Background: The postnatal failures of expression of the hepatic glucose-6-phosphatase system suggest there are developmental deficiencies in the mechanism to ‘switch-on’ this key enzyme of gluconeogenesis at the time of birth in both preterm and term infants. The evidence for hormonal regulation of this critical enzyme system in animal studies, in adult humans, and studies of cell lines make the possible failure of hormonal control around the time of birth an important hypothesis to test, but before this can be done, further studies of perinatal metabolism and its hormonal control need to be undertaken. Objective: To describe the hormonal and metabolic profiles of ‘unstressed’ term infants delivered by elective caesarean section. Methods: One hundred and fifty three women who had an elective caesarean section for a singleton pregnancy at term in Ninewells Hospital and Medical School, Dundee were recruited between July 2004 and April 2006. Maternal venous blood was taken for glucose and lactate estimations. Umbilical venous cord blood was obtained for the measurement of glucose, lactate, 3-hydroxybutyrate, free fatty acids, amino acids (alanine, arginine, citruline, cystine, GABA, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine ornithine, phenyalanine, serine,taurine, threonine, tyrosine and valine), insulin, glucagon, human growth hormone, cortisol, catechols (EPI, NE, DA, DOPA, DHPG, DOPAC) and their sulfated conjugates (EPI sulfate, NE sulfate, DA sulfate, DOPA sulfate, DHPG sulfate, DOPAC sulfate), and blood gas and acid-base profiles. Results The mean maternal glucose and lactate levels were 4.28 mmol/l and 1.8 mmol/l respectively. Three infants were hypoglycaemic with umbilical blood glucose levels of less than 2.6 mmol/l. The mean infant glucose and lactate levels were as expected for full term infants at 3.3 mmol/l and 2.2 mmol/l respectively. High mean levels of insulin and catechols were noted at birth. There was a significant positive association between umbilical venous cord glucose levels and maternal venous glucose levels (p=<0.001) but no association of umbilical venous cord glucose levels with amino acids, insulin, glucagon, human growth hormone, cortisol and catechols. Conclusions: This extensive data set of levels of metabolites and hormones in infants at birth acts as a reference source and will be valuable for evaluating any effects of antenatal or intrapartum factors on the hormonal and metabolic profiles of infants at birth as well as to investigate the mechanisms to ‘switch-on’ the key enzyme glucose-6-phosphatase. Objective: To describe the hormonal and metabolic profiles of ‘unstressed’ term infants delivered by elective caesarean section. Methods: One hundred and fifty three women who had an elective caesarean section for a singleton pregnancy at term in Ninewells Hospital and Medical School, Dundee were recruited between July 2004 and April 2006. Maternal venous blood was taken for glucose and lactate estimations. Umbilical venous cord blood was obtained for the measurement of glucose, lactate, 3-hydroxybutyrate, free fatty acids, amino acids (alanine, arginine, citruline, cystine, GABA, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine ornithine, phenyalanine, serine, taurine, threonine, tyrosine and valine), insulin, glucagon, human growth hormone, cortisol, catechols (EPI, NE, DA, DOPA, DHPG, DOPAC) and their sulfated conjugates (EPI sulfate, NE sulfate, DA sulfate, DOPA sulfate, DHPG sulfate, DOPAC sulfate), and blood gas and acid-base profiles. Results: The mean maternal glucose and lactate levels were 4.28 mmol/l and 1.8 mmol/l respectively. Three infants were hypoglycaemic with umbilical blood glucose levels of less than 2.6 mmol/l. The mean infant glucose and lactate levels were as expected for full term infants at 3.3 mmol/l and 2.2 mmol/l respectively. High mean levels of insulin and catechols were noted at birth. There was a significant positive association between umbilical venous cord glucose levels and maternal venous glucose levels (p=<0.001) but no association of umbilical venous cord glucose levels with amino acids, insulin, glucagon, human growth hormone, cortisol and catechols.

