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The DA is a fetal arterial shunt vessel connecting the pulmonary artery with the aortic arch. During fetal life, the DA directs deoxygenated blood away from the pulmonary circulation and [...], The ductus arteriosus (DA) is a fetal shunt vessel between the pulmonary artery and the aorta that closes promptly after birth. Failure of postnatal DA closure is a major cause of morbidity and mortality particularly in preterm neonates. The events leading to DA closure are incompletely understood. Here we show that platelets have an essential role in DA closure. Using intravital microscopy of neonatal mice, we observed that platelets are recruited to the luminal aspect of the DA during closure. DA closure is impaired in neonates with malfunctioning platelet adhesion or aggregation or with defective platelet biogenesis. Defective DA closure resulted in a left-to-right shunt with increased pulmonary perfusion, pulmonary vascular remodeling and right ventricular hypertrophy. Our findings indicate that platelets are crucial for DA closure by promoting thrombotic sealing of the constricted DA and by supporting luminal remodeling. A retrospective clinical study revealed that thrombocytopenia is an independent predictor for failure of DA closure in preterm human newborns, indicating that platelets are likely to contribute to DA closure in humans. more...

Byline: Tamara Seidl (1), Orsolya Genzel-Boroviczeny (1), Jan-Michael Abicht (2), Frank Christ (2) Keywords: Red blood cell transfusion; Anemia of prematurity; Near infrared photoplethysmography; Peripheral blood flow Abstract: Objective Transfusion practices for neonates are controversial and based on limited scientific information. We examined the use of the plethysmographic volume pulse to assess anemia. Design We used near-infrared photoplethysmography (NIRP) to investigate signal strength parameters as area under the curve (AUC) and the first derivate of the amplitude (flux) in anemic infants before and after elective transfusion. Setting Tertiary intensive care unit. Patients Thirty-four neonates on day 25+-15 of life with a pretransfusion hemoglobin level of 8+-0.9 g/dl. Four infants were excluded for incomplete data. Interventions Transfusion of 10 ml packed red cells per kilogram body weight Measurements and results The volume pulse signal was obtained with a sensor attached to the sole of the foot. After transfusion we found a significant decrease in number of bradycardia episodes per hour (0.35 vs. 0.16) and episodes of pulse oximeter desaturation less than 85% per hour (1.8 vs. 1.3) and a significant increase in daily weight gain (12+-7 vs. 20+-18 g), but neither of the microcirculatory parameters changed significantly (AUC 102+-38 vs. 101+-44 flux 435+-160 vs. 405+-120). Conclusions Even though infants were transfused at very low levels of hemoglobin with significant clinical effects, microcirculation assessed by NIRP seemed not be affected. Infrared photoplethysmographs present flow not only in the nutritive capillaries but mainly in the subpapillary plexus at a greater depth. This thermoregulatory flow seems not be affected by blood transfusions of anemic infants. Author Affiliation: (1) Division of Neonatology, Department of Gynecology and Obstetrics, Munich Grosshadern, Ludwig Maximilian University, Marchioninistrasse 15, 81366, Munich, Germany (2) Clinic for Anesthesiology, Ludwig Maximilian University, Munich Grosshadern, Marchioninistrasse 15, 81366, Munich, Germany Article History: Registration Date: 29/03/2004 Received Date: 25/09/2003 Accepted Date: 26/03/2004 Online Date: 30/04/2004 more...

We have previously shown in a retrospective study including 123 infants born prematurely at 24-30 weeks' gestation that thrombocytopenia is associated with a higher incidence of patent ductus arteriosus (PDA) [...] more...

Objective: Obtaining a systematic medical history (MH) from a patient is a core competency in medical education and plays a vital role in the diagnosis of diseases. At the Faculty of Medicine at LMU Munich, students have their first course in MH taking during their second year. Due to the COVID-19 pandemic, the traditional bedside MH taking course had to be transformed into an online course (OC). Our objectives were to implement an online MH taking course, to evaluate its feasibility and to compare the evaluation results to a historic cohort that had undertaken the traditional bedside teaching course (BTC).Methods: 874 second-year students participated in the OC (BTC=827). After teaching the theoretical background via asynchronous online lectures, students participated in a practical exercise with fellow students using the video communication platform Zoom where they were able to practice taking a MH on the basis of fictitious, text-based patient cases. Students were then asked to evaluate the course through a standardized online survey with 31 questions on teaching quality and self-perceived learning success, which had also been used in previous years. The survey results were compared to the results of the historic cohort using the Mann-Whitney U test.Results: A total of n=162 students (18.5%) evaluated the OC. In the historic cohort, n=252 (30.5%) completed the survey. 85.3% of the OC respondents thought that the atmosphere during the practical exercise was productive and 83.0% greatly appreciated the flexibility in terms of time management. Moreover, they appreciated the online resources as well as having the opportunity to undertake a MH taking course during the COVID-19 pandemic. 27.7% of the respondents thought that traditional BTCs should be supplemented through more online activities in the future. With respect to the ability of independently taking a MH upon completion of the course, the OC was rated significantly lower relative to the BTC (mean OC=2.4, SD=±1.1 vs. mean BTC=1.9, SD=±1.1 (1=strongly agree; 5=strongly disagree); p more...

