Intracranial neonatal neurosonography: an update

Association between patent ductus arteriosus flow and home oxygen therapy in extremely preterm infants

BACKGROUND

Central blood flow measurements include the estimation of right and left ventricular output (RVO, LVO), superior vena cava (SVC) flow, and calculated patent ductus arteriosus (PDA) flow. We aimed to provide an overview of the maturation patterns of these values and the relationship between PDA flow and the need for home oxygen therapy.

METHODS

This prospective single-center study was conducted in infants born at <26 weeks of gestation. We performed echocardiographic measurements five times during their life (from the 4th post-natal day to the 36th postmenstrual week).

RESULTS

Sixty patients with a mean birth weight of 680 (590, 760) g were included. Postnatal development of LVO and PDA flow peaked at the end of the second postnatal week (427 and 66 mL/kg/min, respectively). The RVO increased between days 4 and 7-8. The SVCF was most stable. The development curves of PDA flow differed between the groups with (n = 28; 47%) and without home oxygen therapy.

CONCLUSION

We present the central blood flow values and their postnatal development in infants <26 weeks of gestation. This study demonstrates the association between PDA flow and the future need for home oxygen therapy.

IMPACT

This study enriches our knowledge of the long-term development of central blood flow parameters and derived patent ductus arteriosus (PDA) flow in extremely preterm infants (<26 weeks). While pulmonary resistance decreased, PDA flow continued to increase from day 4 to the end of the second week of life. Similarly, left ventricular output increased as a marker of preload. The superior vena cava flow remained stable. The observed association between PDA flow and an unfavorable respiratory outcome is important for future studies focusing on the prevention of chronic lung disease.

Red blood cell transfusions and potentially related morbidities in neonates under 32 weeks' gestation

BACKGROUND

Preterm neonates are likely to require red blood cell (RBC) transfusion, and extremely low birth weight infants almost invariably receive multiple transfusions. Transfusion-reduction strategies can reduce transfusion rates, and might diminish certain adverse outcomes associated with transfusions.

MATERIALS AND METHODS

In a single centre, we retrospectively evaluated RBC transfusion rates among preterm infants ≤32 weeks' gestational age (GA), over a 6-year period before and after adopting national transfusion-reduction strategies. We compared demographic data, adverse events, and outcomes between transfused vs not-transfused neonates. Univariate logistic regression was used to evaluate associations between dichotomous outcomes and number of transfusions, and day of first transfusion. Multivariate logistic regression evaluated the correlation between dichotomous outcomes and transfusion as an independent risk factor.

RESULTS

During the 6 years studied, 181 infants born at ≤32 weeks' GA were admitted to our Neonatal Intensive Care Unit of whom 80 (44%) received at least one RBC transfusion. The transfusion rate tended downwards after adopting transfusion-reduction strategies, reaching 31% in 2018. The reduction was largely due to a marked fall in transfusions of neonates born at 29-32 weeks' GA (p<0.001). The number of transfusions received correlated with odds of having intraventricular haemorrhage (IVH) (OR=1.9; 95% CI: 1.3-2.7; p=0.0001) and the duration of oxygen supplementation (rho=0.51; 95% CI: 0.33-0.66; p≤0.0001). In multivariate logistic regression analysis, transfusion was an independent risk factor for IVH (adjusted OR=7.38; 95% CI: 2.24-24.30; p=0.0001).

DISCUSSION

The application of national, standardised transfusion-reduction strategies was associated with a lower transfusion rate in neonates born at 29-32 weeks' GA, but was less effective among neonates ≤28 weeks, in whom transfusions appeared to be an independent risk factor for severe IVH.

Imaging diagnosis of ventriculomegaly: fetal, neonatal, and pediatric

Ventriculomegaly is the term used to describe abnormal enlargement of ventricles in the brain. Neuroimaging, whether it is by ultrasound, computed tomography, or magnetic resonance imaging, is the key to its identification and can help to diagnose its cause and guide management in many cases. The implementation of the imaging modalities and potential differential considerations varies from the fetus, infant, and pediatric patient. Here we discuss how the imaging modalities can be used in these patient populations and review some of the differential considerations.

