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dc.contributor.authorSortica da Costa, Cristine
dc.date.accessioned2018-10-09T08:22:10Z
dc.date.available2018-10-09T08:22:10Z
dc.date.issued2018-10-20
dc.date.submitted2018-02-27
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/283240
dc.description.abstractMonitoring of cerebral oxygenation, cerebrovascular reactivity and circulatory function in preterm infants Brain injury in the preterm infant is associated with death and lifelong disability. Cerebral hypoxia and fluctuations in cerebral blood flow in the first two days of life have been implicated in the pathophysiology of haemorrhagic and ischaemic brain injury. Monitoring of haemodynamic changes during the early transitional circulation from in-utero to ex-utero life are currently based on standard measurements of systemic oxygenation and mean arterial blood pressure, with no reliable assessment of end-organ perfusion. In this thesis, measurements using near-infrared spectroscopy (NIRS) and functional echocardiography were made to assess cerebral perfusion and systemic blood flow in a cohort of preterm infants undergoing intensive care. This thesis is divided into four sections: i) The feasibility of continuous monitoring of cerebral oxygenation and cerebrovascular reactivity is demonstrated in a series of case reviews, and the association between cerebral oxygenation and cerebrovascular reactivity with outcome of brain injury and mortality is described. ii) Combining measurements of systemic blood flow with end organ perfusion was applied to define MABPOPT in preterm infants based on an index of cerebrovascular reactivity. Deviations below MABPOPT were associated with intraventricular haemorrhage and mortality. iii) The complexity of brain and systemic signals was studied by using multi-scale entropy analysis. Most studies using cerebral NIRS or systemic measurements of blood flow use linear analysis; however, a complex biological system, such as the human brain, includes many regulatory mechanisms that interact in a complex manner, resulting in effects that cannot be understood wholly through the analysis of its individual constituents. Lower complexity of brain signals was observed in infants who developed intraventricular hemorrhage or died. iv) Changes in systemic and cerebral oxygenation in a cohort of preterm infants in the first 48 hours of life was assessed using functional echocardiography. The patterns of changes in cardiac output and cerebral oxygenation in infants who did and did not have intraventricular haemorrhage are discussed. Furthermore, the relationship between the presence of a haemodynamically significant ductus arteriosus and brain injury is assessed.
dc.description.sponsorshipCambridge Overseas Trust & Capes Scholarship
dc.language.isoen
dc.rightsAll rights reserved
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectPrematurity
dc.subjectCerebral autoregualtion
dc.subjectCerebrovascular reactivity
dc.subjectArterial blood pressure
dc.subjectNIRS
dc.subjectBrain injury
dc.subjectFunctional echocardiography
dc.titleMonitoring of cerebral oxygenation, cerebrovascular reactivity and circulatory function in preterm infants
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentObstetrics and Gynaecology
dc.date.updated2018-10-02T11:25:25Z
dc.identifier.doi10.17863/CAM.30604
dc.publisher.collegeTrinity Hall
dc.type.qualificationtitlePhD in Neonatal Neuroscience
cam.supervisorAustin, Topun
cam.supervisorCzosnyka, Marek
cam.thesis.fundingfalse
rioxxterms.freetoread.startdate2019-10-09


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