Fabrice Galia - Academia.edu (original) (raw)

Papers by Fabrice Galia

Research paper thumbnail of Supervision automatique de la ventilation artificielle en soins intensifs : investigation d'un système existant et propositions d'extensions

Ce travail a été effectué au laboratoire de recherche Respiratory Team du service de réanimation ... more Ce travail a été effectué au laboratoire de recherche Respiratory Team du service de réanimation médicale de l'hôpital Henri Mondor de Créteil, dirigé par le Pr. Brochard. Cette thèse a été financée par la société Dräger Medical via une bourse CIFRE (ANRT). Je souhaite exprimer mes remerciements à : Monsieur le Professeur Brochard, pour avoir initié et dirigé cette thèse, pour sa patience et toute l'aide qu'il a pu m'apporter. Monsieur Dojat pour avoir co-dirigé cette thèse, et pour son expérience du projet ainsi que son soutien. Messieurs les Professeur Mancebo et Professeur Baconnier pour leur difficile travail de rapporteurs. Qu'ils trouvent ici le témoignage de ma reconnaissance. Messieurs les Professeur Guérin et Docteur Heyer pour leur concours à ce jury de thèse. La société Dräger Medical et plus particulièrement à Messieurs Mercier, Mersmann, Baier-Loewenstein et Katschewitz pour leur contribution, leur patience et leur aide à ce projet de thèse. Tous les membres de la Respiratory Team durant ces trois années et plus particulièrement à Aissam et Ferran pour m'avoir soutenu. Résumé 3/188 Résumé Titre : Supervision automatique de la ventilation artificielle en soins intensifs : investigation d'un système existant et propositions d'extensions. Les objectifs de la thèse sont l'analyse approfondie d'un système de supervision automatique de la ventilation artificielle destiné à des patients hospitalisés en réanimation et l'élaboration de solutions pour améliorer et étendre son champ d'application. Ce système adapte l'assistance de la ventilation spontanée en modifiant la pression délivrée en aide inspiratoire (AI) grâce à un rétrocontrôle, basé sur la fréquence respiratoire du patient et, utilisant aussi comme variables de "sécurité", le volume courant et le CO 2 de fin d'expiration (etCO 2). Il établit ainsi une classification ventilatoire qui permet de régler un niveau de pression d'AI. Il applique ensuite une procédure de sevrage consistant à réduire le niveau d'AI jusqu'à un seuil minimal qui permet de tester la capacité du patient à respirer seul. Sur la base d'études publiées rapportant des limitations de ce mode, de l'analyse rétrospective d'une base de données acquises sur patient et générée à cette fin, d'études sur banc-test et d'études observationnelles prospectives chez les patients, nous avons étudié en profondeur le fonctionnement et avons exploré les limites du système automatisé. Des solutions ont été évaluées sur banc-test. A partir de données cliniques , nous avons ainsi proposé une amélioration de la procédure de traitement du signal etCO 2. En nous basant sur les observations de la base de données, nous avons décrit une procédure automatisée de diminution de la PEP car un niveau supérieur à 5 mbar empêchait le sevrage automatique par le système. Sur le même principe, nous avons proposé d'automatiser en amont de l'AI un changement de mode depuis la ventilation assistée contrôlée vers le système de ventilation et de sevrage automatisés. Au travers d'une étude clinique, nous avons déterminé des critères ventilatoires qui pourraient permettre d'automatiser ce changement de mode. En conclusion, ce travail a défini et évalué un ensemble de procédures pour améliorer et étendre un système automatisé permettant la supervision de la ventilation artificielle des patients ventilés en réanimation médicale.

Research paper thumbnail of Reduction of patient-ventilator asynchrony by reducing tidal volume during pressure-support ventilation

Intensive Care Medicine, Apr 24, 2008

Objective: To identify ventilatory setting adjustments that improve patient-ventilator synchrony ... more Objective: To identify ventilatory setting adjustments that improve patient-ventilator synchrony during pressure-support ventilation in ventilator-dependent patients by reducing ineffective triggering events without decreasing tolerance. Design and setting: Prospective physiological study in a 13-bed medical intensive care unit in a university hospital. Patients and participants: Twelve intubated patients with more than 10% of ineffective breaths while receiving pressure-support ventilation. Interventions: Flow, airway-pressure, esophageal-pressure, and gastricpressure signals were used to measure patient inspiratory effort. To decrease ineffective triggering the following ventilator setting adjustments were randomly adjusted: pressure support reduction, insufflation time reduction, and change in end-expiratory pressure. Measurements and results: Reducing pressure support from 20.0 cm H 2 O (IQR 19.5-20) to 13.0 (12.0-14.0) reduced tidal volume [10.2 ml/kg predicted body weight (7.2-11.5) to 5.9 (4.9-6.7)] and minimized ineffective triggering

Research paper thumbnail of A new classification for sleep analysis in critically ill patients