Pediatric encephalic ultrasonography: the essentials

Nowadays, cranial ultrasonography (US) of the newborn represents the first imaging method in brain damage study and its possible outcomes. This exam is performed using the natural fontanelles, especially the anterior one. It is fast, non-invasive and does not produce any side effect. Ultrasonographic examination is usually performed in cases of prematurity, especially in children with birth weight less than 1500 g, because important informations about the possible presence of pathologies such as cerebral hemorrhage and hypoxic-ischemic encephalopathy are given. This approach can be useful also in the study of pre- and post-natal infections, for example, type II Herpes Simplex virus or Cytomegalovirus infections, or pointing out vascular malformations such as vein of Galen aneurysm. Although less important than methods such as computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of trauma and tumors, ultrasound can provide useful informations or be used in first instance in the suspicion of a brain mass.

Neonatal Head Ultrasound: A Review and Update-Part 1: Techniques and Evaluation of the Premature Neonate

Ultrasound of the infant brain has proven to be an important diagnostic tool in the evaluation of neonatal brain morphology and pathology since its introduction in the late 1970s and early 1980s. It is a relatively inexpensive examination that can be performed in the isolette in the neonatal intensive care unit. There is no radiation exposure and no need for sedation. This article will discuss gray scale and Doppler techniques and findings in normal head ultrasounds of premature neonates. It will discuss intracranial pathologies noted in such neonates and their neurodevelopmental outcome.

Neonatal Head Ultrasound: A Review and Update-Part 2: The Term Neonate and Analysis of Brain Anomalies

Neonatal head ultrasound has a key role in triaging neonates with antenatal imaging or postnatal clinical concerns. This article will discuss key features of various intracranial pathologies of concern in term infants. It will also illustrate various congenital malformations.

Effect of red blood cell transfusion on short-term outcomes in very low birth weight infants

BACKGROUND

Red blood cell (RBC) transfusion improves cardiorespiratory status of preterm infants by increasing circulating hemoglobin, improving tissue oxygenation, and reducing cardiac output. However, RBC transfusion itself has also been suggested to negatively affect short-term outcomes such as intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC) in premature infants.

PURPOSE

This study aimed to analyze the relationship between RBC transfusion and short-term outcomes in very low birth weight (VLBW) infants (birth weight, <1,500 g).

METHODS

We retrospectively reviewed the medical records of VLBW infants admitted to the Soonchunhyang University Bucheon Hospital between October 2010 and December 2017. Infants who died during hospitalization were excluded. The infants were divided into 2 groups according to RBC transfusion status. We investigated the relationship between RBC transfusion and short-term outcomes including BPD, ROP, NEC, and IVH.

RESULTS

Of the 250 enrolled VLBW infants, 109 (43.6%) underwent transfusion. Univariate analysis revealed that all shortterm outcomes except early-onset sepsis and patent ductus arteriosus were associated with RBC transfusion. In multivariate analysis adjusted for gestational age, birth weight and Apgar score at 1 minute, RBC transfusion was significantly correlated with BPD (odds ratio [OR], 5.42; P<0.001) and NEC (OR, 3.40; P= 0.009).

CONCLUSION

RBC transfusion is significantly associated with adverse clinical outcomes such as NEC and BPD in VLBW infants. Careful consideration of the patient's clinical condition and appropriate guidelines is required before administration of RBC transfusions.

Management of Multi Organ Dysfunction in Neonatal Encephalopathy

Neonatal Encephalopathy (NE) describes neonates with disturbed neurological function in the first post-natal days of life. NE is an overall term that does not specify the etiology of the encephalopathy although it often involves hypoxia-ischaemia. In NE, although neurological dysfunction is part of the injury and is most predictive of long-term outcome, these infants may also have multiorgan injury and compromise, which further contribute to neurological impairment and long-term morbidities. Therapeutic hypothermia (TH) is the standard of care for moderate to severe NE. Infants with NE may have co-existing immune, respiratory, endocrine, renal, hepatic, and cardiac dysfunction that require individualized management and can be impacted by TH. Non-neurological organ dysfunction not only has a negative effect on long term outcome but may also influence the efficacy of treatments in the acute phase. Post resuscitative care involves stabilization and decisions regarding TH and management of multi-organ dysfunction. This management includes detailed neurological assessment, cardio-respiratory stabilization, glycaemic and fluid control, sepsis evaluation and antibiotics, seizure identification, and monitoring and responding to biochemical and coagulation derangements. The emergence of new biomarkers of specific organ injury may have predictive value and improve the definition of organ injury and prognosis. Further evidence-based research is needed to optimize management of NE, prevent further organ dysfunction and reduce neurodevelopmental impairment.

