Does height catch-up in schoolchildren have an effect on bone mass in adolescents? Analysis in a Brazilian birth cohort / Catch-up de estatura em escolares tem efeito sobre massa óssea em adolescentes? Análise em uma coorte brasileira de nascimento

Abstract Objective: To analyze the effect of height catch-up at school age on the bone mass of adolescents of a Brazilian birth cohort. Methods: A cohort study using data obtained from the three moments (birth, 7/9 years and 18/19 years of age) of the Cohorts-RPS study. Height catch-up was defined based on the difference between the schoolchild's z-score and birth z-score. The adolescents' bone mineral mass was analyzed using the z-score index for the lumbar spine measured by dual emission X-ray absorptiometry. A theoretical model was developed for the proposed analysis using directed acyclic graphs paired through the nearest-neighbor matching propensity score using the STATA software, version 14.0. The level of significance was set at 5%. Results: Of the 297 studied children, 24.5% achieved height catch-up. The bone mass below the expected for age was observed in 5.39% of the subjects. The mean lumbar spine z-score was −0.34 (±1.01). After the adjustment, no effect was observed between height catch-up at school age and bone mass in adolescents (Coeff = 0.598; 95% CI −0.117 to 1.313; p = 0.101). Conclusion: Even using the directed acyclic graphs and the causal inference method by adjusting the propensity score, the height catch-up did not seem to affect bone mass in adolescents, a result perhaps related to the sample size.

Resumo: Objetivo: Analisar o efeito do catch-up de estatura na idade escolar na massa óssea em adolescentes em uma coorte brasileira de nascimento. Métodos: Estudo de coorte, utilizando dados dos três momentos (nascimento, aos 7/9 anos e 18/19 anos) da pesquisa Coortes-RPS. Catch-up de estatura foi definida a partir da diferença entre o Z-score do escolar e Z-score do nascimento. Para a análise da massa óssea em adolescentes foi utilizado o índice Z-score da coluna lombar medido pela densitometria por dupla emissão de raio X. Para análise proposta, foi construído modelo teórico usando os gráficos acíclicos direcionados e pareado por escore de propensão do tipo vizinho mais próximo utilizando o software STATA versão 14.0. O nível de significância adotado foi de 5%. Resultados: Das 297 crianças, 24,58% realizaram o catch-up estatural. Massa óssea abaixo do esperado para a idade foi de 5,39%. O Z-score médio da coluna lombar foi −0,34 (± 1,01). Após ajuste, não foi observado efeito entre catch-up de estatura na idade escolar e massa óssea no adolescente (Coef = 0,598; IC 95% −0,117-1,313; p = 0,101). Conclusão: Mesmo com os gráficos acíclicos direcionados e o método de inferência causal por ajuste do escore de propensão, o catch-up de estatura parece não afetar a massa óssea em adolescentes, resultado talvez relacionado ao tamanho da amostra.

Does height catch-up in schoolchildren have an effect on bone mass in adolescents? Analysis in a Brazilian birth cohort.

OBJECTIVE: To analyze the effect of height catch-up at school age on the bone mass of adolescents of a Brazilian birth cohort. METHODS: A cohort study using data obtained from the three moments (birth, 7/9 years and 18/19 years of age) of the Cohorts-RPS study. Height catch-up was defined based on the difference between the schoolchild's z-score and birth z-score. The adolescents' bone mineral mass was analyzed using the z-score index for the lumbar spine measured by dual emission X-ray absorptiometry. A theoretical model was developed for the proposed analysis using directed acyclic graphs paired through the nearest-neighbor matching propensity score using the STATA software, version 14.0. The level of significance was set at 5%. RESULTS: Of the 297 studied children, 24.5% achieved height catch-up. The bone mass below the expected for age was observed in 5.39% of the subjects. The mean lumbar spine z-score was -0.34 (±1.01). After the adjustment, no effect was observed between height catch-up at school age and bone mass in adolescents (Coeff=0.598; 95% CI -0.117 to 1.313; p=0.101). CONCLUSION: Even using the directed acyclic graphs and the causal inference method by adjusting the propensity score, the height catch-up did not seem to affect bone mass in adolescents, a result perhaps related to the sample size.

Factors associated with height catch-up and catch-down growth among schoolchildren.