Sleep Medicine, 2012

Background: Patients in intensive care units (ICUs) experience severe sleep alterations and conve... more Background: Patients in intensive care units (ICUs) experience severe sleep alterations and conventional sleep scoring rules are difficult to use in these patients. In a previous study, we showed that abnormal sleep EEG and wake EEG patterns could predict the outcome of noninvasive ventilation in a group of patients treated for acute respiratory failure. Our aims were to assess the prevalence of these abnormal sleep/wake EEG patterns in a larger group and search for objective parameters to help their identification. Methods: We reviewed sleep studies previously performed with full polysomnography during 17-h in conscious nonsedated ICU patients receiving invasive ventilation during weaning or noninvasive ventilation for acute respiratory failure. Results: We included 57 patients. Sleep scoring using conventional rules was not feasible in 16 (28%) patients due to the absence of stage-2 markers. Wake EEG in these 16 patients, although recognizable, showed abnormal features, including decreased reactivity to eye opening and slower peak EEG frequency compared to patients with normal sleep-wake EEGs. Conclusion: In almost one third of awake mechanically ventilated ICU patients, sleep cannot be classified with standard criteria. Two new states, atypical sleep and pathologic wakefulness, need to be added. We suggest rules for scoring these states. The origin and links with outcomes of these abnormal EEG patterns deserve investigation.

Research paper thumbnail of Bench test evaluation of volume delivered by modern ICU ventilators during volume-controlled ventilation

Intensive Care Medicine, Sep 23, 2010

In collaboration with the ''Groupe de Travail sur les Respirateurs AP-HP''.

Research paper thumbnail of Sleep in Hypercapnic Critical Care Patients Under Noninvasive Ventilation

Critical Care Medicine, 2013

To compare sleep quality between two types of ventilators commonly used for noninvasive ventilati... more To compare sleep quality between two types of ventilators commonly used for noninvasive ventilation: conventional ICU ventilators and dedicated noninvasive ventilators; and to evaluate sleep during and between noninvasive ventilation sessions in critically ill patients. Physiological sleep study with a randomized assessment of the ventilator type. Medical ICU in a university hospital. Twenty-four patients admitted for acute hypercapnic respiratory failure requiring noninvasive ventilation. Patients were randomly assigned to receive noninvasive ventilation with either an ICU ventilators (n = 12) or a dedicated noninvasive ventilators (n = 12), and their sleep and respiratory parameters were recorded by polysomnography from 4 PM to 9 AM on the second, third, or fourth day after noninvasive ventilation initiation. Sleep architecture was similar between ventilator groups, including sleep fragmentation (number of arousals and awakenings/hr), but the dedicated noninvasive ventilators group showed a higher patient-ventilator asynchrony-related fragmentation (28% [17-44] vs. 14% [7.0-22]; p = 0.02), whereas the ICU ventilators group exhibited a higher noise-related fragmentation. Ineffective efforts were more frequent in the dedicated noninvasive ventilators group than in the ICU ventilators group (34 ineffective efforts/hr of sleep [15-125] vs. two [0-13]; p < 0.01), possibly as a result of a higher tidal volume (7.2 mL/kg [6.7-8.8] vs. 5.8 [5.1-6.8]; p = 0.04). More sleep time occurred and sleep quality was better during noninvasive ventilation sessions than during spontaneous breathing periods (p < 0.05) as a result of greater slow wave and rapid eye movement sleep and lower fragmentation. There were no observed differences in sleep quality corresponding to the type of ventilator used despite slight differences in patient-ventilator asynchrony. Noninvasive ventilation sessions did not prevent patients from sleeping; on the contrary, they seem to aid sleep when compared with unassisted breathing.

Research paper thumbnail of Comparison of Sleep Quality With Mechanical Versus Spontaneous Ventilation During Weaning of Critically Ill Tracheostomized Patients*

Critical Care Medicine, Jul 1, 2013

Background: In mechanically ventilated patients under mechanical ventilation in the ICU, ventilat... more Background: In mechanically ventilated patients under mechanical ventilation in the ICU, ventilatory mode or settings may influence sleep quality. The aim of this study was to evaluate the direct impact of mechanical ventilation per se on sleep quantity and quality in patients who were able to tolerate separation from mechanical ventilation over prolonged periods. Design and Setting: Randomized crossover clinical trial in a medical ICU. Patients: Sixteen conscious patients, free of sedation and tracheostomized because of prolonged weaning from mechanical ventilation, were included in the study when able to tolerate at least 5 hours of spontaneous ventilation. 'See also p. 1808.

Research paper thumbnail of Comparison of three high flow oxygen therapy delivery devices: a clinical physiological cross-over study

