Transfusions de globules rouges aux soins intensifs pédiatriques : épidémiologie et déterminants

Les transfusions de globules rouges (GR) sont fréquentes aux soins intensifs pédiatriques (SIP). Cependant, il n’y a pas de donnée récente sur les pratiques transfusionnelles aux SIP. Les objectifs de notre étude étaient 1) de décrire les pratiques transfusionnelles aux SIP du CHU Sainte-Justine en y déterminant la fréquence des transfusions de GR et en caractérisant les déterminants de ces transfusions, 2) de comparer ces pratiques avec celles observées il y a dix ans, et 3) d’évaluer le degré d’adhérence à la recommandation principale d’une large étude randomisée contrôlée, l’étude TRIPICU, laquelle proposait une pratique précise chez les patients stabilisés. Nous avons réalisé une étude monocentrique prospective observationnelle d’une durée d’un an. L’information requise a été extraite des dossiers médicaux. Les déterminants des transfusions ont été recherchés quotidiennement jusqu’à la première transfusion pour les cas transfusés, ou jusqu’à la sortie des SIP pour les cas non transfusés. Les justifications des transfusions déclarées par les médecins traitants ont été compilées à l’aide d’un questionnaire. Il y a eu 913 admissions consécutives durant la période d’étude, dont 842 ont été retenues. Au moins une transfusion a été donnée à 144 patients (17.1%). Le taux moyen d’hémoglobine avant la première transfusion était de 77.3±27.2 g/L. Les déterminants d’un premier événement transfusionnel à l’analyse multivariée étaient le jeune âge (< 12 mois), la présence d’une cardiopathie congénitale, un nadir d’hémoglobine ≤ 70 g/L, la gravité de la maladie, et certaines dysfonctions d’organe. Les trois justifications de transfusions les plus fréquemment évoquées par les médecins étaient une hémoglobine basse, un transport en oxygène insuffisant et une instabilité hémodynamique. La recommandation principale de l’étude TRIPICU a été appliquée dans 96.4% des premiers événements transfusionnels. En conclusion, les transfusions de GR sont fréquentes aux SIP. Jeune âge, cardiopathie congénitale, hémoglobine basse, gravité de la maladie et certaines dysfonctions d’organes sont des déterminants significatifs de transfusions de GR aux SIP. La plupart des premiers événements transfusionnels furent prescrits en accord avec les récentes recommandations.Red blood cell (RBC) transfusions are common in pediatric intensive care unit (PICU). However, there are no recent data on transfusion practices in PICU. Our objective was 1) to describe transfusion practice in PICU, which means that we aimed to determine the incidence rate and to characterize the determinants of RBC transfusion, 2) to compare this practice with that observed ten years earlier, and 3) to estimate the compliance to the recommendation of a large randomized clinical trial, the TRIPICU study. We conducted a single center prospective observational study over a one-year period. Information was abstracted from medical charts. Determinants of transfusion were searched for daily until the first transfusion in transfused cases or until PICU discharge in non-transfused cases. The justifications for transfusions claimed by the attending physicians were assessed using a questionnaire. Among 913 consecutive admissions, 842 were enrolled. At least one RBC transfusion was given in 144 patients (17.1%). The mean hemoglobin level before the first transfusion was 77.3±27.2 g/L. The determinants of a first transfusion event retained in the multivariate analysis were young age (< 12 months), congenital heart disease, lowest hemoglobin level ≤ 70 g/L, severity of illness, and some organ dysfunctions. The three most frequently quoted justifications for RBC transfusion were a low hemoglobin level, intent to improve oxygen delivery, and hemodynamic instability. The main recommendation of the TRIPICU study was applied in 96.4% of the first transfusion events. In conclusion, RBC transfusions are frequent in PICU. Young age, congenital heart disease, low hemoglobin level, severity of illness and some organ dysfunctions are significant determinants of RBC transfusions in PICU. Most first transfusion events were prescribed according to recent recommendations

Disentangling the involvement of primary motor cortex in value-based reinforcement learning and value-based decision making.

