Treating hypotension in the preterm infant: when and with what: a critical and systematic review

Dempsey, Eugene M.; Barrington, Keith J.

doi:10.1038/sj.jp.7211774

Cited by 137 publications

(102 citation statements)

References 74 publications

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“…Accordingly, hypotension is not a perfect representation of poor tissue perfusion. Moreover, there is considerable debate about the most appropriate definition of hypotension and likewise, about its management (41,42). Our data further support the use of individualized thresholds for hypotension (41), given the important BP changes observed over time and effects of perinatal variables such as gestational age and birth weight.…”

Section: Discussionsupporting

confidence: 51%

“…Moreover, there is considerable debate about the most appropriate definition of hypotension and likewise, about its management (41,42). Our data further support the use of individualized thresholds for hypotension (41), given the important BP changes observed over time and effects of perinatal variables such as gestational age and birth weight. Additional studies using other markers of tissue perfusion are needed to further evaluate the relationships among perinatal factors, circulatory regulation, and neonatal outcome.…”

Section: Discussionsupporting

confidence: 51%

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Early Postnatal Blood Pressure in Preterm Infants: Effects of Chorioamnionitis and Timing of Antenatal Steroids

et al. 2009

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Previous studies suggest postnatal blood pressure in preterm infants to be decreased by chorioamnionitis and increased by antenatal steroids (AS). We examined the adjusted effects of both antenatal modulators on postnatal blood pressure (BP), with separate effects reported for histologic chorioamnionitis with or without fetal involvement and timing of AS. General characteristics, BP, and heart rate values during the first 72 h after birth were obtained from 271 infants with gestational age Յ32.0 wk. In unadjusted analyses, chorioamnionitis was associated with lower BP, most prominently so in infants with fetal involvement, without an effect on hypotension incidence. AS increased BP and decreased the incidence of hypotension when administered within 7 d before birth. In a multivariable mixed model analysis, the AS effect remained significant, whereas chorioamnionitis was not independently predictive of postnatal BP. Other variables associated with increased postnatal BP were gestational age and umbilical artery pH, whereas hemolysis, elevated liver enzymes, low platelets syndrome was associated with decreased BP.

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Section: Discussionsupporting

confidence: 51%

Section: Discussionsupporting

confidence: 51%

Early Postnatal Blood Pressure in Preterm Infants: Effects of Chorioamnionitis and Timing of Antenatal Steroids

et al. 2009

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“…Chronic lung disease was diagnosed if the infant required oxygen after 36 weeks PMA. In the absence of a universally accepted definition, hypotension was diagnosed if newborns were treated with saline boluses or vasopressors for low blood pressure (7). Postnatal infection was defined according to Stoll's criteria, but given the sample size, a summary variable of "any clinical infection", including clinical and culture-positive infections, was analyzed (8).…”

Section: Methodsmentioning

confidence: 99%

Tractography-Based Quantitation of Corticospinal Tract Development in Premature Newborns

Adams

Chau

Poskitt

et al. 2010

The Journal of Pediatrics

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Objective-To evaluate the impact of early brain injury and neonatal illness on corticospinal tract (CST) development in premature newborns serially studied with diffusion tensor tractography (DTT).Study design-Fifty-five premature newborns (median 27.6 weeks PMA) were scanned with MRI early in life and at term-equivalent age. Moderate-severe brain abnormalities (abnormal-MRI) were characterized by moderate-severe white matter injury or ventriculomegaly. DTT was used to measure CST diffusion parameters which reflect microstructural development: fractional anisotropy (FA) and average diffusivity (D av ). The effect of abnormal-MRI and neonatal illness on FA and D av were assessed using multivariate regression for repeated measures adjusting for age at scan.Results-Twenty-one newborns (38%) had abnormal-MRI on either scan. FA increased with age significantly slower in newborns with abnormal-MRI (0.008/week) relative to newborns without these MRI abnormalities (0.011/week) (interaction term P=0.05). D av was higher in newborns with abnormal-MRI (1.5×10 −5 mm 2 /sec; P<0.001) for any given age at scan. In the 23 newborns (42%) with postnatal infection, FA increased more slowly (interaction term P=0.04), even when adjusting for the presence of abnormal-MRI.Conclusions-CST microstructural development is significantly impaired in premature newborns with abnormal-MRI or postnatal infection, with a pattern of diffusion changes suggesting impaired glial cell development.Corresponding Author: Steven P. Miller, MAS MDCM FRCPC, British Columbia Children's Hospital, Department of Pediatrics/ Division of Neurology -University of British Columbia, K3-180, 4480 Oak Street, Vancouver, British Columbia, V6H 3V4, CANADA, Telephone: 604-875-2345 ext. 5904/ Facsimile: 604-875-2285.bc.ca. The authors declare no conflicts of interest.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Diffusion tensor imaging (DTI) enables in vivo quantification of microstructural development of these white matter pathways by measuring the overall extent (average diffusivity; D av ) and directionality (fractional anisotropy; FA) of water diffusion (2, 3). Previous DTI studies suggest that early brain injury impairs white matter development, even in brain regions that are normal on conventional MRI (4). However, the region of interest (ROI)-based approach used in these studies may not be optimally sensitive to changes in an individual white matter functional pathway. Diffusion tensor tractography (DTT) is a more sophisticated DTI technique for the 3D reconstruction of specific white matter tracts (5), such as the cor...

