Eun Sun Kim1, Jeffrey R Kaiser2, Danielle R Rios3, Renee A Bornemeier4, Christopher J Rhee3. 1. Department of Pediatrics, Kangwon National University School of Medicine, Chuncheon, Republic of Korea, naivesun1@hanmail.net. 2. Division of Neonatal-Perinatal Medicine, Departments of Pediatrics and Obstetrics and Gynecology, Penn State Health Children's Hospital, Hershey, Pennsylvania, USA. 3. Section of Neonatology, Department of Pediatrics,Texas Children's Hospital/Baylor College of Medicine, Houston, Texas, USA. 4. Department of Pediatrics, Arkansas Children's Hospital/University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Abstract
INTRODUCTION: Although patent ductus arteriosus (PDA) has been implicated to play a role in the development of cerebral ischemia and intraventricular hemorrhage (IVH) through a cerebral steal phenomenon, there is conflicting data on the impact of PDA size on cerebral blood flow (CBF). Cerebral autoregulation is the brain's innate protective mechanism to maintain constant CBF despite changes in blood pressure, and it is unclear if it is influenced by PDA hemodynamics. OBJECTIVE: To delineate the relationship between PDA size and CBF velocity (CBFv) in premature infants. METHODS: 113 premature infants born at 23-29 weeks' gestation had echocardiograms performed during the first week after birth to evaluate for PDA. The infants were divided into 3 groups according to PDA size: none-to-small, moderate, or large. All infants had continuous recordings of umbilical artery blood pressure (ABP) and CBFv during the first week after birth. Critical closing pressure (CrCP) was calculated from ABP and CBFv tracings. Diastolic closing margin (DCM), defined as diastolic blood pressure minus CrCP, was calculated as a marker for the risk of developing IVH. RESULTS: Infants with a large PDA (n = 16) had the lowest ABP across all phases of the cardiac cycle (systole [p = 0.003], mean [p = 0.005], and diastole [p = 0.012]) compared to infants with a moderate (n = 19) or none-to-small PDA (n = 78). Despite blood pressure being different, systolic, mean, and diastolic CBFv were not different across groups. Cerebral autoregulation, as measured during systole, was intact regardless of the PDA size. CrCP and DCM were also not different across groups. CONCLUSIONS: In this cohort, CBFv and cerebral autoregulation during systole were not influenced by PDA size. Intact cerebral autoregulation may play a role in maintaining CBFv regardless of PDA size and differences in ABP.
INTRODUCTION: Although patent ductus arteriosus (PDA) has been implicated to play a role in the development of cerebral ischemia and intraventricular hemorrhage (IVH) through a cerebral steal phenomenon, there is conflicting data on the impact of PDA size on cerebral blood flow (CBF). Cerebral autoregulation is the brain's innate protective mechanism to maintain constant CBF despite changes in blood pressure, and it is unclear if it is influenced by PDA hemodynamics. OBJECTIVE: To delineate the relationship between PDA size and CBF velocity (CBFv) in premature infants. METHODS: 113 premature infants born at 23-29 weeks' gestation had echocardiograms performed during the first week after birth to evaluate for PDA. The infants were divided into 3 groups according to PDA size: none-to-small, moderate, or large. All infants had continuous recordings of umbilical artery blood pressure (ABP) and CBFv during the first week after birth. Critical closing pressure (CrCP) was calculated from ABP and CBFv tracings. Diastolic closing margin (DCM), defined as diastolic blood pressure minus CrCP, was calculated as a marker for the risk of developing IVH. RESULTS:Infants with a large PDA (n = 16) had the lowest ABP across all phases of the cardiac cycle (systole [p = 0.003], mean [p = 0.005], and diastole [p = 0.012]) compared to infants with a moderate (n = 19) or none-to-small PDA (n = 78). Despite blood pressure being different, systolic, mean, and diastolic CBFv were not different across groups. Cerebral autoregulation, as measured during systole, was intact regardless of the PDA size. CrCP and DCM were also not different across groups. CONCLUSIONS: In this cohort, CBFv and cerebral autoregulation during systole were not influenced by PDA size. Intact cerebral autoregulation may play a role in maintaining CBFv regardless of PDA size and differences in ABP.
Authors: Haim Bassan; Kimberlee Gauvreau; Jane W Newburger; Miles Tsuji; Catherine Limperopoulos; Janet S Soul; Gene Walter; Peter C Laussen; Richard A Jonas; Adré J du Plessis Journal: Pediatr Res Date: 2004-11-05 Impact factor: 3.756
Authors: Georgios V Varsos; Hugh Richards; Magdalena Kasprowicz; Karol P Budohoski; Ken M Brady; Matthias Reinhard; Alberto Avolio; Peter Smielewski; John D Pickard; Marek Czosnyka Journal: J Cereb Blood Flow Metab Date: 2012-11-14 Impact factor: 6.200