When one makes the decision to act in the physical world, the neural activity in primary motor cortex (M1) encodes the competition between potential action choices. Traditional approaches have viewed this activity as reflecting the unfolding of the outcome of a decision process taking place upstream. However, a recently emerging theoretical framework posits that the motor neural structures directly contribute to the decision process. We recently tested this hypothesis (Zenon et al., 2015, Brain Stimulation) by using continuous theta burst stimulation (cTBS) to alter activity in M1 while participants performed a task that required them to select between two fingers in the right hand based on the color of a stimulus (green or red, explicit instruction). Importantly, this finger choice was biased such that, to earn more money, the subjects also had to take into account the shape of the stimulus (circle or square, undisclosed manipulation). So the motor response depended, on the one hand, on a perceptual decision process, interpreting the color of the stimulus according to instructed rules and, on the other hand, on a value-based decision process relying on reinforcement learning. Interestingly, cTBS over M1 modified the extent to which the value-based process influenced the subjects' decisions whereas it had no effect on their ability to make a choice based on perceptual evidence. Importantly, in that study, cTBS was applied at the very beginning of the experiment, before the subjects had learned the task. Hence, we cannot tell from that work whether the effect of M1 cTBS was due to an alteration of value-based reinforcement learning or of value-based decision making, which takes place once learning is complete. Here, we present a study in which we intend to use the same task but with cTBS applied at different times in order to assess the contribution of M1 to the two value-based processes (learning and decision making). More precisely, the experiment will extend over three sessions, each occurring at 24-hours interval. Each experimental session will consist of six blocks, each lasting about 4 minutes. Pilot data suggest that the value-based process begins to effectively shape the subject decisions in the middle of the second session. Given this, cTBS over M1 will be applied either at the beginning of the first session (before learning) or at the beginning of the third session (after learning). This procedure will allow us to disentangle the involvement of M1 in value-based reinforcement learning and value-based decision making

Performance of the PEdiatric Logistic Organ Dysfunction-2 score in critically ill children requiring plasma transfusions

BACKGROUND: Organ dysfunction scores, based on physiological parameters, have been created to describe organ failure. In a general pediatric intensive care unit (PICU) population, the PEdiatric Logistic Organ Dysfunction-2 score (PELOD-2) score had both a good discrimination and calibration, allowing to describe the clinical outcome of critically ill children throughout their stay. This score is increasingly used in clinical trials in specific subpopulation. Our objective was to assess the performance of the PELOD-2 score in a subpopulation of critically ill children requiring plasma transfusions. METHODS: This was an ancillary study of a prospective observational study on plasma transfusions over a 6-week period, in 101 PICUs in 21 countries. All critically ill children who received at least one plasma transfusion during the observation period were included. PELOD-2 scores were measured on days 1, 2, 5, 8, and 12 after plasma transfusion. Performance of the score was assessed by the determination of the discrimination (area under the ROC curve: AUC) and the calibration (Hosmer-Lemeshow test). RESULTS: Four hundred and forty-three patients were enrolled in the study (median age and weight: 1 year and 9.1 kg, respectively). Observed mortality rate was 26.9 % (119/443). For PELOD-2 on day 1, the AUC was 0.76 (95 % CI 0.71-0.81) and the Hosmer-Lemeshow test was p = 0.76. The serial evaluation of the changes in the daily PELOD-2 scores from day 1 demonstrated a significant association with death, adjusted for the PELOD-2 score on day 1. CONCLUSIONS: In a subpopulation of critically ill children requiring plasma transfusion, the PELOD-2 score has a lower but acceptable discrimination than in an entire population. This score should therefore be used cautiously in this specific subpopulation

A new experiment for the determination of the 18F(p,alpha) reaction rate at nova temperatures