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2013

High-flow-oxygen-therapy is provided by various techniques and patient interfaces, resulting in v... more High-flow-oxygen-therapy is provided by various techniques and patient interfaces, resulting in various inspired-fraction of oxygen (FiO2) and airway-pressure levels. However, tracheal measurements have never been performed. Three oxygen-delivery-devices were evaluated: 1) standard-high-flow-oxygen-facemask with reservoir-bag, 2) Optiflow(TM)-high-flow-nasal-cannulae and 3) Boussignac(TM)-oxygen-therapy-system. Main judgment criteria were airway-pressure and FiO2 measured in the trachea. The three devices were randomly evaluated in cross-over in 10 Intensive-Care-Unit patients using three oxygen flow-rates (15, 30 and 45 L/min) and two airway-tightness conditions (open and closed mouth). Airway-pressures and FiO2 were measured by a tracheal-catheter inserted through the hole of a tracheotomy tube. Comfort was evaluated by self-reporting. Data are presented as median [25-75th]. 1) Regarding oxygen-delivery devices, BoussignacTM provided the highest mean tracheal pressure (13.9 [10.4-14.5] cmH20) compared to Optiflow(TM) (2 [1-2.3] cmH2O, P<0.001). BoussignacTM provided both positive inspiratory and expiratory airway-pressures, whereas Optiflow(TM) provided only positive expiratory airway-pressure. Reservoir-bag-facemask provided airway pressure close to zero. For FiO2, highest value was obtained for both Optiflow(TM) and facemask (90%) compared to Boussignac(TM) (80%), P<0.01. 2) Regarding oxygen-flow, airway-pressure and FiO2 systematically increased with oxygen-flow with the three devices except airway-pressure for the facemask. 3) Regarding the open-mouth position, mean airway-pressure decreased with Optiflow(TM) only (2 [1.2-3.3] vs. 0.6 [0.3-1] cmH2O, P<0.001). Opening the mouth had little impact on FiO2. 4) finally, discomfort-intensities were low for both Optiflow(TM) and reservoir-bag-facemask compared to Boussignac(TM), P<0.01. On one hand, Boussignac(TM) is the only device that generates a relevant positive-airway-pressure during both inspiration-and-expiration, independently of mouth-position. Optiflow(TM) provides a low positive-airway-pressure (<4 cmH2O), highly dependent of mouth-closing. The reservoir-bag-facemask provides no positive-airway-pressure. On the other hand, FiO2 are slightly but significantly higher for Optiflow(TM) and reservoir-bag-facemask than for Boussignac(TM). Discomfort was lesser for Optiflow(TM) and reservoir-bag-facemask.

Research paper thumbnail of A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compressed gas-based ventilators

Intensive Care Medicine, Apr 8, 2009

This study was conducted in collaboration with the ''Groupe de Travail sur les Respirateurs.'' El... more This study was conducted in collaboration with the ''Groupe de Travail sur les Respirateurs.'' Electronic supplementary material The online version of this article

Research paper thumbnail of Sleep quality in mechanically ventilated patients: Comparison of three ventilatory modes

Critical Care Medicine, Jun 1, 2008

To compare the influence of three ventilatory modes on sleep. Design: Prospective, comparative, c... more To compare the influence of three ventilatory modes on sleep. Design: Prospective, comparative, crossover study. Setting: Medical intensive care unit in a university hospital. Patients: Fifteen conscious, nonsedated, mechanically ventilated patients. Interventions: Patients were successively ventilated with assist-control ventilation, clinically adjusted pressure support ventilation (cPSV), and automatically adjusted pressure support ventilation (aPSV). Sleep polysomnography was performed during three consecutive 6-hr periods, one with each mode in random order. Airway pressure and thorax and abdomen plethysmography were used to diagnose central apneas and ineffective efforts. Measurements and Main Results: The main abnormalities were a low percentage of rapid eye movement (REM) sleep counting, for a median (25th-75th percentiles) of 10% (3.5-12.5) of total sleep, and a highly fragmented sleep with 29 arousals and awakenings per hour of sleep. REM sleep duration was similar in the three ventilatory modes, 7% in assist-control, 4% in aPSV, and 1% during cPSV (p ‫؍‬ .54), as well as in the fragmentation index, 31 arousals and awakenings per hour in assist-control, 32 in aPSV, and 34 during cPSV (p ‫؍‬ .62). Ineffective efforts occurred similarly with the three modes (seven per hour of sleep in assistcontrol, 16 in aPSV, and 12 during cPSV) or central apneas during PSV (five in aPSV, seven during cPSV). Minute ventilation was similar with the three modes. Conclusions: In conscious, mechanically ventilated patients, sleep architecture was highly abnormal, with a short REM stage and a high degree of fragmentation. The ventilatory mode did not influence sleep pattern, arousals, awakenings, and ineffective efforts.

Research paper thumbnail of Poor sleep quality is associated with late noninvasive ventilation failure in patients with acute hypercapnic respiratory failure*

Critical Care Medicine, Feb 1, 2010

oninvasive ventilation (NIV) is the treatment of choice for hypercapnic exacerbations in patients... more oninvasive ventilation (NIV) is the treatment of choice for hypercapnic exacerbations in patients with chronic respiratory failure. Nevertheless, the failure rate remains relatively high, with 5% to 40% of patients requiring endotracheal intubation (1-3). Most NIV failures occur within 24 hrs to 48 hrs after admission to the intensive care unit (ICU) (1). Several studies have evaluated early NIV failure and a number of predictors of early NIV failure have been identified: a very low pH, marked mental status alterations at NIV initiation, and a high severity score (4). However, approximately 15% to 25% of patients experience late NIV failure (after Ն48 hrs), in some cases despite an initial improvement (5, 6). Despite the poor prognosis for these patients (5, 6), few studies have investigated the poorly understood causes of late NIV failure. Chronic comorbidities (5) and a greater number of complications at hospital admission (6) may predict late NIV failure but lack specificity. Patients receiving endotracheal mechanical ventilation exhibit severe sleep disturbances, even after sedation is withdrawn during weaning (7, 8). Although the consequences of sleep disturbances in ICU patients are unknown, studies in ambulatory patients have shown multiple cardiovascular, respiratory, metabolic, and cognitive alterations (9). Sleep disturbance may promote delirium, an independent risk factor for death in ICU patients receiving mechanical ventilation (10). Additionally, poor sleep quality has been reported during NIV (11). The main objective of our study was to determine whether sleep disturbances that occur shortly after initiation of NIV in the ICU were associated with late NIV failure in patients with hypercapnic respiratory failure requiring Ͼ48 hrs of NIV. MATERIALS AND METHODS The study was approved by the Ethics Committee of the Société de Réanimation de Langue Française. All patients gave their informed consent. Patients Consecutive patients admitted to our medical ICU between November 2006 and August 2007 and requiring NIV were screened for eligibility. All patients with hypercapnic acuteon-chronic respiratory failure treated by NIV for Ͼ24 hrs were eligible. Hypercapnic respiratory failure was defined as a respiratory rate Ͼ22 breath/min, pH Ͻ7.35, and PaCO 2 Ͼ45 torr (Ͼ6 kPa). We focused on patients with chronic obstructive pulmonary disease and on elderly patients with cardiogenic pulmonary edema. In this last group, we included only patients aged Ͼ65 yrs, assuming that most *See also p. 705.

