[Basics and novelties of neonatal resuscitation]. / Újszülöttek újraélesztésének alapjai és újdonságai.

This recommendation summarizes the recent neonatal resuscitation guidelines of the European Resuscitation Council (ERC), but it takes into account the guidelines of the American Heart Association (AHA) and the statements of the International Liaison Committee on Resuscitation (ILCOR) Consensus on Science with Treatment Recommendations (CoSTR) for neonatal life support. The goal of the management of the newly born infants is to support the cardiorespiratory transition. Personnel and equipment should be prepared for neonatal life support before every delivery. After birth, the heat loss of the newborn must be prevented and, if possible, the clamping of the cord should be delayed. Initially the newborn must be assessed and, if possible, the baby should be kept with the mother in skin-to-skin contact. The infant must be placed under radiant warmer and the airways must be opened, if respiratory or circulatory support is needed. Decisions about the further steps of resuscitation are based on the evaluation of breathing, heart rate and oxygen saturation. If the baby is apnoeic or has a low heart rate, positive pressure ventilation must be started. The effectiveness of the ventilation must be checked, and failures are to be corrected if necessary. If the heart rate is <60/min despite effective ventilation, chest compressions should be started. Rarely, administration of medications is also necessary. After successful resuscitation, post-resuscitation care must be started. In the case of unsuccessful resuscitation, discontinuing management can be considered. Orv Hetil. 2023; 164(12): 474-480.

Acceleration during neonatal transport and its impact on mechanical ventilation.

OBJECTIVE: During interhospital transfer, critically ill neonates frequently require mechanical ventilation and are exposed to physical forces related to movement of the ambulance. In an observational study, we investigated acceleration during emergency transfers and if they result from changes in ambulance speed and direction or from vibration due to road conditions. We also studied how these forces impact on performance of the fabian+nCPAP evolution neonatal ventilator and on patient-ventilator interactions. METHODS: We downloaded ventilator parameters at 125 Hz and acceleration data at 100 Hz sampling rates, respectively, during the emergency transfer of 109 infants. Study subjects included term, preterm and extremely preterm infants. We computationally analysed the magnitude, direction and frequency of ambulance acceleration. We also analysed maintenance and variability of ventilator parameters and the shape of pressure-volume loops. RESULTS: While acceleration was <1 m/s2 most of the time, most babies were occasionally exposed to accelerations>5 m/s2. Vibration was responsible for most of the acceleration, rather than speed change or vehicle turning. There was no significant difference between periods of high or low vibration in ventilation parameters, their variability and how well targeted parameters were kept close to their target. Speed change or vehicle turning did not affect ventilator parameters or performance. However, during periods of intense vibration, pressure-volume ventilator loops became significantly more irregular. CONCLUSIONS: Infants are exposed to significant acceleration and vibration during emergency transport. While these forces do not interfere with overall maintenance of ventilator parameters, they make the pressure-volume loops more irregular.

OPETH: Open Source Solution for Real-Time Peri-Event Time Histogram Based on Open Ephys.

Single cell electrophysiology remains one of the most widely used approaches of systems neuroscience. Decisions made by the experimenter during electrophysiology recording largely determine recording quality, duration of the project and value of the collected data. Therefore, online feedback aiding these decisions can lower monetary and time investment, and substantially speed up projects as well as allow novel studies otherwise not possible due to prohibitively low throughput. Real-time feedback is especially important in studies that involve optogenetic cell type identification by enabling a systematic search for neurons of interest. However, such tools are scarce and limited to costly commercial systems with high degree of specialization, which hitherto prevented wide-ranging benefits for the community. To address this, we present an open-source tool that enables online feedback during electrophysiology experiments and provides a Python interface for the widely used Open Ephys open source data acquisition system. Specifically, our software allows flexible online visualization of spike alignment to external events, called the online peri-event time histogram (OPETH). These external events, conveyed by digital logic signals, may indicate photostimulation time stamps for in vivo optogenetic cell type identification or the times of behaviorally relevant events during in vivo behavioral neurophysiology experiments. Therefore, OPETH allows real-time identification of genetically defined neuron types or behaviorally responsive populations. By allowing "hunting" for neurons of interest, OPETH significantly reduces experiment time and thus increases the efficiency of experiments that combine in vivo electrophysiology with behavior or optogenetic tagging of neurons.

