A comparison of ultrafast and conventional spectral Doppler ultrasound to measure cerebral blood flow velocity during inguinal hernia repair in infants.

BACKGROUND: Ultrafast cerebral Doppler ultrasound enables simultaneous quantification and visualization of cerebral blood flow velocity. The aim of this study is to compare the use of conventional and ultrafast spectral Doppler during anesthesia and their potential to show the effect of anesthesiologic procedures on cerebral blood flow velocities, in relation to blood pressure and cerebral oxygenation in infants undergoing inguinal hernia repair. METHODS: A single-center prospective observational cohort study in infants up to six months of age. We evaluated conventional and ultrafast spectral Doppler cerebral ultrasound measurements in terms of number of successful measurements during the induction of anesthesia, after sevoflurane induction, administration of caudal analgesia, a fluid bolus and emergence of anesthesia. Cerebral blood flow velocity was quantified in pial arteries using conventional spectral Doppler and in the cerebral cortex using ultrafast Doppler by peak systolic velocity, end diastolic velocity and resistivity index. RESULTS: Twenty infants were included with useable conventional spectral Doppler images in 72/100 measurements and ultrafast Doppler images in 51/100 measurements. Intraoperatively, the success rates were 53/60 (88.3%) and 41/60 (68.3%), respectively. Cerebral blood flow velocity increased after emergence for both conventional (end diastolic velocity, from 2.01 to 2.75 cm/s, p < 0.001) and ultrafast spectral Doppler (end diastolic velocity, from 0.59 to 0.94 cm/s), whereas cerebral oxygenation showed a reverse pattern with a decrease after the emergence of the infant (85% to 68%, p < 0.001). CONCLUSION: It is possible to quantify cortical blood flow velocity during general anesthesia using conventional and ultrafast spectral Doppler cerebral ultrasound. Cerebral blood flow velocity and blood pressure decreased, while regional cerebral oxygenation increased during general anesthesia. Ultrafast spectral Doppler ultrasound offers novel insights into perfusion within the cerebral cortex, unattainable through conventional spectral ultrasound. Yet, ultrafast Doppler is curtailed by a lower success rate and a more rigorous learning curve compared to conventional method.

Efficacy of Levetiracetam as Add-On Therapy in the Treatment of Seizures in Neonates.

INTRODUCTION: There is no consensus regarding the efficacy of add-on therapy with levetiracetam (LEV) in the treatment of seizures in neonates. The aim of this study was to evaluate the efficacy of add-on therapy with LEV for achieving >80% seizure reduction after phenobarbital (PB) treatment. METHODS: Retrospective cohort study of near term neonates admitted to the neonatal intensive care unit with EEG-confirmed seizures despite treatment with PB as first-line therapy and using LEV as 2nd-, 3rd- or 4th-line treatment. Antiseizure medication was administered according to national guidelines. All neonates were monitored with 2-channel amplitude-integrated electroencephalography. The total seizure burden in minutes, 2 h before and 4 h after administration of LEV, was calculated using raw EEG. Primary outcome was the efficacy of LEV in achieving >80% seizure reduction. The efficacy of additional midazolam (MDZ) and lidocaine (LDC) was also calculated. RESULTS: A total of 47 full-term neonates were included. The mean total loading dose of LEV was 40 mg/kg (36-44 mg/kg). Seizure etiology consisted of hypoxic-ischemic encephalopathy (n = 11), hemorrhagic or ischemic stroke (n = 16), central nervous system infection (n = 8), genetic (n = 8), metabolic disorders (n = 3), and unknown (n = 1). Following LEV administration, >80% seizure reduction was observed in 17% (8/47) of neonates, whereas it was 23% (6/26) after MDZ and 92% (23/25) after LDC administration. DISCUSSION: Although the cumulative loading dose of LEV was low and the group of infants studied was heterogeneous, the efficacy of LEV as add-on therapy for the treatment of seizures in neonates was limited. The highest seizure reduction rate was seen after LDC administration.

The Current Knowledge of Cerebral Magnetic Resonance Imaging in Monochorionic Twins: A Systematic Review of the Last 20 Years.

The distinct placental angioarchitecture in monochorionic (MC) pregnancies increases the risk of complications such as twin-twin transfusion syndrome (TTTS), twin anemia polycythemia sequence (TAPS), and selective fetal growth restriction (sFGR). The aim of this systematic review was to evaluate the incidence, type, and severity of cerebral injury and structural brain development on fetal and/or neonatal cerebral magnetic resonance imaging (MRI) in MC twins with or without complications. Twenty-three studies were included, covering a wide range of complications observed during MC pregnancies, with studies involving sIUFD (n = 12), TTTS (n = 7), mixed complications (n = 2), TAPS (n = 1), and uncomplicated MC pregnancy (n = 1). TAPS and sFGR were largely underrepresented in the current literature. The included studies reported that MC pregnancies with single intrauterine fetal demise (sIUFD) are most at risk for cerebral injury during the fetal period. The overall median incidence of cerebral injury after sIUFD was 28.3% (0-55%). Severe antenatal cerebral injury after sIUFD was detected antenatally in 6.5% (0-36%) of the cases. Three of the included studies described the incidence, type, and severity of cerebral injury on neonatal MRI in MC twins. Structural brain development based on cerebral biometry was only assessed in two studies, revealing significantly smaller biometric measurements of the cerebrum in cases of single sIUFD or smaller twins compared to singleton pregnancies. To enhance our understanding of the potential risks and pathophysiological mechanisms associated with cerebral injury and structural brain development in MC twins, there is a need for future studies and standardized protocols using serial fetal and neonatal MRI imaging in addition to routine ultrasound imaging.