Research paper thumbnail of Diaphragmatic dysfunction in patients with ICU-acquired weakness and its impact on extubation failure

Intensive Care Medicine, Nov 16, 2015

Research paper thumbnail of Fraction of mask pressure transmitted to the trachea using the Boussignac's CPAP facemask

HAL (Le Centre pour la Communication Scientifique Directe), Mar 1, 2014

Research paper thumbnail of Intérêt de l’évaluation de la fonction diaphragmatique par stimulation magnétique au cours du sevrage ventilatoire chez les patients ayant une neuromyopathie de réanimation

Annales Francaises D Anesthesie Et De Reanimation, Sep 1, 2013

Research paper thumbnail of Détermination de l’épreuve de ventilation spontanée représentative du travail respiratoire post-extubation lors du sevrage de la ventilation mécanique du patient obèse en réanimation

Annales Francaises D Anesthesie Et De Reanimation, Sep 1, 2013

Research paper thumbnail of Interaction patient–ventilateur en ventilation spontanée en aide inspiratoire et en Intellivent, nouveau mode entièrement automatisé à boucle fermée durant le sevrage de la ventilation mécanique

Annales Françaises d'Anesthésie et de Réanimation, 2013

Research paper thumbnail of Additional file 7: of Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Figure S6. difference in the work of breathing expressed in J/min between each test and the post-... more Figure S6. difference in the work of breathing expressed in J/min between each test and the post-extubation period. Dashed line represents the absence of difference between the test and the post-extubation period. (JPG 44Â kb)

Research paper thumbnail of Risque barotraumatique avec des valves de non réinhalation de Waters : étude comparative sur banc d’essai

Annales Françaises d'Anesthésie et de Réanimation, 2013

Objectif.-La ventilation manuelle au ballon peut se faire au bloc opé ratoire et/ou en ré animati... more Objectif.-La ventilation manuelle au ballon peut se faire au bloc opé ratoire et/ou en ré animation chez le patient intubé ou non intubé , à l'aide de diffé rentes interfaces utilisant des valves de non-ré inhalation. La valve de Waters « nouvelle gé né ration » a progressivement remplacé la valve de Waters « historique ». L'objectif de cette é tude sur banc é tait d'é valuer la pression dé livré e par ces 2 valves dans diffé rentes conditions d'utilisation. Type d'e´tude.-É tude sur banc d'essai. Mate´riels et me´thodes.-Au total, 32 conditions ont é té testé es, en fonction de 2 dé bits d'oxygè ne (10 et 20 L/min), sans (condition statique) ou avec insufflation manuelle (condition dynamique) et 4 niveaux de pression d'ouverture de la valve. Le critè re de jugement principal é tait la mesure de la pression maximale à la sortie de la valve qui é tait connecté e à un poumon test et un banc de mesure. Re´sultats.-Les pressions mesuré es entre les 2 valves é taient diffé rentes pour la plupart des conditions é valué es. L'augmentation du dé bit d'oxygè ne de 10 à 20 L/min augmentait significativement la pression maximale pour les 2 valves. L'augmentation du niveau de pression d'ouverture de la valve entraînait une augmentation significative de la pression maximale trè s marqué e pour la valve de nouvelle gé né ration (de 4 à 61 cmH 2 O en conditions statiques et de 18 à 68 cmH 2 O en conditions dynamiques), alors que pour la valve historique la pression maximale augmentait de façon significative, mais restait toujours infé rieure à 15 cmH 2 O en conditions statiques et dynamiques. Conclusion.-L'utilisation de la valve de Waters nouvelle gé né ration doit être diffé rente de l'utilisation de la valve de Waters historique. En effet, un barotraumatisme peut être provoqué par des ré glages de pression d'ouverture de valve inadapté s. ß 2013 Socié té française d'anesthé sie et de ré animation (Sfar). Publié par Elsevier Masson SAS. Tous droits ré servé s.

Research paper thumbnail of To cite this version

A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compres... more A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compressed gas-based ventilators.

