Can infant lung function predict respiratory morbidity during the first year of life in preterm infants?

Compared with term-born infants, preterm infants have increased respiratory morbidity in the first year of life. We investigated whether lung function tests performed near term predict subsequent respiratory morbidity during the first year of life and compared this to standard clinical parameters in preterms.The prospective birth cohort included randomly selected preterm infants with and without bronchopulmonary dysplasia. Lung function (tidal breathing and multiple-breath washout) was measured at 44 weeks post-menstrual age during natural sleep. We assessed respiratory morbidity (wheeze, hospitalisation, inhalation and home oxygen therapy) after 1 year using a standardised questionnaire. We first assessed the association between lung function and subsequent respiratory morbidity. Secondly, we compared the predictive power of standard clinical predictors with and without lung function data.In 166 preterm infants, tidal volume, time to peak tidal expiratory flow/expiratory time ratio and respiratory rate were significantly associated with subsequent wheeze. In comparison with standard clinical predictors, lung function did not improve the prediction of later respiratory morbidity in an individual child.Although associated with later wheeze, noninvasive infant lung function shows large physiological variability and does not add to clinically relevant risk prediction for subsequent respiratory morbidity in an individual preterm.

Rhinovirus Infections and Associated Respiratory Morbidity in Infants: A Prospective Cohort Study.

BACKGROUND Risk factors promoting rhinovirus (RV) infections are inadequately described in healthy populations, especially infants. OBJECTIVES To determine the frequency of symptomatic and asymptomatic RV infections and identify possible risk factors from host and environment among otherwise healthy infants. METHODS In a prospective birth cohort, respiratory health was assessed in 41 term-born infants by weekly telephone interviews during the first year of life, and weekly nasal swabs were collected to determine RV prevalence. In a multilevel logistic regression model, associations between prevalence and respiratory symptoms during RV infections and host/environmental factors were determined. RESULTS 27% of nasal swabs in 41 infants tested positive for RVs. Risk factors for RV prevalence were autumn months (OR=1.71, p=0.01, 95% CI 1.13-2.61), outdoor temperatures between 5-10 °C (OR=2.33, p=0.001, 95% CI 1.41-3.86), older siblings (OR=2.60, p=0.001, 95% CI 1.50-4.51) and childcare attendance (OR=1.53, p=0.07, 95% CI 0.96-2.44). 51% of RV-positive samples were asymptomatic. Respiratory symptoms during RV infections were less likely during the first three months of life (OR=0.34, p=0.003, 95% CI 0.17-0.69) and in infants with atopic mothers (OR=0.44, p=0.008, 95% CI 0.24-0.80). Increased tidal volume (OR=1.67, p=0.03, 95% CI 1.04-2.68) and outdoor temperatures between 2-5 °C (OR=2.79, p=0.02, 95% CI 1.17-6.61) were associated with more symptoms. CONCLUSIONS RVs are highly prevalent during the first year of life, and most infections are asymptomatic. Frequency of RV infections is associated with environmental factors, while respiratory symptoms during RV infections are linked to host determinants like infant age, maternal atopy, or premorbid lung function.

Effect of air pollution on pediatric respiratory emergency room visits and hospital admissions

In order to assess the effect of air pollution on pediatric respiratory morbidity, we carried out a time series study using daily levels of PM10, SO2, NO2, ozone, and CO and daily numbers of pediatric respiratory emergency room visits and hospital admissions at the Children's Institute of the University of São Paulo Medical School, from August 1996 to August 1997. In this period there were 43,635 hospital emergency room visits, 4534 of which were due to lower respiratory tract disease. The total number of hospital admissions was 6785, 1021 of which were due to lower respiratory tract infectious and/or obstructive diseases. The three health end-points under investigation were the daily number of emergency room visits due to lower respiratory tract diseases, hospital admissions due to pneumonia, and hospital admissions due to asthma or bronchiolitis. Generalized additive Poisson regression models were fitted, controlling for smooth functions of time, temperature and humidity, and an indicator of weekdays. NO2 was positively associated with all outcomes. Interquartile range increases (65.04 µg/m³) in NO2 moving averages were associated with an 18.4% increase (95% confidence interval, 95% CI = 12.5-24.3) in emergency room visits due to lower respiratory tract diseases (4-day moving average), a 17.6% increase (95% CI = 3.3-32.7) in hospital admissions due to pneumonia or bronchopneumonia (3-day moving average), and a 31.4% increase (95% CI = 7.2-55.7) in hospital admissions due to asthma or bronchiolitis (2-day moving average). The study showed that air pollution considerably affects children's respiratory morbidity, deserving attention from the health authorities.

