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Aim: To determine changes in brain haemodynamics produced by dexamethasone; to evaluate the pathophysiological conditions involved in the effect of dexamethasone.Methods: A prospective study was made of 12 ventilated preterm infants who received dexamethasone (0.25 mg/kg/12 hours) for ongoing chronic lung disease or extubation failure. Cerebral blood flow (CBF), absolute cerebral blood volume (CBV), and cerebral blood volume changes (delta CBV) were estimated by near infrared spectroscopy, before and 10, 30, 60, 120, 180 and 240 minutes after the first, third, and fifth doses of dexamethasone. All patients were monitored continuously using pulse oximetry, transcutaneous blood gases, and blood pressure.Results: There were significant short term changes in delta CBV on each day of the study; delta CBV increased significantly at 240 minutes compared with values before the first dose, and from 120 minutes onward during the third and fifth doses. However, mean CBV values averaged over 240 minutes after the first, third, and fifth doses did not vary. Mean CBF values averaged over 240 minutes increased progressively up to the fifth dose (significant differences between the first and fifth dose). The short term changes in CBF consisted of a significant increase 60 minutes after dexamethasone administration compared with the before and 10 minute values in every study. Blood pressure was significantly higher in the third and fifth doses than in the first dose. Blood pressure showed no short term changes. There was no correlation between CBF and blood pressure changes. TcPCO2 (transcutaneous PCO2) decreased significantly throughout the study period, with the average mean value in the fifth dose significantly lower than in the first dose. Nevertheless, no short term changes in TcPCO2 were observed.Conclusions: Postnatal systemic dexamethasone administration produced significant changes in cerebral haemodynamics that seemed to be related to both a direct effect on regional vessel walls and the cumulative effect of dexamethasone. [ABSTRACT FROM AUTHOR]

Therapeutic hypothermia (TH) initiated within 6 h from birth is the most effective therapeutic approach for moderate to severe hypoxic-ischemic encephalopathy (HIE). However, underlying mechanisms and effects on the human metabolism are not yet fully understood. This work aims at studying the evolution of several energy related key metabolites in newborns with HIE undergoing TH employing gas chromatography - mass spectrometry. The method was validated following stringent FDA requirements and applied to 194 samples from a subgroup of newborns with HIE (N = 61) enrolled in a multicenter clinical trial (HYPOTOP) for the determination of lactate, pyruvate, ketone bodies and several Krebs cycle metabolites at different sampling time points. The analysis of plasma samples from newborns with HIE revealed a decrease of lactate, pyruvate and β-hydroxybutyrate concentrations, whereas rising malate concentrations were observed. In healthy control newborns (N = 19) significantly lower levels of pyruvate and lactate were found in comparison to age-matched newborns with HIE undergoing TH, whereas acetoacetate and β-hydroxybutyrate levels were clearly increased. Access to a validated analytical method and a controlled cohort of newborns with HIE undergoing hypothermia treatment for the first time allowed the in-depth study of the evolution of key metabolites of metabolic junctions in this special population.

This study reports on the process and results of the Second Clinical Consensus of the Ibero-American Society of Neonatology. Eighty neonatologists from 23 countries were invited to collaborate and participate in the event. Several questions of clinical-physiological importance in the hemodynamic management of newborns were addressed. Participants were divided into groups to facilitate interaction and teamwork, with instructions to respond to three to five questions by analyzing the literature and local factors. Meeting in Mar del Plata, Argentina, the Consensus Group served as a form for various presentations and discussions. In all, 54 neonatologists from 21 countries attended, with the objective of reaching a consensus on such matters as concepts and definitions of hemodynamic instability, the physiopathology of hemodynamic compromise, recommended therapy strategies, and hemodynamic monitoring. It is hoped that this international experience will serve as a useful initiative for future consensus building and reduction of the existing disparities among the countries of the Region in terms of treatment and outcomes.

Background: Cardiovascular drugs play a major role in the pre- and postoperative care in neonates with congenital heart disease. Management strategies aim to optimise contractility, improve diastolic function, maintain adequate preload, and reduce afterload. Levosimendan, a novel inodilator agent, enhances myocardial contractility and causes peripheral and coronary vasodilation., Objectives: A systematic approach was used to evaluate the acute haemodynamic effects of levosimendan in critically ill infants with low cardiac output syndrome (LCOS)., Methods: Infants received a continuous infusion of levosimendan, at a dose increased stepwise (range 0.1-0.2 μg/kg/min), during 48 h. Two near-infrared units were used to assess cerebral (frontal-parietal, c) and peripheral (thigh, p) perfusion and oxygenation. The changes in cerebral blood volume (ΔCBV), cerebral (cΔHbD) and peripheral (pΔHbD) intravascular oxygenation and the cerebral (cTOI) and peripheral (pTOI) tissue oxygenation index that followed levosimendan administration were continuously monitored. Blood pressure, heart rate, and temperature were continuously recorded. In addition, baseline and end-of-study pH, blood gases, lactate and haematocrit were determined., Results: Seven doses of levosimendan were investigated. The mean study time was 13.3 (7-19) h. Levosimendan produced an increase in cΔHbD (p < 0.05) and pΔHbD (NS) and a decrease in heart rate (p < 0.001) and lactate (p < 0.05). Trends showed an increase in mean blood pressure (NS). These results were independent of the effect of time. Mixed linear model analysis identified blood pressure changes and levosimendan as factors independently associated with cΔHbD., Conclusions: Levosimendan improves cerebral and systemic perfusion and oxygenation in critically ill infants suffering from LCOS., (Copyright © 2010 S. Karger AG, Basel.)