Research paper thumbnail of Additional file 4: of Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Figure S3. difference in the esophageal pressure time product between each test and the post-extu... more Figure S3. difference in the esophageal pressure time product between each test and the post-extubation period. Dashed line represents the absence of difference between the test and the post-extubation period. (JPG 49Â kb)

Research paper thumbnail of Additional file 1: of Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Supplementary material. (DOCX 44Â kb)

Research paper thumbnail of Supervision automatique de la ventilation artificielle en soins intensifs : investigation d'un système existant et propositions d'extensions

Ce travail a été effectué au laboratoire de recherche Respiratory Team du service de réanimation ... more Ce travail a été effectué au laboratoire de recherche Respiratory Team du service de réanimation médicale de l'hôpital Henri Mondor de Créteil, dirigé par le Pr. Brochard. Cette thèse a été financée par la société Dräger Medical via une bourse CIFRE (ANRT). Je souhaite exprimer mes remerciements à : Monsieur le Professeur Brochard, pour avoir initié et dirigé cette thèse, pour sa patience et toute l'aide qu'il a pu m'apporter. Monsieur Dojat pour avoir co-dirigé cette thèse, et pour son expérience du projet ainsi que son soutien. Messieurs les Professeur Mancebo et Professeur Baconnier pour leur difficile travail de rapporteurs. Qu'ils trouvent ici le témoignage de ma reconnaissance. Messieurs les Professeur Guérin et Docteur Heyer pour leur concours à ce jury de thèse. La société Dräger Medical et plus particulièrement à Messieurs Mercier, Mersmann, Baier-Loewenstein et Katschewitz pour leur contribution, leur patience et leur aide à ce projet de thèse. Tous les membres de la Respiratory Team durant ces trois années et plus particulièrement à Aissam et Ferran pour m'avoir soutenu. Résumé 3/188 Résumé Titre : Supervision automatique de la ventilation artificielle en soins intensifs : investigation d'un système existant et propositions d'extensions. Les objectifs de la thèse sont l'analyse approfondie d'un système de supervision automatique de la ventilation artificielle destiné à des patients hospitalisés en réanimation et l'élaboration de solutions pour améliorer et étendre son champ d'application. Ce système adapte l'assistance de la ventilation spontanée en modifiant la pression délivrée en aide inspiratoire (AI) grâce à un rétrocontrôle, basé sur la fréquence respiratoire du patient et, utilisant aussi comme variables de "sécurité", le volume courant et le CO 2 de fin d'expiration (etCO 2). Il établit ainsi une classification ventilatoire qui permet de régler un niveau de pression d'AI. Il applique ensuite une procédure de sevrage consistant à réduire le niveau d'AI jusqu'à un seuil minimal qui permet de tester la capacité du patient à respirer seul. Sur la base d'études publiées rapportant des limitations de ce mode, de l'analyse rétrospective d'une base de données acquises sur patient et générée à cette fin, d'études sur banc-test et d'études observationnelles prospectives chez les patients, nous avons étudié en profondeur le fonctionnement et avons exploré les limites du système automatisé. Des solutions ont été évaluées sur banc-test. A partir de données cliniques , nous avons ainsi proposé une amélioration de la procédure de traitement du signal etCO 2. En nous basant sur les observations de la base de données, nous avons décrit une procédure automatisée de diminution de la PEP car un niveau supérieur à 5 mbar empêchait le sevrage automatique par le système. Sur le même principe, nous avons proposé d'automatiser en amont de l'AI un changement de mode depuis la ventilation assistée contrôlée vers le système de ventilation et de sevrage automatisés. Au travers d'une étude clinique, nous avons déterminé des critères ventilatoires qui pourraient permettre d'automatiser ce changement de mode. En conclusion, ce travail a défini et évalué un ensemble de procédures pour améliorer et étendre un système automatisé permettant la supervision de la ventilation artificielle des patients ventilés en réanimation médicale.

Research paper thumbnail of Reduction of patient-ventilator asynchrony by reducing tidal volume during pressure-support ventilation

Intensive Care Medicine, Apr 24, 2008

Objective: To identify ventilatory setting adjustments that improve patient-ventilator synchrony ... more Objective: To identify ventilatory setting adjustments that improve patient-ventilator synchrony during pressure-support ventilation in ventilator-dependent patients by reducing ineffective triggering events without decreasing tolerance. Design and setting: Prospective physiological study in a 13-bed medical intensive care unit in a university hospital. Patients and participants: Twelve intubated patients with more than 10% of ineffective breaths while receiving pressure-support ventilation. Interventions: Flow, airway-pressure, esophageal-pressure, and gastricpressure signals were used to measure patient inspiratory effort. To decrease ineffective triggering the following ventilator setting adjustments were randomly adjusted: pressure support reduction, insufflation time reduction, and change in end-expiratory pressure. Measurements and results: Reducing pressure support from 20.0 cm H 2 O (IQR 19.5-20) to 13.0 (12.0-14.0) reduced tidal volume [10.2 ml/kg predicted body weight (7.2-11.5) to 5.9 (4.9-6.7)] and minimized ineffective triggering

Research paper thumbnail of A new classification for sleep analysis in critically ill patients

Sleep Medicine, 2012

Background: Patients in intensive care units (ICUs) experience severe sleep alterations and conve... more Background: Patients in intensive care units (ICUs) experience severe sleep alterations and conventional sleep scoring rules are difficult to use in these patients. In a previous study, we showed that abnormal sleep EEG and wake EEG patterns could predict the outcome of noninvasive ventilation in a group of patients treated for acute respiratory failure. Our aims were to assess the prevalence of these abnormal sleep/wake EEG patterns in a larger group and search for objective parameters to help their identification. Methods: We reviewed sleep studies previously performed with full polysomnography during 17-h in conscious nonsedated ICU patients receiving invasive ventilation during weaning or noninvasive ventilation for acute respiratory failure. Results: We included 57 patients. Sleep scoring using conventional rules was not feasible in 16 (28%) patients due to the absence of stage-2 markers. Wake EEG in these 16 patients, although recognizable, showed abnormal features, including decreased reactivity to eye opening and slower peak EEG frequency compared to patients with normal sleep-wake EEGs. Conclusion: In almost one third of awake mechanically ventilated ICU patients, sleep cannot be classified with standard criteria. Two new states, atypical sleep and pathologic wakefulness, need to be added. We suggest rules for scoring these states. The origin and links with outcomes of these abnormal EEG patterns deserve investigation.

