Elevated Diastolic Closing Margin Is Associated with Intraventricular Hemorrhage in Premature Infants

Rhee, Christopher J.; Kaiser, Jeffrey R.; Rios, Danielle R.; Kibler, Kathleen K.; Easley, R. Blaine; Andropoulos, Dean B.; Czosnyka, Marek; Smielewski, Peter; Varsos, Georgios V.; Rusin, Craig G.; Gauss, C. Heath; Williams, David; Brady, Ken

doi:10.1016/j.jpeds.2016.03.066

Cited by 20 publications

(14 citation statements)

References 33 publications

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“…Several methodologies have been used to assess cerebrovascular reactivity in both term and preterm infants. 36,37 Both transcranial Doppler and NIRS-derived reactivity indices examined the relationship between spontaneous slow wave oscillations (0.003–0.05 Hz) in mean arterial blood pressure (MABP), Doppler flow velocity, 37 cerebral blood volume (CBV) 16 and cerebral oxygenation 38–42 in the time domain. Similarly, coherence and gain have been used in frequency domain analysis.…”

Section: Introductionmentioning

confidence: 99%

Pressure passivity of cerebral mitochondrial metabolism is associated with poor outcome following perinatal hypoxic ischemic brain injury

Mitra

Bale

Highton

et al. 2017

J Cereb Blood Flow Metab

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Hypoxic ischemic encephalopathy (HIE) leads to significant morbidity and mortality. Impaired autoregulation after hypoxia-ischaemia has been suggested to contribute further to injury. Thalamic lactate/N-Acetylasperate (Lac/NAA) peak area ratio of > 0.3 on proton ( 1 H) magnetic resonance spectroscopy (MRS) is associated with poor neurodevelopment outcome following HIE. Cytochrome-c-oxidase (CCO) plays a central role in mitochondrial oxidative metabolism and ATP synthesis. Using a novel broadband NIRS system, we investigated the impact of pressure passivity of cerebral metabolism (CCO), oxygenation (haemoglobin difference (HbD)) and cerebral blood volume (total haemoglobin (HbT)) in 23 term infants following HIE during therapeutic hypothermia (HT). Sixty-minute epochs of data from each infant were studied using wavelet analysis at a mean age of 48 h. Wavelet semblance (a measure of phase difference) was calculated to compare reactivity between mean arterial blood pressure (MABP) with oxCCO, HbD and HbT. OxCCO-MABP semblance correlated with thalamic Lac/NAA (r ¼ 0.48, p ¼ 0.02). OxCCO-MABP semblance also differed between groups of infants with mild to moderate and severe injury measured using brain MRI score (p ¼ 0.04), thalamic Lac/NAA (p ¼ 0.04) and neurodevelopmental outcome at one year (p ¼ 0.04). Pressure passive changes in cerebral metabolism were associated with injury severity indicated by thalamic Lac/NAA, MRI scores and neurodevelopmental assessment at one year of age.

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Section: Introductionmentioning

confidence: 99%

Pressure passivity of cerebral mitochondrial metabolism is associated with poor outcome following perinatal hypoxic ischemic brain injury

Mitra

Bale

Highton

et al. 2017

J Cereb Blood Flow Metab

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“…The full derivation of the method has been described in detail and validated previously [19]. For each session, the DCM, i.e., diastolic ABP minus CrCP, was calculated as a marker for the risk of developing IVH [13].…”

Section: Methodsmentioning

confidence: 99%

Cerebral Hemodynamics Are Not Affected by the Size of the Patent Ductus Arteriosus

Kim

Kaiser

Rios³

et al. 2020

Neonatology

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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 di-astolic 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.

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“…29 The corresponding frequency spectrum has one peak corresponding to the heart rate of the infant (110/min) and one peak at low frequency (5-7/min), which represents the observed slow periodic flow oscillations seen in the Doppler velocity curves However, there is increasing evidence that arterial blood pressure is an inadequate measure of cerebral perfusion pressure and CBF in neonates. 30 Furthermore, a recent study using continuous NIRS monitoring 31 found that cerebral oxygenation was lower in infants who developed IVH, and loss of cerebrovascular reactivity was present just before or during the hemorrhage. High-grade fluctuations in the perfusion waveform of the internal cerebral vein has also been shown to be associated with a high incidence of IVH.…”

Section: New Features Obtained With Neodopplermentioning

confidence: 99%

NeoDoppler: New ultrasound technology for continuous cerebral circulation monitoring in neonates

et al. 2019

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BACKGROUND: There is a strong need for continuous cerebral circulation monitoring in neonatal care, since suboptimal cerebral blood flow may lead to brain injuries in preterm infants and other critically ill neonates. NeoDoppler is a novel ultrasound system, which can be gently fixed to the anterior fontanel and measure cerebral blood flow velocity continuously in different depths of the brain simultaneously. We aimed to study the feasibility, accuracy, and potential clinical applications of NeoDoppler in preterm infants and sick neonates. METHOD: Twenty-five infants born at different gestational ages with a variety of diagnoses on admission were included. The probe was placed over the anterior fontanel, and blood flow velocity data were continuously recorded. To validate NeoDoppler, we compared the measurements with conventional ultrasound; agreement was assessed using Bland-Altman plots. RESULTS: NeoDoppler can provide accurate and continuous data on cerebral blood flow velocity in several depths simultaneously. Limits of agreement between the measurements obtained with the two methods were acceptable. CONCLUSION: By monitoring the cerebral circulation continuously, increased knowledge of cerebral hemodynamics in preterm infants and sick neonates may be acquired. Improved monitoring of these vulnerable brains during a very sensitive period of brain development may contribute toward preventing brain injuries.

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Elevated Diastolic Closing Margin Is Associated with Intraventricular Hemorrhage in Premature Infants

Cited by 20 publications

References 33 publications

Pressure passivity of cerebral mitochondrial metabolism is associated with poor outcome following perinatal hypoxic ischemic brain injury

Pressure passivity of cerebral mitochondrial metabolism is associated with poor outcome following perinatal hypoxic ischemic brain injury

Cerebral Hemodynamics Are Not Affected by the Size of the Patent Ductus Arteriosus

NeoDoppler: New ultrasound technology for continuous cerebral circulation monitoring in neonates

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