Made available in DSpace on 2015-03-26T13:47:21Z (GMT). No. of bitstreams: 1 texto completo.pdf: 238713 bytes, checksum: 7e42918a5e51d885e8e4ce32bf3cf3bc (MD5) Previous issue date: 2003-04-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The caesarean section is an emergency procedure that should depend upon safe anaesthetic techniques for both the mother and foetus and, at the same time, allow the realization of the surgery in due time, freeing the puppies in a vigorous state. All of the anaesthetic drugs used in caesarians quickly cross through the placenta which can affect the foetus. Foetal and neonatal depression of a variable degree occurs following the anaesthetic induction, depending upon the induction agent used, its dosage and the time passed since the induction until the freeing of the foetus. On this study there is a comparison of the foetal and maternal effects of propofol, etomidate and thiopental used as anaesthesia induction drugs for the maintenance with halothane as well as a verification of the possible advantages in substituting these inducting drugs by epidural anesthesia, following direct induction with halotane administered through mask, in caesarean section in bitches. For so, 20 bitches and 129 puppies were used distributed in four groups. In group 1 ( 5 bitches and 39 newborns) the anaesthetic induction was made with propofol, in group 2 (5 bitches and 25 newborns) with etomidate, in group 3 (5 bitches and 26 newborns) with thiopental and in group 4 (5 bitches and 39 newborns) epidural anesthesia and induction with halothane through mask were used. In all the cases the pre-anaesthetic medication was made with midazolam in a dosage of 0,22 mg/kg IM, and the anaesthetic maintenance with halothane in a semiclosed circuit and a initial concentration of 3%. The evaluated variables on the bitches were: rectal temperature, heart rate, breath rate, oxi-hemoglobin (SpO2) saturation, sistolic, mean and diastolic blood arterial pressure. For the effect evaluation of the different techniques of anaesthetic induction, the newborns were measured for cardiac frequency, respiratory effort, muscular movement, mucosa coloration and reflex irritability, and interpreted through the modified Apgar score . Besides these variables, there was also the evaluation of the newborn's SpO2. The results showed that all of the protocols were adequate for the mothers with minimal systemic effects. For the newborn, epidural anaesthesia usage followed by induction and maintance with halothane was superior to the protocols that used injectable agents in the unaesthetic induction. / A cesariana, geralmente um procedimento de emergência, deve contar com técnicas anestésicas seguras para mãe e fetos, que ao mesmo tempo, possibilite a realização da cirurgia em tempo hábil, liberando os filhotes em estado vigoroso. Todos os fármacos anestésicos utilizados em cesarianas atravessam rapidamente a placenta, podendo de alguma forma afetar o feto, Ocorrendo depressão fetal e neonatal de grau variável seguindo a indução anestésica, dependendo do agente utilizado, de sua dose e do tempo transcorrido desde a indução até a retirada do feto. Neste trabalho foi comparado o efeito fetal e materno do propofol, etomidato e tiopental, utilizados como fármacos indutores de anestesia para a manutenção com halotano, e verificado as possíveis vantagens da substituição dessas drogas indutoras, por anestesia epidural lombossacra, seguida de indução direta com halotano administrado através de máscara, em cesarianas de cadelas. Para tanto, foram utilizadas 20 cadelas e 129 filhotes distribuídos em quatro grupos. No grupo 1 ( 5 cadelas e 39 neonatos) a indução anestésica foi feita com propofol, no grupo 2 (5 cadelas e 25 neonatos) com etomidato, no grupo 3 (5 cadelas e 26 neonatos) com tiopental e no grupo 4 (5 cadelas e 39 neonatos) utilizou-se anestesia epidural e indução com halotano através de máscara. Em todos os casos, a medicação pré-anestésica foi feita com midazolam na dose de 0,22 mg/kg via IM, e a manutenção anestésica com halotano em circuito semifechado e concentração inicial de 3%. As variáveis avaliadas nas cadelas foram: temperatura retal, freqüência cardíaca, freqüência respiratória, saturação da oxi-hemoglobina (SpO2), pressão arterial sistólica, média e diastólica. Para avaliação dos efeitos das diferentes técnicas de indução anestésica, foram mensurados nos recém-nascidos, a freqüência cardíaca, o esforço respiratório, os movimentos musculares a coloração das mucosas e a irritabilidade reflexa, e interpretados através do escore de Apgar modificado . Além destas variáveis, foi avaliada também a SpO2 do neonato. Os resultados mostraram que todos os protocolos foram adequados para as mães com mínimos efeitos sistêmicos. Para o neonato, a utilização de anestesia epidural seguida de indução e manutenção com halotano foi superior aos protocolos que usaram agentes injetáveis na indução anestésica.