Mannose-binding lectin cord blood levels and respiratory symptoms during infancy: a prospective birth cohort study

Respiratory infections cause considerable morbidity during infancy. The impact of innate immunity mechanisms, such as mannose-binding lectin (MBL), on respiratory symptoms remains unclear. The aims of this study were to investigate whether cord blood MBL levels are associated with respiratory symptoms during infancy and to determine the relative contribution of MBL when compared with known risk factors. This is a prospective birth cohort study including 185 healthy term infants. MBL was measured in cord blood and categorized into tertiles. Frequency and severity of respiratory symptoms were assessed weekly until age one. Association with MBL levels was analysed using multivariable random effects Poisson regression. We observed a trend towards an increased incidence rate of severe respiratory symptoms in infants in the low MBL tertile when compared with infants in the middle MBL tertile [incidence rate ratio (IRR) = 1.59; 95% confidence interval (CI): 0.95-2.66; p = 0.076]. Surprisingly, infants in the high MBL tertile suffered significantly more from severe and total respiratory symptoms than infants in the middle MBL tertile (IRR = 1.97; 95% CI: 1.20-3.25; p = 0.008). This association was pronounced in infants of parents with asthma (IRR = 3.64; 95% CI: 1.47-9.02; p = 0.005). The relative risk associated with high MBL was similar to the risk associated with well-known risk factors such as maternal smoking or childcare. In conclusion the association between low MBL levels and increased susceptibility to common respiratory infections during infancy was weaker than that previously reported. Instead, high cord blood MBL levels may represent a so far unrecognized risk factor for respiratory morbidity in infants of asthmatic parents.

Comparisons of Mortality and Pre-discharge Respiratory Outcomes in Small-for-gestational-age and Appropriate-for-gestational-age Premature Infants.

BACKGROUND: There are differences in the literature regarding outcomes of premature small-for-gestational-age (SGA) and appropriate-for gestational-age (AGA) infants, possibly due to failure to take into account gestational age at birth. OBJECTIVE: To compare mortality and respiratory morbidity of SGA and AGA premature newborn infants. DESIGN/METHODS: A retrospective study was done of the 2,487 infants born without congenital anomalies at RESULTS: Controlling for GA, premature SGA infants were at a higher risk for mortality (Odds ratio 3.1, P = 0.001) and at lower risk of respiratory distress syndrome (OR = 0.71, p = 0.02) than AGA infants. However multivariate logistic regression modeling found that the odds of having respiratory distress syndrome (RDS) varied between SGA and AGA infants by GA. There was no change in RDS risk in SGA infants at GA 32 wk (OR = 0.41, 95% CI 0.27 - 0.63; p < 0.01). After controlling for GA, SGA infants were observed to be at a significantly higher risk for developing chronic lung disease as compared to AGA infants (OR = 2.2, 95% CI = 1.2 - 3.9, P = 0.01). There was no significant difference between SGA and AGA infants in total days on ventilator. Among infants who survived, mean length of hospital stay was significantly higher in SGA infants born between 26-36 wks GA than AGA infants. CONCLUSIONS: Premature SGA infants have significantly higher mortality, significantly higher risk of developing chronic lung disease and longer hospital stay as compared to premature AGA infants. Even the reduced risk of RDS in infants born at >/=32 wk GA, (conferred possibly by intra-uterine stress leading to accelerated lung maturation) appears to be of transient effect and is counterbalanced by adverse effects of poor intrauterine growth on long term pulmonary outcomes such as chronic lung disease.

Indoor and outdoor atmospheric fungal spores in the São Paulo metropolitan area (Brazil): species and numeric concentrations

The aim of this study was to estimate the indoor and outdoor concentrations of fungal spores in the Metropolitan Area of Sao Paulo (MASP), collected at different sites in winter/spring and summer seasons. The techniques adopted included cultivation (samples collected with impactors) and microscopic enumeration (samples collected with impingers). The overall results showed total concentrations of fungal spores as high as 36,000 per cubic meter, with a large proportion of non culturable spores (around 91 per cent of the total). Penicillium sp. and Aspergillus sp. were the dominant species both indoors and outdoors, in all seasons tested, occurring in more than 30 per cent of homes at very high concentrations of culturable airborne fungi [colony forming units(CFU) m−3]. There was no significant difference between indoor and outdoor concentrations. The total fungal spore concentration found in winter was 19 per cent higher than that in summer. Heat and humidity were the main factors affecting fungal growth; however, a non-linear response to these factors was found. Thus, temperatures below 16°C and above 25°C caused a reduction in the concentration (CFU m−3) of airborne fungi, which fits with MASP climatalogy. The same pattern was observed for humidity, although not as clearly as with temperature given the usual high relative humidity (above 70 per cent) in the study area. These results are relevant for public health interventions that aim to reduce respiratory morbidity among susceptible populations