The 18F(p,alpha) reaction was recognized as one of the most important for gamma ray astronomy in novae as it governs the early 511 keV emission. However, its rate remains largely uncertain at nova temperatures. A direct measurement of the cross section over the full range of nova energies is impossible because of its vanishing value at low energy and of the short 18F lifetime. Therefore, in order to better constrain this reaction rate, we have performed an indirect experiment taking advantage of the availability of a high purity and intense radioactive 18F beam at the Louvain La Neuve RIB facility. We present here the first results of the data analysis and discuss the consequences.Comment: Contribution to the Classical Novae Explosions conference, Sitges, Spain, 20-24 May 2002, 5 pages, 3 figure

Prevention of ventilator‑associated pneumonia by noble metal coating of endotracheal tubes: a multi‑center, randomized, double‑blind study

BACKGROUND: Ventilator-associated pneumonia (VAP) causes increased mortality, prolonged hospital stay and increased healthcare costs. Prevention of VAP in intensive care units (ICUs) is currently based on several measures, and application of noble metal coating on medical devices has been shown to inhibit the bacterial adherence of microorganisms to the surface. The objective of this study was to evaluate the potential benefit of noble metal coating of endotracheal tubes for the prevention of VAP. METHODS: This was a multi-center, randomized, controlled, double-blind, prospective study including ventilated patients from nine ICUs from four hospital sites in Belgium. Patients were randomly intubated with identical appearing noble metal alloy (NMA) coated (NMA-coated group) or non-coated (control group) endotracheal tubes (ETT). Primary endpoint was the incidence of VAP. Secondary endpoints were the proportion of antibiotic days during ICU stay and tracheal colonization by pathogenic bacteria. RESULTS: In total, 323 patients were enrolled, 168 in the NMA-coated group and 155 in the control group. During ventilation, VAP occurred in 11 patients (6.5%) in the NMA-coated group and in 18 patients (11.6%) in the control group (p  = 0.11). A higher delay in VAP occurrence was observed in the NMA-coated group compared with the control group by Cox proportional hazards regression analysis (HR 0.41, 95% CI 0.19–0.88, p  = 0.02). The number of antibiotic days was 58.8% of the 1,928 ICU days in the NMA-coated group and 65.4% of the 1774 ICU days in the control group (p  = 0.06). Regarding tracheal colonization, bacteria occurred in 38 of 126 patients in the NMA-coated group (30.2%) and in 37 of 109 patients in the control group (33.9%) (p  = 0.57). CONCLUSIONS: This study provides preliminary evidence to support the benefit of noble metal coating in the prevention of VAP. A confirmatory study in a larger population would be valuable. Trial registration: Clinical trial number: NCT04242706 (http://www.clinicaltrials.gov

Corticosteroid therapy is associated with a decrease in mortality in a multicenter cohort of mechanically ventilated COVID-19 patients

peer reviewedRetrospectively analyzing the data of a multicenter cohort, we observed that mortality of patients with SARS-CoV-2 pneumoniatreated with mechanical ventilation was as high as 45% and median survival time was 82 days. In this series, the risk factors for mortality included age, renal and circulatory dysfunction, lymphopenia and the absence of corticosteroid use during the first week of mechanical ventilation. Corticosteroid therapy during the first week of mechanical ventilation was associated with a lower mortality (34% vs 48%) (p = 0,01)

Génération automatique d'un modèle de bâtiment à partir d'un croquis

peer reviewe

Anemia at discharge from pediatric intensive care unit : prevalence, risk markers and management

