Autoregulation preterm

BACKGROUND: Pulse oximetry is commonly used to monitor arterial oxygen saturation and heart rate during the transition period and reference intervals have been determined. However, the effect of the change in arterial oxygen saturation on tissue oxygenation does not seem to be the same. So, a non-invasive method for monitoring cerebral or regional tissue oxygenation will be potentially useful for vulnerable infants. This study aims to evaluate the effectiveness of cerebral autoregulation in the first 10 min after delivery in term and late preterm newborns without resuscitation requirement...

BACKGROUND: Intraventricular haemorrhage (IVH) often arises as a cerebral complication directly related to preterm birth. The impaired autoregulation of cerebral blood flow is closely associated with IVH in preterm neonates. Three-dimensional pseudo-continuous arterial spin labelling (3D-pCASL) is a noninvasive magnetic resonance imaging (MRI) technique used for evaluating cerebral perfusion. OBJECTIVE: This study aimed to compare cerebral blood flow values among three distinct groups using 3D-pCASL: preterm neonates with and without IVH and preterm neonates at term-equivalent age...

UNLABELLED: Point-of-care brain ultrasound and transcranial doppler or color-coded doppler is being increasingly used as an essential diagnostic and monitoring tool at the bedside of critically ill neonates and children. Brain ultrasound has already established as a cornerstone of daily practice in the management of the critically ill newborn for diagnosis and follow-up of the most common brain diseases, considering the easiness to insonate the brain through transfontanellar window. In critically ill children, doppler based techniques are used to assess cerebral hemodynamics in acute brain injury and recommended for screening patients suffering from sickle cell disease at risk for stroke...

Necrotizing enterocolitis (NEC) and periventricular leukomalacia (PVL) are relatively common conditions in premature infants with low birth weight (VLBW). However, in the current literature, there are limited case reports of patients with concomitant NEC and PVL. We report a case of a premature female born at a gestational age of 25 weeks and five days who developed cystic intracranial lesions after emergent bowel resection due to NEC. Transcranial ultrasound and magnetic resonance imaging confirmed the presence of cystic PVL in the right middle cerebral artery distribution...

OBJECTIVE: To describe the relationship between cerebral oxygenation, cardiac output, arterial blood pressure (BP), and cerebral blood flow velocity in extremely low gestational age neonates (ELGANs) during transition. METHODS: This study comprises secondary analyses from a prospective observational study conducted at a tertiary Neonatal Intensive Care Unit. Recruited ELGANs underwent cerebral saturation (CrSO2 ) monitoring and serial echocardiography during 72 h from birth...

OBJECTIVE: The aim of this qualitative systematic review was to identify publications on blood pressure monitoring in combination with cerebral tissue oxygenation monitoring during the first week after birth focusing on cerebral autoregulation. METHODS: A systematic search was performed on PubMed. The following search terms were used: infants/newborn/neonates, blood pressure/systolic/diastolic/mean/MAP/SAP/DAP, near-infrared spectroscopy, oxygenation/saturation/oxygen, and brain/cerebral...

OBJECTIVES: To compare LISA with INSURE technique for surfactant administration in preterm with gestational age (GA) < 36 weeks with RDS in respect to the incidence of pneumothorax, bronchopulmonary dysplasia (BPD), need for mechanical ventilation (MV), regional cerebral oxygen saturation (rSO2), peri‑intraventricular hemorrhage (PIVH) and mortality. METHODS: A systematic search in PubMed, Embase, Lilacs, CINAHL, SciELO databases, Brazilian Registry of Randomized Clinical Trials (ReBEC), Clinicaltrials...

The ability of an organism to maintain a constant blood flow to the brain in response to sudden surges in systemic blood pressure (BP) is known as cerebral autoregulation (CAR), which occurs in the carotid artery. In contrast to full-term neonates, preterm neonates are unable to reduce the cerebral blood flow (CBF) in response to increased systemic BP. In preterm neonates, this exposes the fragile cerebral vessels to high perfusion pressures, leading to their rupture and brain damage. Ex vivo studies using wire myography have demonstrated that carotid arteries from near-term fetuses constrict in response to the activation of adrenergic alpha1 receptors...

OBJECTIVE: To assess whether blood pressure (systolic (SABP), diastolic (DABP), and mean arterial blood pressure (MABP) and cerebral-regional-oxygen-saturation (crSO2) and cerebral-fractional-tissue-oxygen-extraction (cFTOE) are associated after immediate fetal-to-neonatal transition in preterm neonates with and without respiratory support. STUDY DESIGN: Post-hoc analyses of secondary outcome parameters of prospective observational studies were performed. We included moderate and late preterm neonates with and without respiratory support with cerebral NIRS monitoring (INVOS 5100c) and an oscillometric blood pressure measurement at minute 15 after birth...

Preterm birth is the leading cause of death in children under 5 years of age. Premature infants who receive life-saving oxygen therapy often develop bronchopulmonary dysplasia (BPD), a chronic lung disease. Infants with BPD are at a high risk of abnormal neurodevelopment, including motor and cognitive difficulties. While neural progenitor cells (NPCs) are crucial for proper brain development, it is unclear whether they play a role in BPD-associated neurodevelopmental deficits. Here, we showed that hyperoxia-induced experimental BPD in newborn mice led to life-long impairments in cerebrovascular structure and function, as well as impairments in NPC self-renewal and neurogenesis...