Genotoxic potential generated by biomass burning in the Brazilian Legal Amazon by Tradescantia micronucleus bioassay: a toxicity assessment study

Background: The Brazilian Amazon has suffered impacts from non-sustainable economic development, especially owing to the expansion of agricultural commodities into forest areas. The Tangara da Serra region, located in the southern of the Legal Amazon, is characterized by non-mechanized sugar cane production. In addition, it lies on the dispersion path of the pollution plume generated by biomass burning. The aim of this study was to assess the genotoxic potential of the atmosphere in the Tangara da Serra region, using Tradescantia pallida as in situ bioindicator. Methods: The study was conducted during the dry and rainy seasons, where the plants were exposed to two types of exposure, active and passive. Results: The results showed that in all the sampling seasons, irrespective of exposure type, there was an increase in micronucleus frequency, compared to control and that it was statistically significant in the dry season. A strong and significant relationship was also observed between the increase in micronucleus incidence and the rise in fine particulate matter, and hospital morbidity from respiratory diseases in children. Conclusions: Based on the results, we demonstrated that pollutants generated by biomass burning in the Brazilian Amazon can induce genetic damage in test plants that was more prominent during dry season, and correlated with the level of particulates and elevated respiratory morbidity.

Morbilidade Respiratória e Exposição a Partículas Inaláveis na Cidade de Lisboa

Introdução: Os efeitos adversos das partículas em suspensão na saúde humana expressam-se sob efeitos agudos e crónicos, não existindo nenhum limiar abaixo do qual se considere que a exposição a partículas não origine efeitos na saúde da população. À semelhança de outras capitais europeias, a cidade de Lisboa apresenta elevados níveis de partículas, principalmente nas áreas de maior tráfego. Objectivo: Neste estudo procurou-se analisar os efeitos na saúde humana decorrentes da exposição ambiental a partículas em suspensão na atmosfera (PM10 e PM2.5). Metodologia: O estudo centrou-se nos efeitos das partículas inaláveis na saúde respiratória da população infanto-juvenil residente em Lisboa. Para o efeito, foram caracterizados os níveis de partículas (PM10 e PM2.5) em Lisboa e procedeu-se a uma avaliação da morbilidade respiratória, utilizando métodos indirectos relacionados com a procura e utilização dos serviços de saúde em situação de urgência, tendo como base os atendimentos da Urgência Pediátrica de um Hospital de Lisboa. Resultados: Verificou-se que um terço das urgências pediátricas hospitalares é de natureza respiratória, destacando-se quatro principais patologias: infecção aguda das vias aéreas superiores, infecção aguda das vias aéreas inferiores, asma e pneumonia. Os modelos estatísticos explicativos foram desenvolvidos com vista a aferir as variáveis ambientais mais relevantes para avaliar os impactes da poluição atmosférica por PM na saúde respiratória infantil, identificando-se um desfasamento temporal, de poucos dias, entre as ocorrências de elevadas concentrações de partículas e os efeitos respiratórios. Conclusão: Nestes modelos a temperatura mínima surge como importante variável explicativa, assim como as concentrações de partículas medidas em estações de fundo (mais representativas dos níveis de concentrações de PM de zonas residenciais) em detrimento das estações de tráfego. Foi evidente uma relação entre a zona de residência das crianças com problemas respiratórios atendidas na urgência e as áreas da cidade com maiores níveis de partículas.

Multiple courses of antenatal corticosteroids for preterm birth (MACS): a randomised controlled trial.