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“…Pryds et al (3) described a loss of autoregulation in very sick preterm infants, which resulted in the hypothesis that there was a loss of autoregulation in preterm infants and that controlling blood pressure would prevent cerebral damage. However, there is no good evidence that a correlation (COR) between blood pressure and cerebral damage exists, indicating that autoregulation is more complex in premature infants than originally thought (4). Even with very low blood pressures, normal cerebral blood flow (CBF) was described in very LBW infants (5).…”

mentioning

confidence: 99%

Cerebral Tissue Oxygenation and Regional Oxygen Saturation Can Be Used to Study Cerebral Autoregulation in Prematurely Born Infants

et al. 2011

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ABSTRACT:The coupling of cerebral intravascular oxygenation (dHbD) with mean arterial blood pressure (MABP) was taken as a reflection of autoregulation assuming constant arterial oxygen content. However, this method is sensitive to movement artifacts. We examined whether the cerebral tissue oxygenation index (cTOI) and regional oxygen saturation (rScO 2 ) may replace dHbD and changes in total Hb (dHbT), respectively. Correlation (COR) and coherence (COH) were used to measure the agreement of MABP with rScO 2 /dHbT and cTOI/dHbD. dHbD/cTOI and dHbT/rScO 2 recordings of, respectively, 34 and 20 preterm infants in need for intensive care were studied during the first days of life. dHbD and cTOI were obtained with the NIRO300 and rScO 2 and dHbT with the INVOS4100. Invasive MABP was measured continuously. COR and COH scores of MABP versus dHbD/ dHbT were compared with the corresponding ones by replacing dHbD/ dHbT by cTOI/rScO 2 , respectively. Generally, no significant score differences were found for dHbD/cTOI. Differences for dHbT/rScO 2 were slightly larger but still within the normal variation of the parameters. Differences become insignificant when restricting calculations to epochs of larger variation in MABP (Ͼ10 mm Hg). Hence, we suggest that cTOI and rScO 2 can be used to study cerebral autoregulation in newborns. (Pediatr Res 69: 548-553, 2011) L assen (1) was the first to describe cerebral autoregulation in man. Cerebral autoregulation is a property of arteries in the brain to constrict in response to an increase in transmural blood pressure and to dilate in response to a decrease in blood pressure, with the effect of keeping blood flow more or less constant within a range of arterial blood pressures. This response has a limited capacity and as a result blood flow will decrease or increase when blood pressure decreases below a lower threshold or increases above an upper threshold, respectively (2). Pryds et al. (3) described a loss of autoregulation in very sick preterm infants, which resulted in the hypothesis that there was a loss of autoregulation in preterm infants and that controlling blood pressure would prevent cerebral damage. However, there is no good evidence that a correlation (COR) between blood pressure and cerebral damage exists, indicating that autoregulation is more complex in premature infants than originally thought (4). Even with very low blood pressures, normal cerebral blood flow (CBF) was described in very LBW infants (5). Both dynamic and static autoregulation are described. Dynamic autoregulation describes the response of autoregulation within 5 to 10 s after a change in blood pressure and can be assessed noninvasively with Doppler ultrasound (6 -8) and near-infrared spectroscopy (NIRS) (9). Tsuji et al. (10) were the first to report on the use of NIRS to assess autoregulation. In a previous study (11), the authors validated changes in the cerebral intravascular oxygenation (dHbD) as a measure of CBF in an experimental model. dHbD, representing the difference between changes in o...

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Treating hypotension in the preterm infant: when and with what: a critical and systematic review

Cited by 137 publications

References 74 publications

Early Postnatal Blood Pressure in Preterm Infants: Effects of Chorioamnionitis and Timing of Antenatal Steroids

Early Postnatal Blood Pressure in Preterm Infants: Effects of Chorioamnionitis and Timing of Antenatal Steroids

Tractography-Based Quantitation of Corticospinal Tract Development in Premature Newborns

Cerebral Tissue Oxygenation and Regional Oxygen Saturation Can Be Used to Study Cerebral Autoregulation in Prematurely Born Infants

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