According to the World Health Organization (WHO), 15 million babies are born preterm each year. Preterm infants are those born at less than 37 weeks, while extremely and very preterm neonates include those born at 22 to less than 32 weeks gestational age. Infants that fail to make it to term are missing a key part in neurodevelopment, as weeks 24 to 40 are a critical period of brain development. Neonatal brain injury is a crucial predictor for mortality and morbidity in premature and low birth weight (<1500 g) infants...

Perinatal hypoxia-ischemia (HI) is still a significant contributor to mortality and adverse neurodevelopmental outcomes in term and preterm infants. HI brain injury evolves over hours to days, and involves complex interactions between the endogenous protective and pathological processes. Understanding the timing of evolution of injury is vital to guide treatment. Post-HI recovery is associated with a typical neurophysiological profile, with stereotypic changes in cerebral perfusion and oxygenation. After the initial recovery, there is a delayed, prolonged reduction in cerebral perfusion related to metabolic suppression, followed by secondary deterioration with hyperperfusion and increased cerebral oxygenation, associated with altered neurovascular coupling and impaired cerebral autoregulation...

INTRODUCTION: Concentration of fetal hemoglobin (HbFc) in human neonates determines oxygen-carrying capacity of blood and the position of oxyhemoglobin dissociation curve. Near-infrared spectroscopy enables the measurement of regional cerebral tissue oxygen saturation (rScO2) and in combination with measurements of pulsatile arterial oxygen saturation (SpO2), the calculation of cerebral fractional tissue oxygen extraction (cFTOE). METHODS: We aimed to investigate the impact of HbFc on rScO2, cFTOE, and SpO2 in preterm and term neonates during the first 15 min after birth...

BACKGROUND: Obstructive sleep apnea is associated with adverse pregnancy outcomes. The impact therapy for obstructive sleep apnea has on these pregnancy outcomes remains under investigated. OBJECTIVE: This study aimed to determine the effects of targeted autoregulated positive airway pressure in women at risk of obstructive sleep apnea on adverse pregnancy outcomes, cost, and natural history of obstructive sleep apnea. STUDY DESIGN: Pregnant women at high risk of obstructive sleep apnea were randomized to either a sleep study screening group receiving autoregulated positive airway therapy or a group not screened for obstructive sleep apnea receiving standard obstetrical care (control)...

Free radicals play a role of paramount importance in the development of neonatal brain injury. Depending on the pathophysiological mechanisms underlying free radical overproduction and upon specific neonatal characteristics, such as the GA-dependent maturation of antioxidant defenses and of cerebrovascular autoregulation, different profiles of injury have been identified. The growing evidence on the detrimental effects of free radicals on the brain tissue has led to discover not only potential biomarkers for oxidative damage, but also possible neuroprotective therapeutic approaches targeting oxidative stress...

BACKGROUND: Titration of inspired oxygen is a challenge in preterm infants with hypoxemic respiratory failure (HRF). Monitoring of brain oxygen by near-infrared spectroscopy (NIRS) has been proven to minimize the burden of hyperoxia and hypoxemia; with a better understanding of cerebral autoregulation, integrating NIRS and pulse oximetry for titrating inspired oxygen in preterm infants is a novel approach. METHODS: We studied the impact of integrated monitoring of oxygen saturation by pulse oximetry (SpO2 ) and cerebral regional tissue oxygen (crRTO) by NIRS during a stepwise oxygen reduction test (ORT) on reducing oxygen requirement in preterm infants with HRF...

Abnormal patterns of cerebral perfusion/oxygenation are associated with neuronal damage. In preterm neonates, hypoxemia, hypo-/hypercapnia and lack of cerebral autoregulation are related to peri-intraventricular hemorrhages and white matter injury. Reperfusion damage after perinatal hypoxic ischemia in term neonates seems related with cerebral hyperoxygenation. Since biological tissue is transparent for near infrared (NIR) light, NIR-spectroscopy (NIRS) is a noninvasive bedside tool to monitor brain oxygenation and perfusion...

BACKGROUND: The impact of the permissive hypotension approach in clinically well infants on regional cerebral oxygen saturation (rScO2 ) and autoregulatory capacity (CAR) remains unknown. METHODS: Prospective cohort study of blinded rScO2 measurements within a randomized controlled trial of management of hypotension (HIP trial) in extremely preterm infants. rScO2 , mean arterial blood pressure, duration of cerebral hypoxia, and transfer function (TF) gain inversely proportional to CAR, were compared between hypotensive infants randomized to receive dopamine or placebo and between hypotensive and non-hypotensive infants, and related to early intraventricular hemorrhage or death...

The American Academy of Pediatrics and until recently the Canadian Paediatric Society recommend preterm infants undergo an Infant Car Seat Challenge test prior to discharge to rule out systemic oxygen desaturation when placed at a 45-degree angle in a car seat. Near-infrared spectroscopy (NIRS) provides objective measurements of the impact of systemic oxygen (SO2 ) desaturation, bradycardia, or both on cerebral regional oxygen saturation (rSO2 ). OBJECTIVE: To characterize baseline cerebral rSO2 during a car seat trial in preterm infants ready for discharge...

BACKGROUND: As neonates transition from a relatively hypoxic environment to extra-uterine life, arterial oxygen saturation dramatically increases. This transition occurs while most organs have not fully matured. The ability for immature tissue to adequately extract and utilize oxygen remains largely unknown. With the development of near-infrared spectroscopy (NIRS), measuring specific tissue oxygen saturation (StO2) noninvasively, clinicians can measure StO2 and determine if adequate tissue oxygenation is maintained...