Volume-targeted ventilation with a Fabian ventilator: maintenance of tidal volumes and blood CO2.

OBJECTIVE: To analyse the performance of the Fabian +NCPAP evolution ventilator during volume guarantee (VG) ventilation in neonates at maintaining the target tidal volume and what tidal and minute volumes are required to maintain normocapnia. METHODS: Clinical and ventilator data were collected and analysed from 83 infants receiving VG ventilation during interhospital transfer. Sedation was used in 26 cases. Ventilator data were downloaded with a sampling rate of 0.5 Hz. Data were analysed using the Python computer language and its data analysis packages. RESULTS: ~107 hours of ventilator data were analysed, consisting of ~194 000 data points. The median absolute difference between the actual expiratory tidal volume (VTe) of the ventilator inflations and the target tidal volume (VTset) was 0.29 mL/kg (IQR: 0.11-0.79 mL/kg). Overall, VTe was within 1 mL/kg of VTset in 80% of inflations. VTe decreased progressively below the target when the endotracheal tube leak exceeded 50%. When leak was below 50%, VTe was below VTset by >1 mL/kg in less than 12% of inflations even in babies weighing less than 1000 g. Both VTe (r=-0.34, p=0.0022) and minute volume (r=-0.22, p=0.0567) showed a weak inverse correlation with capillary partial pressure of carbon dioxide (Pco2) values. Only 50% of normocapnic blood gases were associated with tidal volumes between 4 and 6 mL/kg. CONCLUSIONS: The Fabian ventilator delivers volume-targeted ventilation with high accuracy if endotracheal tube leakage is not excessive and the maximum allowed inflating pressure does not limit inflations. There is only weak inverse correlation between tidal or minute volumes and Pco2.

Volume Guaranteed Ventilation During Neonatal Transport.

OBJECTIVES: To compare tidal volumes, inflating pressures and other ventilator variables of infants receiving synchronized intermitted mandatory ventilation with volume guarantee during emergency neonatal transport with those of infants receiving synchronized intermitted mandatory ventilation without volume guarantee. DESIGN: Retrospective observational study. SETTING: A regional neonatal emergency transport service. PATIENTS: We enrolled 77 infants undergoing emergency neonatal transfer. Forty-five infants were ventilated with synchronized intermittent mandatory ventilation with volume guarantee and 32 with synchronized intermitted mandatory ventilation without volume guarantee. INTERVENTIONS: Infants received synchronized intermitted mandatory ventilation with or without volume guarantee during interhospital emergency neonatal transport using a Fabian + nCPAP evolution neonatal ventilator (Software Version: 4.0.1; Acutronic Medical Instruments, Hirzel, Switzerland). MEASUREMENTS AND MAIN RESULTS: We downloaded detailed ventilator data with 0.5 Hz sampling rate. We analyzed data with the Python computer language and its data science packages. The mean expiratory tidal volume of inflations was lower and less variable in infants ventilated with volume guarantee than in babies ventilated without volume guarantee (group median 4.8 vs 6.0 mL/kg; p = 0.001). Babies ventilated with synchronized intermittent mandatory ventilation with volume guarantee had on average lower and more variable peak inflating pressures than babies ventilated without volume guarantee (group median 15.5 vs 19.5 cm H2O;p = 0.0004). With volume guarantee, a lower proportion of the total minute ventilation was attributed to ventilator inflations rather than to spontaneous breaths between inflations (group median 66% vs 83%; p = 0.02). With volume guarantee, babies had fewer inflations with tidal volumes greater than 6 mL/kg and greater than 8 mL/kg (group medians 3% vs 44% and 0% vs 7%, respectively; p = 0.0001). The larger tidal volumes in the non-volume guarantee group were not associated with significant hypocapnia except in one case. CONCLUSIONS: During neonatal transport, synchronized intermittent mandatory ventilation with volume guarantee ventilation reduced the occurrence of excessive tidal volumes, but it was associated with larger contribution of spontaneous breaths to minute ventilation compared with synchronized intermitted mandatory ventilation without volume guarantee.

Asphyxiated neonates who received active therapeutic hypothermia during transport had higher rates of hypocapnia than controls.

