Use of Heated Humidified Gases for Early Stabilization of Preterm Infants: A Meta-Analysis

Developmen

Improving newborn respiratory outcomes with a sustained inflation: a systematic narrative review of factors regulating outcome in animal and clinical studies

Respiratory support is critically important for survival of newborns who fail to breathe spontaneously at birth. Although there is no internationally accepted definition of a sustained inflation (SI), it has commonly been defined as a positive pressure inflation designed to establish functional residual capacity and applied over a longer time period than normally used in standard respiratory support (SRS). Outcomes vary distinctly between studies and to date there has been no comprehensive investigation of differences in SI approach and study outcome in both pre-clinical and clinical studies. A systematic literature search was performed and, after screening, identified 17 animal studies and 17 clinical studies evaluating use of a SI in newborns compared to SRS during neonatal resuscitation. Study demographics including gestational age, SI parameters (length, repetitions, pressure, method of delivery) and study outcomes were compared. Animal studies provide mechanistic understanding of a SI on the physiology underpinning the cardiorespiratory transition at birth. In clinical studies, there is considerable difference in study quality, delivery of SIs (number, pressure, length) and timing of primary outcome evaluation which limits direct comparison between studies. The largest difference is method of delivery, where the role of a SI has been observed in intubated animals, as the inflation pressure is directly applied to the lung, bypassing the obstructed upper airway in an apnoeic state. This highlights a potential limitation in clinical use of a SI applied non-invasively. Further research is required to identify if a SI may have greater benefits in subpopulations of newborns.Developmen

Elektrochemische Potentiale während Hochfrequenz-Katheterablation von Herzrhythmusstörungen : In vitro und in vivo Experimente und erste klinische Erfahrungen

Einleitung: Die temperaturkontrollierte Katheterablation besitzt eine Reihe von Limitationen wie u.a. moderate Korrelation mit der Gewebetemperatur und Läsionsentwicklung. Ziel der vorliegenden Arbeit war es, ein Steuerungsparameter zu entwickeln, der die Qualität des Elektrodenkontaktes mit dem Gewebe und das Wachstum der Koagulationsnekrose direkt anhand zellulärer bzw. biologischer Prozesse des Zielgewebes wiedergibt. Material und Methodik: Endomyokard-Präparate frisch geschlachteter Rinder wurden in einem Tankbad mit physiologischer Kochsalzlösung für die in vitro Experimente verwandt, wo bei das elektrochemische Potential (eP) wie bei allen Untersuchungen zwischen der distalen und der proximalen Elektrode abgeleitet wurde. Tierexperimente wurden bei 8 intubiert, beatmeten Schweinen durchgeführt, wobei der experimentelle Aufbau adäquat zu den Bedingungen in vitro- elektrochemisches Potential zwischen distaler und proximaler Elektrode - war. Die ersten klinischen Untersuchungen wurden an 50 konsekutiven Patienten (m/w 29:21; 49,7 ± 9,8 Jahre), die zur elektiven Katheter-Ablation von supraventrikulären Tachykardien AVNRT bzw. WPW-Syndrom eingewiesen wurden, durchgeführt. Der meßtechnische Aufbau war unverändert zu den in vitro bzw. Tierexperimenten. Ergebnisse: Der Nachweis von eP gelang sowohl invitro, tierexperimentell als auch im klinischen Teil der Arbeit. Ferner konnte eine hohe Korrelation des elektrochemischen Potentials mit dem bisher üblichen Parameter \u27Temperatur\u27 errechnet werden (r=0,87). Eine ebenfalls hohe Korrelation wurde zwischen der Läsionsentwicklung und den eP festgestellt: r=0,85; p<0,001. Auch bei den \u27Routine-Kateterablationen\u27 konnte die Messung der eP bei Patienten durchgeführt werden. Ferner konnte mittels eP-gesteuerter Energieabgabe die Durchführbarkeit einer Katheterablation mit dem Parameters \u27eP\u27 gezeigt werden. Diskussion: Der Ursprung des eP liegt in der Läsionsentwicklung durch Erhitzung des myokardialen Gewebes. Die elektromotorische Kraftquelle des eP ist die Diffusion von freien Radikalen und intrazellulären Elektrolyten aus der Koagulationsläsion. Die eP stellt einen zusätzlichen Parameter neben der Temperatur und Impedanz - mit besserer Korrelation zur Läsion- dar. Die Steuerung der HF-Strom-Energieabgabe durch die eP ist möglich und erlaubt den Einsatz thermosensorfreier Elektroden. Potentiell klinische Anwendungen stellen die gekühlte Ablation sowie der Einsatz von multipolaren Ablationskathetern dar.Introduction: Temperature controlled radiofrequency catheter ablation (TRF) is widely introduced in current clinical practice with several limitations as the moderate correlation between catheter tip temperature (CTT) and lesion size (LS), and the increase in stiffness of multielectrode thermosensor catheters for the creation of linear lesions. Thermal injury of subendocardial tissue leads to a release of electrolytes and free radicals from the intracellular site creating a change in potential (dP) between distal and proximal catheter tip electrode. The aim of the doctorate was to verify the detection of ablation-induced release of electrolytes and free radicals and the possibility to control energy delivery in ablation by measuring dP. Energieabgabe die Durchführbarkeit einer Katheterablation mit dem Parameters \u27eP\u27 gezeigt werden. Methods and Results: In vitro tests at constant flow condition were performed in a 10 l bath of physiological saline solution and cattle blood. Endomyocardial preparations of fresh cattle hearts were used. Closed-loop temperature-controlled and closed-loop dP-controlled ablations were performed. In vivo animal investigations were performed in anesthetized and ventilated pigs. The existence of the dP was established in the tank model and was confirmed in the animal investigations. Good correlations were found between dP and CTT (r=0.87) and between maximum dP and induced LS (r=0.85). A high correlation (r=0.85, p<0.001) was found between dP and lesion volume. During routinely catheter ablation in 50 patients with supraventicular tachycardia dP-measurement was performed. Energieabgabe die Durchführbarkeit einer Katheterablation mit dem Parameters \u27eP\u27 gezeigt werden. Conclusions: Control of energy delivery during RF-ablation by the measurement of dP is feasible. In comparison to TRF, ablation steered by dP-measurement revealed superior correlation to induced LS. During irrigated catheter ablation, dP measurement is the only tool for energy control. To our knowledge, this is the first report on this novel method of ablation control