BACKGROUND: One course of antenatal corticosteroids reduces the risk of respiratory distress syndrome and neonatal death. Weekly doses given to women who remain undelivered after a single course may have benefits (less respiratory morbidity) or cause harm (reduced growth in utero). We aimed to find out whether multiple courses of antenatal corticosteroids would reduce neonatal morbidity and mortality without adversely affecting fetal growth. METHODS: 1858 women at 25-32 weeks' gestation who remained undelivered 14-21 days after an initial course of antenatal corticosteroids and continued to be at high risk of preterm birth were randomly assigned to multiple courses of antenatal corticosteroids (n=937) or placebo (n=921), every 14 days until week 33 or delivery, whichever came first. The primary outcome was a composite of perinatal or neonatal mortality, severe respiratory distress syndrome, intraventricular haemorrhage (grade III or IV), periventricular leucomalacia, bronchopulmonary dysplasia, or necrotising enterocolitis. Analysis was by intention to treat. All patients and caregivers were unaware of the treatment given. This trial is registered as number ISRCTN2654148. FINDINGS: Infants exposed to multiple courses of antenatal corticosteroids had similar morbidity and mortality to those exposed to placebo (150 [12.9%] vs 143 [12.5%]). Those receiving multiple doses of corticosteroids also weighed less at birth than those exposed to placebo (2216 g vs 2330 g, p=0.0026), were shorter (44.5 cm vs 45.4 cm, p<0.001), and had a smaller head circumference (31.1 cm vs 31.7 cm, p<0.001). INTERPRETATION: Multiple courses of antenatal corticosteroids, every 14 days, do not improve preterm-birth outcomes, and are associated with a decreased weight, length, and head circumference at birth. Therefore, this treatment schedule is not recommended. FUNDING: Canadian Institutes of Health Research.

Application of continuous positive airway pressure in the delivery room: a multicenter randomized clinical trial

This study evaluated whether the use of continuous positive airway pressure (CPAP) in the delivery room alters the need for mechanical ventilation and surfactant during the first 5 days of life and modifies the incidence of respiratory morbidity and mortality during the hospital stay. The study was a multicenter randomized clinical trial conducted in five public university hospitals in Brazil, from June 2008 to December 2009. Participants were 197 infants with birth weight of 1000-1500 g and without major birth defects. They were treated according to the guidelines of the American Academy of Pediatrics (APP). Infants not intubated or extubated less than 15 min after birth were randomized for two treatments, routine or CPAP, and were followed until hospital discharge. The routine (n=99) and CPAP (n=98) infants studied presented no statistically significant differences regarding birth characteristics, complications during the prenatal period, the need for mechanical ventilation during the first 5 days of life (19.2 vs 23.4%, P=0.50), use of surfactant (18.2 vs 17.3% P=0.92), or respiratory morbidity and mortality until discharge. The CPAP group required a greater number of doses of surfactant (1.5 vs 1.0, P=0.02). When CPAP was applied to the routine group, it was installed within a median time of 30 min. We found that CPAP applied less than 15 min after birth was not able to reduce the need for ventilator support and was associated with a higher number of doses of surfactant when compared to CPAP applied as clinically indicated within a median time of 30 min.

Indoor and outdoor atmospheric fungal spores in the So Paulo metropolitan area (Brazil): species and numeric concentrations

The aim of this study was to estimate the indoor and outdoor concentrations of fungal spores in the Metropolitan Area of Sao Paulo (MASP), collected at different sites in winter/spring and summer seasons. The techniques adopted included cultivation (samples collected with impactors) and microscopic enumeration (samples collected with impingers). The overall results showed total concentrations of fungal spores as high as 36,000 per cubic meter, with a large proportion of non culturable spores (around 91% of the total). Penicillium sp. and Aspergillus sp. were the dominant species both indoors and outdoors, in all seasons tested, occurring in more than 30% of homes at very high concentrations of culturable airborne fungi [colony forming units(CFU) m(-3)]. There was no significant difference between indoor and outdoor concentrations. The total fungal spore concentration found in winter was 19% higher than that in summer. Heat and humidity were the main factors affecting fungal growth; however, a non-linear response to these factors was found. Thus, temperatures below 16A degrees C and above 25A degrees C caused a reduction in the concentration (CFU m(-3)) of airborne fungi, which fits with MASP climatalogy. The same pattern was observed for humidity, although not as clearly as with temperature given the usual high relative humidity (above 70%) in the study area. These results are relevant for public health interventions that aim to reduce respiratory morbidity among susceptible populations.