AIM: We investigated the association between active hypothermia and hypocapnia in neonates with moderate-to-severe hypoxic-ischaemic encephalopathy (HIE) transported after birth. METHODS: This was a retrospective cohort study of neonates with HIE born between 2007 and 2011 and transported to Semmelweis University, Hungary, for hypothermia treatment before and after we introduced active cooling during transport in 2009. Of these, 71 received intensive care plus controlled active hypothermia during transport, while the 46 controls just received standard intensive care. Incident hypocapnia was defined as a partial pressure of carbon-dioxide (pCO2 ) that decreased below 35 mm Hg during transport. Multivariable logistic regression investigated the relationship between hypothermia and incident hypocapnia. RESULTS: Incident hypocapnia was more frequent in the actively cooled transport group (36.6%) than control group (17.4%; p = 0.025). pCO2 decreased from a median of 45 to 35 mm Hg (p < 0.0001) in the intervention group, but remained unchanged in the controls. After adjusting for confounders, hypothermia remained an independent risk factor for hypocapnia with an odds ratio (OR) of 4.23 and 95% confidence interval (95% CI) of 1.30-13.79. Sedation was associated with a reduction in OR of hypocapnia, at 0.35 (95% CI 0.12-0.98). CONCLUSIONS: Hypothermia increased the risk of hypocapnia in neonates with HIE during transport.

Feasibility and Safety of Controlled Active Hypothermia Treatment During Transport in Neonates With Hypoxic-Ischemic Encephalopathy.

OBJECTIVES: To evaluate the feasibility and safety of controlled active hypothermia versus standard intensive care during neonatal transport in patients with hypoxic-ischemic encephalopathy. DESIGN: Cohort study with a historic control group. SETTING: All infants were transported by Neonatal Emergency & Transport Services to a Level-III neonatal ICU. PATIENTS: Two hundred fourteen term newborns with moderate-to-severe hypoxic-ischemic encephalopathy. An actively cooled group of 136 newborns were compared with a control group of 78 newborns. INTERVENTIONS: Controlled active hypothermia during neonatal transport. MEASUREMENTS AND MAIN RESULTS: Key measured variables were timing of hypothermia initiation, temperature profiles, and vital signs during neonatal transport. Hypothermia was initiated a median 2.58 hours earlier in the actively cooled group compared with the control group (median 1.42 [interquartile range, 0.83-2.07] vs 4.0 [interquartile range, 2.08-5.79] hours after birth, respectively; p < 0.0001), and target temperature was also achieved a median 1.83 hours earlier (median 2.42 [1.58-3.63] vs 4.25 [2.42-6.08] hours after birth, respectively; p < 0.0001). Blood gas values and vital signs were comparable between the two groups with the exception of heart rate, which was significantly lower in the actively cooled group. The number of infants in the target temperature range (33-34°C) on arrival was 79/136 (58.1%) and the rate of overcooling was 16/136 (11.8%) in the actively cooled group. In the overcooled infants, Apgar scores, pH, base deficit, and eventual death rate (7/16; 43.8%) indicated more severe asphyxia suggesting poor temperature control in this subgroup of patients. Adverse events leading to pulmonary or circulatory failure were not observed in either groups during the transport period. CONCLUSIONS: Therapeutic hypothermia during transport is feasible and safe, allowing for significantly earlier initiation and achievement of target temperature, possibly providing further benefit for neonates with hypoxic-ischemic encephalopathy.

Core collapse via coarse dynamic renormalization.

In the context of the recently developed "equation-free" approach to computer-assisted analysis of complex systems, we extract the self-similar solution describing core collapse of a stellar system from numerical experiments. The technique allows us to sidestep the core "bounce" that occurs in direct N-body simulations due to the small-N correlations that develop in the late stages of collapse, and hence to follow the evolution well into the self-similar regime.

Evolution of binary supermassive black holes via chain regularization.

A chain regularization method is combined with special purpose computer hardware to study the evolution of massive black hole binaries at the centers of galaxies. Preliminary results with up to N = 0.26 x 10(6) particles are presented. The decay rate of the binary is shown to decrease with increasing N, as expected on the basis of theoretical arguments. The eccentricity of the binary remains small.