Cerebral autoregulation in premature infants during the first 96 hours of life and relationship to adverse outcomes

Abstract

ObjectiveTo test the hypothesis that impaired cerebral autoregulation (ICA) increases the susceptibility of premature infants to adverse outcomes, we determined the relationship of ICA and cerebral reactivity (CR) measured in the first 96 hours of life to the outcome of grade 3 or 4 intraventricular haemorrhage (IVH) and/or death within 1 month.SettingSingle-centre level IV neonatal intensive care unit.PatientsNeonates 24–29 weeks’ gestation less than 12 hours old with invasive blood pressure monitoring.DesignCerebral saturations and mean arterial blood pressure were recorded every 30 s for 96 hours. For each 10 min epoch, the correlation coefficient (r) was calculated for mean arterial blood pressure versus cerebral saturations. The epoch was considered to have ICA if r>0.5 and CR if r<0.ResultsSixty-one subjects were included. During the first 96 hours, ICA occurred 17.6% and CR occurred 41% of recorded time. In those without adverse outcomes, ICA decreased and CR increased by postnatal day (p<0.05). Adjusted for birth weight and gestational age, those with IVH and those who died spent more time with ICA and less time with CR (p<0.05) over the entire recording period. Those with IVH had 1.5-fold increase in time with ICA on day 2 (p=0.021), and decrease in time with CR on day 3 (p=0.036). Compared with survivors, non-survivors spent more time with ICA on days 3 and 4 (p<0.005), and less with CR on day 3 (p=0.032).ConclusionICA and CR vary by postnatal day and these patterns are associated with adverse outcomes.

The association between carbon dioxide, cerebral blood flow, and autoregulation in the premature infant

“…This is a secondary exploratory analysis of a prospectively enrolled cohort study of subjects 24 0 -29 6 weeks gestation admitted to the University of Maryland Medical Center level IV neonatal intensive care unit (NICU) between June 2013 and September 2016 who had continuous intra-arterial blood pressure monitoring within the first 12 h of life [4]. Exclusion criteria including major congenital anomalies, or less than 12 h of monitoring.…”

“…The data were retrospectively reviewed and artifacts in MAP and rScO 2 such as those due to blood sampling and movement were removed manually prior to analysis. Time periods with significant hypoxemia, SpO 2 < 80%, were removed from analysis according with previous methodology [4,6].…”

“…Cerebral autoregulation (CA), the protective mechanism that maintains stable cerebral blood flow despite fluctuating cerebral perfusion pressures, is often impaired in preterm infants [4,5] in association with both brain injury and death [4,6,7]. Though there is no direct means to assess cerebral blood flow in preterm infants, near infrared spectroscopy (NIRS) has been used as a surrogate marker assuming stable oxygenation and metabolic demand [8].…”

Cerebral venous volume changes and pressure autoregulation in critically ill infants: an editorial comment

“…Several studies performed in extremely and very preterm infants, partly already referenced by the authors, confirm that hyperperfusion with or without substantial blood pressure swings was "related" with an increased incidence of PIVH in patients with blood pressure passivity [3][4][5]. Also treatment with positive inotropics for supposed hypotension of prematurity may affect autoregulatory ability of the cerebral vascular bed and hence increase PIVH incidence [6].…”

Usefulness of a finger-mounted tissue oximeter with near-infrared spectroscopy for evaluating the intestinal oxygenation and viability in rats

“…The thickness of the small intestinal wall is less than 3 or 4 mm, therefore the depth of measurement with previous NIRS devices was considered to be too deep [26,27]. Recently, the cerebral blood flow of infants or the placental oxygen saturation of fetuses were analyzed using advanced technology of NIRS [28][29][30]. More recently, a finger-mounted tissue oximeter was developed to measure oxygen saturation of the fetal head, transvaginally [6].…”