Research paper thumbnail of Bench test evaluation of volume delivered by modern ICU ventilators during volume-controlled ventilation

Intensive Care Medicine, Sep 23, 2010

In collaboration with the ''Groupe de Travail sur les Respirateurs AP-HP''.

Research paper thumbnail of Sleep in Hypercapnic Critical Care Patients Under Noninvasive Ventilation

Critical Care Medicine, 2013

To compare sleep quality between two types of ventilators commonly used for noninvasive ventilati... more To compare sleep quality between two types of ventilators commonly used for noninvasive ventilation: conventional ICU ventilators and dedicated noninvasive ventilators; and to evaluate sleep during and between noninvasive ventilation sessions in critically ill patients. Physiological sleep study with a randomized assessment of the ventilator type. Medical ICU in a university hospital. Twenty-four patients admitted for acute hypercapnic respiratory failure requiring noninvasive ventilation. Patients were randomly assigned to receive noninvasive ventilation with either an ICU ventilators (n = 12) or a dedicated noninvasive ventilators (n = 12), and their sleep and respiratory parameters were recorded by polysomnography from 4 PM to 9 AM on the second, third, or fourth day after noninvasive ventilation initiation. Sleep architecture was similar between ventilator groups, including sleep fragmentation (number of arousals and awakenings/hr), but the dedicated noninvasive ventilators group showed a higher patient-ventilator asynchrony-related fragmentation (28% [17-44] vs. 14% [7.0-22]; p = 0.02), whereas the ICU ventilators group exhibited a higher noise-related fragmentation. Ineffective efforts were more frequent in the dedicated noninvasive ventilators group than in the ICU ventilators group (34 ineffective efforts/hr of sleep [15-125] vs. two [0-13]; p < 0.01), possibly as a result of a higher tidal volume (7.2 mL/kg [6.7-8.8] vs. 5.8 [5.1-6.8]; p = 0.04). More sleep time occurred and sleep quality was better during noninvasive ventilation sessions than during spontaneous breathing periods (p < 0.05) as a result of greater slow wave and rapid eye movement sleep and lower fragmentation. There were no observed differences in sleep quality corresponding to the type of ventilator used despite slight differences in patient-ventilator asynchrony. Noninvasive ventilation sessions did not prevent patients from sleeping; on the contrary, they seem to aid sleep when compared with unassisted breathing.

Research paper thumbnail of Comparison of Sleep Quality With Mechanical Versus Spontaneous Ventilation During Weaning of Critically Ill Tracheostomized Patients*

Critical Care Medicine, Jul 1, 2013

Background: In mechanically ventilated patients under mechanical ventilation in the ICU, ventilat... more Background: In mechanically ventilated patients under mechanical ventilation in the ICU, ventilatory mode or settings may influence sleep quality. The aim of this study was to evaluate the direct impact of mechanical ventilation per se on sleep quantity and quality in patients who were able to tolerate separation from mechanical ventilation over prolonged periods. Design and Setting: Randomized crossover clinical trial in a medical ICU. Patients: Sixteen conscious patients, free of sedation and tracheostomized because of prolonged weaning from mechanical ventilation, were included in the study when able to tolerate at least 5 hours of spontaneous ventilation. 'See also p. 1808.

Research paper thumbnail of Comparison of three high flow oxygen therapy delivery devices: a clinical physiological cross-over study