Hypothermia during umbilical catheterization in preterm infants

Objective: To describe the effect of umbilical catheterization (UC) on skin temperature and cardiorespiratory status in preterm infants.Materials and methods: In a prospective observational study of infants <32 weeks of gestation, the duration of UC, course of skin temperature, and cardiorespiratory status were registered. Hypothermia was defined as a temperature below 36.5C.Results: UC was performed in 55 infants with a median (range) gestational age of 28 weeks (24-31) and birth weight of 1120g (625-2091). Mean (SD) temperature first decreased 0.6 (0.6)degrees C during UC followed by a rise of 0.4 (0.4)degrees C after reaching the minimal temperature. Hypothermia already existed in 69% (38/55) of the infants before start of UC, which increased to 89% (49/55) during UC (p = .001). Duration of UC was not associated with the development of hypothermia during the procedure (p = .48). Heart rate (mean(SD)) significantly increased (162 (17) versus 152 (15); p <.001) and there was a trend toward an increase in supplemental oxygen (mean(SD)) (0.31 (0.17) versus 0.28 (0.13); p = .78), but both changes were only temporary.Conclusion: Hypothermia was frequent in preterm infants before start of UC and increased during UC. Postponing UC until the infant has a normal temperature should be considered.Developmen

Advances in neonatal critical care: pushing at the boundaries and connecting to long-term outcomes

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Maternal acceptability of pulse oximetry screening at home after home birth or very early discharge

Developmen

The effect of breathing on ductus arteriosus blood flow directly after birth

Research into fetal development and medicin

Ductal flow ratio as a measure of transition in preterm infants after birth: a pilot study

Background: Cardiovascular changes during the transition from intra- to extrauterine life, alters the pressure gradient across the ductus arteriosus (DA). DA flow ratio (R-L/L-R) has been suggested to reflect the infant's transitional status and could potentially predict neonatal outcomes after preterm birth.Aim: Determine whether DA flow ratio correlates with oxygenation parameters in preterm infants at 1 h after birth.Methods: Echocardiography was performed in preterm infants born < 32 weeks gestational age (GA), as part of an ancillary study. DA flow was measured at 1 h after birth. DA flow ratio was correlated with FiO(2), SpO(2), and SpO(2)/FiO(2) (SF) ratio. The DA flow ratio of infants receiving physiological-based cord clamping (PBCC) or time-based cord clamping (TBCC) were compared.Results: Measurements from 16 infants were analysed (median [IQR] GA 29 [27-30] weeks; birthweight 1,176 [951-1,409] grams). R-L DA shunting was 16 [17-27] ml/kg/min and L-R was 110 [81-124] ml/kg/min. The DA flow ratio was 0.18 [0.11-0.28], SpO(2) 94 [93-96]%, FiO(2) was 23 [21-28]% and SF ratio 4.1 [3.3-4.5]. There was a moderate correlation between DA flow ratio and SpO(2) [correlation coefficient (CC) -0.415; p = 0.110], FiO(2) (CC 0.384; p = 0.142) and SF ratio (CC -0.356; p = 0.175). There were no differences in DA flow measurements between infants where PBBC or TBCC was performed.Conclusion: In this pilot study we observed a non-significant positive correlation between DA flow ratio at 1 h after birth and oxygenation parameters in preterm infants.Developmen

The effect of automated oxygen control on clinical outcomes in preterm infants: a pre- and post-implementation cohort study

Several studies demonstrated an increase in time spent within target range when automated oxygen control (AOC) is used. However the effect on clinical outcome remains unclear. We compared clinical outcomes of preterm infants born before and after implementation of AOC as standard of care. In a retrospective pre-post implementation cohort study of outcomes for infants of 24-29 weeks gestational age receiving respiratory support before (2012-2015) and after (2015-2018) implementation of AOC as standard of care were compared. Outcomes of interest were mortality and complications of prematurity, number of ventilation days, and length of stay in the Neonatal Intensive Care Unit (NICU). A total of 588 infants were included (293 pre- vs 295 in the post-implementation cohort), with similar gestational age (27.8 weeks pre- vs 27.6 weeks post-implementation), birth weight (1033 grams vs 1035 grams) and other baseline characteristics. Mortality and rate of prematurity complications were not different between the groups. Length of stay in NICU was not different, but duration of invasive ventilation was shorter in infants who received AOC (6.4 +/- 10.1 vs 4.7 +/- 8.3, p = 0.029). Conclusion: In this pre-post comparison, the implementation of AOC did not lead to a change in mortality or morbidity during admission.What is Known:Prolonged and intermittent oxygen saturation deviations are associated with mortality and prematurity-related morbidities.Automated oxygen controllers can increase the time spent within oxygen saturation target range.What is New:Implementation of automated oxygen control as standard of care did not lead to a change in mortality or morbidity during admission.In the period after implementation of automated oxygen control, there was a shift toward more non-invasive ventilation.Developmen

Repetitive versus standard tactile stimulation of preterm infants at birth - A randomized controlled trial

Development and application of statistical models for medical scientific researc