed the Brazilian Society of Pediatrics guidelines. The choice of the equipment was at the neonatologist’s discretion in each delivery. The main outcome measures were survival to hospital discharge without bronchopulmonary dysplasia, severe peri-intraventricular haemorrhage and periventricular leucomalacia. Logistic regression adjusted for confounding variables was applied for main outcome. Results 1456 (74%) were only ventilated with T-piece resuscitator and 506 (26%) with the self-inflating bag. The characteristics of those ventilated with T-Piece resuscitator versus self-inflating bag were birth weight 969 ± 277 vs 941 ± 279 g, gestational age 28.2±2.5 vs 27.8±2.7 weeks and survival to hospital discharge without major morbidities 47% vs 35%. Logistic regression adjusted for maternal characteristics, obstetric and neonatal morbidities showed that the T-piece resuscitator increased the chance of survival to hospital discharge without major morbidities (OR=1.38; 95% CI 1.06 to 1.80; Hosmer-Lemeshow goodness of fit: 0.695). Conclusion This study is the first that highlights the effectiveness of T-piece resuscitator ventilation in improving relevant outcomes in preterm neonates.

Comparação de técnicas não invasivas para medir a pressão arterial em recém-nascidos

OBJECTIVE: To compare blood pressure measurements in newborn infants using the flush method, pulse oximetry and oscillometry according to Doppler findings. METHODS: Noninvasive blood pressure measurements were made using three techniques (flush method, pulse oximetry and oscillometry) in three groups of newborns: 15 normal term infants, 16 stable preterm infants, and 14 critically ill infants. All measurements were video recorded, edited separately, coded and analyzed independently by three neonatologists. RESULTS: Fifty-seven measurements were made using each method. The flush method and pulse oximetry had a better correlation with Doppler findings than oscillometry (correlation coefficients: 0.89, 0.85, 0.71; p < 0.01). The difference between measurement means, their standard deviations and the 95% confidence intervals when compared with Doppler findings were: -5.2±7.9 (-21.1:10.7) mmHg for the flush method; 0.4±8.9 (-17.5:18.2) mmHg for pulse oximetry; and 6.4±16.1 (-25.8:8.6) mmHg for oscillometry. The flush method had a better agreement with Doppler findings for the diagnosis of hypotension than oximetry and oscillometry. CONCLUSIONS: The flush method and pulse oximetry seem to be useful techniques to measure systolic blood pressure in newborn infants; oscillometry had the poorest agreement with Doppler findings to detect hypotension.

Comparison of noninvasive techniques to measure blood pressure in newborns.

OBJECTIVE To compare blood pressure measurements in newborn infants using the flush method, pulse oximetry and oscillometry according to Doppler findings. METHODS Noninvasive blood pressure measurements were made using three techniques (flush method, pulse oximetry and oscillometry) in three groups of newborns: 15 normal term infants, 16 stable preterm infants, and 14 critically ill infants. All measurements were video recorded, edited separately, coded and analyzed independently by three neonatologists. RESULTS Fifty-seven measurements were made using each method. The flush method and pulse oximetry had a better correlation with Doppler findings than oscillometry (correlation coefficients: 0.89, 0.85, 0.71; p < 0.01). The difference between measurement means, their standard deviations and the 95% confidence intervals when compared with Doppler findings were: -5.2 ± 7.9 (-21.1:10.7) mmHg for the flush method; 0.4 ± 8.9 (-17.5:18.2) mmHg for pulse oximetry; and 6.4 ± 16.1 (-25.8:8.6) mmHg for oscillometry. The flush method had a better agreement with Doppler findings for the diagnosis of hypotension than oximetry and oscillometry. CONCLUSIONS The flush method and pulse oximetry seem to be useful techniques to measure systolic blood pressure in newborn infants; oscillometry had the poorest agreement with Doppler findings to detect hypotension.

Rapid diagnosis of respiratory distress syndrome by oral aspirate in premature newborns

OBJECTIVE The stable microbubble test on gastric aspirate and on amniotic fluid has been used for the diagnosis of respiratory distress syndrome in the newborn. However, no study has performed this test on oral aspirates from premature infants. The objective of this study was to evaluate the performance of the stable microbubble test on oral aspirates from preterm newborns to predict respiratory distress syndrome. METHOD This study included infants with gestational age <34 weeks. Oral fluids were obtained immediately after birth and gastric fluids were collected within the first 30min of life. The samples were frozen and tested within 72h. RESULTS The sample was composed of paired aspirates from 64 newborns, who were divided into two groups: respiratory distress syndrome group (n=21) and control group (n=43). The median (interquartile range) of the stable microbubble count in the oral samples of infants with respiratory distress syndrome was significantly lower than that of infants who did not develop respiratory symptoms: respiratory distress syndrome group=12 (8-22) stable microbubbles/mm2; control group=100 (48-230)microbubbles/mm2 (p<0.001). The correlation between microbubble count in gastric and oral aspirates was 0.90 (95% confidence interval=0.85-0.95; p<0.001). Considering a cut-off point of 25microbubbles/mm2, the sensitivity and the specificity of the stable microbubble test were 81.4% and 85.7%, respectively. CONCLUSION The study suggests that the stable microbubble test performed on oral aspirate is a reliable alternative to that performed on gastric fluid for the prediction of respiratory distress syndrome in the newborn.