HAL (Le Centre pour la Communication Scientifique Directe), Dec 1, 2013

High-flow-oxygen-therapy is provided by various techniques and patient interfaces, resulting in v... more High-flow-oxygen-therapy is provided by various techniques and patient interfaces, resulting in various inspired-fraction of oxygen (FiO2) and airway-pressure levels. However, tracheal measurements have never been performed. Three oxygen-delivery-devices were evaluated: 1) standard-high-flow-oxygen-facemask with reservoir-bag, 2) Optiflow(TM)-high-flow-nasal-cannulae and 3) Boussignac(TM)-oxygen-therapy-system. Main judgment criteria were airway-pressure and FiO2 measured in the trachea. The three devices were randomly evaluated in cross-over in 10 Intensive-Care-Unit patients using three oxygen flow-rates (15, 30 and 45 L/min) and two airway-tightness conditions (open and closed mouth). Airway-pressures and FiO2 were measured by a tracheal-catheter inserted through the hole of a tracheotomy tube. Comfort was evaluated by self-reporting. Data are presented as median [25-75th]. 1) Regarding oxygen-delivery devices, BoussignacTM provided the highest mean tracheal pressure (13.9 [10.4-14.5] cmH20) compared to Optiflow(TM) (2 [1-2.3] cmH2O, P<0.001). BoussignacTM provided both positive inspiratory and expiratory airway-pressures, whereas Optiflow(TM) provided only positive expiratory airway-pressure. Reservoir-bag-facemask provided airway pressure close to zero. For FiO2, highest value was obtained for both Optiflow(TM) and facemask (90%) compared to Boussignac(TM) (80%), P<0.01. 2) Regarding oxygen-flow, airway-pressure and FiO2 systematically increased with oxygen-flow with the three devices except airway-pressure for the facemask. 3) Regarding the open-mouth position, mean airway-pressure decreased with Optiflow(TM) only (2 [1.2-3.3] vs. 0.6 [0.3-1] cmH2O, P<0.001). Opening the mouth had little impact on FiO2. 4) finally, discomfort-intensities were low for both Optiflow(TM) and reservoir-bag-facemask compared to Boussignac(TM), P<0.01. On one hand, Boussignac(TM) is the only device that generates a relevant positive-airway-pressure during both inspiration-and-expiration, independently of mouth-position. Optiflow(TM) provides a low positive-airway-pressure (<4 cmH2O), highly dependent of mouth-closing. The reservoir-bag-facemask provides no positive-airway-pressure. On the other hand, FiO2 are slightly but significantly higher for Optiflow(TM) and reservoir-bag-facemask than for Boussignac(TM). Discomfort was lesser for Optiflow(TM) and reservoir-bag-facemask.

Research paper thumbnail of A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compressed gas-based ventilators

Intensive Care Medicine, Apr 8, 2009

This study was conducted in collaboration with the ''Groupe de Travail sur les Respirateurs.'' El... more This study was conducted in collaboration with the ''Groupe de Travail sur les Respirateurs.'' Electronic supplementary material The online version of this article

Research paper thumbnail of Sleep quality in mechanically ventilated patients: Comparison of three ventilatory modes

Critical Care Medicine, Jun 1, 2008

To compare the influence of three ventilatory modes on sleep. Design: Prospective, comparative, c... more To compare the influence of three ventilatory modes on sleep. Design: Prospective, comparative, crossover study. Setting: Medical intensive care unit in a university hospital. Patients: Fifteen conscious, nonsedated, mechanically ventilated patients. Interventions: Patients were successively ventilated with assist-control ventilation, clinically adjusted pressure support ventilation (cPSV), and automatically adjusted pressure support ventilation (aPSV). Sleep polysomnography was performed during three consecutive 6-hr periods, one with each mode in random order. Airway pressure and thorax and abdomen plethysmography were used to diagnose central apneas and ineffective efforts. Measurements and Main Results: The main abnormalities were a low percentage of rapid eye movement (REM) sleep counting, for a median (25th-75th percentiles) of 10% (3.5-12.5) of total sleep, and a highly fragmented sleep with 29 arousals and awakenings per hour of sleep. REM sleep duration was similar in the three ventilatory modes, 7% in assist-control, 4% in aPSV, and 1% during cPSV (p ‫؍‬ .54), as well as in the fragmentation index, 31 arousals and awakenings per hour in assist-control, 32 in aPSV, and 34 during cPSV (p ‫؍‬ .62). Ineffective efforts occurred similarly with the three modes (seven per hour of sleep in assistcontrol, 16 in aPSV, and 12 during cPSV) or central apneas during PSV (five in aPSV, seven during cPSV). Minute ventilation was similar with the three modes. Conclusions: In conscious, mechanically ventilated patients, sleep architecture was highly abnormal, with a short REM stage and a high degree of fragmentation. The ventilatory mode did not influence sleep pattern, arousals, awakenings, and ineffective efforts.

Research paper thumbnail of Poor sleep quality is associated with late noninvasive ventilation failure in patients with acute hypercapnic respiratory failure*

Critical Care Medicine, Feb 1, 2010

oninvasive ventilation (NIV) is the treatment of choice for hypercapnic exacerbations in patients... more oninvasive ventilation (NIV) is the treatment of choice for hypercapnic exacerbations in patients with chronic respiratory failure. Nevertheless, the failure rate remains relatively high, with 5% to 40% of patients requiring endotracheal intubation (1-3). Most NIV failures occur within 24 hrs to 48 hrs after admission to the intensive care unit (ICU) (1). Several studies have evaluated early NIV failure and a number of predictors of early NIV failure have been identified: a very low pH, marked mental status alterations at NIV initiation, and a high severity score (4). However, approximately 15% to 25% of patients experience late NIV failure (after Ն48 hrs), in some cases despite an initial improvement (5, 6). Despite the poor prognosis for these patients (5, 6), few studies have investigated the poorly understood causes of late NIV failure. Chronic comorbidities (5) and a greater number of complications at hospital admission (6) may predict late NIV failure but lack specificity. Patients receiving endotracheal mechanical ventilation exhibit severe sleep disturbances, even after sedation is withdrawn during weaning (7, 8). Although the consequences of sleep disturbances in ICU patients are unknown, studies in ambulatory patients have shown multiple cardiovascular, respiratory, metabolic, and cognitive alterations (9). Sleep disturbance may promote delirium, an independent risk factor for death in ICU patients receiving mechanical ventilation (10). Additionally, poor sleep quality has been reported during NIV (11). The main objective of our study was to determine whether sleep disturbances that occur shortly after initiation of NIV in the ICU were associated with late NIV failure in patients with hypercapnic respiratory failure requiring Ͼ48 hrs of NIV. MATERIALS AND METHODS The study was approved by the Ethics Committee of the Société de Réanimation de Langue Française. All patients gave their informed consent. Patients Consecutive patients admitted to our medical ICU between November 2006 and August 2007 and requiring NIV were screened for eligibility. All patients with hypercapnic acuteon-chronic respiratory failure treated by NIV for Ͼ24 hrs were eligible. Hypercapnic respiratory failure was defined as a respiratory rate Ͼ22 breath/min, pH Ͻ7.35, and PaCO 2 Ͼ45 torr (Ͼ6 kPa). We focused on patients with chronic obstructive pulmonary disease and on elderly patients with cardiogenic pulmonary edema. In this last group, we included only patients aged Ͼ65 yrs, assuming that most *See also p. 705.