In developed countries, children with intrauterine growth restriction (IUGR) or born preterm (PT) tend to achieve catch-up growth. There is little information about height catch-up in developing countries and about height catch-down in both developed and developing countries. We studied the effect of IUGR and PT birth on height catch-up and catch-down growth of children from two cohorts of liveborn singletons. Data from 1,463 children was collected at birth and at school age in Ribeirão Preto (RP), a more developed city, and in São Luís (SL), a less developed city. A change in z-score between schoolchild height z-score and birth length z-score ≥ 0.67 was considered catch-up; a change in z-score ≤ -0.67 indicated catch-down growth. The explanatory variables were: appropriate weight for gestational age/PT birth in four categories: term children without IUGR (normal), IUGR only (term with IUGR), PT only (preterm without IUGR) and preterm with IUGR; infant's sex; maternal parity, age, schooling and marital status; occupation of family head; family income and neonatal ponderal index (PI). The risk ratio for catch-up and catch-down was estimated by multinomial logistic regression for each city. In RP, preterms without IUGR (RR = 4.13) and thin children (PI<10(th) percentile, RR = 14.39) had a higher risk of catch-down; catch-up was higher among terms with IUGR (RR = 5.53), preterms with IUGR (RR = 5.36) and children born to primiparous mothers (RR = 1.83). In SL, catch-down was higher among preterms without IUGR (RR = 5.19), girls (RR = 1.52) and children from low-income families (RR = 2.74); the lowest risk of catch-down (RR = 0.27) and the highest risk of catch-up (RR = 3.77) were observed among terms with IUGR. In both cities, terms with IUGR presented height catch-up growth whereas preterms with IUGR only had height catch-up growth in the more affluent setting. Preterms without IUGR presented height catch-down growth, suggesting that a better socioeconomic situation facilitates height catch-up and prevents height catch-down growth.

Carga de trabalho de profissionais da saúde e eventos adversos durante ventilação mecânica em unidades de terapia intensiva neonatal / Staff workload and adverse events during mechanical ventilation in neonatal intensive care units

OBJETIVO: Investigar uma possível associação entre a carga de trabalho de profissionais da saúde e eventos adversos intermediários, tais como extubação acidental, obstrução do tubo endotraqueal e desconexão acidental do circuito do ventilador, durante ventilação mecânica neonatal em unidades neonatais de alto risco. MÉTODO: Este estudo de coorte prospectiva analisou os dados referentes a 543 recém-nascidos de unidades de terapia intensiva neonatal (UTINs) de São Luís (MA) por 6 meses, durante os quais 136 recém-nascidos foram submetidos a ventilação mecânica em 1.108 turnos e foram observados 4.554 vezes. RESULTADOS: Ocorreram eventos adversos 117 vezes durante esse período. As associações entre carga de trabalho e eventos adversos foram analisadas por meio de equações de estimação generalizada. As variáveis de ajuste foram: peso de nascimento, gênero, maternidade estudada, pontuação no índice de risco clínico para bebês (clinical risk index for babies) e demanda de cuidados, determinada pela escala desenvolvida pela Northern Neonatal Network. Quanto maior o número de recém-nascidos classificados de acordo com a demanda de cuidados (RCDCs) por enfermeiro e técnico em enfermagem, maior a probabilidade da ocorrência de eventos adversos intermediários relacionados à ventilação mecânica. Um número de RCDCs > 22 por enfermeiro [risco relativo (RR) = 2,86] e > 4,8 por enfermeiro auxiliar (RR = 3,41) esteve associado a uma maior prevalência de eventos adversos intermediários. CONCLUSÕES: A carga de trabalho dos profissionais de UTINs parece interferir nos resultados intermediários do cuidado neonatal e, portanto, deve ser levada em conta na avaliação dos desfechos na UTIN.

OBJECTIVE: To investigate a possible association between the intensity of staff workload and intermediate adverse events, such as accidental extubation, obstruction of the endotracheal tube, and accidental disconnection of the ventilator circuit, during neonatal mechanical ventilation in high-risk neonatal units. METHOD: This prospective cohort study analyzed data of 543 newborns from public neonatal intensive care units (NICUs) in the city of São Luís, state of Maranhão, Northeastern Brazil, for 6 months, during which 136 newborns were submitted to mechanical ventilation in 1,108 shifts and were observed a total of 4,554 times. RESULTS: Adverse events occurred 117 times during this period. The associations between workload and adverse events were analyzed by means of generalized estimating equations. The adjustment variables were: birth weight, gender, maternity unit, Clinical Risk Index for Babies score, and care demand, the latter measured by the Northern Neonatal Network Scale. The larger the number of newborns classified by care demand (NCCD) per nurse and nursing technician, the more likely the occurrence of intermediate adverse events linked to mechanical ventilation. A number of NCCD > 22 per nurse (relative risk [RR] = 2.86) and > 4.8 per auxiliary nurse (RR = 3.41) was associated with a higher prevalence of intermediate adverse events. CONCLUSIONS: The workload of NICU professionals seems to interfere with the intermediate results of neonatal care and thus should be taken into consideration when evaluating NICU outcomes.

