Impact of early enteral versus parenteral nutrition on mortality in patients requiring mechanical ventilation and catecholamines: study protocol for a randomized controlled trial (NUTRIREA-2)

BACKGROUND: Nutritional support is crucial to the management of patients receiving invasive mechanical ventilation (IMV) and the most commonly prescribed treatment in intensive care units (ICUs). International guidelines consistently indicate that enteral nutrition (EN) should be preferred over parenteral nutrition (PN) whenever possible and started as early as possible. However, no adequately designed study has evaluated whether a specific nutritional modality is associated with decreased mortality. The primary goal of this trial is to assess the hypothesis that early first-line EN, as compared to early first-line PN, decreases day 28 all-cause mortality in patients receiving IMV and vasoactive drugs for shock. METHODS/DESIGN: The NUTRIREA-2 study is a multicenter, open-label, parallel-group, randomized controlled trial comparing early PN versus early EN in critically ill patients requiring IMV for an expected duration of at least 48 hours, combined with vasoactive drugs, for shock. Patients will be allocated at random to first-line PN for at least 72 hours or to first-line EN. In both groups, nutritional support will be started within 24 hours after IMV initiation. Calorie targets will be 20 to 25 kcal/kg/day during the first week, then 25 to 30 kcal/kg/day thereafter. Patients receiving PN may be switched to EN after at least 72 hours in the event of shock resolution (no vasoactive drugs for 24 consecutive hours and arterial lactic acid level below 2 mmol/L). On day 7, all patients receiving PN and having no contraindications to EN will be switched to EN. In both groups, supplemental PN may be added to EN after day 7 in patients with persistent intolerance to EN and inadequate calorie intake. We plan to recruit 2,854 patients at 44 participating ICUs. DISCUSSION: The NUTRIREA-2 study is the first large randomized controlled trial designed to assess the hypothesis that early EN improves survival compared to early PN in ICU patients. Enrollment started on 22 March 2013 and is expected to end in November 2015. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01802099 (registered 27 February 2013)

Analyse de la spécificité temporelle des indices électrophysiologiques corticaux rapportés aux performances comportementales dans des tâches de discrimination de durées

Nos recherches s'intéressent à la participation des structures corticales dans le traitement des durées et tentent de répondre aux interrogations suivantes : L'implication du cortex préfrontal dans les mécanismes décisionnels est-elle spécifique de la discrimination des durées ? La participation du réseau fronto-pariétal dépend-elle de la charge cognitive et de la nature du stimulus à discriminer ? Existe-t-il une asymétrie hémisphérique dans le traitement des durées ? Nos données ont permis de démontrer que 1) La participation des structures préfrontales dans les mécanismes décisionnels n'est pas spécifique du traitement temporel 2) l'encodage et la comparaison des durées reposent sur une boucle fonctionnelle pariéto-frontale, laquelle détermine les performances temporelles des sujets 3) Le réseau pariéto-frontal témoigne d'une plasticité face à la charge cognitive 4) La discrimination des durées dépend de l'intégrité des fonctions assurées par l'hémisphère droit.Our research focuses on the participation of cortical structures in temporal processing and try to answer to the following questions: Does the prefrontal cortex involvement in decision-making is specific to temporal discrimination? Does the involvement of fronto-parietal network depends on the cognitive load and the nature of the stimulus to discriminate? Is there a hemispheric asymmetry in the temporal treatment? Our data have shown that 1) The involvement of prefrontal structures in the decision-making is not specific to temporal processing 2) Encoding and comparison of temporal information are based on a parieto-frontal functional loop, which determines the temporal performances of subjects 3)The parieto-frontal network reflects plasticity toward the cognitive load 4) Temporal discrimination periods depends on the integrity of the functions assured by the right hemisphere.ROUEN-BU Lettres (764512101) / SudocSudocFranceF

EEG investigations of duration discrimination: the intermodal effect is induced by an attentional bias.

Previous studies indicated that empty time intervals are better discriminated in the auditory than in the visual modality, and when delimited by signals delivered from the same (intramodal intervals) rather than from different sensory modalities (intermodal intervals). The present electrophysiological study was conducted to determine the mechanisms which modulated the performances in inter- and intramodal conditions. Participants were asked to categorise as short or long empty intervals marked by auditory (A) and/or visual (V) signals (intramodal intervals: AA, VV; intermodal intervals: AV, VA). Behavioural data revealed that the performances were higher for the AA intervals than for the three other intervals and lower for inter- compared to intramodal intervals. Electrophysiological results indicated that the CNV amplitude recorded at fronto-central electrodes increased significantly until the end of the presentation of the long intervals in the AA conditions, while no significant change in the time course of this component was observed for the other three modalities of presentation. They also indicated that the N1 and P2 amplitudes recorded after the presentation of the signals which delimited the beginning of the intervals were higher for the inter- (AV/VA) compared to the intramodal intervals (AA/VV). The time course of the CNV revealed that the high performances observed with AA intervals would be related to the effectiveness of the neural mechanisms underlying the processing of the ongoing interval. The greater amplitude of the N1 and P2 components during the intermodal intervals suggests that the weak performances observed in these conditions would be caused by an attentional bias induced by the cognitive load and the necessity to switch between modalities

Making decisions about time: Event-related potentials and judgements about the equality of durations

International audienc

Electrophysiological activity recorded during the short interval.

<p>Data collected at prefrontal (FP1, FP2, FPz), fronto-central (F3, F4, Fz, FCz, C3, C4, Cz), parietal (P3, P4, Pz) and occipital electrodes (O1, O2, Oz) are presented.</p

Mean CNV amplitude.

<p>Mean amplitude recorded during AA, AV, VA and AA intervals at fronto-central (F3, F4, Fz, FCz, C3, C4, Cz) (A) and parietal (P3, P4, Pz) (B) sites. Bars are standard errors.</p

Schematic representation of the experimental paradigm.

<p>The task was to discriminate empty intervals delimited by auditory (A) and/or visual (V) signals. In two sessions, the intervals were defined by two signals of the same modality (intramodal intervals: AA or VV) while in the other two, the signals were delivered from different modalities (intermodal intervals: AV or VA). Each trial began with a fixation point (FP), followed by the presentation of an empty interval (ISI= 450 or 550 ms) bounded by auditory and/or visual stimuli (33 ms each) (S1 and S2 = Stimuli 1 and 2). Then, after the presentation of a fixation point (FP), a visual instruction asked the participants to indicate whether the empty interval corresponded to the short or long interval by pressing respectively “1” or “2” on a Serial Response Box.</p

Electrophysiological activity recorded during the long interval.

<p>Data collected at prefrontal (FP1, FP2, FPz), fronto-central (F3, F4, Fz, FCz, C3, C4, Cz), parietal (P3, P4, Pz) and occipital electrodes (O1, O2, Oz) are presented.</p

Discrimination levels.

<p>Percentage of correct responses obtained for the AA, AV, VA and VV intervals. Bars are standard errors.</p