L'anémie est fréquente à l'admission et durant le séjour en réanimation pédiatrique, et elle est associée à un mauvais pronostic en réanimation. En outre, des stratégies transfusionnelles restrictives sont actuellement recommandées pour les enfants séjournant en réanimation. Il est dès lors licite de s'interroger sur la prévalence de l'anémie à la sortie de réanimation.Cette question est pertinente, car l'anémie est associée à un pronostic défavorable dans divers contextes non réanimatoires. Il est donc plausible que l'anémie de sortie de réanimation soit associée à un moins bon pronostic post-réanimation. Or, le pronostic post-réanimation est très important, particulièrement compte tenu du faible taux de mortalité observé de nos jours en réanimation pédiatrique.La finalité de notre programme de recherche est d'évaluer l'effet de l'anémie sur le pronostic post-réanimation, et éventuellement l'effet du traitement de cette anémie sur ce pronostic. Mais il est avant tout nécessaire de déterminer l'importance du problème. Or, les données actuellement publiées sur l'anémie à la sortie de réanimation pédiatrique sont pratiquement inexistantes.La présente thèse est la première étape de notre programme de recherche. Les objectifs de cette thèse sont donc de déterminer la prévalence de l'anémie à la sortie de réanimation, ses marqueurs de risque ainsi que sa prise en charge par les réanimateurs pédiatriques.Pour atteindre ces objectifs, nous allons conduire 3 études: un étude monocentrique incluant une cohorte d'enfants admis en réanimation pédiatrique durant une période de 1 an dans un centre pédiatrique tertiaire à Montréal, Canada; une étude bi-centrique incluant une cohorte d'enfants admis en réanimation pédiatrique durant une période de 5 ans dans les centres pédiatriques tertiaires de Lille et de Lyon; et une enquête internationale distribuée à des réanimateurs pédiatriques à travers le monde et visant à évaluer leurs pratiques en termes de prescription de globules rouges, de fer et d'érythropoïétine.L'étude de la prévalence de l'anémie est fondamentale pour se faire une idée de l'ampleur du problème. L'étude des marqueurs de risque est quant à elle nécessaire pour identifier des sous-groupes plus à risque d'anémie et pour élaborer des hypothèses étiologiques. Enfin, l'évaluation de la prise en charge de l'anémie par les réanimateurs pédiatriques est intéressante pour déterminer la perception qu'ils ont de l'anémie de sortie de réanimation (la traitent-ils comme l'anémie de la phase aiguë du séjour en réanimation?) et pour aider à l'interprétation de l'évolution du taux d'hémoglobine après la sortie de réanimation, qui devra être étudié ultérieurement.Anemia is frequent at pediatric intensive care unit (PICU) admission and during PICU stay, and it is associated with bad outcomes during critical illness. Moreover, restrictive transfusional strategies are currently recommended for most of the critically ill children. Therefore, it makes sense to wonder about anemia at discharge from PICU.This is a relevant question: indeed, anemia is associated with worse outcomes in several non-critical settings. It is thus plausible that anemia at PICU discharge is associated with bad post-PICU outcomes, which is particularly relevant nowadays considering the low mortality rate reported in PICU.The main finality of our research program is the association between post-PICU anemia and post-PICU outcomes, and eventually the impact of the treatment of anemia on post-PICU outcomes. However, to date, published data on anemia at discharge from PICU are almost non-existent. The first step of our research program is thus to obtain a global picture of the current situation: this is the aim of this thesis.The objectives of this thesis are to determine the prevalence of anemia at discharge from PICU, its risk markers, and its management by pediatric intensivists. To reach these goals, we plan to conduct three studies: a prospective monocenter study including a cohort of children admitted during a 1-year period in a tertiary PICU in Montreal, Canada; a retrospective bi-center study including a cohort of children admitted during a 5-year period in the tertiary PICUs of Lille and Lyon; and an international survey distributed to PICU physicians across the world and aiming to assess their prescriptions of red blood cells, iron and erythropoietin to children anemic at PICU discharge.These studies are required to assess the importance of the problem, to identify subgroups of children at risk of anemia after critical illness, to raise hypotheses on the causes of this anemia, and to determine the way pediatric intensivists perceive and treat discharge anemia (do they treat it like they treat anemia during the acute phase of critical illness?). These data will help to construct future studies on this topic and to interpret the results of these future studies