Research paper thumbnail of Diaphragmatic dysfunction in patients with ICU-acquired weakness and its impact on extubation failure

Intensive Care Medicine, Nov 16, 2015

Research paper thumbnail of Fraction of mask pressure transmitted to the trachea using the Boussignac's CPAP facemask

HAL (Le Centre pour la Communication Scientifique Directe), Mar 1, 2014

Research paper thumbnail of Intérêt de l’évaluation de la fonction diaphragmatique par stimulation magnétique au cours du sevrage ventilatoire chez les patients ayant une neuromyopathie de réanimation

Annales Francaises D Anesthesie Et De Reanimation, Sep 1, 2013

Research paper thumbnail of Détermination de l’épreuve de ventilation spontanée représentative du travail respiratoire post-extubation lors du sevrage de la ventilation mécanique du patient obèse en réanimation

Annales Francaises D Anesthesie Et De Reanimation, Sep 1, 2013

Research paper thumbnail of Interaction patient–ventilateur en ventilation spontanée en aide inspiratoire et en Intellivent, nouveau mode entièrement automatisé à boucle fermée durant le sevrage de la ventilation mécanique

Annales Françaises d'Anesthésie et de Réanimation, 2013

Research paper thumbnail of Additional file 7: of Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Figure S6. difference in the work of breathing expressed in J/min between each test and the post-... more Figure S6. difference in the work of breathing expressed in J/min between each test and the post-extubation period. Dashed line represents the absence of difference between the test and the post-extubation period. (JPG 44Â kb)

Research paper thumbnail of Risque barotraumatique avec des valves de non réinhalation de Waters : étude comparative sur banc d’essai

Annales Françaises d'Anesthésie et de Réanimation, 2013

Objectif.-La ventilation manuelle au ballon peut se faire au bloc opé ratoire et/ou en ré animati... more Objectif.-La ventilation manuelle au ballon peut se faire au bloc opé ratoire et/ou en ré animation chez le patient intubé ou non intubé , à l'aide de diffé rentes interfaces utilisant des valves de non-ré inhalation. La valve de Waters « nouvelle gé né ration » a progressivement remplacé la valve de Waters « historique ». L'objectif de cette é tude sur banc é tait d'é valuer la pression dé livré e par ces 2 valves dans diffé rentes conditions d'utilisation. Type d'e´tude.-É tude sur banc d'essai. Mate´riels et me´thodes.-Au total, 32 conditions ont é té testé es, en fonction de 2 dé bits d'oxygè ne (10 et 20 L/min), sans (condition statique) ou avec insufflation manuelle (condition dynamique) et 4 niveaux de pression d'ouverture de la valve. Le critè re de jugement principal é tait la mesure de la pression maximale à la sortie de la valve qui é tait connecté e à un poumon test et un banc de mesure. Re´sultats.-Les pressions mesuré es entre les 2 valves é taient diffé rentes pour la plupart des conditions é valué es. L'augmentation du dé bit d'oxygè ne de 10 à 20 L/min augmentait significativement la pression maximale pour les 2 valves. L'augmentation du niveau de pression d'ouverture de la valve entraînait une augmentation significative de la pression maximale trè s marqué e pour la valve de nouvelle gé né ration (de 4 à 61 cmH 2 O en conditions statiques et de 18 à 68 cmH 2 O en conditions dynamiques), alors que pour la valve historique la pression maximale augmentait de façon significative, mais restait toujours infé rieure à 15 cmH 2 O en conditions statiques et dynamiques. Conclusion.-L'utilisation de la valve de Waters nouvelle gé né ration doit être diffé rente de l'utilisation de la valve de Waters historique. En effet, un barotraumatisme peut être provoqué par des ré glages de pression d'ouverture de valve inadapté s. ß 2013 Socié té française d'anesthé sie et de ré animation (Sfar). Publié par Elsevier Masson SAS. Tous droits ré servé s.

Research paper thumbnail of To cite this version

A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compres... more A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compressed gas-based ventilators.

Research paper thumbnail of Additional file 4: of Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Figure S3. difference in the esophageal pressure time product between each test and the post-extu... more Figure S3. difference in the esophageal pressure time product between each test and the post-extubation period. Dashed line represents the absence of difference between the test and the post-extubation period. (JPG 49Â kb)

Research paper thumbnail of Additional file 1: of Spontaneous breathing trial and post-extubation work of breathing in morbidly obese critically ill patients

Supplementary material. (DOCX 44Â kb)