Staff workload and adverse events during mechanical ventilation in neonatal intensive care units.

OBJECTIVE: To investigate a possible association between the intensity of staff workload and intermediate adverse events, such as accidental extubation, obstruction of the endotracheal tube, and accidental disconnection of the ventilator circuit, during neonatal mechanical ventilation in high-risk neonatal units. METHOD: This prospective cohort study analyzed data of 543 newborns from public neonatal intensive care units (NICUs) in the city of São Luís, state of Maranhão, Northeastern Brazil, for 6 months, during which 136 newborns were submitted to mechanical ventilation in 1,108 shifts and were observed a total of 4,554 times. RESULTS: Adverse events occurred 117 times during this period. The associations between workload and adverse events were analyzed by means of generalized estimating equations. The adjustment variables were: birth weight, gender, maternity unit, Clinical Risk Index for Babies score, and care demand, the latter measured by the Northern Neonatal Network Scale. The larger the number of newborns classified by care demand (NCCD) per nurse and nursing technician, the more likely the occurrence of intermediate adverse events linked to mechanical ventilation. A number of NCCD > 22 per nurse (relative risk [RR] = 2.86) and > 4.8 per auxiliary nurse (RR = 3.41) was associated with a higher prevalence of intermediate adverse events. CONCLUSIONS: The workload of NICU professionals seems to interfere with the intermediate results of neonatal care and thus should be taken into consideration when evaluating NICU outcomes.

Young maternal age and preterm birth.

The association between young maternal age and preterm birth (PTB) remains controversial. In some studies the association disappeared after controlling for socio-economic and reproductive factors, thus indicating that social disadvantage rather than biological factors may be the explanation. However, in other studies the association persisted after adjustment. The relation between young maternal age and PTB was studied in a city located in Brazil, an underdeveloped country, where the prevalence of teenage pregnancy was high, 29%. A systematic sampling of 2541 hospital births, stratified by hospital, was performed in São Luís, Northeast Brazil, from March 1997 to February 1998. The risks of PTB for infants born to two groups of young mothers (<18 and 18-19 years) were calculated with and without adjustment for confounding factors (family income, marital status, mode of delivery, parity, health insurance, and short maternal stature) in a logistic regression model, using mothers 25-29 years of age as the reference group. In the unadjusted analysis, the risk of PTB was higher for mothers < 18 years [odds ratio (OR) = 2.42, 95% confidence interval (CI) 1.64, 3.57]. Those aged 18 or 19 years were not at a higher risk of PTB (OR = 0.89, 95% CI 0.58, 1.38). After adjustment, the risk of PTB for mothers < 18 years was lower but remained significant after controlling for confounding (OR = 1.70, 95% CI 1.11, 2.60). After performing a stratified analysis according to parity, the risk of PTB among very young primiparae (<18 years) remained significant (OR = 1.77, 95% CI 1.02, 3.08), whereas the risk among non-primiparous adolescents was not significantly higher than the risk among mothers in the reference group. This suggests that the association between young maternal age and PTB may have a biological basis or an artifactual explanation (errors in gestational age estimation may be more common among very young mothers) or may be due to residual confounding.

Posicao do tubo traqueal em recem-nascidos / Position of the tracheal tube in infant newborns

Complicacoes associadas a intubacao traqueal sao frequentes em recem-nascidos. Condicao fundamental para uma ventilacao adequada e que o tubo traqueal esteja bem posicionado, uma vez que tubos com localizacao alta estao predispostos a extubacao acidental e os colocados em posicao baixa associam-se a atelectasia, intubacao e pneumotorax. O objetivo do presente trabalho foi determinar, em nosso servico, a posicao do tubo traqueal em 910 radiografias de torax, utilizando um criterio anatomico que correlaciona a traqueia com a coluna vertebral. O primeiro RX obtido imediatamente apos a intubacao foi analisado separadamente das radiografias subsequentes por uma radiologista pediatrica. Nossos resultados demonstram que 49% dos tubos traqueais estavam mal-posicionados. A incidencia de tubos em posicao alta foi significantemente maior do que a daqueles situados em posicao baixa (35% vs 14% p < 0.005). Esta relacao nao varia em funcao da faixa de peso do recem-nascido intubado. Comparando-se o 1o. com os demais, observamos uma tendencia em se reposicionarem mais frequentemente os tubos traqueais cuja localizacao inicial era baixa .