Background: Levels or fluctuations in the partial pressure of CO2 (PCO2) may affect outcomes for extremely low birth weight infants. Objectives: In an exploratory analysis of a randomized trial, we hypothesized that the PCO2 values achieved could be related to significant outcomes. Methods: On each treatment day, infants were divided into 4 groups: relative hypocapnia, normocapnia, hypercapnia, or fluctuating PCO2. Ultimate assignment to a group for the purpose of this analysis was made according to the group in which an infant spent the most days. Statistical analyses were performed with analysis of variance (ANOVA), the Kruskal-Wallis test, the χ2 test, and the Fisher exact test as well as by multiple logistic regression. Results: Of the 359 infants, 57 were classified as hypocapnic, 230 as normocapnic, 70 as hypercapnic, and 2 as fluctuating PCO2. Hypercapnic infants had a higher average product of mean airway pressure and fraction of inspired oxygen (MAP × FiO2). For this group, mortality was higher, as was the likelihood of having moderate/severe bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), and poorer neurodevelopment. Multiple logistic regression analyses showed an increased risk for BPD or death associated with birth weight (p < 0.001) and MAP × FiO2 (p < 0.01). The incidence of adverse neurodevelopment was associated with birth weight (p < 0.001) and intraventricular hemorrhage (IVH; p < 0.01). Conclusions: Birth weight and respiratory morbidity, as measured by MAP × FiO2, were the most predictive of death or BPD and NEC, whereas poor neurodevelopmental outcome was associated with low birth weight and IVH. Univariate models also identified PCO2. Thus, hypercapnia seems to reflect greater disease severity, a likely contributor to differences in outcomes. [ABSTRACT FROM AUTHOR] more...

Background: Tolerating higher partial pressures of carbon dioxide (PCO2) in mechanically ventilated extremely low birthweight infants to reduce ventilator-induced lung injury may have long-term neurodevelopmental side effects. This study analyses the results of neurodevelopmental follow-up of infants enrolled in a randomised multicentre trial.Methods: Infants (n=359) between 400 and 1000 g birth weight and 23 0/7-28 6/7 weeks gestational age who required endotracheal intubation and mechanical ventilation within 24 hours of birth were randomly assigned to high PCO2 or to a control group with mildly elevated PCO2 targets. Neurodevelopmental follow-up examinations were available for 85% of enrolled infants using the Bayley Scales of Infant Development II, the Gross Motor Function Classification System (GMFCS) and the Child Development Inventory (CDI).Results: There were no differences in body weight, length and head circumference between the two PCO2 target groups. Median Mental Developmental Index (MDI) values were 82 (60-96, high target) and 84 (58-96, p=0.79). Psychomotor Developmental Index (PDI) values were 84 (57-100) and 84 (65-96, p=0.73), respectively. Moreover, there was no difference in the number of infants with MDI or PDI <70 or <85 and the number of infants with a combined outcome of death or MDI<70 and death or PDI<70. No differences were found between results for GMFCS and CDI. The risk factors for MDI<70 or PDI<70 were intracranial haemorrhage, bronchopulmonary dysplasia, periventricular leukomalacia, necrotising enterocolitis and hydrocortisone treatment.Conclusions: A higher PCO2 target did not influence neurodevelopmental outcomes in mechanically ventilated extremely preterm infants. Adjusting PCO2 targets to optimise short-term outcomes is a safe option.Trial Registration Number: ISRCTN56143743. [ABSTRACT FROM AUTHOR] more...

Objectives Increased carotid intima-media thickness (cIMT) and loss of capillary density are antecedents of cardiovascular disease in adults. Former preterm infants are at risk for metabolic precursors of vascular disease, but vascular changes have not yet been studied in this population. Patients and methods In 54 former preterm (birth weigh (BW) 753±152 g) and 12 term children (BW 3395±558 g), functional vessel density (FVD) on the forearm and cIMT were obtained at a mean (±SD) age of 11.8±1.5 years. FVD was measured using sidestream dark field imaging before, during and after arterial occlusion, and cIMT using high resolution B-mode ultrasonography. Statistical comparisons were made using the t test, Mann-Whitney U test and the sign test for symmetry, with a two-sided p value as appropriate. Results The systolic blood pressure of the former preterm children was significantly increased compared to reference values (females 119±8, z score 1.23; males 118±11, z score 1.14 mm Hg), as were the cIMT values (0.45±0.03 mm vs 0.38±0.04 mm; p<0.001). FVD was significantly higher in former preterm children compared to controls at baseline (mean±SD 33.6±14.5 cm/cm² vs 23.0±7.1 cm/cm²; p=0.002) with decreased reactivity during arterial occlusion (x² 7.14, p=0.008). Conclusions Preterm birth is associated with significant permanent alteration in the microcirculation and increased cIMT and systolic blood pressure. It is unknown whether these changes are due to preterm birth and rapid maturation of the skin or to nutritional factors, as previously thought. This is an important area of future research. [ABSTRACT FROM AUTHOR] more...