Cistos subependimários diagnosticados pelo ultra-som transfontanelar

Objetivos: avaliar a evolução ultra-sonográfica de cistos subependimários (CSE) do ângulo externo dos ventrículos laterais, e a evolução clínica dos pacientes. Comparar os pacientes com CSE isolados e os com CSE associados a outras lesões. Métodos: foram diagnosticados um a vários cistos no ângulo externo de um ou de ambos os ventrículos laterais, por meio de ultra-som transfontanelar (US) de rotina, realizado nos primeiros dias de vida, caracterizando os CSE. Durante o período de 1981-2000, 66 recém-nascidos tiveram CSE evidenciados na UTI neonatal do Hospital de Port-Royal. Foram constituídos dois grupos: G-I, com CSE isolados (n=21), e G-II, com CSE associados a outras lesões (n=45). Resultados: os recém-nascidos do GI apresentaram maior maturidade, melhores condições de nascimento e menor morbidade respiratória em relação a GII. A incidência de malformações congênitas foi elevada em ambos os grupos. Houve baixa taxa de infecção bacteriana e ausência de infecção congênita. Os CSE foram uni ou bilaterais, únicos ou múltiplos (colar de pérolas), sem diferença entre os grupos estudados, e predominaram à esquerda. US seriados foram realizados em 49/66 pacientes (74%), mostrando aumento no tamanho do cisto em 21/49 (45%), no primeiro mês de vida, enquanto 12 CSE (24%) desapareceram. O óbito ocorreu em dez recém-nascidos com lesões neurológica graves (quatro leucomalácias periventriculares, cinco hemorragias peri e intraventriculares), e somente um com hérnia diafragmática não apresentava outras lesões ao US transfontanelar. Conclusões: as características dos CSE não diferiram quando esses estavam associados a outras lesões. O nítido predomínio no lado esquerdo sugere uma etiologia vascular. Foi encontrada uma alta taxa de malformações associadas, alertando para a possibilidade de uma etiologia malformativa. Ambas hipóteses sugerem um desvio de desenvolvimento, e não de uma fetopatia viral.

Efeitos da fisioterapia respiratória convencional versus aumento do fluxo expiratório na saturação de O2, freqüência cardíaca e freqüência respiratória, em prematuros no período pós-extubação

INTRODUÇÃO: Recém-nascidos (RN) prematuros apresentam elevada morbidade respiratória e necessidade de ventilação mecânica, assim, a fisioterapia respiratória é parte integrante da assistência neonatal. Objetivo: Comparar os efeitos da fisioterapia respiratória convencional (FRC) versus aumento do fluxo expiratório (AFE), na saturação de O2 (SpO2), freqüência cardíaca (FC) e na freqüência respiratória (FR) em prematuros no período pós-extubação. Método: Ensaio clínico randomizado realizado na UTI Neonatal do Hospital das Clínicas de BotucatuUNESP, comparando duas técnicas fisioterapêuticas, aplicadas em recém-nascidos prematuros, nas primeiras 48 horas pós-extubação. Para a análise estatística foram utilizados o teste t Student, Mann-Whitney, Qui-quadrado e o teste exato de Fisher, com nível de significância em 5%. Resultados: Os dois grupos de estudo: Grupo FRC (n= 20) e grupo AFE (n= 20), não diferiram quanto à idade gestacional (média de 28 semanas) e peso de nascimento (média de 1100 gramas). em ambos os grupos a síndrome do desconforto respiratório (SDR) foi o principal diagnóstico. A mediana da idade no início da fisioterapia foi de sete dias no grupo AFE e 11 dias na FRC. Ambas as técnicas produziram aumento significativo da SpO2 aos 10 e 30 minutos, sem alterações na FR. A FC aumentou significativamente após a FRC e não se alterou após o AFE. Conclusão: Os resultados sugerem que o AFE é menos estressante que a FRC e pode ser aplicado em prematuros no período pós-extubação. Nestes recém-nascidos o AFE parece ser seguro e benéfico a curto prazo.

Three-Dimensional Ultrasonographic Assessment of Fetal Total Lung Volume as a Prognostic Factor in Primary Pleural Effusion

Objectives-The purpose of this study was to predict perinatal outcomes using fetal total lung volumes assessed by 3-dimensional ultrasonography (3DUS) in primary pleural effusion.Methods-Between July 2005 and July 2010, total lung volumes were prospectively estimated in fetuses with primary pleural effusion by 3DUS using virtual organ computer-aided analysis software. The first and last US examinations were considered in the analysis. The observed/expected total lung volumes were calculated. Main outcomes were perinatal death (up to 28 days of life) and respiratory morbidity (orotracheal intubation with mechanical respiratory support >48 hours).Results-Twelve of 19 fetuses (63.2%) survived. Among the survivors, 7 (58.3%) had severe respiratory morbidity. The observed/expected total lung volume at the last US examination before birth was significantly associated with perinatal death (P < .01) and respiratory morbidity (P < .01) as well as fetal hydrops (P < .01) and bilateral effusion (P = .01).Conclusions-Fetal total lung volumes may be useful for the prediction of perinatal outcomes in primary pleural effusion.