Neurosonography: Assessing the Premature Infant

Neurosonography has proven to be helpful in neonatal brain diagnosis. Premature infants are at great risk for intraventricular hemorrhage and periventricular leukomalacia, key abnormalities affecting developmental outcome. Here we discuss technique, anatomy, variants and key points for diagnosis.

Neonatal Hypoxic-ischemic Encephalopathy: A Radiological Review

Neonatal hypoxic-ischemic encephalopathy (HIE) is a devastating condition that may result in death or severe neurologic deficits in children. Neuroimaging with cranial ultrasound (US), computed tomography and magnetic resonance imaging are valuable tools in the workup of patients with HIE. The pattern of brain injury depends on the severity and duration of hypoxia and degree of brain maturation. Mild to moderate HI injury results in periventricular leukomalacia and germinal matrix bleed in preterm neonates, and parasagittal watershed infarcts in full-term neonates. Severe HI injury involves deep gray matter in both term and preterm infants. Treatment of HIE is largely supportive. The current article reviews the etiopathophysiology and clinical manifestations of HIE, role of imaging in the evaluation of the condition, patterns of brain injury in term and preterm neonates, the treatment and the prognosis.

Instituting a program to reduce the erythrocyte transfusion rate was accompanied by reductions in the incidence of bronchopulmonary dysplasia, retinopathy of prematurity and necrotizing enterocolitis

Bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC) all likely involve oxidative damage to immature tissues. It has been postulated that transfusions of adult erythrocytes contribute to the risk of developing these morbidities, as a consequence of adult hemoglobin releasing non-physiological quantities of O₂ to developing tissues. In 2009, we instituted a concerted effort to diminish erythrocyte transfusions in our NICU, and in 2013 we performed a before vs. after practice change analysis of the incidence of BPD, ROP and NEC during the 8-year period spanning this change. The transfusion rate fell from a high of 14.8% of admissions in 2007 to a low of 6.3% in 2011 (p < 0.001). Concordant with this reduction patients had a lower incidence of; BPD (from 3.2% to 0.9%; OR, 3.722; CI 1.897-7.302), ROP (from 4.6% to 2.4%; OR 1.958, CI 1.247-3.073), and a trend toward less NEC (from 0.7% to 0.2%; OR 3.090, CI 0.835-11.443).

Sonography of the Neonatal Brain

Neurosonography is a critical part of the care of the sick newborn. Sonography is superior to other modalities in imaging of the brain because it can be performed at the bedside, is easily reproducible, and does not require ionizing radiation or sedation. This article refreshes the sonographer in the normal anatomy and appearance of the neonatal brain using sonography, as well as some of the more common pathologic conditions that may be encountered.

Neonatal hypoxic-ischemic encephalopathy: multimodality imaging findings

Diffuse hypoxic-ischemic brain injury in the neonate results in neonatal hypoxic-ischemic encephalopathy (HIE). Because of differences in brain maturity at time of insult, severity of hypotension, and duration of insult, there are four distinct patterns of brain injury. Cranial ultra-sonography and computed tomography reveal periventricular leukomalacia, germinal matrix hemorrhage, and hydrocephalus. Magnetic resonance imaging is the most sensitive modality for evaluating the patterns of brain injury. In preterm neonates, mild hypotension causes periventricular injury; severe hypotension results in infarction of the deep gray matter, brainstem, and cerebellum. In term neonates, mild hypotension causes parasagittal cortical and subcortical injury; severe hypotension causes characteristic injury of the lateral thalami, posterior putamina, hippocampi, corticospinal tracts, and sensorimotor cortex. Prompt recognition of these imaging findings can help exclude other causes of encephalopathy, affect prognosis, and facilitate earlier (although mostly supportive) treatment.

Magnetic resonance and ultrasound brain imaging in preterm infants

Cranial ultrasonography has been used to identify brain injury in preterm neonates for more than two decades. More recently, magnetic resonance imaging has been used to evaluate brain development and pathology in these infants. In this review we describe how well findings from these two imaging modalities agree with histology findings and neuro-developmental outcome. In addition, we discuss studies comparing ultrasound and magnetic resonance imaging findings.