DEVELOPMENT OF CARDIOVASCULAR CONTROL DURING SLEEP IN HUMAN INFANTS AFTER PRETERM BIRTH
Funder
National Health and Medical Research Council
Funding Amount
$358,537.00
Summary
Infants spend the major part of their life in sleep, and the period between birth and 6 months of age sees dramatic changes in their sleep organisation. Coincidently, there are dramatic developmental changes in the infant's heart and blood pressure control systems, and the ability to compensate for stress such as falls of blood pressure (hypotension) or in the level of oxygen in the blood (hypoxaemia). In infants born preterm, the risks of hypoxaemia, and even death are significantly greater dur ....Infants spend the major part of their life in sleep, and the period between birth and 6 months of age sees dramatic changes in their sleep organisation. Coincidently, there are dramatic developmental changes in the infant's heart and blood pressure control systems, and the ability to compensate for stress such as falls of blood pressure (hypotension) or in the level of oxygen in the blood (hypoxaemia). In infants born preterm, the risks of hypoxaemia, and even death are significantly greater during sleep than during wakefulness, but why this is so is uncertain. This study will examine the ability of infants to respond to stress during sleep. Four groups of infants will be examined: healthy infants born at normal gestation; healthy infants born prematurely (preterm); preterm infants who have experienced mild hypoxaemia soon after birth; and preterm infants who have suffered more severe hypoxaemia because of lung disease. Infants will be studied in a sleep laboratory during day-time sleep, and their ability to control blood pressure will be determined. By contrasting the effectiveness of blood pressure control between the infant groups we aim to determine whether preterm infants have lasting problems as a result of their premature birth, or their exposure to hypoxaemia. By contrasting infants in sleep and wakefulness, we aim to assess whether the risks of poorer blood pressure control are greater in sleep.Read moreRead less
A Randomised Controlled Trial Of Whole Body Cooling On The Outcome Of Term Infants With Hypoxic Ischaemic Encephalopathy
Funder
National Health and Medical Research Council
Funding Amount
$386,732.00
Summary
The aim of this project is to investigate whether the brain damage caused by a serious lack of oxygen around the time of birth can be prevented or reduced by cooling the baby's temperature to 34C for 72 hours. The consequences, of a lack of oxygen, to the brain, around the time of birth can be devastating. Over 30% of those babies with abnormal brain function soon after birth either die or survive with severe permanent brain damage. There is no specific treatment for these infants. Evidence from ....The aim of this project is to investigate whether the brain damage caused by a serious lack of oxygen around the time of birth can be prevented or reduced by cooling the baby's temperature to 34C for 72 hours. The consequences, of a lack of oxygen, to the brain, around the time of birth can be devastating. Over 30% of those babies with abnormal brain function soon after birth either die or survive with severe permanent brain damage. There is no specific treatment for these infants. Evidence from studies in animals, as well as human adults and a small number of newborn infants, suggests that moderate body cooling started soon after birth in babies with serious abnormal brain function might prevent or reduce brain damage. This project is a multicentre trial, where infants who have suffered from a severe lack of oxygen around birth, are randomised to body cooling to 34C for 72 hours. This will be started as soon as possible after birth at their hospital of birth. If the baby needs to be transported this will be started when the newborn transport team collects the baby for transfer to a newborn intensive care unit. This new treatment will be compared with maintaining the baby's temperature at 37C. This project will investigate a new, simple and pragmatic treatment that might reduce brain damage. If it finds that cooling infants who have been severely deprived of oxygen is an effective and safe treatment, the information will be applicable to any of the very large number of babies around the world who suffer from a serious lack of oxygen around the time of birth.Read moreRead less
Previous research has shown that SIDS victims have a number of subtle abnormalities that set them apart from the normal population. These include the occurrence of upper airway obstruction in sleep, a reduced ability to awaken from sleep and abnormalities of the automatic control of heart rate and blood pressure in sleep. These body functions are controlled by a component of the brain called the autonomic nervous system which controls the heart and other internal functions by means of nerves cal ....Previous research has shown that SIDS victims have a number of subtle abnormalities that set them apart from the normal population. These include the occurrence of upper airway obstruction in sleep, a reduced ability to awaken from sleep and abnormalities of the automatic control of heart rate and blood pressure in sleep. These body functions are controlled by a component of the brain called the autonomic nervous system which controls the heart and other internal functions by means of nerves called the parasymmpathetic and sympathetic systems. The purpose of this project is to undertake studies of the autonomic system in normal infants and in those infants who are considered to be at risk for SIDS. As SIDS occurs almost exclusively in sleep it is important to study the infant?s heart rate and blood pressure responses to various challenges whilst asleep. All infants (both controls and subjects) enrolled in the protocol will therefore undergo overnight sleep studies during which their automatic responses to a variety of stimuli will be measured. Once we have established the normal response to these stimuli we can then compare them to the results of the at risk group. If, as we anticipate, there is a difference between our at risk group and the normal controls in automatic function then we will measure some of the stress hormones in the body which reflect the function of the autonomic nervous system. If there is a difference in the levels of these hormones between the normal and the at risk groups which correlates with the expected subtle abnormalities in function we may be able to devise an accessible and quantifiable measure for those infants at risk of SIDSRead moreRead less