Background: Very occasionally, when a fetus is developing in the womb, problems occur with the normal processes controlling closure of the muscles of the abdominal wall and, as a result, some of the abdominal contents develop outside of the body. This is known as an abdominal wall defect. If the pregnancy continues to term, the newborn infant will need specialised surgical care. This situation occurs so infrequently that even a dedicated surgical centre will care for very few of these women and their babies in a year. Many centres have shared their experiences of managing these babies in the published literature but the majority of reports have included only a few infants. The focus of most previous studies has been to describe what happens to these newborn infants between birth and first discharge from hospital from a purely clinical perspective. Aim: To explore methodologies to holistically understand the short and longer-term outcomes of children born with abdominal wall defects and to use the information to improve the care of future affected infants. Methods: The quality of the published literature on short-term outcomes of children born with gastroschisis was scrutinised in a systematic review. The accompanying meta-analysis used published data as a means of identifying population outcome estimates. Two national population-based cohort studies were undertaken, exploring the short-term outcomes of children born with exomphalos and the outcomes at seven to ten years of children born with gastroschisis. The latter study included an assessment of childhood outcomes from the point of view of the children themselves, along with their parents. Further parental perspectives on experiences of care were explored in a qualitative analysis of in-depth interviews with parents of children born with exomphalos. Findings: Short-term outcomes of children born with gastroschisis have been published in a large number of small studies. Pooling the published data, where possible allowed the production of population estimates but heterogeneity between studies was marked. One in fourteen children born with gastroschisis died before their first birthday when managed in developed countries. Those who developed bowel complications in utero, had an increased risk of dying before one-year. The assessment of childhood outcomes for this latter group of children, who made up 11% of the population cohort, revealed a bleak outlook for many, of with one in three either dying or requiring complex surgery to gain allow them to be able to be fed via their gut, before their ninth birthday. Due to methodological limitations, the extent of neurological and gastrointestinal morbidity among survivors in the cohort is unclear, but the findings of both the highly selected responses from the parent report and those of the clinical study provide enough concern to suggest that alternative methodologies need to be explored to identify the extent of ongoing sequelae as children grow older. The live-born population of children with exomphalos is highly varied and a large burden of comorbidity was identified, however, two-thirds of infants were able to be have their abdominal wall defect surgically closed with a low-rate of early complications. A variety of techniques are employed by UK surgeons when the defect cannot be easily closed and evidence to guide management choice will be difficult to obtain using standard techniques due to the small number of these infants born annually in the UK. Parental experiences echoed the variability in management approach and in some cases highlighted a lack of respect for parental perspectives on management choice. Conclusion: Children born with abdominal wall defects represent a spectrum from those with severe comorbidity who will need ongoing care, to those who have a straightforward course and a relatively short stay in hospital. Methods of risk-stratifying infants for the purposes of outcome assessment have been explored. This approach is crucial to contextualising the progress of an individual infant and counselling their parents about their likely prognosis.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-02-09T16:06:33Z No. of bitstreams: 1 TESEDOUTORADO_ANA PAULA DA SILVA_2016.pdf: 3643578 bytes, checksum: aee17ef8cffb8a82bfd826eb5c41ddac (MD5) / Made available in DSpace on 2017-02-09T16:06:33Z (GMT). No. of bitstreams: 1 TESEDOUTORADO_ANA PAULA DA SILVA_2016.pdf: 3643578 bytes, checksum: aee17ef8cffb8a82bfd826eb5c41ddac (MD5) / Coordenação de Aperfeiçoamento de Pessoal Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica, Niterói, RJ. / O Óxido nitroso (N2O) é um importante gás do efeito estufa que contribui para as mudanças climáticas globais através do aquecimento radiativo e depleção do ozônio estratosférico. Segundo o IPCC a concentração atmosférica de N2O aumenta a taxas de 0,2 a 0,3% anualmente, e aumentou do período pré-industrial de 270 ppb para 329 ppb em 2016. A emissão deste gás por solos resulta principalmente dos processos de nitrificação e desnitrificação. O melhor conhecimento da contribuição de cada processo poderá ajudar a prever e mitigar as emissões de N2O por solos. Os métodos atuais para a investigação das taxas brutas de nitrificação e desnitrificação envolvem aplicação de inibidores químicos e/ou marcadores isotópicos 15N, os quais alteram a composição da atmosfera do solo. Neste trabalho a teoria do método da separação barométrica de processos (BaPS) foi utilizada para quantificar as taxas brutas de nitrificação e desnitrificação através de medidas de variações da pressão do ar num sistema hermético e isotérmico sem aplicação de inibidores ou marcadores químicos. Câmaras para incubação do solo equipadas com sensores de pressão, temperatura, O2 e CO2 foram construídas e amostras de solo de uma região que emite altos fluxos de óxido nitroso localizada em Jardim Catarina em São Gonçalo (RJ) foram selecionadas para o estudo dos processos de produção do gás. O fluxo in situ foi medido e o resultado médio foi de 25 ngN2O-Ncm-2h-1. A alta emissão de N2O in situ foi observada após período de alagamento da área de amostragem pelas águas poluídas do Rio Alcântara. O método BaPS foi utilizado para determinar as taxas de respiração do solo, nitrificação bruta e desnitrificação em experimentos no laboratório. Os resultados mostraram que as taxas brutas de desnitrificação foram sempre maiores que as taxas brutas de nitrificação e que os maiores fluxos de N2O gerados estão associados ao processo de desnitrificação. / climate change through radiative warming and the depletion of stratospheric ozone. According to the IPCC, the concentration of N2O atmospheric increases at rates of 0.2 to 0.3% annually, and increased had risen from the pre-industrial period from 270 ppb to 324 ppb by 2011. Its emission from soils results mainly from denitrification and nitrification process. A better knowledge of the contribution of each process should help to predict and mitigate N2O emissions by soils. Current methods for investigation of gross nitrification and denitrification rates involve N tracers and acetylene inhibition techniques These methods have the disadvantage of introducing labeled material into soil or changing the composition of soil atmosphere. In this work, the barometric process separation technique (BaPS) was applied to quantify gross nitrification and denitrification rates by measuring air pressure variations in a hermetic and isothermal system without the application of chemical inhibitors or markers. Soil incubation chambers equipped with pressure, temperature, O2 and CO2 sensors were constructed and soil samples from a region known to emit high nitrous oxide flows located in Jardim Catarina, São Gonçalo (RJ) were selected for this study. In situ flow was measured and the mean result resulted in 25 ngN2O-Ncm-2h-1. The high N2O emission in situ was observed after a period of flooding in the polluted waters of the Alcântara River. The BaPS method was used to determine the rates of soil respiration, gross nitrification and denitrification. The results showed that the gross denitrification rate was always greater than nitrification and that the higher N2O fluxes generated are associated with the denitrification process